construction stage analysis of shored excavation

8/10/2019 Construction Stage Analysis of Shored Excavation

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IV. Ground Module

Effects on Adjacent Structures due to Ground Excavation

Parallel Tunnel Analysis for Change in Lateral Pressure Coefficients

Main Tunnel Lining Analysis

Construction Stage Analysis of Shored Excavation


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SoilWorks

Ground00. Table of Contents

01. Learning Objective 3

02. Overview 4

1. Overview of Shoring Wall Numerical Analysis

2. Allowable Settlements of Structures

3. Wall-Interface-Ground Modeling

4. Composition of Modeling

03. Set Work Environment & Define Material Properties 10

1. Start SoilWorks / Import File

2. Define Ground Properties

3. Define Structural Properties

04. Modeling 14

1. Create Surfaces & Assign Material Properties

2. Generate Mesh

3. Create Anchor Elements

4. Create Interface Elements

5. Define Loading Conditions

6. Define Boundary Conditions

05. Analysis 20

.

2. Define Construction Stages Define Stage Models

3. Define Analysis Cases

4. Define Design Options

5. Define Design Members & Adjacent Structures

6. Analysis

06. Results Analysis & Report Generation 27

1. Analysis of Results

2. Report Generation

07. Analysis Guide 32

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SoilWorks

Ground01. Learning Objective

From this tutorial, the user will understand the workflow associated with the review of the effects

on underground structures due to shored excavation. The user will also learn the use of various

basic functions and the workflow of SoilWorks in the process, which involves construction stageanalysis of shoring wall. Result analysis and report generation will be also covered.

The workflow of shored excavation construction stage analysis is as follows:

Import the CAD model for the targetedgeometry for analysis

Create surfaces & assign material properties

STEP 01

STEP 02

Auto-generate meshSTEP 03

e ne oun ary oa ng con ons

Define construction stages

STEP 05

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Define analysis cases & design optionsSTEP 06

Execute analysisSTEP 07

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[Workflow in SoilWorks]

Analyze results & generate reportsSTEP 08

Construction Stage Analysis of Shored Excavation |

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SoilWorks

Ground02. Overview

1. Overview of Shoring Wall Numerical Analysis

1. Overview of numerical analysis of shoring wallFor urban ground excavation, not only is the review of the stability of shoring wall required, but

the effects on the adjacent ground and structures ensuring their stability is also required.

In order to closely estimate the actual ground movement due to ground excavation in the process

of designing the shoring wall, accurate ground material properties and the interaction between

the shoring structure and ground must be reflected. In addition, the analytical model needs to

closely reflect the excavation sequence.

Analysis of shoring wall structures has been researched and improved over the years.

Depending on the application of external loads (soil pressure, water pressure, overburden, etc.)

and the inclusion of ground interaction, the analysis methods are classified as follows:

1) Classical analysis

This simplified method uses the apparent lateral soil pressures. It is widely used for analysis

of soil retention structures of shallow excavations in non-urban areas. The soil pressures are

based on empirical pressures of a rectangular or trapezoidal distribution pattern by Terzaghi-

Peck or Tshebotarioff.

2) Analysis by soil pressure theories

Deep excavations In urban areas are undertaken in close proximity to existing structures for

which accurate prediction of displacements of and stresses in the shoring wall structuresbecomes an issue. The classical method is an approximate approach for excavations within

15m in depth supported by temporary structures. Rather than using the apparent empirical

soil pressures, triangular soil pressures by Rankine-Resal or Coulomb are used to estimate

variable soil pressures relative to the displacements of walls from which forces in the

supports and displacements and stresses of the shoring walls are calculated. The elasto-

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plastic method is a typical analysis method using the soil pressure theories.

3) Analysis by ground-structure interaction

Ground-structure interaction analysis is carried out by the finite element and finite difference

methods. The finite element method is applied to large scale, deep excavations in the

design and construction of shoring wall and support systems. The method inherently

addresses the stresses and displacements of the shoring structures as well as the

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deformations in the surrounding ground and structures simultaneously. This method

calculates displacements and stresses reflecting the elasto-plastic behavior of ground and

interaction with the shoring wall and support structures, without having to apply separate soil

pressures. SoilWorks thus evaluates the stability of shoring walls through such interaction.

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SoilWorks

Ground02. Overview


Allowable settlements for structures due to excavations are outlined in the tables 1 to 5 below.

