The Analysis and Checking summary table appears on the DeepEX main screen, exactly after the model calculation. This table originally presents the most critical results among all stages for each design section.

With the summary table, we can see on a glance if the model converged, and if there is any issue with any structural item by reviewing fast the most critical results and structural rations for walls and supports, as well as the wall embedment safety factors.

Figure 5.1.1: Analysis and checking summary table – All design sections

If any partial result is above the limits, the result box will be read, and the first box for the specific design section “Calculation Succeeded” will be read as well, letting us know that at least one of the structural items (walls – supports) fail structurally or geotechnically, or the wall embedment is not sufficient. Please review sections 5.6 to 5.8 for more information about the results interpretation. At any point, as ;ong as the model is calculated, we can select to load the analysis and checking summary table from the Report tab of DeepEX.

Figure 5.1.2: Open analysis and checking summary table – All design sections

In the Analysis and Checking summary table, we can select the option “One Design Section” from the menu on the left side of the dialog. There we open and review the most critical results of each construction stage for a selected design section. This way we can locate the most critical stage and we can review in which stages any failure or issue might occur. Please review sections 5.6 to 5.8 for more information about the results interpretation.

Figure 5.2.1: Analysis and checking summary table – All design sections

In the menu on the left side of the dialog we can load a series of partial results that are not presented in the extended summary table (support force and stresses vs stage, lagging results, cost estimation results, wale beam results etc.).

Figure 5.2.2: Analysis and checking summary table – Partial results

After the analysis is completed, we can review all calculated results in graphs on the model area for each construction stage. Reviewing the graphical results for each stage is significant for the model optimization. We can select which results to be presented in the Results tab of DeepEX.

Reviewing Graphical Wall Results

Figure 5.3.1: Graphical results – Wall moment and shear diagrams

Figure 5.3.2: Graphical results – Wall axial diagram and structural ratios

Figure 5.3.3: Graphical results – Wall displacement diagram and surface settlements

Reviewing Graphical Support Results

Figure 5.3.4: Graphical results – Support reactions and ratios

Reviewing Graphical Soil Pressures Diagrams

Figure 5.3.5: Graphical results – Soil horizontal, total vertical and effective vertical stresses

Reviewing Graphical Surcharge and Seismic Pressures Diagrams

Figure 5.3.6: Graphical results – Surcharge and seismic pressures diagrams

Reviewing Graphical Water Pressures Diagrams

Figure 5.3.7: Graphical results – Water pressures: (a): Simplified flow, (b): Hydrostatic,
(c): 2D flownet pressures, (d): 2D flownet shadings

Reviewing Graphical Net Pressures Diagram

The net pressures diagram is the final diagram that is used in the wall design. The net pressures diagram includes all pressures that are acting on the wall horizontally in each stage (soil horizontal pressures, water pressures, surcharge pressures, seismic pressures).

Figure 5.3.8: Net pressures calculation procedure

Figure 5.3.9: Graphical results – Net pressures diagram

Editing Diagram Values (Min-Max, Envelopes)

In the Results tab of DeepEX, we can define which values should be presented on the diagrams. The option “Min Max Vals” toggles the value presentation on the graphs on and off. The option “Show Env.” presents next to every value on the diagrams the most critical value of the same item among all stages of the examined design section. The option “Global Env.” Presents next to every value on the diagrams the most critical value of the same item among all stages of all calculated linked design sections.

Figure 5.3.10: Show/Hide values on graphs

Figure 5.3.11: Show/Hide local and global result envelops

Reviewing Results Tables and Graphs

In the Results tab of DeepEX (after the analysis is completed), we can select the options “Tables” and “Diagrams”. The option “Tables” opens a table dialog that includes extensive results for each node of the wall in each construction stage, The option “Diagrams” opens a new dialog that presents all result graphs (moments, shear stresses, axial forces etc.), presenting the graph for each construction stage along with the graph envelopes.

