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0BChapter 1. Analysis settings and settings administrator
This chapter explains the correct use of Settings administrator that serves to choose standards,
partial factors and verification methodology. It is the basic step needed for all GEO5 programs.
Introduction
GEO5 software is used in 90 countries worldwide. Engineering tasks are the same everywhere
to prove that the construction is safe and well designed.
The basic characteristic of structures (eg. geometry of wall, terrain, localization of anchors
etc.) are the same all over the world; the way of proving that the construction is safe and the theory
of analysis used are different. Large quantities of new theories and mainly partial factors of analysis
lead to input of large amounts of data and complicated programs. The Settings administrator wascreated in GEO5 for version 15 to simplify this process.
In the Settings administrator are defined all input parameters, including standards, methods
and coefficients for the current country. The idea is that each user will understand the Settings defined
in the program (or will define a new Setting of analysis), which the user then uses in their work.
To the Settings administrator and Settings editor the user then goes only occasionally.
Assignment:
Perform an analysis of a gravity wall per the picture below for overturning and slip according to
these standards and procedures:
1)
CSN 73 0037
2) EN 1997 DA1
3) EN 1997 DA2
4) EN 1997 DA3
5)
Safety factor on SF=1.6
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Scheme of the gravity wall for analysis
Solution
Firstly, input the data about the construction and geological conditions in the frames:
Geometry, Assign and Soils. Skip the other frames because they are not important for this
example.
Frame Geometry input of dimensions of the gravity wall
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Table with the soil parameters
Soil
(Soil classification)
Unit weight
3mkN
Angle of
internal friction
[ ]ef
Cohesion
of soil
[ ]kPacef
Angle of friction
structure soil
[ ]=
MG Gravelly silt,
firm consistency19,0 30,0 0 15,0
In the frame Assign, the first soil will be assigned automatically to the layer or layers.
This can be changed when necessary.
When the basic input of construction is done, we can choose standards, and then finally run
the analysis of the gravity wall.
In the frame Settings click the button Select and choose number 8 Czech Republic
old standards CSN (73 1001, 73 1002, 73 0037).
Dialog window Settings list
Note: The look of this window depends on standards that are currently active in the Settings
administrator more information in the help of the program (press F1). If the setting you want to use
isn`t on the list in the dialog window Settings list, you can activate it in the Settings administrator.
Now, open up the frame Verification and after analyzing the example record the utilization
of construction (in the frame Verification)  53,1% resp. 66,5%.
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Frame Verification results of the analysis using CSN 73 0037 standard
Then return to the frame Settings and choose number 3 Standard EN 1997 DA1.
Dialog window Settings list
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Again, open the frame Verification and record the result (55,6% and 74,7%)
for EN 1997, DA1.
Frame Verification results of analysis for EN 1997, DA1
Repeat this procedure for settings number 4 Standard EN 1997 DA2 and number 5
Standard EN 1997 DA3.
The analyzed utilization of constructions are (77,8% and 69,7%) for EN 1997, DA2 or (53,5%
and 74,7%) for EN 1997, DA3.
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Variant 5 (analysis using Safety factors) is not as simple. In the frame Settings click on
Edit. This will show you the current analysis settings. Change the verification methodology to
Safety factors (ASD) and then input safety factor for overturning and sliding resistance as 1.6.
Dialog window Edit current settings: Gravity wall
Press OK and run the analysis. (69,0% and 77,1%).
Frame Verification analysis results for SF = 1.6
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If you would like to use this setting more often, it is good to save this setting by clicking
on Add to administrator, rename is as shown below, and next time use it as a standard setting.
Dialog window Add current settings to the Administrator
Dialog window Settings list then looks like this:
Dialog window Settings list
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Verification
Utilization in percentage using each standard is:
Overturning Slip
1) CSN 73 0037 53,1 66,5
2)
EN 1997 DA1 55,6 74,7
3)
EN 1997 DA2 77,8 69,7
4) EN 1997 DA3 53,3 74,7
5)
Safety factor on SF=1.6 69,0 77,1
The analysis is satisfactory using the selected analysis standards.
Note: This simple method can be used to compare retaining structures or stability analyses. When
analyzing foundations, the load (basic input data) must be computed according to relevant standards.
That is the reason why it doesnt make sense, to compare foundation design by various standards
with the same values of load (nominal values).
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Dialog window Settings list
In the frame Geometry choose the wall shape and enter its dimensions.
Frame Geometry
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In the frame Material enter the material of the wall.
Frame Material Input of material characteristics of the structure
Then, define the parameters of soil by clicking Add in the frame Soils. Wall stem is normally
analyzed for pressure at rest. For pressure at rest analysis, select Cohesionless.
Dialog window Add new soils
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Note: The magnitude of active pressure depends also on the friction between the structure and soil. The friction
angle depends on the material of construction and the angle of internal soil friction normally entered in the
interval ) ef 3231
Table with the soil parameters
Soil
(Soil classification)
Profile
[ ]m
Unit weight
3mkN
Angle of
internal
friction
[ ]ef
Cohesion
of soil
[ ]kPacef
Angle of
friction
structure soil
[ ]=
SF Sand with trace of
fines, medium dense soil0,0 4,0 17,5 28,0 0,0 18,5
MS Sandy silt, stiff
consistency, 8,0
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Frame Water
In the next frame define Surcharge. Here, select permanent and strip surcharge on the terrain acting as
a dead load.
Dialog window New surcharge
In the frame FF resistance select the terrain shape in front of the wall and then define other parameters
of resistance on the front face.
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Frame FF resistance
Note: In this case, we do not consider the resistance on the front face, so the results will be conservative. The
FF resistance depends on the quality of soil and allowable displacement of the structure. We can consider
pressure at rest for the original soil, or well compacted soil. It is possible to consider the passive pressure if
displacement of structure is allowed. (for more information, see HELP F1)
Then, in the frame Stage settings choose the type of design situation. In this case,
it will be permanent. Also choose the pressure acting on the wall. In our case, we will choose active pressure,
as the wall can move.
Frame Stage settings
Note: Wall stem is dimensioned always on earth pressure at rest, i.e., the wall cant be moved. The possibility of
evaluating the stem and the wall of the active pressure is considered only in exceptional cases  such as the
effects of the earthquake (seismic design situation with partial coefficient equals 1.0).
Now, open up the frame Verification, where you analyze the results of overturning and slip of the cantilever
wall.
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Frame Verification
Note: The button In detail in the right section of the screen opens a dialog window with detailed information
about the analysis results.
Analysis results:
The verification of slip is not satisfactory, utilization of structure is
Overturning: 52,8 % 97,10933,208 =>= klvzd MM [kNm/m] SATISFACTORY.
Slip: 124,6 % 94,8178,65 =
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Change of the design: change of the geometry of the wall
Return to the frame Geometry and change the shape of the cantilever wall. For increasing
the resistance against slip we introduce a base jump.
Frame Geometry (Changing dimensions of cantilever wall)
Note: A base jump is usually analyzed as an inclined footing bottom. If the influence of the base jump
is considered as front face resistance, then the program analyses it with a straight footing bottom, but FF
resistance of the construction is analyzed to the depth of the down part of the base jump (More info in HELP
F1)
Thenanalyze the newly designed construction for overturning and slip.
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Frame Verification
Now, the overturning and slip of the wall are both satisfactory.
Then, in the frame Bearing capacity, perform an analysis for design bearing capacity
of the foundation soil 175 kPa.
Frame Bearing capacity
Note: In this case, we analyze the bearing capacity of the foundation soil on an input value, which we can get
from geological survey, resp. from some standards. These values are normally highly conservative, so it is
generally better to analyze the bearing capacity of the foundation soil in the program Spread footing that takes
into account other influences like inclination of load, depth of foundation etc.
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Next, in the frame Dimensioning chose wall stem check. Design the main reinforcement into the stem
10pcs. 12 mm, which satisfies in point of bearing capacity and all design principles.
Frame Dimensioning
Then, open up the frame Stability and analyze the overall stability of the wall. In our case, we will use
the method Bishop, which result in conservative results. Perform the analysis with optimization of circular
slip surfaceand then leave the program by clicking OK. Results or pictures will be shown in the report of
analysis in the program Cantilever wall.
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Slope stability program
Conclusion/ Result of analysis bearing capacity:
Overturning: 49,5 % 16,10852,218 =>= klvzd MM [kNm/m] SATISFACTORY
Slip: 64,9 % 47,6427,99 =>= posvzd HH [kN/m] SATISFACTORY
Bearing capacity: 86,3 00,17506,151 =>= dR [kPa] SATISFACTORY
Wall stem check: 78,7 % 71,13392,169 =>= EdRd MM [kNm] SATISFACTORY
Overall stability: 40,8 % Method Bishop (optimization) SATISFACTORY
This cantilever wall is SATISFACTORY.
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Chapter 3. Verification of gravity wall
In this chapter an analysis of an existing gravity wall for permanent and accidental design situations is
performed. Construction stages are also explained.
Assignment
Using EN 19971 (EC 71, DA2) standard, analyze an existing gravity wall for stability, overturning,
and slip .
Road traffic acts on the wall with magnitude of 10 kPa. Check the possibility to install the barrier on
the top of the wall. An accidental load from a car crash is considered as 50 kN/m and it acts
horizontally at 1,0 m. Dimensions and shape of the concrete wall can be seen in the picture below.
Inclination of the terrain behind the construction is 10 , the foundation soil consists of silty sand.
The friction angle between the soil and wall is 18 .
Determination of bearing capacity and dimensioning of the wall is not part of this task. In this
analysis, consider effective parameters of soil.
Scheme of the gravity wall  assignment
Solution:
For analyzing this task, use the GEO5 program Gravity wall. In this text, we will describe
the steps of analyzing this example in two construction stages.
1
st
construction stageanalyzing the existing wall for road traffic. 2
ndconstruction stageanalyzing impact of vehicle to the barrier on the top of the wall.
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Basic input: Stage 1
In the frame Settings click on Select and choose Nr. 4 Standard EN 1997DA2.
Dialog window Settings list
Then, in the frame Geometry, select the shape of the gravity wall and define its parameters.
Frame Geometry
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In the next step, input the material of the wall and geological profile. Unit weight of wall is
324 mkN . Wall is made from concrete C 12/15 and steel B500. Then define parameters of soil
and assign them to the profile.
Table with the soil parameters
Soil
(Soil classification)
Unit weight
3mkN
Angle of
internal friction
ef
Cohesion
of soil
kPacef
Angle of friction
structuresoil
MSSandy silt,
firm consistency18,0 26,5 12,0 18,0
Dialog window Add new soils
Note: The magnitude of active pressure depends also on friction between the structure and soil in the
angle ef 32
31 . In this case we consider the influence of friction between the structure
and soil with value of ef
3
2
( =18
), when analyzing earth pressure. (More info in HELPF1).
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In the frame Terrain select the shape of terrain behind the wall. Define its parameters, in
terms of embankment length and slope angle as shown below.
Frame Terrain
In the next frame, define Surcharge. Input the surcharge from road traffic as Strip, with
its location on terrain, and as a type of action select Variable.
Dialog window Edit surcharge
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In the frame FF resistance choose the shape of the terrain in front of the wall and define the
other parameters of front face resistance.
Frame Front face resistance
Note: In this case, we do not consider resistance on the front face, so the results will be conservative.
The FF resistance depends on the quality of soil and allowable displacement of the structure. We
consider pressure at rest for the original soil or well compacted soil. It is possible to consider passive
pressure only if displacement of structure is allowed. (More info in HELPF1).
In the frame Stage settings select the type of design situation. In the first construction stage,
consider the permanent design situation.
Frame Stage settings
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Now open up the frame Verification, where we analyse the gravity wall for overturning
and slip.
Frame Verification stage 1
Note: The button In detail in the right section of the screen opens a dialog window with detailed
information about the results of the analysis.
Dialog window Verification (in detail)
Note: For analyses based on EN1997, the program determins if the force acts favorably or
unfavorably. Next each force is multiplied by the corresponding partial factor which is them on the
report.
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Then, open up the frame Stability and analyze the overall stability of the wall. In our case,
we will use the method Bishop, which results in conservative results. Perform an analysis
with optimization of circular slip surface and then validate everything by clicking OK.
Results or pictures will be shown in the report of analysis in the program Gravity wall.
Program Slope stability stage 1
Analysis results: Stage 1
When analyzing bearing capacity, we are looking for values of overturning and slip of the wall
on the footing bottom. Then we need to know its overall stability. In our case, the utilization of the
wall is:
Overturning: 70,0 % 73,26391,376 klvzd MM [kNm/m] SATISFACTORY.
Slip: 90,6 % 17,13853,152 posvzd HH [kN/m] SATISFACTORY.
Overall stability: 72,3 % MethodBishop (optimization) SATISFACTORY.
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Basic input: Stage 2
Now, add construction stage 2 using tool bar in the upper left corner of the screen.
Toolbar Stage of construction
In this stage, define the load from the impact of the vehicle to the barrier, using the frame
Inputforces. The load ais accidental and considers the impact of a vehicle with a weight of 5 tons.
Dialog window Edit forceconstruction stage 2 (accidental design situation)
Then open the frame Stage settings change the design situation on accidental.
Frame Stage settings
The data in the other frames that we entered in stage 1 has not changed , so we dont have toopen these frames again. Select the frame Verification to perform the verification on overturning
and slip again.
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Frame Verification stage 2
Analysis results: Stage 2
From the results, we see, that the existing wall is not satisfactory for impact of a vehicle
to the barrier. In this case, utilization of the wall is:
Overturning: 116,3 % 13,56862,488 klvzd MM [kNm/m] NOT OK.
Slip: 102,9 % 35,14239,138 posvzd HH [kN/m] NOT OK.
Conclusion
The existing gravity wall in case of bearing capacity satisfies only for the first construction
stage, where road traffic acts. For the second construction stage, which is represented as impact to the
barrier on the top of the wall by a vehicle of 5 tons, the wall is not satisfactory.
As a solution to increase bearing capacity for overturning and slip it is possible to introduce
soil anchors. alternatively it is possible to place a barrier on the edge of the road, so the wall is not
loaded by a force from the crashing car.
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Chapter 4. Design of nonanchored restraint retaining wall
In this chapter is the design of nonanchored retaining wall for permanent and accidental loads
(flooding).
Assignment
Design nonanchored retaining wall from pile sheeting using the EN 19971 (EC 71,
DA3) standard in nonhomogenous geologic layers. The depth of excavation is 2,5 m.
The ground water table is at a depth of 1,0 m. Analyze the construction also for flooding; when
the water is 1,0 m above the top of the wall (mobile antiflood barriers should be installed).
