Hello everyone, welcome to our Bentley G technical analysis. Monthly special interest group webinar. I'll just wait. A little bit like a one minute a delate to make sure that everybody can attend and login. I'm so just start in a little bit. So thanks for waiting. Let's get started. So again, welcome to our monthly technical analysis. Special interest group virtual workshop today will be talking about groundwater flow. First of all, all are Bentley users are nominations are open for the year and infrastructure. Show in October 2020 will host a conference in Vancouver and nominees of each of the categories will be eligible to present there. Project in Vancouver this year, so make sure if you have interesting. Project please submit. Show me this before May 1st to also participate in the award ceremony. Some minor tips during the presentation. All windows are recyclable and movable the side there and you find their resource list for some helpful resources and links. If questions, please submit them in the Q&A session, then we are able to. Answer the questions at the end. Maybe have time in between depending on what's going to happen, but the. So yeah, questions just add them. So welcome today, we're talking about a combination of places in Plex flow, so we're going to do a groundwater flow analysis. Show my name is Michelle from this load. Shut down present this special interest group Virtual Workshop 45 to 60 minutes. Note that this will be recorded and will be available only meant fear. the Bentley events webpage or available through your personal link that you have in your email, so we can always watch it later. You'll be eligible for one personal development hour, um. If you have issues with that, please contact bentley.instituteadvantage.com. And of course, these six are complementary for all our Bentley users. There's also an possibility to download your certificate at the end of this live session, so at the bottom you will find this. I can that will be give you access to the badly injured certificate. If you watch a group, you can add the participants and they can download the certificates together. Thank you for attending email. OK, so we're going to talk about today. Today we're going to talk about the. Settings all set up the model for ground with the flow analysis. We are going to the side. Which boundary conditions will work for your situation, so we just have a quick overview of the different boundary conditions and what use when. And we're going to do in demonstration, doing air standalone ship each analysis. But also we're going to combine his ground with low nails with the deformation analysis for a fully coupled flowed information analysis and give you more insight of the development of defective safety in time. Please note that the UM, everything I tell you today is both applicable to classes 2D N 2 classes, 3D. The difference is that lectures, 20 miles are easy to set up, a bit quicker to run, so that is more suitable for today's presentation. But the same applies to plexus 3D, where we have the same type of boundary conditions in the same type of mechanisms. That same type for results. So that's also applicable to that situation. But for simplicity, just keep with access to the full. Now to show you the basics of doing. Black flow groundwater flow calculation. What causes poor precious in the soil before we going to dive into? How can we do a ground flow analysis? Good to understand what are precious in. How are these generated in soil? So if you look at real life in reality we have poor pressures caused by a frantic level. Basically controls on the water. For instance, if you look at the. She bad, which is definitely billowed. She water the sea level so this this is typically on the water, but it also could have been confined aquifer's, for instance, or when you just have a threat level in tried to assure mouse. Another option where we see a generation of poor precious is when we have undrained loading conditions, so when we load the soil and soil contains water, an escaped quick enough we see that we get additional accessport pressures. So that's also a cost 4 precious in the soil is Andre in soil behavior. When we load the soil where in some guys we so we load the soil. Then in plexus, how do we calculate these portraits in our finite element calculation there are two ways, 1. One is that we calculate separately the poor pressures to do is Frederick Level an once the that we do by using the under control behavior? And we we can call this in an access port pressure analysis. What we do is that we calculate the poor pressures due to Frederick level. We call them be steady. So it's a steady state for pressure which is caused by your hydraulic conditions and we have the full pressures to under install behavior, which is the access for pressure. So this is basically have an underlying soil that you load and then we get Access Corporation. We can calculate this independently or the second option. We can calculate the just the total pressure, it's just a total head analysis or daughter pressure analysis and we only have one more pressure. The total pressure be water. So there's no distinction between the two, and it's just only for pressure. What causes groundwater flow in soil so it will look in reality? What's happening? We have differences in water levels in Frederick levels. When the soldiers on the water, then indeed we see that the water will flow from the high potential to the low potential. Another word, groundwater flow causes consolidation. Say that we load an example. In typical cases where we have access for pressure developed under an embankment. Then we see that 2 two consultation, these access for pressure will flow. Flow to part where don't have this access for pressure or not so much so we also have an. Groundwater flow, but caused by consultation effects for dissipation of these access port pressure. So how do we calculate this groundwater flow inside our final calculation, we can calculate the flow separately to the Frederick level and due to consolidation it's another. Is called an uncovered or shaming coupled analysis so we can we do a steady state groundwater flow analysis to changes over Frederick level and then once that is completed, we use that as an input and we do a trenchant flow. That consolidation in Plex. We call it the consolidation analysis. But this is also a time dependent flow of access for fresh. So it's a transient floated. The consolidation is a consultation process. Another option is that we calculated only on the total poor precious. It's a fully coupled analysis that we do instruction. Total float is no separation between changes into a hydraulic boundary conditions and changes due to under install behavior. It's all combined as one for pressure, so it's usually that groundwater had potential to calculate the ground flow. So those are the two options that we can use to calculate this for our deformation analysis. If we just look at ground floor only. We can. Tune flow only calculation. We can choose flow only as the initial type in the initial phase. Subsequently also all phases will be flow only types of calculations. So we were initials, fair face. We set the flow only to be dead. We only do ground flow analysis, so there will be no calculation of any information, no strength stability analysis, no factor of safety calculation. It's only ground the flow analysis, so it's only assessing the grandmother had potential groundwater flow, but nothing else. The floor that we calculate in the subsequent phases can be steady state, so it's a constant in time, so it's basically an end of time equilibrium steady state solution, so it will not fluctuate in time anymore. Or we can do a transient analysis and then we can have fluctuating inputs in time also or or also the poor precious can change in time. We had boundary conditions stay constant but the change happens gradually in time and we can set it up independently for our faces. Want to use groundwater flow analysis in another type of calculation? For instance, in are in a plastic calculation consultation and safety analysis and dynamics the ground with the flow field that we calculate is considered to be constant during such analysis. So basically what we do, we calculate the flow for prior to this deformation analysis and the results of the flow calculation needs are considered as an input to be analysis. So in here in this case we have what we call have the steady. Now just stays there. Pressure always are flow is, but in this definition steady state, so it's the end of time equilibrium situation. Fully covered flowed information answers. That is the total head analysis or Delta pressure analysis. In this case, going with the flow analysis is integrated in consultation and information analysis. Such a fully hydro mechanical coupling. Hum showed that means that while you have deformations you can trigger. Pressure that can also then lead to additional flow. So we can have fluctuating boundary conditions all that then in anytime that you do this type of analysis, the flows by definition trenchant. So in any case this flow that we define trenchant. So it varies in time. So if we look at the with change with our tax calculation that we do. But