Figure 5.3.12: Detailed result tables

Figure 5.3.13: Result diagrams

Reviewing The Wall Embedment Results

In the Results tab of DeepEX (after the analysis is completed), we can select the option “Wall Embed FS”. This button shows on the model area the tables, presenting the wall embedment and basal stability safety factors of each wall, in the selected construction stage.

Figure 5.3.14: Wall embedment and basal stability result tables

Partial results for each wall can be reviewed in the Edit wall dialog. After the calculation is completed, we can select a construction stage and double-click on any wall. In the dialog that appears we can select the option “Show full calculations”. This button opens an xml file, presenting all equations and calculation procedure for the structural design of the selected wall, in the selected stage. The calculation procedure is described based on the selected design standard, according to the wall section type (reinforced concrete or steel sections).

Figure 5.4.1: Wall equations and calculation procedure (selected stage)

Partial results for each support can be reviewed in the Edit supports dialog. After the calculation is completed, we can select a construction stage and double-click on any support. In the dialog that appears we can access the tab “Results” and review the partial results (forces, capacities, structural ratios) of the selected support in the selected construction stage. In the same dialog we can select the option “Show full calculations” or some support types (struts, rakers and concrete slabs). This button opens an xml file, presenting all equations and calculation procedure for the structural design of the selected wall, in the selected stage. The calculation procedure is described based on the selected design standard, according to the wall section type (reinforced concrete or steel sections).

Figure 5.5.1: Support partial results (selected stage)

Figure 5.5.2: Support equations and calculation procedure (selected stage)

The wall results can be reviewed either from the analysis and checking summary tables (see sections 5.1 and 5.2), or graphically from the model area (see section 5.3). We can review from tables and graphs the wall stresses (moments, shear and axial diagrams), the calculated capacities, the structural ratios and the wall displacements for each construction stage. This way, the most critical results and stages can be located, and we can decide to take an action to optimize the wall sections either manually, or with the use of the software automatic optimization tools (see section 5.9).

Evaluating the Wall Displacements

The maximum wall displacements for each construction stage can be reviewed in the Analysis and checking summary table and graphically in the model area, after the analysis is completed. This way, we can recognize if the estimated displacements would exceed or are far less than any required maximum displacement value, and decide to take an action.

Figure 5.6.1: Review the calculated wall displacements for each stage

NOTE: The displacements through stages are not cumulative when the Limit Equilibrium Analysis method is used. By default, the LEM analysis estimates the displacement diagrams independently in each stage, a procedure that could lead to unrealistic results, especially in models with multiple support levels. We should be careful evaluating the displacements in LEM analysis.

 

The wall displacements are affected by the soil properties, structural wall sections, support locations and excavation depth. We can select to change these parameters in order to adjust the wall displacements, in case that the estimated values exceed or are far less than the required limit. In DeepEX, several cases can be examined, so the we can locate easily the most efficient solution. The graphical interface of the software allows the quick adjustment of all project properties. We can access and edit all items, run the analysis and in a few seconds the new results will be produced. We could take any of the following actions:

A. Double-click on the wall and increase or decrease the wall structural sections (thickness, reinforcement size).

B. Double-click on the wall and select a different wall section type (soldier piles, secant piles etc.).

C. Double-click on the wall and reduce/increase the spacing of soldier piles (if soldier pile and lagging walls are used).

Figure 5.6.2: Edit the wall structural section manually

IMPORTANT: In DeepEX, the same wall section could be used in more than one walls, in the same or different design sections in the specific software file. By editing a wall section, the same changes will apply to all walls that use the same section. While optimizing a specific wall, we have to keep this parameter into consideration and if needed, we can create a new wall section, optimize it and use it in the examined wall. This way, the changes will affect this and only this wall.

 

D. Consider changing the support locations/excavation elevations in each stage. In general, we can consider moving the supports up and excavate less in each stage, producing smaller displacements. When following this method we have to review the excavation depths for each construction stage.

Figure 5.6.3: Edit the support location and excavation elevation manually

NOTE: Sometimes, optimizing the support locations and excavation levels is more efficient than simply increase the wall section.