Scheme of nonanchored wall from pile sheeting assignment
Solution:
For solving this problem, we will use the GEO5 program, Sheeting design. In this text,
we will explain each step to solve this example:
1stconstruction stage: permanent design situation
2ndconstruction stage: accidental design situation
Design of geometry of the pile sheeting
Analysis result (conclusion).
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Basic input: Construction stage 1
In the frame Settings click on Select and then choose Nr. 5 Standard EN 1997
DA3.
Dialog window Settings list
Then, input the geological profile, parameters of soil and assign them to the profile.
Dialog window Add new soils
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Table with the soil parameters
Soil
(Soil classification)
Profile
[ ]m
Unit weight
3
mkN
Angle of
internal
friction
[ ]ef
Cohesion
of soil
[ ]kPacef
Angle of friction
structure soil
[ ]=
SF Sand with trace
of fines, medium
dense soil
0,0 1,5 17,5 29,5 0,0 14,0
SC Clayey sand,
medium dense soil1,5 2,5 18,5 27,0 8,0 14,0
CL, CI Clay with
low or mediumplasticity,
firm consistency
from 2,5 21,0 19,0 12,0 14,0
In the frame Geometry, select the shape of bottom of the excavation and input
its depth.
Frame Geometry
Note: coefficient of reduction of earth pressure below the ditch is considered while analyzing
braced sheeting (retaining wall with soldier beams) only; for a standard sheeting pile wall it
equals 1,0 For more information, see HELP (F1).
In this case, we do not use the frames Anchors, Props, Supports, Pressure
determination, Surcharge and Applied forces. The frame Earthquake also has no
influence for this analysis, because the construction is not located in seismicactive area.
In the frame Terrain, it remains horizontal.
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In the frame Water input the GWT value 1,0 m.
Frame Water 1stconstruction stage
Then, in the frame Stage settings, select the design situation as permanent.
Frame Stage settings
Now, open up the frame Analysis and click on the button Analyze. This will
perform the analysis of the retaining wall.
Frame Analysis
Note: For cohesive soils is recommended by many standards to use minimal dimensioning
pressure acting on the retaining wall. The standard value for the coefficient of minimal
dimensioning pressure is Ka = 0,2. It means that minimum pressure on the structure is 0,2
of geostatic stress never less.
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Within the design of pile sheeting retaining wall, we are interested in the depth
of construction in the soil and internal forces on the structure. For the 1st construction stage,
the results of analysis are:
Length of structure: m83,4
Needed depth in the soil: m33,2
Maximum bending moment: mkNmM 21,28max,1 =
Maximum shear force: mkNQ 98,56max,1 =
In the next stage, we are going to show you how to analyse the minimum depth in soil
and internal forces in the soil for the accidental design situation floods.
Basic input Construction stage 2
Now, select stage 2 on the toolbar Stage of construction on the upper left corner
of your screen. (If needed, add a new one)
Toolbar: Stage of construction
In the frame Water, change the GWT behind the structure to a value 1,0 m. We will
not consider water in front of the structure.
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Frame Water
Then, in the frame Stage settings, select the design situation Accidental.
Frame Stage settings
All other values are the same as in the 1stconstruction stage, so we dont have to change
data in other frames, so we go on to the frame Analysis and click again on the button
Analyze.
Frame Analysis
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In the 2ndconstruction stagethe analysis results are:
Length of structure: m56,6
Needed depth in the soil: m06,4
Maximum bending moment: mkNmM 00,142max,2 =
Maximum shear force: mkNQ 17,185max,2 =
Using the maximum bending moment, we will design pile sheeting.
The minimum length of pile sheeting is set as the maximum of necessary length
from construction stage 1 and construction stage 2.
Design of pile sheeting:
We design the pile sheeting based on the maximum bending moment using the table of pile
sheeting with allowable bearing capacities shown below.
Design of pile sheeting according to CSN EN 10 2481 standards.
Based on the chart, we will select the pile sheeting VL 503 (500 340 9,7 mm) ,
the steel grade S 270 GP, of which the maximum bending moment is mkNM 0,224max = .
Safe design of structure is verified by equation:
mkNmMmkNMdov 142224 max =>=
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Analysis result:
In the design of nonanchored restraint retaining wall, we are verifying values
of minimum depth of the structure in the soil, and the internal forces in the structure:
Minimum depth of the structure in first stage: 2,33 m
Minimum depth of the structure in second stage: 4,06 m
So, we will design a pile sheeting with depth in the soil of 4,1 m and overall length
of 6,6 meters.
Conclusion:
The designed pile sheeting retaining wall VL 503 from S 270 steel with length of 6,6 meterssatisfies.
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Chapter 5. Design of anchored retaining wall
In this chapter, we will show you how to design a retaining wall with one row of anchors.
Assignment:
Design a retaining wall with one anchor row made from pile sheeting using EN 19971
(EC 71, DA3) standard. The depth of ditch is 5,0 m. The anchor row is 1,5 m below
the surface. The soils, geological profile, ground water table and shape of terrain are the same as
in the last task. Remove construction stage two so as to not consider flooding.
Scheme of the anchored wall from pile sheeting assignment
Solution:
For solving this problem, we will use a GEO5 program, Sheeting design. In this text,
we will explain each step of this example:
Analysis 1: permanent design situation  wall fixed at heel
Analysis 2: permanent design situation  wall hinged at heel
Analysis result (conclusion)
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Basic input: Analysis 1
Leave the frames Settings, Profile, Soils, Terrain, Water and Stage settings
from the previous problem without changes. Also, delete construction stage 2 if you are reusing
the file from problem 4.
In the frame Geometry, input the depth of the ditch as 5,0 m.
Open up the frame Anchors and click on the button Add. For this case, add one
anchor row in the depth of 1,5 m below the top of the wall with anchor spacing at 2,5 m.
Also define the length of the anchors (which has no effect in the Sheeting design program,
it is only for visualization) and slope of the anchors (15 degrees).
In frame Stage Settings choose permanent.
Frame Anchors
In the frame Analysis select support at heel. For now, select Wall fixed at heel.
Now perform the analysis.
Frame Analysis Stage of construction 1 (Wall fixed at heel)
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In our case, we need to know the sheet pile embedment depth and also the anchor force. For the
wall fixed at heel, the values are:
Length of construction: m72,10
Depth in soil: m72,5
Anchor force: kN77,165
Maximum moment: mkNm /16,89
Maximum shear force: mkN/27,128
Now, perform an analysis for wall hinged at heel (construction stage 2). Then, compare
the results and, depending on comparison, design the embedment depth.
Basic input: Analysis 2
Now, add a new verification in the upper left corner of the frame.
Toolbar: Verification
Select the option Wall hinged at heel and perform the analysis.
Frame Analysis Stage of construction 2 (Wall hinged at heel)
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For the wall hinged at heel, the values are:
Length of construction: m85,7
Depth in soil: m85,2
Anchor force: kN68,201
Maximum moment: mkNm /35,119
Maximum shear force: mkN/84,69
The results of analysis
The overall length of the structure should be in the interval of Hfixed Hhinged.
For wall fixed at heel is the length of the structure is longer, but the anchor force is smaller.
For wall hinged at heel, it is the opposite, so larger anchor force and shorter length
of the construction. It is the users task to design the dimensions of the structure.
Conclusion
In our design, we will use pile sheeting VL 503 from steel S 270 with an overall length
of 9,0 m, anchors with size of force 240 kN with anchor spacing of 2,5 m. In the next chapter,
we will check this structure in the program Sheeting check.