then we want to run the calculation. Of course we have to tell the plexus programs what type of material are we dealing with such that it can take into account the proper behavior, foreground flow. Now if you set up a material. We of course have to specify different items, which we can set the strength and stiffness parameters in the parameters that sheet. If you just do groundwater flow analysis, we will not utilize these parameters and then these are not relevant for groundwater flow analysis. Of course, it's important important are the. Uh. Groundwater parameters you can find him in the ground with the tab. We have a two parts. Basically of these inputs setting. So the top part is already to the unsaturated zone, so we can think of this as the zone which is above your Frederick level inside your shore Mass. This tells you about how the poor pressure and the saturation behaves above the three attic level. The lower part, the flow parameters. Here we define our hydraulic conductivity or probability. So in 2D FKX&Y in 3D wall, Seven additional parameter in 3D of course KZ. So we have these three controller connectivity parameters. We can give a limit to the answer to his own using the onset. Parameter we have afford ratio specifically for metric specific storage, so this all control your trench in groundwater flow. Specially Formatted specific storage will control your transient groundwater flow. And also we have something which is a change of probability which is used when you do the information analysis. Mostly consultation type of analysis. So when you avoid Rachel changes you can also you can think of that particles become close together is less for each between these particles. So that means that the probability will drop. So we can also control that using the change of probability. So we then look at the input parameter, unsettled its own. This is the typical retention curves that you see here. So the soil watercolorist curves. What we see here, the top with the red line is the relative permeability or furs. The pressure head on the vertical axis. And the bottom graph shows us are. Degree of saturation also by the pressures on the vertical axis. So this is the variation. Now after we defined the soy body and the geometry of course have to give input for our ground with the flow analysis using boundary conditions on the ground with the flow analysis that we have in Plex is you have to set the boundaries on your. Active model boundaries act as the boundary conditions, so these are the top five item TC. We also have items which have an inside the domain. So to look at the items that two 512 secret analysis ahead. I'm sure you can specify specific head closed flow boundary, so that means that we know flow through this boundary. We can set off course and inflow and outflow. So where water infiltrates into the model or where you where water will flow out of the model, giving a specific discharge. We also have infiltration precipitation options. So. In pleasure studi any line implicitly you have these boundary conditions and you can set them as desired. Then make sure that they did. You said the Boundary Commission on the active model boundaries. And then Judy serve as an input for the analysis. Well should have options which happened inside the domain. You can think of as drain element. Drain element is a line element which has a 04 pressure boundary condition with well element. We can also set a discharge value of infiltration or extraction so we can just set up a shared discharge there. And especially a specific element foreground flow our screens. And we use interface elements for these, so by default these are set to close on your activate them. But we also have options to adjust the screens to have certain cross probability Anna drainage parallel to line. So these are the options that we can do. These are used in the calculation. If you use a groundwater level. So the one that you define in pleasure studio or black history D. Those will implicitly set the boundary conditions. So what what happens is that if once you have draw a Frederick level. The UM the boundaries which are below this. General global frantic level. This will be shot to the head condition acting on what's happening at that boundary and what is above this reading level. Be considered sheepridge, so Frederick level implicitly set this boundary conditions. So let's go to an example. To a float rune embankment and 1st going to start with the flow only calculation considering mean water level from a River which the River is here at the right hand side. And then we going to raise the water level up onto very high level. That's considered to be the maximum discount to be applicable for this situation. So let's share my screen and start plexus to the. So here we are. Let's start a new project. And I'm going to call it. Demo Lexi Lowe I'm going to keep applying strain model $50 elements. I use the default unit for length, force and time in this case. These temperature energem power are related to the thermal flow which will not cover it. Today we have a contour here which are set to the dimension of the model minus 5 + 5. The tool generates. My basic geometry, this with the viewpoint of the geometry, will not be utilizing the borehole today with just for simplicity. In this case. Here we're going to just create a shortfall again so quickly to generate this. Item so I can draw here. If I hold the shift button while drawing, I can. And you can see here he went out the shift button and I've only moved perfectly horizontal, perfectly vertical, so that makes drawing this a little bit easier and quicker. So they should be go to minus 2. And then we go to 44. Minus 2 then it 35. 10 or 20. 2 Five and then here is it. 80 Today is the drawing of my embankment. And then of course we have to sign a material to it. So let's create the material. This case, let's take a cynic material. For his first part, it's not the material model and range type are not important because these are used for the. Information analysis I'm just going to fill them in because we lay there. We're going to use them for the second example. In that case, we just interested in the stability, so we can just use the more column. So we just interested in the strength more looking for deformation based analysis. It's better to use more advanced model that takes into account for instance over constellation. Um stress dependency in those kind of things. Show we have here 30. Megapascal stiffness and one guy. Gives a 28 degree friction angle. Then go to the groundwater tab sheet and here you can see we have different types of Inputs. So we can hear choose datasets so standard, which means we have just a. We can choose to course medium meaning fine, which will give us a different particle distribution. Here from this triangle. This gives us the The Prince of chance Shields. And place. So we we can set different distribution type there also 3D predefined. Datasets here high presses European classification system used. The A is from the United States Department of Agriculture starring Dutch. Show classification system and use defined here that we can fill up our own far North in relationship parameters. This guys I will just stick with starring Anne. Choose an. Non lo mechant. And this gives me the graph of my unsaturated show behavior. So here you can see the. The relative term building. So what happens with the probability above the theoretic surface? Or we have positive? For Precious. And here we have the. Degree of saturation so I can see all that. It decreases with the pressure head. Now we can fit in our own probabilities if we don't have that information, you can maybe friends, usually from data set as a first good suggestion. So that helps you also too quickly set up your analysis. We not only use thermal interface, is already mentioned something about setting different probabilities for the interface. You can choose impermeable, so in this activate there was no water shipping through this interface. Elements semipermeable show. Here we can set up hydraulic resistance. An fully permeable, which means that actually. Now this will not even notice that there is an interface there, so we just counted have the same probability as the surrounding soil. We also can have drains connectivity and then we have flow. Parallel to the line through this interface, elements were considered to zero and impermeable, so we don't have any. Must be fully close screen. Ever going to use them later on in the exercise? So let's check OK in the sign in material, so this helps set up the geometry and theory model. So we can generate the mesh. what I will do I will. Refine this boundary twice this boundary once 'cause I know that from the given threading services that the. The display side the water table is set and that might vary in time. He won't have enough tense measures, it will capture all the different gradients for ground with the flow and go ahead. And also in this case, since it's. A boundary where water will seep through hours wanted to be correct. Let's generate the mesh and I will discuss. Use a fine mesh which calculates relatively fast. In this case, gives us three under the folder two elements. Let's look at the. Generated mesh. Today