 

E. Use CALTRANS approximate method for displacements. CALTRANS suggests the use of a fixity point below the excavation for the displacements. This method reduces the wall displacements in the cantilever stage, leading to more realistic displacement diagrams. This method can be selected in the Analysis tab of DeepEX, by selecting the option “Additional options for California Trenching Manual approach”

Figure 5.6.4: Use the CALTRANS approximate method for displacements

Evaluating the Wall Moment and Shear Ratios

The maximum wall moment and shear values and ratios for each construction stage can be reviewed in the Analysis and checking summary table and graphically in the model area, after the analysis is completed. The structural ratios are the maximum applied moment (or shear) divided by the maximum moment (or shear) capacity, as calculated according to the selected structural code specifications. Apparently, the ratios values should be below the value “1” in all construction stages, and at the same time, the closer the maximum ratio to the value “1” is, the more efficient is the solution.

Figure 5.6.5: Review the calculated wall moments and shear stresses for each stage

The wall moment and shear ratios are affected by the soil properties, structural wall sections, support locations and excavation depth. The soil stresses and excavation depths affect the produced moments and shears on the wall. The structural section affects the calculated structural capacities, used for the calculation of the structural ratios in each construction stage. We can select to change these parameters in order to adjust the wall forces or capacities, in case that the calculated ratios exceed or are far less than the limit value “1”.

In DeepEX, several cases can be examined, so that we can locate easily the most efficient solution. The graphical interface of the software allows the quick adjustment of all project properties. We can access and edit all items, run the analysis and in a few seconds the new results will be produced. We could take any of the following actions:

A. Double-click on the wall and increase or decrease the wall structural sections (thickness, reinforcement size).

B. Double-click on the wall and select a different wall section type (soldier piles, secant piles etc.).

C. Double-click on the wall and reduce/increase the spacing of soldier piles (if soldier pile and lagging walls are used).

Any of the 3 options above would affect the calculated structural capacities.

IMPORTANT: In DeepEX, the same wall section could be used in more than one walls, in the same or different design sections in the specific software file. By editing a wall section, the same changes will apply to all walls that use the same section. While optimizing a specific wall, we have to keep this parameter into consideration and if needed, we can create a new wall section, optimize it and use it in the examined wall. This way, the changes will affect this and only this wall.

 

D. Consider changing the support locations/excavation elevations in each stage. In general, we can consider moving the supports up and excavate less in each stage, producing smaller moments and shear stresses on the walls. When following this method we have to review the excavation depths for each construction stage.

NOTE: Sometimes, optimizing the support locations and excavation levels is more efficient than simply increase the wall section.

 

Our general recommendation is to check wall displacements and structural ratios together. This way we can optimize the model, locating the most efficient solution that satisfies all local parameters.

 

The support results can be reviewed either from the analysis and checking summary tables (see sections 5.1 and 5.2), or graphically from the model area (see section 5.3). We can review from tables and graphs the support reactions and the calculated structural and geotechnical ratios for each construction stage. This way, the most critical results and stages can be located, and we can decide to take an action to optimize the supports either manually, or with the use of the software automatic optimization tools (see section 5.9).

Figure 5.7.1: Review the calculated support reactions and ratios for each stage

The support structural and geotechnical ratios are affected by the structural support sections, support spacing, length of the bonded part (for ground anchors), support locations and excavation depth. The soil stresses, support spacing and excavation depths affect the produced support reactions. The structural section affects the calculated structural capacities, used for the calculation of the structural ratio in each construction stage and the bonded part length, along with the grout diameter affect the calculated geotechnical capacity, used for the calculation of the geotechnical ratio in each construction stage (for ground anchors). We can select to change these parameters in order to adjust the support forces or capacities, in case that the calculated ratios exceed or are far less than the limit value “1”.

In DeepEX, several cases can be examined, so that we can locate easily the most efficient solution. The graphical interface of the software allows the quick adjustment of all project properties. We can access and edit all items, run the analysis and in a few seconds the new results will be produced. We could take any of the following actions:

A. Double-click on the support and increase or decrease the support structural section. This action would affect the calculated structural capacities.

B. Double-click on the ground anchor and increase or decrease the Lfix value (bonded part length).

C. Double-click on a tieback and change the tieback installation angle. This way a tieback could be directed to a more dense soil layer (if present).

D. Double-click on the tieback and increase or decrease the grout grade or diameter.

Any of the 3 options above would affect the calculated geotechnical capacities.

IMPORTANT: In DeepEX, the same support section could be used in more than one supports, in the same or different design sections in the specific software file. By editing a support section, the same changes will apply to all supports that use the same section. While optimizing a specific support, we have to keep this parameter into consideration and if needed, we can create a new section, optimize it and use it in the examined support.

 

E. Double-click on the support and reduce/increase the support spacing. This action affects the calculated support reactions.

F. Consider changing the support locations/excavation elevations in each stage. In general, we can consider moving the supports up and excavate less in each stage, producing smaller support reactions. When following this method we have to review the excavation depths for each construction stage.

NOTE: Sometimes, optimizing the support locations and excavation levels is more efficient than simply increase the support structural section.

 

The wall embedment safety factors can be reviewed either from the analysis and checking summary tables (see sections 5.1 and 5.2), or graphically from the model area (see section 5.3). We can review the calculated wall embedment and basal stability factors for each construction stage. This way, the most critical results and stages can be located, and we can decide to take an action to optimize the wall depth either manually, or with the use of the software automatic optimization tools (see section 5.9). Sections 4.12 and 4.12 present more information about the calculated embedment and basal stability factors.

Figure 5.8.1: Review the calculated embedment and basal stability factors for each stage

The required wall embedment safety factor is usually described by local design standards and should be determined by the user. Some standards (i.e. Eurocode 7), when in use, they suggest a value of “1”. In most cases we should target for a factor of at least 1.2, 1.3, even 1.5.

In case that the minimum wall embedment safety factor is less of far more than the required factor value, we can adjust the wall depth (double-click on the wall and increase/decrease the wall depth), run the analysis and in a few seconds we could review the new results and achieve an effective and safe wall depth.

NOTE: In DeepEX, the wall embedment safety factors appear only when the LEM or the LEM+NL analysis methods are selected.

 

Figure 5.8.2: Manually optimize the wall depth with use of the wall embedment FS

As mentioned in the sections 5.7 to 5.9, we can review the model results and take specific actions to optimize all model items manually. This is the suggested method, because it allows us to review all partial results and locate the most efficient solution. DeepEX software offers a series of automatic optimization tools in the Optimize and Design tabs that can assist us with the partial optimization of several items.

Defining Redesign Options

In the Optimize tab of DeepEX, we can select the button “Redesign options”. By selecting this option, in the dialog that appears we can design the search limits for the walls and supports structural sections. We can define the minimum and maximum section thicknesses, rebar sizes, tieback bonded part lengths etc.

Figure 5.9.1: Automatic optimization redesign options

Automatic Optimization of a Design Section

After the analysis is completed, we can select the option “Optimize Design Section” from the Optimize tab of DeepEX. This action will start optimizing automatically all structural members (walls and supports), if the calculated rations are above the limit “1”.

For each wall in the selected design section, the software will check and report different structural sections of the selected wall reinforcement type (H piles, pipes, channel sections, sheet piles or rebar configurations by using the software implemented steel sections and rebar sizes databases), along with the calculated structural ratios. We can select from the provided list with sections and ratios which section should be applied in each wall.

Figure 5.9.2: Automatic design section optimization – Select a wall section

For the ground anchors structural optimization, the software will optimize the number of strands using the specified strand diameter, so that the produced structural capacity is bigger than the applied support reaction. DeepEX will repeat the procedure for each ground anchor and notify us about the section change.

For the ground anchors geotechnical optimization, the software will start increasing the anchor bonded length by the value DL that can be edited by the user in the Redesign options dialog (see Figure 5.9.1), calculate the geotechnical ratio for each step and stop the analysis when the calculated geotechnical capacity is more than enough to cover the applied load, or the limit length in the Redesign options dialog is reached.

For each support (struts, concrete slabs, rakers) in the selected design section, the software will check and report different structural sections of the selected support reinforcement type (H piles, pipes, square hollow sections or rebar configurations by using the software implemented steel sections and rebar sizes databases), along with the calculated structural ratios. We can select from the provided list with sections and ratios which section should be applied in each support.

Figure 5.9.3: Automatic design section optimization – Select a support section

After optimizing each support and wall in the selected design section, DeepEX will load a file describing all the changes performed by the software on structural sections and anchor lengths.

Figure 5.9.4: Automatic design section optimization – Optimization report

IMPORTANT: The structural optimization affects directly the structural member selected section. If the same structural section is used in other structural members (walls or supports) in the same or in different design sections, the change will affect these members as well. It is recommended to create and assign different structural sections for each member, even if they are identical, to avoid this optimization side effect.

 

Automatic Optimization of Support Locations

After the analysis is completed, we can select the option “Optimize Support Locations” from the Optimize tab of DeepEX. In the dialog that appears (see Figure 5.9.5), we can specify the initial and maximum depth for each support, as well as, the depth increment which the software will use to move each support and the maximum desired wall displacement. DeepEX will start a long-lasting procedure, where it will use all possible combinations for each support on the model area using the defined limits and depth increment, it will perform the analysis for each combination and return the position combination that produces the optimum wall moments and displacement diagrams.

Figure 5.9.5: Automatic optimization of support locations options

Automatic Optimization of a Single Support (Structural)

After the analysis is completed, we can select the option “Autodesign a support (STR)” and select a support on the model area. For a ground anchors structural optimization, the software will optimize the number of strands using the specified strand diameter, so that the produced structural capacity is bigger than the applied support reaction. For struts, concrete slabs or rakers, the software will check and report different structural sections of the selected support reinforcement type (H piles, pipes, square hollow sections or rebar configurations by using the software implemented steel sections and rebar sizes databases), along with the calculated structural ratios. We can select from the provided list with sections and ratios which section should be applied to the selected support (similar to Figure 5.9.3).

Automatic Optimization of a Single Support (Structural)

After the analysis is completed, we can select the option “Autodesign a support (STR)” and select a support on the model area. The software will check and report different structural sections of the selected wall reinforcement type (H piles, pipes, channel sections, sheet piles or rebar configurations by using the software implemented steel sections and rebar sizes databases), along with the calculated structural ratios. We can select from the provided list with sections and ratios which section should be applied in each wall (similar to Figure 5.9.2).

Automatic Optimization of a Single Ground Anchor Fixed Length (Geotechnical)

After the analysis is completed, we can select the option “Autodesign fixed length for a ground anchor (GEO)” from the Optimize tab of DeepEX and select a specific tieback in the model area. The software will start increasing the anchor bonded length by the value DL that can be edited by the user in the Redesign options dialog (see Figure 5.9.1), calculate the geotechnical ratio for each step and stop the analysis when the calculated geotechnical capacity is more than enough to cover the applied load, or the limit length in the Redesign options dialog is reached.

Automatic Wall Depth Optimization (LEM Analysis Only)

When the Limit Equilibrium Analysis Method (LEM) is selected, the option “Optimize wall embedment for safety factors” appears in the Design tab of DeepEX. By selecting this option, we can define the required safety factors for the cantilever stage and the stages with supports, as well as, the increment DL that will be used for the wall embedment optimization. The software will start increasing the wall depth from the excavation depth using the defined increment and calculate all wall embedment safety factors (passive, rotational and length – see section 4.11) for each step. DeepEX will stop the analysis at the point where all calculated factors are above the defined limits and return that depth.

Figure 5.9.6: Automatic wall depth optimization (LEM analysis only)

The following can be issues causing a model to not converge in Non-linear analysis:

A. The two surface points on each wall side have different elevations at the initial stage.

In NL analysis, the soil springs need to start from an at-rest situation to receive the initial values, so it is required the two surface points on each wall side to have the exact same elevation. Excavations and support installations need to be performed in upcoming stages, following a strict staging schedule.

Figure 5.10.1: Surface elevations on each wall side – Stage 0

B. The wall is unstable because of insufficient wall embedment.

If the wall embedment safety factors in LEM analysis are too small, it is possible that the model collapses in the NL analysis before the analysis finishes. In that case we would need to double-click on the wall and increase the wall depth before selecting to run the analysis.

Our general recommendation is to optimize the wall depth using the LEM analysis first.

 

C. The mesh density is either too small or too big (number of nodes in the wall).

The mesh density defines the density of the soil springs and it can be defined in the Analysis tab of DeepEX.

Figure 5.10.2: Non Linear Analysis – Mesh Density

D. The clay strength and OCR parameters are not properly defined resulting in a small calculated undrained shear strength of a clay.

In the NL analysis, the user-defined clay undrained shear strength is used as a maximum value. The undrained strength is increased with depth, with the use of the Over consolidation ratio (OCR), which can be defined in the Edit Borings dialog.

Figure 5.10.3: Clay undrained strength and OCR

E. Ground anchors are not prestressed in the non-linear analysis model.

The ground anchors should be prestressed in the support installation stage. The prestress force is taken into consideration in Non Linear analysis method and the absence of it can lead to big displacements that can force the wall to collapse.

Our general recommendation is to run the model with Limit Equilibrium Analysis method, review the maximum reaction for each support level and use a percentage of this support reaction (usually 80%) as a prestress force in the support installation stage).

 

F. No wall friction has been assumed in the non-linear analysis. This is equivalent to the interface strength reduction factor in an FE analysis.

G. In very rare cases, the stiffness matrix becomes close to a unity matrix. In this case, changing the mesh density can solve the problem. 

Once a project is analyzed, full analysis reports can be generated by selecting the Reports – Options option at the Report tab. By selecting this, we can modify the included output sections.

Figure 5.11.1: Open the report manager

Selecting Report Design Sections and Construction Stages

On the left side of the dialog, we can select which design sections and stages will be included in the current report. Initially, we have to unselect any design section that should not be reported. The, by expanding this design section name, we can select/unselect the construction stages of the expanded design section.

Figure 5.11.2: Report manager – Select design sections and construction stages

Selecting the Report Sections and Defining the Sections Order

From the Available Report Sections area, we can select the results and options that shall be included in the final report. In this middle section, a lot of possible report section categories are included (results, graphs, partial results, equations and calculation procedure and more). We can expand these categories and drag and drop any desired section to the Report Format column on the right side of the dialog. By drag and drop we can also change the order of the report sections in the Report Format column.

Figure 5.11.3: Report manager – Select design sections and construction stages

Figure 5.11.4: Report manager – Change the report sections order

Defining Graphs and Sketches Layout Options

At the bottom left area of the report manager, we can select which result graphs should be included in the final report. By selecting a graph category (Lateral pressures, Bending moments, Lateral wall deflection, Shear forces), additional options appear to the right and we can select whether or not the graphs should be reported.

At the bottom middle area of the report manager, we can select whether or not borders should be used in the reported sketches, as well as the sketch layout (Vertical-half page, Vertical-full page, Landscape).

Figure 5.11.5: Report manager – Graphs and sketches layout options

Previewing and Exporting a Report

From the bottom right side of the report manager dialog, we can select to preview the report, save it to PDF or save it to MS Word format.

NOTE: The generated reports include a lot of screenshots and images that are generated at the time of the report export. The generated file is a considerably big one, and the screenshot creation and save consumes a lot of the local device memory. In some cases, it is recommended to preview the report first, make sure that all required pages and sections are correctly generated and then select to save this generated preview file as PDF.

 

Figure 5.11.6: Report manager – Preview and export report options