Note: The design cannot be taken as the final and it needs to be checked in the Sheeting check
program, because on the real structure there is redistribution of earth pressure
due to anchoring.
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Chapter 6. Verification of retaining wall with one anchor row
In this chapter, we will show you how to verify a designed retaining wall with verification of inner stability
of the anchors and overall stability of the structure.
Assignment
Verify the retaining wall that you designed in task 5.
Solution:
For solving this problem, we will use the GEO5 program, Sheeting check. In this text,
we will explain each step to solve this task:
Construction stage 1: excavation of ditch to a depth of 2,0 m + geometry of the wall
Construction stage 2: anchoring of the wall + excavation of ditch to a depth of 5,0 m.
Basic input: Construction stage 1
To make our work easier, we can copy the data from the last task, when we designed the wall
in the Sheeting design program by clicking in this program on Edit on the upper toolbar and selecting
Copy data. In Sheeting check program click on Edit and then Paste data. Now we have most
of the important data from the last task copied in to this program, so we dont have to input much
of the needed data.
Dialog window Insert data
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In the frame Settings, select again the number 5 Standard EN 1997, DA3. Select the
analysis of depending pressures as Reduce according to analysis settings. Leave the coefficient
for minimum dimensioning pressure as 0,20.
Frame Settings (Analysis of pressures)
Note: the selection Analysis of depending pressures do not reduce allows the analysis of limit
pressures (active and passive) without the reduction of input parameters by partial factors. This is better
for estimation of real behavior of construction. On the other hand, it does not follow EN 19971 Standard.
(More info in HELP F1)
Then, open up the frame Modulus hk , and choose the selection analyze Schmitt.
This method for the determination of modulus of subsoil reaction depends on the oedometric modulus and
stiffness of the structure. (More info in HELP F1)
Frame Modulus hk
Note: the modulus of subsoil reaction is an important input when analyzing a structure by the method
of dependent pressures (elastoplastic nonlinear model). The modulus hk affects the deformation, which is
needed to reach active or passive pressures. (More info in HELP F1)
In the frame Soils enter the following values for each soil type. Poissons ratio and the oedometric
modulus were not entered in the previous program, so they must be entered here.
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Soil Type
(Soil classification)
Poissons ratio
[ ]
Oedometric Modulus
[ ]MPaEoed
SF  Sand with trace of fines,
medium dense0,30 21,0
SC  Clayey sand, medium dense 0,35 12,5
CL  Clay with low or medium
plasticity, firm consistency0,40 9,5
In the frame Geometry define the parameters of the sheet pile type of wall, section length,
coefficient of pressure reduction below ditch bottom, geometry and material of the construction. From the
sheet pile database, select the VL 503 (500 340 9,7 mm).
Dialog window Edit section
Now, in the frame Excavation define the first ditch depth 2,50 m for the first
construction stage.
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Frame Excavation Stage of construction 1
Now, go to frame Analysis. In the left part of the frame, you can see the modulus of subsoil
reaction, in the right section earth pressures and displacement. (For more information, see HELP F1)
Frame Analysis Stage of construction 1
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Basic input: Construction stage 2
Add another construction stage as indicated below. Here we define the anchoring of the wall and
overall excavation. We cannot change the frames Settings, Profile, Modulus Kh, Soils
and Geometry, because these data are the same for all construction stages. We will only change datain the frames Excavation and Anchors.
In the frame Excavation, change the depth of the ditch to the final depth 5,0 m.
Frame Excavation Stage of construction 2
Then, go to the frame Anchors and click on the button Add. For this structure, we will add
a row of anchors to a depth 1,5 m below the top of the wall (below the surface). Also define other
important parameters: overall length of the Anchor input as 10 m, slope angle as 15 and anchor spacing as
2,5 m. Enter a prestress force equal to 240 kN and the diameter of the anchor.
Frame Anchors Stage of construction 2
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Frame Analysis construction stage 2 (Deformation and pressure on the structure)
Verification of material and cross section:
Maximum moment behind the construction is 116,03 kN/m
Sheet pile VL 503 (500 340 9,7 mm), quality of steel S 270 GP satisfies.
(Allowable moment = mkNmMmkNMu 0,1160,224 max =>= )
Maximum displacement of structure 30,1 mm is also satisfactory.
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Verification of anchor stability
Now, open the frame Internal stability. You can see, that the internal stability of anchors
is not satisfactory. This means, that the anchor could tear from the soil.
Frame Internal stability not satisfactory result (anchor length 7,0 m, k = 0,2)
The reason for this is that the anchor is too short, so in the frame Anchors, change its length
to 9,0 meters. This newly designed anchor then satisfies the internal stability requirements.
Frame Internal stability satisfactory result (anchor length 9,0 m, k = 0,2)
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The last needed check is overall stability of the structure. Click on the button External stability.
This will open the Slope stability program. In the frame Analysis click on Analyze. We can now see,
that the slope stability is acceptable. For external stability we consider length of anchor 7,0 m.
Frame External stability
Analysis results  conclusion:
Analysis done:
Bearing capacity of cross section:
51.8 % mkNmMmkNMu 0,1160,224 max =>= SATISFACTORY.
Internal stability: 81,0 % kNFkNFvzd 24024,296 =>= SATISFACTORY.
Overall stability: 84.8 % Method Bishop (optimization) SATISFACTORY.
In this case, the designed construction satisfies in all checked parameters.
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Chapter 7. Verification of multianchored wall
In this chapter, we are showing how to design and verify a multianchored wall.
Assignment
Verify a multianchored wall made from steel soldier piles I 400 with a length
of 21,0 m. Depth of the ditch is 15,0 m. The terrain is horizontal. The surcharge acts
at the surface and is permanent with size of 20,25 mkN . The GWT behind
the construction is 10,0 m below the surface.
Scheme of the wall anchored in multiple layers
Table with the soil and rock parameters
Soil, rock(classification)
Profile[ ]m
Unit
Weight3mkN
Angle of
internalfriction
[ ]ef
Cohesion
of soil
[ ]kPacef
Deformation
modulus
[ ]MPaEdef
Poissons
Ratio[ ]
CL, CI Clay
with low or
medium
plasticity,
firm consistency
0,0 2,0 19,5 20 16 6,0 0,4
CS Sandy
clay,
firm consistency
2,0 4,5 19,5 22 14 7,0 0,35
R4 (good rock), 4,5 12,0 21 27,5 30 40,0 0,3
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low strength
R3 (good rock),
medium
strength
12,0
16,622 40 100 50,0 0,25
R5 (poor rock),
very lowstrength
16,6 17,4
19 24 20 40,0 0,3
R5 (poor rock),
very low
strength
17,4
25,021 30 35 55,0 0,25
R5 (poor rock),
very low
strength
from 25,0 21 40 100 400,0 0,2
Angle of friction between structure and soil is = 5,7 for all layers.
Also, the saturated Unit weight equals the Unit Weight above. Note that the Modulus
of deformation is being used for soil materials.
Table with position and geometry of the anchors
Anchor
no.
Depth
[ ]mz Length
[ ]ml Root
[ ]mlk Slope
[ ] Spacing
[ ]mb Anchor force
[ ]kNF
1 2,5 19,0 0,01 15,0 4,0 300,0
2 5,5 16,5 0,01 17,5 4,0 350,03 8,5 13,0 0,01 20,0 4,0 400,0
4 11,0 10,0 0,01 22,5 4,0 400,0
5 13,0 8,0 0,01 25,0 4,0 400,0
All anchors have a diameter mmd 0,32= , modulus of elasticity
GPaE 0,210= . Anchor spacing is mb 0,4= .