From the structural point of view, differential settlements (or angular displacements) are more

detrimental to the stability compared to absolute settlements. As such, acceptable settlements

are focused on differential settlements.

For railway structures, the limits to the track deformation become the basis for acceptance for

operational safety and passengers comfort levels.

Classification Limits for damage

Structural damage Angular displacement /L > 1/150

Table 1. Limits for damage due to differential settlements in framed structures (Skempton &

Macdonald, 1956)

rc ec ura componen s wa oor amage

* L = Span, = Differential settlement between columns

Classification Spread footing Mat foundation

Table 2. Limits for damage in building structures (Building Code)

Angular displacement 1/300

Max differential

settlement

Clay 44 mm

Sand 32 mm

Total displacement

Clay 76 mm 76 ~ 127 mm

~

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Classification Settlement criteria

Table 3. Settlement proposed by Terzaghi

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Footings of same size founded

at the same locationMax diff settlement Max settlement (max max)

Footings of different sizes

founded at different elevations

Max diff settlement Max settlement (max max)

Max allowable differential settlement in (max max)

* max = Max allowable settlement: 1 in (25.4 mm)


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SoilWorks

Ground02. Overview


Settlement type Type of structure Max settlement

Drainage facility

Entrance, exit

150 ~ 300 mm

300 ~ 600 mm

Table 4. Maximum allowable settlements of various structures (Sower, 1962)

o a se emen Possibility of diff. settlement: masonry, brick structures

Structural skeleton

Chimney, silo, mat

25 ~ 50 mm

50 ~ 100 mm

75 ~ 300 mm

Overturning

Tower, chimney

Loading goods

Crane rail

0.004 S

0.01 S

0.003 S

Brick walls of a building 0.0005 ~ 0.002 S

Differential

settlement

Structural skeleton of reinforced concrete

Structural skeleton of structural steel (continuous)

Structural skeleton of structural steel (discontinuous)

0.003 S

0.002 S

0.005 S

* S: Distance between columns or between two points

Table 5. Allowable differential settlement at rail levels of a structure supporting trains

Displacement

direction

Trainspeed

(km/h)

Dislocation

Bending angle (1/1000)

Parallel movement Bending

L < 30 m L 30 m L < 30 m L 30 m

70 9 9 9 9

ls

Vertical 2

110 7.5 9 9 9

160 5 6 6.5 7

210 4.5 4 5.5 4.5

260 3.5 3 4 3

70 6 6 6 6

oriaHorizontal 2

110 4 5.5 5 6

160 3 3 3.5 4

210 2.5 2 3 2.5

260 1.5 2 1.5 2.5 2

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* L: Distance between columns or between two points

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SoilWorks

Ground02. Overview


Limit for structures sensiti

ve to settlements

Limit for visible overturnin ofhi hrise buildin s

Limit for partitions expected of first cracking

Limit for operating high level cranes

Limit for safety of buildings without any cracking

Limit for safety of buildings with structural

diagonals

Figure 1. Allowable angular displacements of structures (/L) (Bjerrum, 1963)

Allowable settlements and angular displacements of structures have been proposed by

Limit for partition walls or brick walls expected of s ignificant

cracks & general buildings expected of structural damages

numerous geotechnical engineers. SoilWorks provides the criteria proposed by Bjerrum

(1963), Skempton & MacDonald (1956), Sower (1962), Wilun & Starzewski (1975)and Boscardin & Cording (1989).

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SoilWorks

Ground02. Overview

3. Wall-Interface-Ground Modeling

The important aspect of simulating the ground-structure interaction pertains to whether or not theinterface between the ground and the structure is considered.

Interface Element is used to represent the behavior of the contact surface between identical or

different materials, which is a type of Contact Element. The types of Contact Element are

node-to-node, node-to-surface and surface-to-surface, out of which SoilWorks provides the

node-to-node type ofInterface Element. Interface elements In civil structures can be modeled

as 1) Weak Element between the boundary surfaces, 2) Link Element linking the boundary

surfaces, and 3) Zero Thickness defining rigid links between the boundary surfaces.

In modeling the interface elements at the shoring wall, the objective is to closely reflect the

behavior between the ground and wall surfaces by separating the behavior of the wall from the

behavior of the ground. Appropriate stiffness of the interface elements needs to be specified;

otherwise, overlapping interface elements or the failure of the nearby ground may be observed.

The appropriate stiffness may be determined by such references as Belytschco (1984), A

computer method for stability analysis of caverns in jointed rock., International Journal for

numerical method in Geomechanics, Vol.8, pp473-492.) and other technical literatures.

Finding appropriate stiffness of interface elements

Stiffness for interface elements is classified into the normal direction behavior (Kn) and the

tangential direction behavior (Kt). Finding appropriate values is important as convergence is verysensitive to the two values. SoilWorks uses the method by which the value of Kn is defined and a

Scale Factor is multiplied to obtain the value of Kt. The smaller modulus of elasticity of the two

materials in contact is used for the value of Kn first, and the concept of Virtual Thickness is

introduced to be consistent with the unit for the stiffness factor. A value in the range of1~0.1 for

the virtual thickness is used. The modulus of elasticity is divided by the virtual thickness through

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which the unit is changed to that of the stiffness factor. This also has a scaling effect in the

process.

No theoretical background exists for the range of the virtual thickness values. So it is

recommended that a empirical value of 1 be used, which results in the same value as the

modulus of elasticity, but having a different unit. If the modulus of elasticity of the adjacent

elements is defined to a very small magnitude, the effect of overlapping may severely develop in

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which case, a value of about 0.01 is recommended.

The value of Kt is obtained by multiplying the defined Kn value by a factor in the range of1~0.1.

If the nonlinear behavior ofCoulomb Friction needs to be defined for the interface elements,

Cohesion and Internal Friction Angle must be specified. It is recommended that the smaller value

of the two adjacent elements be multiplied by a Scale Factor in the range of1~0.1. Belytschco

1984 ro osed the ran e of Kn values to be 2 to 1,000 times the Ks. This shows that the

| Ground Tutorial

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values of Kn and Ks are widely varied and are dependent on experiences.

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SoilWorks

Ground02. Overview

4. Composition of Modeling

Excavation and construction of shoring wall will cause displacements at the ground surface andin the ground mass, which will in turn cause damages to adjacent structures. This tutorial will

investigate such displacements, the state of distribution of plastic zones and the effects on

adjacent structures. The model and the ground properties are as follows:

1) Composition of Modeling

Weathered rock

Pipes

Weathered soil

Alluvial layer1st stage of excavation

2nd stage of excavation

3rd stage of excavation

Soft rock

2) Material Properties

ompos on o mo e

Ground Properties

No Ground Type Model Type

Modulus of

Elasticity2

Unit Weight

(kN/m3)

Saturated

Unit Weight3

Poissons

Ratio

Cohesion

(kN/m2)

Internal

Friction

Angle

ls

(degree)

1 Alluvial layer Mohr Coulomb 8,000 17 18 0.35 15 20

2 Weathered soil Mohr Coulomb 36,500 18.5 19.5 0.33 17.5 31

3 Weathered rock Mohr Coulomb 150,000 21 22 0.3 50 33

4 Soft rock Mohr Coulomb 1,850,000 24 25 0.28 180 35.5

oria Structural Properties

NoStructure

TypeModel Type

Modulus of

Elasticity

(kN/m2)

Poissons

Ratio

Unit

Weight

(kN/m3)

Horizontal

spacing

(m)

Section

(m)

Design

Strength

(kN/m2)

1 Pipe Beam 230,000,000 0.3 24 1Rectangle


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. ,

2 H-Pile Beam 210,000,000 0.3 77 1.8 H: 298x201x9/14(mm)Yield:

240,000

3 Anchor Embedded

Truss200,000,000 0.3 77 2.7 Area: 0.00039484(m2)

Yield:

1,570,000

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SoilWorks

Ground

1. Start SoilWorks / Import File

03. Set Work Environment & Define Material Properties

Select the SoilWorks execution icon from the desktop.

1. Project Manager > select Ground

2. Set the units for defining the initial variables to kN, m, sec and click

Import a CAD file, which has been prepared for the analysis geometry.

SoilWorksprovides 7modules,

Ground, Slope, Rock, Soft

Ground, Foundation, Seepage

andDynamic.

. .

4. Click the Construction Stage Analysis of Shored Excavation

5. .dwg file and click

6. Key in the command window Z (zoom) > e (Extents) and check the model data.Copy (Ctrl+C) the model

data on CAD and paste

(Ctrl+V) it in SoilWorks. 2

1

4

3

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[Starting SoilWorks & Importing geometry]

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SoilWorks

Ground03. Set Work Environment & Define Material Properties

2. Define Ground Properties

From the Main Menu, select Model > Property > Ground Material Property(command: gm)

1. Click

2. From the ground parameter DB, select 1.1 Schist#1.

3. Select Alluvial Layer, Weathered Soil, Weathered Rock, Soft Rock.

The command entered

in the Command

Window may be used to

directly invoke the menu.

.

5. Click

1

2

5

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SoilWorks



From the Main Menu, select Model > Property > Structural Property

(command: sp)

1. Enter Pipe in Name.

2. Select Beam from the Element Type selection.

3. Section Shape: select Rectangle

The section dimensions

are used to automatically

calculate the section

stiffness data.

4. Section Data tab > H dimension: enter H=0.03, B=1

5. Click

6. Material Data tab > Modulus of Elasticity: enter 230,000,000

7. Material Data tab > Poissons Ratio: enter 0.3

8. Material Data tab > Unit Weight: enter 24

9. Click

10. Enter H-Pile in Name.

11. Standard: select NONE, Horizontal Spacing: enter 1.8

12. Section Shape: select H

13. Material Type: select Steel

14. Section Data tab> H: enter 0.298, B1: enter 0.201, tw: enter 0.009, tf1: enter 0.014

15. Material Data tab> Modulus of Elasticity: enter 210,000,000, Poissons Ratio: enter

SoilWorks contains

section database from

which the user may

select standard sections

materials.

0.3, Unit Weight : enter 77 and Yield Strength: enter 240,000

16. Click17. Enter Anchor in Name.

18. Member type: select Embedded Truss

19. Standard: select NONE, Horizontal Spacing: enter 2.7

20. Section Shape: select Strand

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21. Section: select User Defined

22. Material Type: select Strand

23. Section Data tab> Area: enter 0.00039484

24. Material Data tab> Modulus of Elasticity: enter 200,000,000, Poissons Ratio: enter

0.3, Unit Weight : enter 77 and Yield Strength: enter 1,570,000

25. Click

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26. Click

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SoilWorks



1

2

3

4 5~ 6 8~

9

10

12

1114

15

16

13

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18

17

20

19

23 24

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25 26

21

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[Define Structural Properties]

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SoilWorks

Ground04. Modeling

1. Create Surfaces & Assign Material Properties

Create surfaces to which material properties will be assigned prior to creating mesh.

SoilWorks automatically

generates surfaces

enclosed by curves.

Ground properties can

From the Main Menu, select Geometry > Create > Smart Surface

(command: ss)

1. From the work window, select the Alluvial La er domain.

Assign ground and structural properties to the created surfaces.

e en ass gne o e

created surfaces by

Drag & Drop before

meshing the surfaces.

2. WorksTree > Material Property > Ground Property > drag & drop Alluvial layer into

the work window.

3. From the work window, select the Weathered Soil domain.

4. WorksTree > Material Property > Ground Property > drag & drop Weathered soil into

the work window.

5. Similarl re eat the ste s from 3 to 4 and assi n the ro erties to Weathered Rock &

Soft Rock.

6. From the work window, select the Pipe domain.

7. WorksTree > Material Property > Structural Property > drag & drop Pipe into the work

window.

8. From the work window, select the H-Pile domain.

9. WorksTree > Material Pro ert > Structural Pro ert > dra & dro H-Pile into the

~1 9

work window.

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Weathered Rock

Soft Rock

Weathered Soil

Alluvial Layer

Pipes

H-Pile

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[Assign Ground & Structural Material Properties]

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SoilWorks

Ground04. Modeling

2. Generate Mesh

Using the surfaces assigned with material properties, mesh is generated.

SoilWorks provides

mesh density control in 3

levels. The denser the

mesh, the more accurate

From the Main Menu, select Model > Mesh > Smart Mesh (command: sm)

1. Density > select Very Fine Element.

2. Check on the option Register each Mesh Set by Domains.

3. Clickresu s w e o a ne .

4. Check the generated mesh.

5. Re-define the mesh set names in WorksTree.

1

2

3

4

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[Generated Mesh]

When changing the material properties, use the

5

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Selection Filter ( ) and select the elements or

element mesh sets and drag & drop the material

properties or structural properties to be changed

from the WorksTree into the work window.


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SoilWorks

Ground04. Modeling

3. Create Anchor Elements

Model anchors for ground excavation.

From the Main Menu, select Model > Element > Create Element

1. Mesh Set: enter Level 1 Free-stress Length

2. Element Type: select Embedded Truss Element

3. Referring to the model on Page 9, select the two nodes individually from the diagram and

create the element.

4. Mesh Set: enter Level 1 Anchorage Bond Length

5. Referring to the diagram below, select the two nodes individually and create the element.

6. Similarly repeat the steps from 1 to 5 to create Level 2 Free-stress Length Level 2

Anchorage Bond Length

(In order to stress the free-stress length, the mesh sets for Free-stress Length and

Anchorage Bond length are separated.)

1 4

2

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Level 1 Free-stress Length

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Level 2 Free-stress Length

Bond Length

Level 2 Anchorage

Bond Length

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[Generated Mesh]


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SoilWorks

Ground04. Modeling

4. Create Interface Elements

Create interface elements between the ground and the shoring wall.

From the Main Menu, select Model > Element > Interface Element

1. Method: select Create from Truss/Beam Elements

2. Select the beam elements of H-Pile.

3. Select Property Wizard to reflect the interface element properties by automatically

considering the properties of the surrounding ground.

4. Click , specify Virtual Thickness Factor: 0.5 &

Strength Reduction factor: 1

5. After clicking , enter Mesh Set name: Interface

6. Check on Create Rigid Link automatically

7. Check on Addition of Mesh Set for Interface Elements

8. Click

41

2

3

6

7

4

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8

2

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SoilWorks

Ground04. Modeling

5. Define Loading Conditions

Specify the road overburden load.

From the Main Menu, select Loads | Boundaries > Loads> Pressure Load

(command: pl)

1. Enter Overburden Load in Load Set.

2. Select Object > Type: select Element Boundary Curve and select the element

surface.

3. P1: enter 13 kN/m2 and click1

22`

3

3

[Input Loading Conditions]

Specify prestress load for the anchors free-stress lengths..

From the Main Menu, Load | Boundaries > Load > select Prestress (command: psl)

1. Enter Level 1 Prestress in Load Set.

2. Select Truss Element Type in Element Type

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3. Select 1 element representing Level 1 Free-stress Length.

4. Enter 220 kN in axial Force and select Pretension

5. Click

6. Similarly repeat the steps from 1 to 5 to define Level 2 Prestress

1 6

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3

2

3

4

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[Input Prestress]

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SoilWorks

Ground04. Modeling

6. Define Boundary Conditions

Define boundary conditions to the generated mesh.

From the Main Menu, select Loads | Boundaries > Boundaries > Smart Support

(command: as)

1. Enter Boundary Condition in Boundary Set.

2. Check on Consider All Mesh Sets

3. Click

1

2

3

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[Created Boundary Conditions]

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SoilWorks

Ground05. Analysis

1. Define Construction Stages Define Stages

From the Main Menu, selectAnalysis | Design > Construction Stages > Construct ion

Stages (command: cs)

1. Select Add Construction Stage

2. Number: enter 5 for the number of stages.

3. Click

The construction stages

consist of Original

4. Select Construction Stage 1, enter Original Ground in Name & check on Initialize

Displacement

5. Click

6. Select Construction Stage 2, enter Install Structures in Name & check on

Initialize Displacement

7. Click

Ground > Construction

of adjacent structures &

Loading > Level 1

Excavation > Level 1

Anchor installation >

level 2 Excavation >Level 2 Anchor

installation > Level 3

8. Select Construction Stage 3, enter Level 1 Excavation in Name

9. Click


11. Click


13. Click

Excavation.

14. Click

2

3

ls

4 ~ 113

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[Define Construction Stages]


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SoilWorks

Ground05. Analysis


Define models boundar conditions loadin s etc. for construction sra es to be used in anal sis., , , . .

Continue from the previous page, after clicking1. Stage: select Original Ground

2. Drag & drop Ground (Alluvial layer, Weathered soil, Weathered rock, Soft rock) &

Link element Mesh Sets, Boundary Conditions and Selfweight into Activated

Data the Current Stage.

SoilWorks provides

Tree Style & Table

Style for data input for

.

4. Stage: select Install Structures

5. Drag & drop Pipe inside & Link element into Deactivated Data at the Current

Stage and Pipe, H-Pile, Interface Elements & Overburden Load into

Activated Data the Current Stage.

6. Click

.

.

8. Drag & drop Level 1 Excavation Alluvial layer into Deactivated Data at the

Current Stage and Level 1 Free-stress Length, Level 1 Anchorage Bond Length

& Level 1 Prestress into Activated Data the Current Stage.

9. