DeepEX offers the option to perform analysis both with conventional method (Limit Equilibrium Analysis), and with advanced methods (Non-Linear Analysis method, Finite Element Analysis).

In the basic version of the software, we can select among the following methods:

A. Conventional Limit Equilibrium Analysis Method (LEM).

Limit equilibrium is an analysis methods where limit state conditions are assumed. For excavations and earth retaining structures this usually means that earth pressures are assumed on both the retained and excavated sides. These pressures may represent a failure state such as active or passive lateral earth pressures, or an assumed redistribution such as diagrams by Peck or FHWA.

In Limit Equilibrium Analysis, the retaining wall is analyzed to provide moment and force equilibrium, when possible. Support reactions are also calculated, typically by using the tributary area method.

B. Non-Linear (Beam on elastoplastic foundations) Method (NL).

DeepEX implements a non-linear finite element code for the analysis of the mechanical behavior of flexible earth retaining structures during all the intermediate steps of an open excavation. The non-linear engine is empowered by many unique advanced features. DeepEX offers the following elastoplastic soil models:

a) Linear elastic - perfectly plastic

b) Hyperbolic soil model

c) Subgrade reaction soil model

d) Small Strain Hardening model

On the reloading part, every soil model has a linear reloading elasticity parameter. Such a parameter should typically range from 2 to 4 times the loading elasticity value (with average 3). In excavations, the reloading elasticity parameter typically describes the remaining soil below the excavation while the loading elasticity is mostly applicable for soil on the retained side. In a non-linear analysis the excavation models reduced to a plane problem, in which a unit wide slice of the wall is analyzed, as outlined in the Figure below. Therefore DeepEX is not suitable to model excavation geometries in which three-dimensional effects may play an important role. In the modelling of the soil-wall interaction, the very simple yet popular Winkler approach is adopted. The retaining wall is modelled by means of beam elements with transversal bending stiffness EI; the soil is modelled by means of a double array of independent elastoplastic springs; at each wall grid point, two opposite springs converge at most.

C. Limit Equilibrium and Non-Linear Analysis Combination Method (LEM+NL).

In this case, DeeEX will first use the LEM method in order to calculate the wall embedment safety factors, and then will run the analysis with the soil springs in order to calculate all other parameters (support reactions, soil pressures, wall moment and shear stresses, wall displacements etc.).

If the DeepEX Finite Element Analysis additional optional module is acquired, we can also choose the following analysis methods:

D. Finite Element Analysis Method (FEM).

FEM analysis can consider all construction stage effects and enables us to model full soil-structure interaction. Soil is modelled with a series of triangular nodes. DeepEX does all the stiffness calculations and helps us to estimate FEM analysis parameters.

E. Limit Equilibrium and Finite Element Combination Method (LEM+FEM).

In this case, DeeEX will first use the LEM method in order to calculate the wall embedment safety factors, and then will run the analysis with the finite elements in order to calculate all other parameters (support reactions, soil pressures, wall moment and shear stresses, wall displacements etc.).

Important: The selection of the analysis method is very important for the final analysis. All methods implemented in DeepEX are verified, but the final selection, design and results evaluation is the responsibility of the user and should be based on the project type, the methods that are recommended by the authorities, the designer experience, the quality of the provided geotechnical reports and more.

 

We can select an analysis method from the Analysis tab of DeepEX. Different analysis methods can be assigned to different design sections at the same time, allowing us to check and compare fast different solutions.

Our general recommendation is our users to run all types of analysis and design the project with the most critical.

 

Figure 4.1.1: Defining the analysis method to a design section in DeepEX

In the default DeepEX project file, no specific design standard is selected. The default option is a service limit state, where all partial safety factors have the value 1, and we can define in the Design tab of DeepEX some factors applied on the geotechnical and structural capacities.

Figure 4.2.1: User defined structural and geotechnical safety factors

DeepEX implements all load combinations of several international geotechnical design standards (AASHTO LRFD, CALTRANS LRFD, PENN DOT AASHTO, EUROCODE 7, DM_08 (Italian), DIN 1054 (German), XP P 94 (French), BS 1997 (British) and CN (Chinese)). We can quickly select a standard and apply a load combination on any design section, or generate new design sections automatically, each one using a load combination of a specific standard, simulating at once all load combinations. Also, we can create User Defined combinations, allowing the use of DeepEX in countries that are using codes we might have not yet implemented in the software. All these options are available in the Analysis tab of DeepEX.

Figure 4.2.2: Geotechnical design standards in the Analysis tab

Selecting a Load Combination of a Specific Standard

By pressing on the button “Single” in the Analysis tab of DeepEX, we can select a design standard and a specific load combination of the selected standard. By accepting the change, the assumption table on the right side of the screen expands, presenting all partial safety factors that are used according to the selected combination.

Figure 4.2.3: Apply a load combination of a specific standard

Generating all Load Combinations of a Selected Standard

By pressing on the arrow next to the button “Mult.” in the Analysis tab of DeepEX, we can select to use all load combinations according to a specific standard. In this case, DeepEX will create automatically new design sections linked and identical with the selected section, each one using a load combination of the selected standard.

Figure 4.2.4: Use all load combinations of a specific standard

Generating Custom Load Combinations

By pressing on the button “Mult.” in the Analysis tab of DeepEX, we can select to define a custom load combination, define all partial safety factors and select to add the combination to the project database. Next, by accessing the arrow next to the button “Single”, we can select the option “User Defined Approach”.

Figure 4.2.5: Define a custom load combination

Figure 4.2.6: Option to use a custom load combination

For each clay soil layer, we can define the clay behavior (drained or undrained) in the Edit soils dialog that can be accessed from the General tab of DeepEX (see section 3.2). According to the selected behavior, we should define the undrained (undrained shear strength) or drained (drained shear strength, friction angle) soil properties.

In any construction stage, we can select to change the clay behavior from the default to something else (i.e. from default to drained or undrained). This option allows us to check the model both for short term undrained and for long term drained conditions.

The option to change clay behavior can be located in the Analysis tab of DeepEX.

Figure 4.3.1: Options to change clay behavior

This action will change the behavior of all clays used in the model. If we need to change the clay behavior or a specific clay (or some clays but not all), then we can use a soil change command (see section 3.3).

Figure 4.3.2: Change clay behavior with soil change commands

The software offers the following options for modeling groundwater:

Hydrostatic: Applicable for both conventional and elastoplastic analysis. In ELP, hydrostatic conditions are modeled by extending the “wall lining” effect to 100 times the wall length below the wall bottom.

Simplified flow: Applicable for both conventional and elastoplastic analysis. This is a simplified 1D flow around the wall. In the NL analysis mode, the traditional NL water flow option is employed.

Full Flow Net analysis: Applicable for both conventional and elastoplastic analysis. Water pressures are determined by performing a 2D finite difference flow analysis. In NONLINEAR, water pressures are then added by the UTAB command. The flownet analysis does not account for a drop in the phreatic line.

User pressures: Applicable for both conventional and NL analysis. Water pressures defined by the user are assumed. In the nonlinear analysis, water pressures are added by the UTAB command.

NOTE: In contrast to the non-linear analysis, conventional analyses do not generate excess pore pressures during undrained conditions for clays.

 

The option to select a water pressures method can be located in the Analysis tab of DeepEX.

Figure 4.4.1: Select a water pressures method

DeepEX implements several theories and methods for the earth coefficient calculations in LEM analysis. The thrust options can be defined in the Analysis tab of DeepEX.

Automatic Mode (Recommended Option)

When the automatic mode is selected, DeepEX chooses the best theory methods for the calculations of Ka and Kp values (Coulomb, Rankine, Caquot-Kerisel, Lancellota), taking into consideration the project parameters (wall friction, surface slope, seismic effects).

The automatic mode is recommended for most uses in DeepEX.

Figure 4.5.1: Automatic thrust calculations mode

User Mode

Sometimes we wish to specify different wall friction values for each construction stage. In this case, we can turn the thrust options to user mode and specify the method that will be used for the calculations of earth coefficients in each stage.

Figure 4.5.2: User thrust calculations mode

Manual Mode

In some occasions the model could have complex sliding surfaces that may not be directly captured by the software automatic procedure. In this case we can select the manual mode for the earth coefficient calculations. When this option is selected, we have to access the Soil Types dialog from the General tab of DeepEX and define the Ka and Kp values for each soil manually in the Thrust tab that appears.

NOTES: In order to define the Ka and Kp values manually, the checkbox “Auoestimate Ka-Kp” in the Edit soil types dialog has to be unselected. In order to use the manual mode, you need to have totally horizontal stratigraphy on the model area (no inclined custom layers or slope surfaces).

 

Figure 4.5.3: Manual thrust mode

In DeepEX, the default option is to not use a wall friction. This option is conservative and in certain cases it is recommended to use some wall friction as a percentage of soil friction (i.e. 2/3 or 66% of soil phi etc.). In DeepEX, we can select to apply wall friction to the model, either as a percentage of the soil friction, or as an absolute value. There is also an option to define different wall friction values on the two wall sides (driving and resisting). The wall friction can be defined individually for each wall used in the model.

Figure 4.6.1: Options to add wall friction

Figure 4.6.2: Option to define different wall friction on each wall side

NOTE: When defining wall friction as a percentage of the soil friction angle phi in DeepEX, the values (percentages) that can be defined in the boxes are divided by 100. So, for a wall friction 33%*phi we need to type 33 etc.

 

When we select to perform LEM analysis, DeepEX uses Active pressures by default for all construction stages. Although, DeepEX implements several other pressure methods (At-rest, FHWA Apparent, Peck Apparent, Custom Trapezoidal, Two-Step rectangular, Adaptive Apparent, WMATA manual, User-defined pressures and more).

Selecting a Driving Side Pressures Method

We can define the method that will be used in each construction stage from the Analysis tab of DeepEX.

Figure 4.7.1: Select a method for the calculation of soil driving pressures

Defining Pressure Method Options

In some methods, we can define some additional parameters. Please contact us and request a copy of our Theory manual for further information about methods and options.

Figure 4.7.2: Active pressure diagram

Figure 4.7.3: Active x Load Factor options and pressure diagram

Figure 4.7.4: FHWA Apparent options and pressure diagram

Figure 4.7.5: Custom Trapezoidal options and pressure diagram

Figure 4.7.6: Two Step Rectangular options and pressure diagram

Figure 4.7.7: Adaptive Apparent options and pressure diagram

Defining Minimum Pressures

In some cases, we can select to define minimum pressures to the model. The minimum pressure options can be accessed in the Analysis tab of DeepEX.

Figure 4.7.8: Option to define minimum pressures

Defining User Pressures

We can select the option User pressures and define the pressure diagram manually, by defining elevations and pressure values.

Figure 4.7.9: Defining user active pressures on left wall

When we select to perform LEM analysis, DeepEX uses Passive pressures by default for all construction stages on resisting side. Although, DeepEX implements other pressure methods (At-rest, At-rest x multiplier, Passive pressures/FS, User-defined).

We can define the method that will be used in each construction stage from the Analysis tab of DeepEX.

Figure 4.8.1: Select a method for the calculation of soil resisting pressures

Figure 4.8.2: Passive pressures divided by a safety factor

DeepEX implements a variety of beam analysis methods for the calculation of wall moment and shear diagrams for models with multiple support levels. We can select a beam analysis method when the LEM analysis is selected, from the Analysis tab of DeepEX.

Figure 4.9.1: Select a beam analysis method for models with multiple support levels

Blum’s Method

Blum’s method considers the wall as a continuous beam with pinned supports. It places a virtual support at the point of zero net shear below the excavation subgrade. Figure 4.9.2 summarizes the method and the produced moment and shear diagrams.

Figure 4.9.2: Blum’s method: moment and shear diagrams

FHWA Simple Span Approach

The FHWA simple span method assumes pinned supports below the first support level and at the excavation subgrade, and calculates moments and shears with the simple span method. Figure 4.9.3 summarizes the method and the produced moment and shear diagrams.

Figure 4.9.3: FHWA simple span method: moment and shear diagrams

Simple Span with Negative Moments Method (Combination of FHWA and Blum’s Method)

This method is similar to the FHWA simple span approach. The difference is that the virtual support is used at the point of zero net shear below the excavation subgrade. Figure 4.9.4 summarizes the method and the produced moment and shear diagrams.

Figure 4.9.4: Simple span with negative moments method: moment and shear diagrams

CALTRANS (California Trenching and Shoring Manual) Method

The CALTRANS method assumes pinned supports below the first support level and at the point of zero moment below bottom support, and calculates moments and shears with the simple span method. With CALTRANS method, moments and shears balance out. Figure 4.9.5 summarizes the method and the produced moment and shear diagrams.

Figure 4.9.5: CALTRANS method: moment and shear diagrams

CALTRANS with Negative Moments Method

Sometimes, CALTRANS simple span method is considered very conservative. There is a modified version that assumes negative moments as a percentage of the simple span moments (typically 20%). Figure 4.9.6 summarizes the method and the produced moment and shear diagrams.

Figure 4.9.6: CALTRANS method with negative moments: moment and shear diagrams

WMATA Method (Washington DC)

This method is described in the WMATA Adjacent Construction Manual 2015 and it considers the wall as a continuous beam, using as fixity point the excavation subgrade. Figure 4.9.7 summarizes the method and the produced moment and shear diagrams.

Figure 4.9.7: WMATA method: moment and shear diagrams

Earth retaining structures such as braced excavations and anchored bulkheads experience additional forces during seismic events. The true wall behavior is very complex and can rarely be truly simulated for most earth retaining structures. Instead, engineers have long used widely acceptable simplified models and methods that allow seismic effects to be added as external pressure diagrams. These additional seismic pressures can be essentially divided in three parts: The additional force due to the soil skeleton, the additional hydrodynamic forces and Inertia effects on the retaining structure.

Unyielding walls (i.e. rigid walls that do not move) experience greater forces compared to yielding walls. Hence, permissible wall displacement influences the magnitude of the external forces that a wall might experience during an earthquake. In an elastoplastic analysis (i.e. Nonlinear engine) an automatic simplified procedure is available that gradually reduces pressures from the theoretical rigid wall limit as the wall displaces. Further, water in highly permeable soils may be free to move independently from the soil skeleton, thus adding hydrodynamic pressures on a wall. Water above the ground surface will also add hydrodynamic effects.

To use Seismic pressures in a construction stage in DeepEX, we have to access the Seismic tab of the software, select the option “Include Seismic Loads”, define the earthquake accelerations and select the method for the calculation of seismic pressures.

Figure 4.10.1: Procedure to include seismic loads in a construction stage

Our general recommendation is to add a new construction stage right after the last model stage and use the seismic options there. That way, you can review the non-seismic design of the whole project and at the same time check the case of a seismic activity long term, after the project is constructed.

 

Defining Earthquake Accelerations

The earthquake accelerations in DeepEX can be either defined in the Seismic tab (see Figure 4.10.1), or they can be estimated by the software using the Base Acceleration and some other parameters (site soil response factor, topographic site response, importance factor). The software has implemented also methods for the calculation of the wall flexibility response factor R. All these seismic accelerations estimation tools can be located in the Seismic tab of DeepEX, by pressing on the button “Full Seismic Options”. In the same dialog, we can define the method for the calculation of seismic pressures, the water behavior (pervious, impervious, option to ignore water pressures), and the height up to which the seismic pressures will be taken into consideration (excavation subgrade or full wall depth).

Figure 4.10.2: Full seismic options and seismic accelerations calculation procedure

Selecting a Seismic Pressures Method

DeepEX implements a variety of methods for the calculation of seismic pressures. We can select these methods either directly from the Seismic tab of DeepEX, or from the Full Seismic options dialog (see Figures 4.10.1 and 4.10.2 respectively).

A. Semirigid Pressures Method

In the semirigid approach the seismic pressure is calculated as the product of the total vertical stress at the bottom of the wall (or excavation subgrade depending on user selection) times a factor B, which is a multiplier defined by seismic standards. The default value for B in DeepEX is 0.75. The seismic thrust is then included as an external rectangular pressure diagram.

Figure 4.10.3: Seismic pressures – Semirigid method

B. Mononobe-Okabe Method (for frictional soils)

The M-O method is a direct extension of the static coulomb theory that accounts for acceleration where seismic accelerations are applied to a Coulomb active (or passive) wedge. The software program always includes seismic pressures calculated with the M-O method as external loads. The seismic thrust is redistributed according to the Seed & Whitman (1970) recommendation as an inverse trapezoid with the resultant force acting at 0.6H above the wall bottom (or bottom of excavation depending on the selected height option).

Figure 4.10.4: Seismic pressures – Mononobe-Okabe method

C. User-Defined Seismic Pressures

We can define the user pressures manually in the Full Seismic Options dialog. There, we can define the diagram as a rectangle or trapezoid, by defining the top and bottom elevations and seismic pressures magnitudes.

Figure 4.10.5: Seismic pressures – User-defined pressure diagram

D. Wood Method (Automatic and Manual)

In this approach the first step is to determine the average lateral thrust of the soil according to the wood approach. In the limit equilibrium approach the calculated pressures are applied directly on the wall. Therefore with this approach the wall is implicitly assumed to be rigid. Within the Nonlinear analysis these pressures are applied as the initial seismic thrust pressures at zero additional seismic strain (i.e. rigid wall behavior when the seismic pressures are initially applied). The initial seismic pressures are then gradually readjusted (typically reduced) as the wall gradually displaces due to the additional seismic load until equilibrium is reached.

The Wood Manual approach behaves in exactly the same manner as the Automatic Wood Method with the only difference being that the zero strain seismic pressures are defined directly by the user.

Figure 4.10.6: Seismic pressures – Wood Automatic method pressure diagram

Support walls must be embedded sufficiently to prevent toe stability failure. DeepEX uses classical methods in determining the toe embedment depth for a safety factor of 1.0 and the available safety factor. We can select which wall embedment safety factors should be calculated in each model from the Stability+ tab.

Figure 4.11.1: Stability+ tab – Select wall embedment safety factors

Passive Resistance Safety Factor (Conventional Analysis):

Rotational Safety Factor (Conventional Analysis):

Length based (Conventional Analysis):

Mobilized passive resistance (NONLINEAR):

The mobilized passive resistance is currently calculated with conventional analysis methods (that can include the effects of non-linear ground surface).

Basal Stability FS and Wall Displacements

The basal stability safety factor and the wall displacements estimation methods can be reviewed in the Stability+ tab of DeepEX. The software by default uses the Terzhaghi equations to calculate the basal stability safety factor index, and the Clough method to estimate the wall displacements in each construction stage independently. The option to perform both calculations is selected by default in DeepEX, though we can select not to perform either if needed.

Figure 4.12.1: Stability+ tab – Basal stability and wall displacements options

DeepEX uses the Terzhaghi approach to calculate the basal stability safety factor.

Table 4.12.2: Terzhaghi equations for basal stability safety factor

Since multiple soil types can be included DeepEX averages the undrained shear strength of the soil below the subgrade within one excavation depth below subgrade or until a rock layer is encountered. Note that the frictional component of a soil is included by adding to Su the sum of the vertical effective stress times the tangent of the friction angle on the left and right wall side.

When the classical Limit Equilibrium Analysis method is selected, DeepEX can estimate the wall horizontal displacements using the Clough method.

Clough (Clough et. al., 1989) developed a method for predicting wall deflections based on a normalized system using a stiffness factor and on a factor of safety for basal stability. Clough defines the system stiffness factor as the product of the modulus of elasticity (E) times the inertia (I) of the wall divided by the unit weight of water (gW) times the average brace spacing. This approach of predicting wall deflections has some obvious limitations when applied to stiff walls because: a) the typical spacing between vertical supports varies little from project to project (average 9ft to 12 ft) with 7ft minimum and 17ft maximum, b) the wall thickness typically varies from 2’ to 3’, c) the effects of prestressing braces are totally ignored, and d) the effect of soil conditions is partially accounted in the basal stability factor that is not directly applicable for the majority of the walls that were keyed into a stiff stratum.

Clearly the big limitation of the system stiffness approach is the generic assumption that wall deflections are primarily related to deformations occurring between support levels. In individual projects, there may be several length scales affecting the wall deflections depending on the toe fixity of the wall, the depth to bedrock, the wall embedment below the base of the excavation, the width of the excavation, the size of berms, and the initial unsupported excavation depth. Furthermore, the proposed method of Clough et. al. [1989] takes not account of the stiffness profile in the retained soil.

Figure 4.12.3: Clough method – Predicted wall displacements vs system stiffness

Surface Settlements Estimation

From the Stability+ tab of DeepEX, we can access the Surface Settlements button, where we can define the parameters for the surface settlements calculations.

Boone and Westland reported an interesting approach to estimating ground settlements. This approach associates ground settlements to the basal stability index, a modified system stiffness value, and individual wall displacement components as seen in the following Figure. Wall displacements and surface settlements are divided in two major categories:

A. Cantilever wall – generating the sprandel settlement volume trough Avs

B. Bending wall movements – generating the concave settlement trough Avc

The combination of sprandel and concave settlement troughs results in the combined total settlement profile. Both these areas Avs and Avc are taken as a certain percentage of the corresponding wall movements.

When a non-linear solution is performed (beam on elastic foundations), DeepEX offers the ability to estimate surface settlements directly from computed wall displacements. In addition, DeepEX will add a component for toe translation to the concave settlement. This additional volume is estimated as a triangle by extrapolating a line from the maximum displacement above the wall toe to the displacement at the wall base. The following table provides detailed information and recommendations about using this method.

Figure 4.12.4: Stability+ tab – Surface settlement calculation options

If settlements are used, it is strongly recommended to enable the modifications from the surface settlements tab in the main form (otherwise surface settlements may be greatly overestimated).

 

In DeepEX, we can define a vertical load or an inclined load on the wall. In that case, we have to select the option “Include axial loads on walls” in the Design tab of DeepEX, so the wall axial diagram is produced and the axial wall capacity is calculated. In the Stability+ tab of DeepEX we can select the option “Calculate axial geotechnical capacity”, select the pile installation method and edit the pile calculation settings. This last option is used mostly in the additional optional module Pile Supported Abutments, in order to calculate the bearing capacity of the supporting foundation piles.

Adding an Axial Load on a Wall (Vertical or Inclined)

From the Draw Loads toolbar in the General ab of DeepEX, we can draw on the model area a linear load on the wall (access the toolbar, select the tool, click on the wall and edit the load properties). In the dialog that appears, we can define the load position (elevation on the wall) and the load magnitudes Px (horizontal load component) and Pz (vertical load component).

Figure 4.13.1: Add and edit a vertical load on the top of the wall

Figure 4.13.2: Add and edit an inclined load on the wall

Figure 4.13.3: Option to include axial loads on walls

Figure 4.13.4: DeepEX results – Axial wall diagram

Defining Axial Geotechnical Capacity Parameters

In the Stability+ tab of DeepEX, we can select to include in the calculations the axial geotechnical capacity of piles. We have to select the installation method (drilled, driven, caissons, CFA piles, drilled-in-displacement piles), and we can also define the pile calculation settings (geotechnical axial capacity safety factors, tip resistance options, skin friction options and cohesional shear resistance multipliers and adhesion factors).

Figure 4.13.5: Pile installation methods and calculation settings

DeepEX software has implemented a series of structural codes for the structural design of all project members, depending on the member structural section type (reinforced concrete – construction steel, timber (wood)).

In the Design tab of DeepEX, we can select the structural codes for concrete, steel and timber design, as well as, define an additional safety factor applied on calculated capacities, according to the code type (allowable or LRFD design). These options appear when we press on the button CODE.

Figure 4.14.1: Select structural design codes for concrete, steel and timber

DeepEX: Concrete Codes	DeepEX: Steel Codes	DeepEX: Timber Codes
ACI 318-11	ASD 1989 (Allowable)	Service Φc = 0.18, Φb = 0.34
ACI 318-19	LRFD 13th Edition 2005	AASHTO LRFD 8th Edition
Eurocode 2 2004 (General)	NTC 2008	NYC DEP. Φc = 0.18, Φb = 0.34
Eurocode 2 – National Annexes	ANSI/AISC 360-2010
Eurocode 8 – National Annexes	AISC 360-2010 Allowable
AS 3600-2009 (Australia, New Zealand)	ANSI/AISC 360-2016
CN (China)	AISC 360-2016 Allowable
	Eurocode 3 2005 (General)
	Eurocode 3 2005 – National Annexes
	BS 5950-1 2000 (Britain)
	AS/NZS 4100
	CN (China)

 

Selecting a Code and Defining a Partial Safety Factor

DeepEX will use the selected structural code to calculate the member structural capacity. Next, it will compare the calculated capacity with the calculated force on the member from the model analysis, calculating the member structural ratio.

In some cases, the calculated capacities can be reduced by a factor that is either dictated by the selected structural standard (Allowable design), or defined by the user (i.e. LRFB design). If a geotechnical standard is applied (see chapter 4.2) like AASHTO LRFD or Eurocode, the software will follow an ultimate design code as recommended by the standard and the calculated capacity will be reduced automatically by the standard recommendations.

The following options are available:

A. Select an Allowable Stress Design standard:

This includes a safety factor according to the standard, which will be applied to the calculated capacities.

B. Select an LRFD structural standard and NO geotechnical code combination

In that case, you can assign in the Design tab of DeepEX a user defined safety factor that will be applied on calculated structural capacities

Figure 4.14.2: Define a safety factor applied on calculated structural capacities

C. Select an LRFD structural standard and a geotechnical code combination

In that case, DeepEX will do an ultimate design, using partial factors on loads, no additional user-defined factor is needed in this case.