Solution
For solving this task, use the GEO5 program Sheeting Check. The analysis
will be performed in the classical way without reduction of input data so the real
behavior of the structure will be grasped. Internal stability of the anchor system
and overall stability will be checked with a safety factor of 1,5. This solution assumes
you have entered the soil types and profiles, and permanent load as listed above.
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In the frame Settings select option no. 1 Standard safety factors.
Then, go to frame Geometry and input the basic dimensions of the section, and also
the coefficient of pressure reduction below the ditch bottom, which is in this case 0,4.
Dialog window New section
Note. The coefficient of reduction of earth pressures below the excavation reduces
the pressures in the soil. For classical retaining walls this is equal 1,0. For braced
sheeting it is less than or equal to one. It depends on size and spacing of braces
(More info in help F1).
Now, we will describe the building of the wall stage by stage. It is necessary
to model the task in stages, to reflect how it will be constructed in reality. In each stage
it is necessary to look at values of internal forces and deformation. If the braced
sheeting is not stable in some stage of construction or if the analyzed deformation is too
large, then we need to change structure for example to make the wall embedment
longer, make the ditch shallower, increase the anchor forces etc.
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In construction stage 1, the ditch is made to depth of 3,0 m. In the stage 2,
anchor is placed at a depth of 2,5 m. The GWT behind the structure is at a depth
of 10,0 m beneath the surface.
Frame Anchors Construction stage 2
In the 3rdconstruction stage, the ditch is excavated to a depth of 6,5 m. In the 4 th
stage, anchor is placed at a depth of 5,5 m. The GWT is not changed so far.
Frame Anchors Construction stage 4
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In the 5thconstruction stage, the ditch is excavated to a depth of 9,0 m. In the 6 th
stage, anchor is placed at the depth of 8,5 m. The depth of GWT is not changed.
Frame Anchors Construction stage 6
In 7th construction stage, the ditch is excavated to a depth of 11,5 m.
In 8th
construction stage, an anchor is placed at the depth of 11,0 m. The GWT in frontof the wall is now at a depth of 12,0 m below the surface. The GWT behind
the structure is not changed.
Frame Anchors Construction stage 8
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Note: Due to deformation of the structure the forces in anchors are changing.
These changes depend on the stiffness of the anchors and the deformation
of the anchors head. The force can decrease (due to loss of prestress force)
or increase. The forces can be prestressed in any stage of construction again
to the required force.
Results of analysis
On the pictures below are the analysis results of the last, 11thconstruction stage.
Frame Analysis (Kh + pressures) Stage of construction 11
Frame Analysis (Internal forces) Stage of construction 11
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Frame Analysis (Deformation + stresses) Stage of construction 11
All the stages are satisfactorily analyzed that means that the structure is stable
and functional in all stages of the construction. The deformation must also be checked
that it is not too large, as well as that the anchor force does not exceed the bearing
capacity of the anchor (The user must check this as this is not checked by the program
Sheeting check).
Maximum displacement of the wall is 28,8 mm, which is satisfactory.
Note: If the program does not find a solution in some of the construction stages,
then the data must be revised e.g. to make the structure longer, make the forces
in anchors larger, change the number or position of anchors, etc.
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Verification of crosssection of the structure
Open the frame Envelopes in the 1st construction stage, where you see
the maximum and minimum values of variables.
Maximum shear force: mkN24,237
Maximum bending moment: mkNm80,220
Frame Envelopes
The bending moment is calculated per one meter (foot) of structure, so we have
to calculate the moment acting on the soldier beam. The spacing of soldier beams
in our example is 2,0 m, so the resulting moment is 220,80 * 2,0 = 441,6 KNm.
Users can perform the verification of crosssection I 400 manually or using
another program such as FIN EC STEEL.
Verification (crosssections I 400) output from FIN EC STEEL program
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Overall utilization of crosssection: %8,72
Verification of bearing capacity: kNmMkNmM Ry 6,441582,606 max, ==
This designed crosssection satisfies analysis criteria.
Note: Dimensioning and verification of concrete and steel walls is not part
of the program Sheeting Check, but is planned for a future version.
Analysis of internal stability
Go to the frame Internal stability in the last construction stage and look at maximum
allowable force in each anchor and the specified safety factor. The minimum safety
factor is 1.5.
Frame Internal stability
Note : The verification is done this way. At first we iterate the force in the anchor,
resulting in equilibrium of all forces acting on the earth wedge. This earth wedge
is bordered by construction, terrain, the middle of the roots of anchors
and the theoretical heel of structure. If an anchor is not satisfactory the best way
to resolve the issue is to make it longer or decrease the prestressed force.
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Verification of external stability
The last required analysis is external stability. The button will automatically
open the program Slope stability, where you perform overall stability analysis.
Program Slope stability
Conclusion
The structure was successfully designed with a maximum deformation
of 28,8 mm. This is satisfactory for this type of construction. Additionally, the limits
of forces in anchors were not exceeded.
Verification of bearing capacity of crosssection SATISFACTORY
Internal stability SATISFACTORY
Anchor nr. 4 (analyzed safety factor): 50,1>31,5 amin == SFSF .
External stability SATISFACORY
Safety factors (Bishop optimization): 50,1>92,2 == sSFSF .
The designed sheeting satisfies evaluation criteria.
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Chapter 8. Analysis of slope stability
In this chapter, we are going to show you how to verify the slope stabilityfor critical
circular and polygonal slip surfaces (using its optimization), and the differences between
methods of analysis of slope stability.
Assignment
Perform a slope stability analysis for a designed slope with a gravity wall. This is a
permanent design situation. The required safety factor is SF = 1,50. There is no water in the
slope.
Scheme of the assignment
Solution
For solving this problem, we will use the GEO5 program, Slope stability. In this text,
we will explain each step to solve this problem:
Analysis nr. 1: optimization of circular slip surface (Bishop)
Analysis nr. 2: verification of slope stability for all methods
Analysis nr. 3: optimization of polygonal slip surface (Spencer)
Analysis result (conclusion)
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Basic input Analysis 1:
In the frame Settings click on Select and choose option nr. 1 Standard safety
factors.
Dialog window Settings list
Then model the interface layers, resp. terrain using these coordinates:
Adding interface points
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Firstly, in the frame Interface input the coordinate range of the assignment. Depth of
deepest interface point is only for visualization of the example it has no influence on the
analysis.
Then, input the geological profile, define the parameters of soil, and assign them to the
profile.
Dialog window Add new soils
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Note: In this analysis, we are verifying the longterm slope stability. Therefore we are solving
this task with effective parameters of slip strength of soils (efef c, ). Foliation of soilsworse
or different parameters of soil in one direction  are not considered in the assigned soils.
Table with the soil parameters
Soil
(Soil classification)
Unit weight3
mkN
Angle of internal
friction ef Cohesion of soil
kPacef Assigned Soil
Region
MGGravelly silt,firm consistency
19,0 29,0 8,01
SFSand with traceof fines, dense soil
17,5 31,5 0,03
MSSandy silt, stiff
consistency, 8,0
rS
18,0 26,5 16,04
Model the gravity wall as a Rigid Body with a unit weight of3
0,23 mkN . The
slip surface does not pass through this object because it is an area with large strength. (More
info in HELPF1)
In the next step, define a surcharge, which we consider as permanent and strip with its
location on the terrain surface.
Dialog window New surcharges
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Note: A surcharge is entered on 1 m of width of the slope. The only exception is concentrated
surcharge, where the program calculates the effect of the load to the analyzed profile. For
more information, see HELP (F1).
Skip the frames Embankment, Earth cut, Anchors, Reinforcements andWater. The frame Earthquake has no influence on this analysis, because the slope is not
located in seismically active area.
Then, in the frame Stage settings, select the design situation. In this case, we
consider it as Permanent design situation.
Frame Stage settings
Analysis 1circular slip surface
Now open up the frame Analysis, where the user enters the initial slip surface using
coordinates of the center ( x, y )and its radius or using the mouse directly on the desktopby
clicking on the interface to enter three points through which the slip surface passes.
Note: In cohesive soils rotational slip surfaces occur most often. These are modeled using
circular slip surfaces. This surface is used to find critical areas of an analyzed slope. For
noncohesive soils, an analysis using an polygonal slip surface should be also performed for
slope stability verification (see HELPF1).
Now, select Bishopas the analysis method, and then set type of analysis as
Optimization. Thenperform the actual verification by clicking on Analyze.
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Frame Analysis Bishopoptimization of circular slip surface
Note: optimization consists in finding the circular slip surface with the smallest stabilitythe
critical slip surface. The optimization of circular slip surfaces in the program Slope stability
evaluates the entire slope, and is very reliable. For different initial slip surfaces, we get the
same result for a critical slip surface
The level of stability defined for critical slip surface when using the Bishopevaluation
method is satisfactory :
50,182,1 sSFSF SATISFACTORY.
Analysis 2:
Now select another analysis on the toolbar in upper right corner of your Analysis
frame in GEO5.
Toolbar Analysis
In the frame Analysis, change the analysis type to Standard and as method select
All methods. Then click on Analyze.
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Frame Analysis All methodsstandard type of analysis
Note: Using this procedure, the slip surface made for all methods corresponds to critical slip
surface from the previous analysis scenario using the Bishop method. For better results the
user should choose the method and then perform an optimization of slip surfaces.
The values of the level of slope stability are:
Bishop: 50,182,1 sSFSF SATISFACTORY.
Fellenius / Petterson: 50,161,1 sSFSF SATISFACTORY.
Spencer: 50,179,1 sSFSF SATISFACTORY.
Janbu: 50,180,1 sSFSF SATISFACTORY.
MorgensternPrice: 50,180,1 sSFSF SATISFACTORY.
achuanc: 50,163,1 sSFSF SATISFACTORY.
Note: the selection of method of analysis depends on experience of the user. The most popular
methods are the method of slices, from which the most used is the Bishop method. The Bishop
method does yield conservative results.
For reinforced or anchored slopes other rigorous methods (Janbu, Spencer and Morgenstern
Price) are preferable. These more rigourous methods meet all conditions of balance, and they
better describe real slope behaviour.
It is not needed (or correct) to analyze a slope with all methods of analysis. For example, the
Swedish method FelleniusPetterson yields very conservative results, so the safety factors
could be unrealistically low in the result. Because this method is famous and in some
countries required for slope stability analysis, it is a part of GEO5 software.
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Analysis 3polygonal slip surface
In the last step of analysis, input the polygonal slip surface. As a method of analysis,
select Spencer, as analysis type select optimization, enter a polygonal slip surface and
perform the analysis.
Frame Analysis Spenceroptimization of polygonal slip surface
The values of the level of slope stability are:
50,158,1 sSFSF SATISFACTORY.
Note: Optimization of a polygonal slip surface is gradual and depends on the location of the
initial slip surface. This means that it is good to make several analyses with different initial
slip surfaces and with different numbers of sections. Optimization of polygonal slip surfaces
can be also affected by local minimums of factor of safety. This means the real critical surface
does need to be found. Sometimes it is more efficient for the user to enter the starting
polygonal slip surface in a similar shape and place as an opitimised circular slip surface.
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Local minimums
Note: We often get complaints from users that the slip surface after the optimization
disappeared. For noncohesive soils, where kPacef 0 the critical slip surface is the same
as the most inclined line of slope surface. In this case, the user should change parameters of
the soil or enter restrictions in which the slip surface cant pass.
Conclusion
The slope stability after optimization is:
Bishop (circular  optimization): 50,182,1 sSFSF
SATISFACTORY. Spencer (polygonal  optimization): 50,158,1 sSFSF
SATISFACTORY.
This designed slope with a gravity wall satisfies stability requirements.
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Solution:
For solving this task, use the GEO5 programSlope Stability. In this text, we will describe
the solution of this task step by step.
Construction stage 1: slope modeling, determination of safety factor of the existing
slope;
Construction stage 2: making the earth cut for the parking (only as a working stage)
Construction stage 3: construction of the wall, analysis of internal and external
stability;
Analysis results (Conclusion).
Construction stage 1: slope modeling
In the frame Settings, click on Select and then choose analysis settings nr. 1
Standard safety factors.
Then, model the interface of layers, resp. terrain using these coordinates.
Interface coordinates
Note: If data is entered incorrectly, it can be undone using the button UNDO (shortcut CtrlZ). In the same manner,we can use the opposite function REDO (Shortcut CtrlY).
Buttons Undo and Redo
Then define the soil parameters and assign them to the profile.
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Table with the soil parameters
Soil
(Soil classification)
Unit weight3mkN
Angle of internal
friction ef Cohesion of soil
kPacef
SMSilty sand,
medium dense soil18,0 29,0 5,0
ML, MISilt with low or
medium plasticity, stiff
consistency, 8,0r
S
20,0 21,0 30,0
MSSandy silt,
firm consistency18,0 26,5 12,0
In the frame Stage settings choosepermanent design situation.
Analysis 1
stability of existing slope
Now open up the frame Analysis and run the verification of stability of the original
slope. As a verification method select Bishop and then perform the optimization of circular
slip surface. How to input slip surface and optimization principle is described in more detail
in the previous chapter and in HELP (F1).
Analysis 1stability of the original slope
The factor of safety of the original slope as analyzed by Bishop is:
50,126,2 sSFSF Satisfactory.
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Construction stage 2: earth cut modeling
Now add the second construction stage using the button in the upper left corner of the
window.
Toolbar Construction stages
Add the earth cut to the interface by adding individual points of the considered earth cut
(similar to adding points to the current interface) in the frame Earth cut. The excavation for
the sheeting wall is 0,5 m wide. After you are done with adding the points click on OK.
Coordinates of the earth cut
Note: If you define two points with same x coordinate (see picture), the program asks if you
want to add the new point to the left or right. The scheme of resulting input of the point is
highlighted with red and green color in the dialog window.
Frame Earth cut
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Construction stage 3: construction of the retainig wall
Now design the sheeting wall. In the frame Embankment add the points of the
interface of the embankment. With these we actually model the face of the structure of the
wall (see picture).
The points of embankment
Frame Embankment
Analysis 2internal stability of retaining wall
To verify the internal stability on the circular slip surface it is necessary to
model the structure as a stiff soil with ficticious cohesion, and not as rigid body. If it is
modeled as a rigid body, the slip surface cannot intersect the structure.
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Analysis 3external stability of retaing wall
Now add another analysis using toolbar in the left downward corner of the program.
Toolbar More Analyses
Before running the analysis of the external slope stability, add restrictions on the optimization
procedure using lines that the slip surface cant intersect when it executes the optimization
procedure (More info in HELPF1). In our example the restriction lines are the same as the
borders of the pile sheeting.
Analysis 4  restrictions on the optimization procedure
Note: for analysis of external slope stability it is appropriate to input the retaining wall as asolid body. When the wall is modeled as a solid body, the slip surface doesnt intersect it
during the optimization evaluation.
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Analysis 4slope stability with earth cut and retaining wall (external stability)
From the results of external stability we can see, that the slope with the earth cut and
retaining wall is stable:
50,159,2 sSFSF Satisfactory.
Conclusion
The objective of this chapter was to verify the slope stability and design of earth cut
with retaining wall for the construction of a car park with ananalysis of internal and external
stability. The results of analyses are:
Analysis 1 (stability of existing slope): 50,126,2
sSFSF Satisfactory.
Analysis 2 (internal slope stability): 50,160,1 sSFSF Satisfactory.
Analysis 3 (external slope stability): 50,159,2 sSFSF Satisfactory.
This slope with earth cut and retaining wall from concrete (with width of 0,5 m) in terms of
longterm stability satisfies evaluation criteria.
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Note: this designed retaining wall would need to be checked for stress from the bending
moment of loading from active earth pressure. This bending moment can be analyzed in the
GEO5 programs Sheeting design and Sheeting Check.
For the same bending moment it is also necessary to design and check reinforcementsfor
example in program FIN ECConcrete 2D.
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Chapter 10. Design of geometry of spread footing
In this chapter, we are going to show you how to design spread footing easily and effectively.
Assignment:
Using EN 19971 (EC 71, DA1) standards, design the dimensions of a concentric spread
footing. Forces from columns act on the top of foundation. Input forces are:yxyx MMHHN ,,,,
.
The terrain behind the structure is horizontal; foundation soil consists of SFSand with trace of
fines, medium dense soil. At 6,0 m is Slightly weathered slate. The GWT is also at a depth of 6,0 m.
The depth of foundation is 2,5 m below the original terrain.
Scheme of the assignmentanalysis of bearing capacity of spread footing
Solution
For solving this problem, we will use the GEO5 programSpread footing. Firstly, we input
all the data in each frame, except Geometry. In the Geometry frame, we will then design the spread
footing.
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Basic input
In the frame Settings, click on Select and then choose nr. 3 Standard EN 1997
DA1.
Frame Settingslist
Also select an analysis methodin this case Analysis for drained conditions. We will not
analyze settlement.
Frame Settings
Note: Usually, spread footings are analyzed for drained conditions= using the effective parameters of
soil ( efef c, ). Analysis for undrained conditions is performed for cohesive soils and shortterm
performance using total parameters of soil ( uu c, ). According to EN 1997 total friction considered is
always 0u .
In the next step enter the geological profile, soil parameters and assign them to the profile.
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Table with the soil parameters
Soil, rock
(classification)
Profile
m
Unit weight
3mkN
Angle of internal
friction ef
Cohesion
of soil
kPacef
SFSand with trace of
fines, medium dense soil0,06,0 17,5 29,5 0,0
Slightly weathered slate from 6,0 22,5 23,0 50,0
In the next step, open up the frame Foundation. As a type of foundation, choose Centric spreadfooting and fill in the dimensions such as depth from the original grade, depth of footing bottom,
thickness of foundation and inclination of finished grade. Also, input the weight of overburden, which
is the backfill of spread footing after construction.
Frame Foundation
Note: The depth of the footing bottom depends on many different factors such as natural and climatic
factors, hydrogeology of the construction site and geological conditions. In the Czech Republic the
depth of footing bottom is recommended to be at least 0,8 meters beneath the surface due to freezing.
For clays it is recommended that the depth be greater, such as 1,6 meters. When analyzing the bearing
capacity of a foundation, the depth of the foundation is considered as the minimal vertical distance
between the footing bottom and the finished grade.
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In the frame Load enter the forces and moments acting on the upper part of foundation:
yxyx MMHHN ,,,, . These values we obtained from a structural analysis program and we can import
them to our analysis by clicking on Import.
Frame Load
Note: For design of dimensions of spread footing, generally the design load is the deciding load. ,
However, in this case we are using the analysis settings EN 19971  DA1, and you must enter the
value of service load too, because the analysis requires two design combinations.
Dialog window Edit load
In the frame Material, input the material characteristics of the foundation.
Skip the frame Surcharge, as there is no surcharge near the foundation.
Note: Surcharge around the foundation influences the analysis for settlement and rotation of the
foundation, but not bearing capacity. In the case of vertical bearing capacity it always acts favorably
and no theoretical knowledge leads us to analyze this influence.
In the frame Water enter the ground water depth as 6,0 meters.
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We are not going to enter a sand gravel bed because we are considering permeable
cohesionless soil at the of footing bottom.
Then open up the frame Stage settings and select permanent as the design situation.
Design of dimensions of the foundation
Now, open the frame Geometry and apply the function Dimensions design; with which
the program determines the minimum required dimensions of the foundation. These dimensions can be
edited later.
In the dialog window it is possible to input the bearing capacity of foundation soil Rd or select
Analyze. We will chose Analyse for now. The program automatically analyzes the foundation
weight and weight of soil below foundation and determines the minimum dimensions of the
foundation.
Dialog window Foundation dimensions design
Note: Design of centric and eccentric spread footing is always performed such that that the
dimensions of foundation are as small as they can be and still maintain an adequate vertical bearing
capacity. The option Input designs the dimensions of a spread footing based on the entered bearing
capacity of the foundation soil.
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Chapter 11. Settlement of spread footing
In this chapter, we describe how analysis of settlement and rotation of a spread footing is
performed.
Assignment:
Analyze the settlement of centric spread footing designed in last chapter (10. Design
of dimensions of spread footing). The geometry of the structure, load, geological profile and
soils are the same as in the last chapter. Perform the settlement analysis using the oedometric
modulus, and consider the structural strength of soil. Analyze the foundation in terms of limit
states of serviceability. For a structurally indeterminate concrete structure, of which the
spread footing is a part, the limiting settlement is: 0,60lim, ms mm.
Scheme of the assignmentanalysis of settlement of spread footing
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Solution:
For solving this task, we will use the GEO5 programSpread footing. We will use the
data from the last chapter, where almost all required data is already entered.
Basic Input:
The design of spread footing in the last task was performed using the standard EN
1997, DA1. Eurocodes do not order any theory for the analysis of settlement, so any common
settlement theory can be used. Check the setting in the frame Settings by clicking on Edit.
In the tab Settlement select the method Analysis using oedometric modulus and set
Restriction of influence zone to based on structural strength.
Dialog window Edit current settings
Note: The structural strength represents the resistance of a soil against deformation from a
load. It is only used in Czech and Slovak Republic. In other countries, the restriction of the
influence zone is described by percentage of Initial insitu stress. Recommended values of
structural strength are from CSN 73 1001 standards (Foundation soil below the foundation)
In the next step, define the parameters of soils for settlement analysis. We need to edit
each soil and add values for Poissons ratio, coefficient of structural strength and oedometric
modulus, resp. deformation modulus.
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Table with the soil parameters
Soil, rock
(classification)
Unit
weight3mkN
Angle of
internal
friction ef
Coeff. of
structural
Strengthm
Deformation
modulus
MPaEdef
Poissons
ratio
SFSand with
trace of fines,
medium dense soil
17,5 29,5 0,3 15,5 0,3
Slightly weathered
slate22,5 23,0 0,3 500,0 0,25
Analysis:
Now, run the analysis in the frame Settlement. Settlement is always analyzed for
service load.