is generated mesh. You can see we have an ice dancer mesh here on the upstream side, so that's exactly what we want. Go to stage construction here. What you see here. There's nothing is being activated, so only soil which has been generated by the border we automatically activated. Otherwise we have to manually do it. No, did you see here we go to flow conditions or boundaries, you rush switched off and implicitly means that there are secret boundary. Unless overwritten by our model conditions here, and if I look at the groundwater flow option here, so have model conditions going with the flow. Here are my default boundary conditions, so this means the bottom of the of the model boundary. Why men has been closed? The two little sites X men X Max have been set to open, So what they can just freely flow in and out and the top is also said to be open. As I said, they would want to only want to do a grounder flow analysis. In initial phase. We have here said to flow only. Because here's some information on the type of analysis. So here we just flow, only that we know effective stretch calculation. We're going to support pressure calculation type to define the flow calculation, so in this case studies a ground the floor we're going to choose here. So want to run the calculation, but of course we do not have input defined for our analysis, So what we're going to do, I'm going to create a water level that sets up my boundary conditions implicitly. And this should be at plus one. So here we have our mean water level. You can see here in the attributes library. We have a new usual to level, so this one is a water level created by the user, not by the borehole. These are the world what levels? We didn't use bortles here, so that's why we don't have any entries here. Just have user what level. I'm going to rename it to mean water level MWL so I can quickly reference it later. Shut the global water over here, and as I said before, well defining this global water level, it will implicitly set the boundary conditions. So that means that this part here. B loader global water level here is going to get the head value of minus one. And above the Frederick level, it will be a sheepish boundary all along these boundaries, or have speech boundaries an their boundary has a mixed types at the top here will be she pitch and the bottom part will be set to the. Yes. Had condition. And the same applies to these. These are the boundaries. So he was at 2 + 1. The bottom boundary, although he when I selected here in the selection Explorer you see the settings. So it switched off. Then it will look at the since it's the bottom boundary, it will look at the global ground flow boundary conditions. So here set to be closed. So let's run the calculation and let's see. What happens so I'm not going to select any points for curves at this stage, so I'm not going to see them anymore. Calculations already done that goes quite quick, so let's look at the results and see what we have. So here we see the results of our ground, the flow analysis official in a little bit. By default, lecture shows you the different mesh when you look at the results. But of course we didn't do any deformation analysis or stress analysis, so we do not see any deformations. You only have groundwater flow, so let's look at the ground floor results. And he can see. The magnitude of the groundwater philosophy. So we will get the ground with the flow arrows. We can see the direction and magnitude of the groundwater flow. Actually, errors are skilled relatively. To show the relative magnitudes for all the different results that we have so you can see here out infiltration happens is that he had caused perpendicular to. Are sure fish, while here is very bad in direction, because the here we also have the entry point of the Frederick level. You can see here that the. Come with their level, decreased a little bit while going to the downstream side, and here we see water flowing out of the model and you can see here at the bottom the floors all perpendicular to the boundary because it said to a closed flow boundary. We can also look at the UM. For precious Charlene, Let's look at the active for precious and can see here. Here we have the high. More precious Uh, and it will decrease here. Of course, sometimes it's easier here to not look at the poor precious, but better to look at the grandmother hat and you can see here that it. Nicely decreases from the right hand side. The left hand left hand side. How is it going here? Goes from plus one 2 - 1. So that's that's easy to set up. This type of analysis, the next step, will be let's go back to the. Face here that we want to set up a high water level so the initial phase is basically are mean situation. Let had in your face I'm going to add a new face and let's call it high water. Also, going to the steady state ground with the flow analysis. And then I have to set it up. So let's go to flow conditions and now I want to run the calculation with and different water level. So how pleasures treats these water levels. They basically stored in attributes library as you can see here that which library it contains. Different water levels now is just only one user water level. But what I will do I will create a new water level. I'm going to head to 4.5. So we have a new water level you can children use what the level one's been added. So every renamed it too. High water level HWL Now, what does she still the global? The one highlighted in dark blue is still the original one. In order to do that, we can do. We can click on this item in here should select make global and you can see here now at the global has been changed to the high water level. You can always check it here in the Model Explorer all the way. At the bottom there's an option for water and they will see the global water level set to HWL. So just a high water level so we can also run the calculation. Also done very quickly. Matter of seconds. Anyway, after results for the high water level so you can see here that the water level is now here at the high elevation. The water still is controlled by the boundary condition too. To be admired one. What does she know here happening is that we have. What are shipping out of the to hear? Also, when you look at the. Crown with the flow. Here we can see I'm just here. We have the. Higher village here at the border with the infiltration, but they show here we see that we also have higher philosophies. Never look at the arrows. Now you can see here the thing that you would expect in terms of ground with the flow. And you can see here that indeed water seeps out of the toe of the amendment due to this higher water level. This of course is a steady state solution. So that means this is an equilibrium situation where the water level has been there for a sufficient long enough time. Start that we have this constant flow fields. If you look at their. Groundwater hat you can see. Also see here we have this nice transition of the groundwater head. From plus 4.5 here, 2 - 1, so that's great. So we have two state solutions. Then again, what would be the effect of time for this water level? You can think of that as a input. Is that the River water level will change in time, so we might be some small period of a higher runoff in the River such that we can for instance have this graph, which takes measure points. Measurement points every year half a day and you can see here that it slowly or quite rapidly. Actually the water level increases, stays high for a small amount of days and then again it lowers in time back to the mean level. So how can we run the calculation in this case? Show what will do. Let's go back to the input program an. Since this situation starts from our mean. River level there. I'm going to start from the initial phase. I'm going to add a new face face 2. And let's call it now. River. High water level. Wave. It's not a steady ground floor now spots in the external water pressure varies in time. We're going to call the trends in groundwater flow here. Training ground flow. I'll show the Max number of steps towards I wanted to 20, so by default pledges only stores the last calculation step of any face. In this case, we want to also look into the analysis and then check every day. For instance the water. Or the flow results give us in time. Charlie said to two. Now we have to go to flow condition here we're going to define our groundwater. Are River what the table that version time? Again we have to define a new situation. So fitting situation we have to create a new water level. Now I can. Easy now reuse. Dish water level because it starts from the mean. What mean water level? So I'm going to duplicate this one and I'm going to make it time dependent one. So it's called here again, use whatever one. Which start with the lowest number of of ID die index number, lowest one possible. So again, user with a level one and I'm just going to call it and I will call it. River wave The River wave. We can see it consist of. Three segments segment water second 7. 8 and 9. Chevron 8:00 and 9:00 if I should let them hear 7, eight and nine to watershed with nine in this case. Actually, this is the one that we won't be very in time. So what we want to do? Yeah, we don't want don't want to have this one constant. And we're going to do a time dependent analysis when we do time dependent analysis, we have to specify ahead function. So let's. Here look at that function. And create a new one. Now with that function, basically here we specify the hat value in time. So let's call additional River. What are level? Diane and we can do a harmonic function. Maybe set an amplitude of 3.5 meters and appeared will be 40 days, so this would assume basically. You look here. It should be hard time domain, so here we go from zero to the maximum in 10 days and going to go back to zero at the end of 20 days, which resembles a little bit of what we want to input, but actually. And we have the actual data, so we won't use the actual data here, so we can actually use linear, but there's just an increase from one value to the other, so it's just a straight linear line going to import a table. So here with the actual sheet with the data and I'm just going to copy the whole table here. And then I'm going to paste it here. You can see here will give this. Get the small window. We can also sort of adjust the number of rows and columns. I'm going to start with RO two because the first one is the header from the very for instance the. 1st to be the hat and 2nd to be the time we can change it here. But of course this is not correct. We need to have time an Delta head. So here we have the input. And we can see here we have the nicely the curve going from zero and you have to realize that when you use a input on a theoretical level, it will be the difference compared to this theoretic level. If we have to default boundary conditions set to certain value. Omaha Omaha Boundary Line. Then we have to use the absolute value of that, but instead difference of at varying in time and. So we can do this the table. And what we see now is nothing has changed yet. That's because when we look at the global water level water globe water level should still to them in water level. And here I want to change it to the River wave. Still nothing has changed because the IT should indicate that it's. That, but what you see is the time interval here has been shattered. Jerome and should be 20 days of course. And what does she now we see here, this rectangle that gives an indication of the minimum and maximum values that we can encounter during this transient analysis? So you can see here that it goes up into the maximum of plus 4.5 and minimum would be at the mean water level, which is at plus one. So let's run the calculation. And you can see here it already done quite quickly. Then let's go to the calculation results. Starting the output program. I want to see now at the final stage you can see here at the end of the phase two River high water level wave at step 41. We can see here. Here we have the mean water level. Again, here we have 10 - 1 at the downstream side. And what you see here is that we have. A water table which is slightly different compared to the to our initial case, which is this one. So you can see here this one is nearly straight line an in this case this is clearly not the case. Look Let's look at some of the results. The groundwater flow in this case. Here we can look here, zoom in, and it's funny to see is that here we can see that from this parts apparently still water is flowing from this point about the FedEx level into actually. You can see that the water is actually. Flowing out of this situation, how can it be? That's a good question. Now what we can do, normally we only see the last phase of every step, but we can also switch this one using this button here and we can see all the individual calculation steps that we choose to save using this Mac step stored in a calculation list. So what happens here? Let's start at the time is one point today, so it's just after the increasing what level you can see here about the levels increasing a little bit. And if you zoom in. In the different time steps you can see here that the water level is increasing and also we can see also that slowly the water he is going to infiltrate into the soil. And we then go more in time. We can see here and shouldn't point here. It will reach its maximum. And then in Oudewater slowly is going to lower again. They can see here that all the water here wants to. Yeah there still water left here in the. Sorry buddy, above this drawn fairly certain that also needs to ofcourse flow. To wear this lower potential. And we continue. We can see this indeed happening. I'm also, of course, we can follow the same. Analysis using the grandmother had. So let's start again at at the beginning. This would be your situation just after the. After the mean water level, now slowly the water level is going to rise. You're going to. Shut here, my legends and manual. The top would be. What point 5:00 AM? So I set the maximum two 5,000,000 to one. Eighteenish good enough. OK, and I'm going to fix the. Legend here. So let's start again giving, because then at least we well now we have constant legends, so we don't have a changing over intervals to confuse what we're looking at, so we can see here, slowly increase of our water level. Oh, I should draw it by increasing time. And you can see here that it reaches about his maximum around 8 days. And then he can see that the water Hamish infiltrating into the soil, but now the water they were slowly going to lower again. So you see that it definitely gives you a different port pressure distribution overtime and it doesn't reach this steady state with this high River run off. So you can see it definitely has a benefit of investigating steady state solution. First wrench in situation because it definitely gives us a different port pressure distribution and it will not reach. This high water table inside our embankment. So. Back to the analysis. Now we want to combine ground flow plus our deformations. Um? So we basically want to use the same model we already have set up the input for this, so that's good. We have to change the initial phases because what we have to do is that we have to set up correct initial stretch generation. We cannot directly run aground flow analysis and do everything we have to make sure that we start with the proper initial stress definition. So we also have to change from flow only mode 2 one that also includes stretch generation. George, that we have to make the wanting user steady state analysis word transient analysis. We already saw the trenchant situation with this high River. Runoff is different than just assuming a steady state. And we might want to have a choice of including struction for our deformation analysis so far stretched generation. Or may want to include exclude destruction so this is the. And in the answer his own maybe want to execute that one. For instance, if you want to be bit conservative on the factor of safety you want to exclude destruction because their struction will increase the effective stress a little bit. And of course, when you use a fraction is material as we have now, we will have some additional strength available there, which means that you will, with struction you will get a higher factor of safety. But of course, that depends on the safety philosophy that you use. So let's. Go back to the screen share. Here we are and we're going to. Load the model here. I do not want to save this one here right now. Ann I'm going to load them all you can see is the same geometry that yeah we had before. Use the same mesh refinement here an on this line. Flow conditions, which she still we have. The arrears. Dear usual water levels here. I didn't rename the. What level here? But if the high water wave, the mean water, water level and the high water level the high with the way the test the. Time dependent item here on the River run off. So we get to stage construction and this is also important right now because we also want to do it information analysis. So what we see here we have the initial phase will just double click here so we get more enjoyment into our faces list. It's bigger and so everything is clear, readable, so we have. Here is the initial phase we're going to use. Gravity loading cannot use cannot procedure here because we're dealing with norm or rental services, which is typically one that you want to do. Africa not procedure uhm? Then we use a plastic new step. After gravity loading. I usually do a plastic new step just to make sure that any. How to balance remaining out of bounds portion of resolved? That when we start from zero stress to activating the full weight of the material, usually that cause use out of balance forces. So in that case it's sometimes better to also add an additional plastic new step to make sure that the whole situation is at in equilibrium. So after that here we're going to calculate the factor of safety for them in water level. So you can only do a factor of safety calculation. Of course when you take into account stresses, an strength the soil so we can only do that in a situation where we take that into account using the information and others like plastic calculation consultation or a fully covered flow information analysis. So we have to change that. We cannot directly from a flow calculation go to a factor of safety analysis because we need to have information on sort of strength and sore stresses which. Call, which will control the strength when you use reflections material with the friction angle. So here here's a high water table and then we calculate the factor of safety for the high water level. Basically setting up the high water levels the same as with the ground flow analysis. I will show you here, so let's go to face 2. Here we have again the high water table. And we just add a factor set calculation after this. When we look at the full cup of float information analysis, we can see something different happening. Because in a fully couple slowed information as we always have to take into account the instructions above the Frederick level. But if we have not included in from the start, of course, that means that we generated out of balance that we do not want to consider doing are high during our training ground flow analysis. So to do that, I have entered a new phase here which. Weird, I switched off the ignore struction option. Glitches will give us a warning saying, oh, you change from situation without structure to work situation with suction. Please be careful. So in this case we did it on purpose. We ignore destruction, so actually instructions are reintroduced to generate different stretch configuration. Normally would run this directly from the start, but this situation I just want to do a quick comparison of the cases we can easily interface here and then choose to include the Struction again, because mostly were interested in factor safety and not so much in the actual deformations. Down to the high water wave you can see here again we have the fluctuation of the water they were in time. Here I'm going to get a remove suction calculation. Same plastic calculation using the poor precious from the previous phase, so there's no alteration of depression. I'm just going to remove distractions from the from the analysis and then do a factor of safety calculation. You just have to look at the results. Hey we are and you can see it's a bit exaggerated with the default mesh here with just 4 millimeters of Displacement. But the scale of 500 times it looks a bit. Worth compared to what it actually is, so I'm going to hear you. The scale factor. I'm going to go to a manual scale and let's just 200 times you can see it's already. A bit better. Again, here we can see the same type of analysis from are gone with the flow analysis. In this case, actually it's the hard work that they will reduce the steady state results to calculate it informations with and we can see that we have the same flow field as we had before. Also, we're looking at. Come with that and kisses the same type of distribution here. We can also look at the high water wave at the end of the case. It also gives us this. What the table at the end of the analysis, such that would give us the same type of the same distribution of our poor precious? So this gives us the same conditions, but now we since we use it in also distressed information answers, we can also look at the factors of safety now. First let's inspect the mechanism for the mean water level. To do that, we're going to look at the. Incremental displacements And we can see here with the Increment Displacements an while doing a safety analysis, we only want to sort of Indiana. Reduce the strength of the all the showroom. Material dates as in the model with the same factor, so which is called this? Some am as F factors, restraint reduction factor. Here, uh. We want interested in the incremental deformation due to this. Lowering of the strength parameters. We did the special interest Group Workshop on January 2020, where we went more in detail on this mechanism, so you can also check that one out if you are interested in more so to see here. Here we have the. Most criticals lip service happening here at the. Right hand side, so at the upstream site. Now if you look at the high water level effective safety to high water level. Actually we see the most critical scriptures is at this site, so that's the benefit of using find elements for slip service and safety analysis. Is that the fund element calculation will figure out which is the most critical one due to the method. It's an implicit result of the analysis. And when we look at the. I want a wife and then remove at the faith. In fact of safety. We can also see it's also happening here at this site now. In order to see what the effect of safety is, I have to generate a. New curve generating new curve point. And in this case I want to select. First, the UM upstream node and look at the total deformations. An here I'm going to select lower vertical axis. This Sigma MF parameter showed that the multiplier for strength reduction. And you can see here we have these results. Anti or something is going on, but that's because we selected and so this is the one for the high water level. This is because we selected the. Like there. Then Crest Point at the upstream note while we showed the filling mechanism was at the other side, so we also have to. Then going to add girlfriend prank, current projects and also going to select headnote 1867 which is located 20. 25 Shit OK? And I'm going to come to go to the settings because he can see you have so much deformations and it doesn't really help to see what we want to see. So it's just a one. And also here I'm going to select only the phase for note 1005 is the one on the. Mr one on the upstream side. So we select the high water wave in the mean. What the level fighter safety calculation. And in this case I'm also also going to go to the high water level. Say apply. Select two. Maybe we should do this. A bit lower value. And I'll show. Have to get the factor safety after high water wave and not the high water wave face because that's not doing the factors rate calculation. So OK here we are. Want to see now is that we get a factor of safety for the high water level which is the highest which is set to be at 1.262. And when we look at the results for the, uh? For this is the. Face 5 which is the front look here face five is the factor safety for the mean water level. So this is the fact that the water is not reaching your stable value and so will probably have to do more calculation steps to reach same pattern with this one. Hello, what the level after the High River run off actually? Here it's also not reaching a stable value yet, but it's also quite low value, so it might not even reach a stable value. And that's when things are just sable that numerically, that's difficult to solve. Show it. You might see some fluctuation of the results, but adding more calculation sexual will make this look a bit better. Show So this gives us different results and we can see that after the. The High River runoff. Actually, the calculation like effective safety is lower, which of course that's. Something that's quite interesting. Then the question comes should've again. We also then calculate the factor of safety. In time, yeah, we can do that. In order to do that, what you have to do is that you have to do a calculation up until that specific point in time, so you can add a face that goes from time 02 Day 2 using the same. Grandmother had function that we already find and then go up until day four. They fixed. So you have these different moments in time and for each of these moments in time, you calculate your factor of safety. And we can do that. And what we see here, uh, so back to the presentation slide is what we see here is that we have a transient results factor safety, how it varies in time. So what we see here in the graph on the left access. Machine this reached that, so MF value at the end of the calculation phase. Um? An on the right hand side vertical axis we should external head, so the magenta dashed line is actually the development of our external hat in time. So the the that's the only graph which reflects on this right hand access for external had all the other three lines are for the summer. So we have two stable values when we use the steady state analysis. So steady state high water level, which is the Orange Line which went to around 1.2 six we saw. They also have to eat Gray line, which is a steady state for the mean water level, which was around one point 15. So it's a little short if you would expect that we have some kind of bandwidth which is between those two situations. But actually when we calculate the trench in case for this high River run off in time, we see that we have the that we have an increase of our factor of safety while the the. River water level is rising now that makes sense. The criticals lip service was at the. At the Riverside. And wild water levels increasing. Weldable show has been not fully saturated yet. Actually this water pressure will act as an additional load on top of the soil so we'll see that we have a higher factor safety because of that. Now, once the. The maximum of the High River run of his parcel actually doing the River water level is decreasing again in time, so that happens after. Day 12 we can see also that we get a rapid decrease of our factor of safety and actually it's going lower than the. The one with the steady state mean water level, and that's because when we look at the results, let's go. Results. No. Nearest higher water level. You can see what the results in time want to see at Day 14, for instance. And let's look at the groundwater. Had what we can see is that. Here we have. You still have some water in the show body which needs to, which is leftover from this high water level, which happened outside just a few days before. This this condition, and we see that because of this, actually we have less effective stress in this area. So that means also we have less strength available compared to just the day before. You see, that's why I've rapid decrease of this. Factor of safety. So the blue line. So the blue line in. Line in the graph here is actually going to go lower than the mean water level, probably after the situation has been. Being stable again, this this will also will increase again in time. Next example, a machine running a little bit out of time already. So let's go quickly to the next one. We can also. Get the results for. Adding a screen and structure. Elements. So here we are. Let's turn. Load the model. Here we are, and it's basically the same all of that before. The only difference is that we added here single line with the blade element to represent our she Powell. Yeah, sure we have assigned here material data set. The AU 14 profile. And we added the positive and negative interface so the plate itself does not have any influence on the ground. The flow analysis and of course it has an impression of information, but not on the ground with the flow analysis. So it will be fully permeable. We can only control this by using the interface elements, so these are headed here. OK, and also generate the mesh. Actually we use the same flow conditions. The only difference is in this situation is that I just installed the ship over here in phase one and then do the same analysis. Sorry about that. So when we look at the. Result for our faith. Different factors of safety. Look and see if there's some kind of difference that we might expect, and you might expect that because of the shipper war, we can also have different. What level is first look at the groundwater flow analysis. So here with the high water level, which is the more extreme case. And actually you can see here is that the. High water level here and then we flow around, are employable she Powell and it means also that he what did they were here. Mom is not as high as without the Chippewa. I can also look here at the. The shadings to see the stress concentration around the told the shipper wall and also here we have. What are shipping out of the embankment at though here? We can also look at the. Crumbled heads and we can see nicely that we have to flow here happening around the sheep of all and we have a nice reduction of the climate ahead. Is there something typically that would expect from such a ground with the flow analysis? Show up what does it mean for our factors of safety? Let's go to mean water level so you can see still has nearly the same distribution as before. And let's look at the incremental deformations. I can see here and that the. Factor safety calculation. Here is a little bit uhm. My influence here by the shippable. So there's an increased factor safety compared to the other case. If you look at the high water level. They are still the most critical one here, as it downstream side, but because of the threat level is lower compared to the case without the ship of all this factor states will be a little bit higher or show little bit a little bit later in the comparison between those two. And when we look at the high water wave. Let's just look at the. Crown water flow results at the. Crown Motor Head. I can always also look at this in time to see what's happening. So we can see here that the external water level is increasing in time. Here we are near the maximum and you can see here that. The flows of course restricted by the shipper wall. So it means the will have less water infiltrating into our toy. Bonnie can see it. Social nearly. Fully saturated at that side. And then we also have a lowering of the water table. So it is also a nice. Different result here. He can see here and there still a slight water. Greenwood had difference between the left and right inside of cheaper or after the. High River run off just passed this this embankment. So, uhm. Then we can also look at the factor of safety for this one. Safety after the whole High River run off and also look at the English patient. Can see also still cheaper still. Reflecting a little bit. Show next vector presentation now. So I did the same analysis that we did before. By splitting up the factor safety analysis. So here we see the. Gray line using a steady state mean water level, the Orange Line the steady state high water level, little bit higher compared to the previous case. And then we also did a trenchant and consultancy test this. In time for the factor of safety. And of course, then we want to see what's the difference between having shippable installed in a shippable to reduce the. Groundwater. Infiltration Endura into our magnant told we did here as we see is that. So again, the magenta line representing the external hat on the vertical on the left hand vertical access and on the right hand side we are the factors of safety to reach that someone is after the end of every calculation phase. So the dash line here gives us the blue dash line gives the case without a shipper wall using the steady state high water level. And you can see when we go to the green dash line. It's the case with a shippable using the same high water level, so you can see that for the steady state the factory safety has increased. Quite a bit, but when we compare the trench in case with and without the ship of all, we can see that both of the lines follow nearly the same. Curve and the same development in time. So there's also interesting, so although so we would expect that based on your steady state that you're that you increased your. So safety quite a lot is when we can see the trench in the case in which the steady state solution. Was not reached, not even close. We can see that the sheep our the case without the Super Bowl for this typical run of case for the River gives you nearly the same factor of safety in time I have to realize that when you have to make a judgment based on this factor of safety, these are temporary factors of safety. Concede still above 1, so there's there's no failure, but still. It comes quite close to two effective safety of one. Then again, we we actually destruction here, so that might also influence the results. So we have to look sort of at these temporary results for the factor of safety. If you want to allow them or not. Usually people also from historical types of calculation went with the steady state type of analysis to determine the each factor of safety. This is that you can always just base base that on your past experience. If you only run steady state. Situations to determining factor safety. So here we clearly have an influence of the factor safety in time due to the transient behavior of the soil. So that brings us to the end of today's presentation. So I showed you setting up the model for groundwater flow analysis only an you flow only the initial phase. All subsequent phase will be the only having a current flow analysis being steady state or transient. You have to decide which boundary condition will work for you. If you define a Frederick level sort of global water level implicitly sets head on boundaries. That's good to realize that once you set up. Hat on the boundary it will overrule this implicit setting, so the more detailed you set your boundary conditions just that part of the package will use for calculation. We can, uh, combine a grandmother flow analysis with the deformation analysis for a cup of ground with the flow deformation analysis. These kids are strange results, so it gives us more details what's happening overtime for situation which are not permanent but have limited applicability in time. And also, what's the influence of time on your Frederick surface? And also the influence of time on the development of the factors of safety? Here are some references if you're interested in running and doing a tutorial to understand and get through all the steps in detail in our Bentley communities from Lexington. So vision you can find the Plex tutorials, so here are two good tutorials to start using. Doing ground flow analysis platters, 2D shows you float through an amendment or a few other cases. But it's the first one on ground. The flow and Plexus 3D. We start with the rapid drawdown of dam reservoir, so we also have a combination of ground flow and informations. Would have more information on interface and probability. You can find the link here as well in our communities and we also have a whole section on verifications of ground flow. Comparing analytical solutions with the numerical solutions within patches. Before we go to the questions quick note or upcoming events. In April, will have two on the technical analysis. Embankment using Linda Colibri methods defined download methods will be done beginning of April. We also going to show you how to use Integra Libyan using aspie slope to determining factors of safety and May and June will have two 6 dedicating to do 3D deep excavations. So are there any questions I see during some questions added to the section I see that we have about 15 minutes left, so. I will look into the questions if you do want to have somebody from Bentley contact you, please answer yes here. Then we can follow up with you. Please answer yes if you want to have more information from us. So let's go to the questions. Micro acid you have only three grading points to define the answer, edit probability function. So what happens is, uhm, let's go to the. Screen share here. When we go to our material database, I'll just create a new material here just to what happens here. We have different types of. So we have different data data sets here with the standard or run with these these two or use defined. We can just use a 400 and ship. Or we can actually have spline down there. Actually get the table. You can define your own short water touristic curve would retention curve. If user standards based on this course and setting it will implicitly select combination of factors, some parameters relative related to this particle distribution. And it will not be, uh. A simplified case you can see here it isn't curved one here in the graph is not looking that great with these very high numbers. But you can see and they use the same. The same the distribution is just smaller. Can see it limits here at 100. But every French choose medium fine then it it already looks a bit better in the graphs. So this is a nonlinear relationship. You can find more in a scientific manual on this specific function relationship. For the unsaturated zone. And basically you have to use these input parameters as the residual situation. They fully saturated degree of saturation and this qianqian GL parameters that define the fund relationship. Throughout it answers your question Nadim asked the question can you please explain how to resolve error one or three load advancement procedure fails? I think in general it's good to look at the past Bentley 6 on the Bentley learn server and we specifically targeted it. How do you load these kinds of? Errors. The question is specifically, can this be also be the result of poor was actually in the Delta overburden pressure? Yes, that could be the case, so it could be the case that there's no force equilibrium do too. Kind of. Too high water pressure such that it will sort of give you an uplift problem that could be very well the case and depending a bit only case where I always advise to do when you have to result. To see what's going on, look at the incremental displays and so I'm going to hear or factor safety that is good, so we actually have failure here, so incremental displacements look here at the incremental displays where they happen, or if that's not clear, look at the incremental share shading so you can see here we see sort of concentration of the incremental share strains here on this service, which happened to be at the same location as our incremental deformations. If that's not clear, again. Look at the plastic points. And then he can see with these red points where the favorite criteria of the model has been reached, and then you can also give you good indication of what's happening if it's not. Problem usually sees all these white points and their happening now at the surface, but if they're happening inside your body actually there, you will see all these tension kind of points and then usually have an uplift problem. So I hope that answers your question. You ask the question, could we evaluate the safety reduction factor after floor and only analysis? OK, that's the case actually, which I described here in the second part where we actually have to use the information flow analysis and then run the factor of safety calculation. So the question here for unsalted permeability and show what acoustic curve are derived from Fargo, North, Redlands. There are derived on the back and often relationship. You can find more of this information in the purchase manuals where you can actually see for all the different types of distributions. So from the high press USDA starring what The associated parameters are. What then ask the question? How would you feel them? Few the maximum value for totals discharge? That's a very good nice question, so I'll go here to the. Case where we have the high water. Level. Let's look at the. Ground with the flow. So here we should go with the flow and she's the philosophes. What we can do here is that we. For instance, here, take a cross section just behind the. She Powell. And we can see here we have a ground with the flow and we can also show the mineiros like you see that their water is flowing here from the upstream side to the downstream side. And actually when you make a cross section black it will automatically do a integration of these flow flow station to give you a total discharge an with control plus and minus what you do on your keyboard you can actually move tour. Cross section through your model so we can quickly see that the church is about .15 kilometer per day. Permit out of plane. You can see here of course the infiltration and Ruby bit lower, but here it's nearly constant around .15. Of course, this is an integration over the cross section, so. Today, if you have very cold elements, of course you will see a slight deviation from this value. You can see. Also see here near the two. They will still have to point 15 and if we passed it though, we can see actually do to the ship it around the toad. Actually we have a lower discharge value and you can see that one here at the bottom. OK, the next question is possible to avoid the factors factors safety after transition analysis, adjust which steady state answers. So I think also cover this one. You can definitely see the factor of safety after trenchant analysis but you have to do a fully covered flow information analysis. Yes, the question why defector stages lower lower at low water table then where there's a high water table. So the question here from Krishna Uhm? The question was in Africa back. To the case without the sheep overall to make things with. So deformation. Without she poem. So we have here the case with the eye with a level factor of safety. Any we have the case with the mean water level so this lower water level and they see that the defective safety is lower with the lower. Today will then with the high. Now what happens? Hindi analysis Is that in this case we have our most critical slip surface here happening at this side, so we have. Factor of safety here, controlled by the stresses at this side with aloe water table and is also not much external water pressure. So if we going to increase the water type where? Actually what's happening is stress is increased a little bit. We also have higher external water precious, but will see here at this side is because of this external what level internal water level is raised. Actually the. Internal effective thresh will decrease because if we use a fractional material which means that the strength of the model of the material decreases here at this site so we can also do is that we here. Quickly make just a random cross section. An let's see at the UM, let's take the normal stress as a measure, the moon or affective stress as a measure of the factor of safety. Because we can use them or column Criterion. So as we look here. Treasury of look here we have to. Factor safety with them or computer using this hand box. You can also see what the principle stresses are. With that. We can also see where the most reckless combined with the friction angle. We can see that here. You are close to failure. And actually here. Fill it with C. Now if you look at the uh. But we can now do from this cross section. Use the cross section curves. And I want to come to do. I'm just going to select high water level in the initial phase. Just as a measure for the different pore pressure effective stress. And only the last step of each face. So here what will do I want to change this one show here on the run to actually X coordinate. And what we see for the initial phase is that, UM. Now I water level, we can see actually hear that the. Affected first the degrees, but we also have a higher external water load, acting almost all surface that's also resulting in less driving, so that's also reduction of the driving force, of course. I want to see here also have also a decrease of the effective stress at the downstream side, but there we do not have external water pressure acting on the soul surface to have resistance food because the maybe should better. Have look at the total stretch for there. And also so you can see. Also see here is it. With the high water level, we have also much higher total stretchy conceals here to the external water pressure at the total stress here is at the edge of the cross section, so where the soil surface meeting the River. And still here we have a higher total stress, so this is in the normal stress acting on the element 1. Here we do not have that much increase of the. There's no increase of them. Total normal fresh on the cross section. So this means that there's no additional resistance force acting in this case, so we just have a reduction of the effective stress a little bit so that most critical one will be at the downstream side of the high water level, while with the lower level the most critical one is at the upstream site. So I hope that answers the question motion RC question, how to model a couple of information in the slopes of open pit mines, where the geometry of the model is not. Does not look like a dike. She supposed to grind you the top slope I'm talking about. OK, yeah, that's actually the same type of model that we can do. So I guess you mentioned. This. This one where we do not have nice serve to set up. We did case. You have to specify your boundary conditions yourself. You can do the same in the same way as we showed you in the simple 2D case. Of course, selecting the services will be bit more complicated compared to the very simple case that we had right now, but we can also quickly change these analysis by just setting up the proper boundary condition in the run the calculation. Open pit mines have a difficult team, of course. More in the geometry. If you have really complicated 3D slots ability with flow that you want to assess, it's always good idea to look at the slope so next month will do one on the slope 3D, which is very good interface for defining that for open pit mines. But you also do the Lexus 3D but boundary conditions are indeed a bit difficult to select. They only ask the question, is the difference in the factor of safety between a trenchant Britain without cheaper or related with the numerical convergence? I think the trends between the case with and without shipper war. These are OK. The actual value of the factor of safety, especially for the case which affected safety below around 1.05 or lower. These F can have a numerical convergence issue and then usually suffice to run more calculation steps to do so. Let's see I still have a bunch of questions here. Uhm? Mom and ask the question in alcohol to get flows, but the specific section what I said before we could just make a cross section. Now we can. Of course, if you just really interested in there. Note We can French just use the hidden books here and get the flow of philosophy here. So select his him box tool here. And then move it over your geometry and can see. The absolute value, or maybe you're more interested in the. Horizontal flow flow city and unique announcers. She does she exactly where you are. You can look at the table. The table will give you the results of all the specific notes with their subsequent discharge flow velocity value. Or you may cross section. I could make it here first, go on and then we can see our horizontal. Flow velocity QX, and actually when we integrated over the height of this cross section, we can get the discharge to be this value. Pedro nicest play DoH here. You're welcome. The question I have tomorrow she put in the banquet in European. When the Struction plays an important role in this type of analysis. If you just want the Model C pitching embankment and just using with the flow analysis, I always have to consider the struction behavior for the ground with the flow analysis. If it were steady state analysis, the struction does not really play a big role for the steady state solution. But if you look at 'em deformations, dance instruction can play a significant role in this. Depend a bit on the type of material that you're dealing with friends. If you're dealing with a very coarse gravel, the answer to red zone is not that large. That will not have much influence, but if you're dealing with a clay type of material. Extent quite a big distance so it also has an influence on your deformation pattern. Then for safety analysis, it's up to you to decide. Yeah, do you want to include struction to determine factor of safety? Or do you not want to include this one? So that's a matter of safety philosophy that you have digital engineer have to decide what to do with that. The question here is stochastic analysis can be done considering spatial variability in Plex is. Currently we cannot do that directly. What you can do in flex is is you can model this yourself by defining your whole. Geometry in in small zones, and then you sort of specify for each item you specify a certain material that you want to vary based on your special variability correlations, those kind of things. But that has to be done, for instance using the plexus API using Python for instance, that we cannot do it on mash level or not level. So we have to use Python as a sort of work around to do that. But it's possible. I've already seen some people doing it at different universities. You ask the question can you please upload this pretty simple file? I'll see if I can add the case later to this analysis. He is the question the sheep overall will not increase factor of safety overtime. So if I look back at the. Xits let's go back to the final conclusion. Pedro The question here. So the presence of the sheep of war. If you look at the transient case hardly has any influence on the factor of safety. I think that's right to say, but it has to do with. If I go back to the input, it has to do with the runoff function. Here that we defined it could be that if you have higher. River run off for a more longer extended period of time. It could make a difference if you just look at the steady state solution where we assume that the very high water level is. Concert over a large amount of time where there's enough time for all the water to infiltrate that nearly the whole head. Bangladesh, foolish at rated. Then it's very clearly can see there's a difference for that, but the question of course will the situation appeared in reality, or is the High River run of not so long that the whole and Bangladesh at a rate which is just short amount of time? So in order to investigate that you have to sort of extend this high River run off with additional time. Or maybe you want to do multiple of these. Hum. This sort of high River run offs in that can happen in a given period of time for it for this situation. So in this case, indeed with this River High River run off. For this case, the present the cheaper world does not have any much influence on the factor of safety in time. That's because if you look at the results. This is the way out the cheapo all. So let's look at the. I want a level uhm. No. A merged with the high water level and if we then. Country clothes The other case here. And the one with. She Powell also the high water. Let's dial that. Fruit uninstaller And you can see here this is the influence of the. Shihpoo she can see here because the people will do. This one. Both the high water wave you can see it as a slight influence here on the distribution of the Frederick level. And of course here. We have the effect of the factor of safety. For the high water level case. But then if we look at the case where we have the luxury at ten 11 days, let's look at both cases here. Around 10.3 days. You can see that the poor pressure distribution. Miss nearly the same. In this case you can see the water crowded table here and here. They look quite similar, I'm so there's not much infiltration happening such at the shipper wall has much effect on the poor pressure distribution in the main part of the body of the of the magnet. So let's see. Still have time for two questions and then we have to run from Microsoft to left. Can I monitor piping piping is in effect we have roulette which is calling bye. Local high philosophy of the flow field such that local particles were starting in wrote this is not a concept fits within find elements where we use continuum approach. What you can do is that you can look at. Affective stress And determined based on effective stress you something something called. Critical velocity and then you can look at your flaw city your flow field to see where you reached this critical velocity where you can have to start of piping. That's the only thing that you can do with find elements. OK, that is for all the questions. Thank you for your time I hope to see you. One of the next times, and then we'll see you later online and maybe in real life. So thank you for being here an. I hope to see you next time. Thank you, bye.

Pore pressures can have a large impact on soil behavior, so it is important to define your groundwater definition realistically in order to calculate the proper pore pressure distribution. This can be done in various ways – assume a hydrostatic pressure using phreatic levels or use a groundwater flow calculation. With a groundwater flow calculation, you have the option to control if this is a constant groundwater flow field (i.e. steady state), or that it changes in time. Learn more during this Geotechnical Special Interest Group virtual workshop!

The agenda for the one-hour session includes:

- Setting up the model for a groundwater flow analysis
- Deciding which boundary conditions will work for your situation
- Combining a groundwater flow analysis with a deformation analysis for a coupled groundwater flow-deformation analysis

The Geotechnical Analysis SIG is open to all Bentley users, so invite your colleagues!

***The webcast will be streamed through your computer, so there is no dial-in number. Please make sure your computer speakers (or headset) are turned on and the volume is set to an audible level so you can hear the presenters. #EVENTHELPURL#*