Frame Settlement
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In the frame Settlement it isalso needed to input other parameters:
 Initial insitu stress in the footing bottom is considered from the finished grade
Note: the value of insitu stress in the footing bottom has influence on the amount of
settlement and the depth of influence zonea larger initial insitu stress means less
settlement. The option of insitu stress acting on the footing bottom depends on the time the
footing bottom is open. If the footing bottom is open for a longer period of time, the soil
compaction will be less and it is not possible to consider the original stress conditions of the
soil.

In Reduction coefficient to compute settlement, select the option Consider foundation
thickness effect (1).
Note: the coefficient 1
reflects the influence of the depth of the foundation and gives more
realistic results of the settlement
Results of analysis
The final settlement of the structure is 16,9 mm. Within an analysis of limit states ofserviceability we compare the values of the analyzed settlement with limit values, which are
permissible for the structure.
Note: The stiffness of structure (soilfoundation) has a major influence on the settlement. This
stiffness is described by the coefficient kif k is greater then 1, the foundation is considered
to be stiff and settlement is calculated under a characteristic point (located in 0,37l or 0,37b
from the center of the foundation, where l and b are dimensions of foundation). If coefficient
k is lower then 1, the settlement is calculated under the center of foundation.

Analyzed stiffness of foundation in direction is 10,137k . The settlement is
computed under the characteristic point of foundation.
Note : Informative values of allowable settlement for different kinds of structures can be
found in various standardsfor example CSN EN 19971 (2006) Design of geotechnical
structures.
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The Spread footing program also provides results for the rotation of the foundation, which is
analyzed from the difference of settlement of centers of each edge.
Rotation of the foundationprinciple of the analysis
Rotation in direction x : )1000(tan75,0
Rotation in direction y : )1000(tan776,1
Conclusion
This spread footing in terms of settlement satisfies evaluation criteria.
Settlement: 9,160,60lim, ssm [mm].
It is not necessary to verify rotation of this foundation.
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Chapter 12. Analysis of consolidation under embankment
In this chapter, we are going to explain how to analyze consolidation under a
constructed embankment.
Introduction:
Soil consolidation takes into account the settlement time (calculation of earth
deformation) under the effect of external (constant or variable) loads. The surcharge leads to
an increase in earth formation stress and the gradual extrusion of water from pores, i.e. soil
consolidation. Primary consolidation corresponds to the situation in which there is a complete
dissipation of pore pressures in soil, secondary consolidation affects rheological processes
in the soil skeleton (the so called "creep effect"). This is a timedependent process influenced
by a number of factors (e.g. soil permeability and compressibility, length of drainage paths,
etc.). With regards to the degree of consolidation we distinguish the following cases of ground
settlement:
final settlement corresponding to 100% consolidation from the respective
surcharge
partial settlement corresponding to a particular degree of consolidation from
the respective surcharge
Assignment:
Determine the settlement value under the centre of an embankment constructed
on impermeable clay one year and ten years after its construction. Make the analysis using
CSN 73 1001 standards (using oedometric modulus), limit of influence zone consider using
coefficient of structure strength.
Scheme of the assignment  consolidation
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Solution:
The GEO 5 Settlement program will be used to solve this task. We are going to
model this example step by step:
1st construction stage interface modelling, calculation of the initial geostatic
stress.
2ndconstruction stage adding a surcharge by means of an embankment.
3rd up to 5th construction stages calculation of embankment consolidation
at various time intervals (according to the assignment).
Evaluation of results (conclusion).
Basic assignment (procedure): Stage 1
Check the "Perform consolidation analysis" field in the "Settings" frame. Then select
specific settings for calculation of the settlement from "Settings list". This setting describes
the analysis method for calculation of the settlement and restriction of influence zone.
Frame "Settings"
Note: This calculation considers the so called primary consolidation (dissipation of pore
pressure). Secondary settlement (creep), which may occur mainly with nonconsolidated and
organic soils, is not solved within this example.
Then we enter the layer interface. The objective is to select two layers between which
the consolidation takes place.
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Frame "Interface"
Note: If there is a homogeneous soil, then in order to calculate the consolidation,
it is necessary to enter a fictitious layer (use the same parameters for the two soil layers that
are separated by the original interface), preferably at the depth of the deformation zone.
Then we define the "Incompressible subsoil" (IS) (at a depth of 10 m) by means of
entering coordinates similarly to interface modelling. No settlement takes place under the IS.
The soil parameters are entered in the next step. For soils being consolidated, it is
required to specify either the coefficient of permeability " k" or the coefficient of
consolidation "v
c ". Approximate values can be found in HELP (F1).
Dialog window "Modification of soil parameters"
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Table with the soil parameters
Soil
(Soil classification)
Unit weight3mkN
Poissons
Ratio
[ ]
Oedometric
modulus
[ ]MPaEoed
Coeff. of
structural
strength
[ ]
m
Coeff. of
permeability
[ ]daymk
Clayey soil 18,5 0,3 1,0 0,15100,1
Embankment 20,0 0,35 30,0 0,3 2100,1
Sandy silt 19,5 0,35 30,0 0,3 2100,1
Then we assign the soils to the profile. The frame surcharge in the 1st construction
stage is not taken into consideration, since in this example it will be represented by the actual
embankment body (in stages 2 to 5). In the next step, we shall enter the ground water table
(hereinafter the "GWT") using the interface points, in our case at ground level.
In the frame Stage settings, you can only modify layout and refinement of holes, so
leave the standard settings.
The first "Calculation" stage represents the initial geostatic stress at the initial
construction time. However, it is necessary to specify the basic boundary conditions for the
consolidation calculation in further stages. The top and bottom interface of the consolidating
soil is entered, as well as the direction of water flow from this layer i.e. the drainage path.
"Analysis" Construction stage 1
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"Stage 2 Embankment + Assignment"
Note: The embankment acts as a surcharge to the original ground surface. It is assumed thata wellexecuted (optimally compacted) embankment theoretically does not settle. In a
practice, settlement may occur (poor compaction, soil creep effect), but the program
Settlement does not address this.
In the "Analysis" frame enter the time duration of the2nd stagecorresponding to the
actual embankment construction time. The actual calculation of the settlement cannot be
performed yet because, when determining consolidation, it is first necessary to know
the whole history of the earthwork structure loading, i.e. all construction stages.
Frame "Analysis Construction Stage 2"
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Since the embankment is built gradually, we are considering the linear load growth
in the 2nd construction stage. In subsequent stages, the duration of the stage is entered (1 year
i.e. 365 days 3rd stage, 10 years i.e. 3,650 days 4th stageand the overall settlement 5th
stage) and the whole loading is introduced at the beginning of the stage.
The calculations are performed after enter the last construction stage, which is on the
"Overall settlement", is turned on (you can check it at any stage apart from the first one).
Frame "Calculation Construction Stage 5"
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Analysis results
Upon the calculation of the overall settlement, we can observe partial consolidation
values below the centre of the embankment. We have obtained the following maximum
settlement values in individual construction stages:
Stage 1: only geostatic stress settlement not calculated.
Stage 2 (surcharge by embankment): for 30 days29.2 mm
Stage 3 (unchanged): for 365 days113.7 mm
Stage 4 (unchanged): for 3,650 days311.7 mm
Stage 5: the overall settlement351.2 mm
"Analysis Construction stage 5 (Overall settlement)"
As we are interested in the embankment settlement after its construction,
we will switch to the results view in the 3rd and 4th stages (the button "Values") to "compared
to stage 2" which subtracts the respective settlement value.
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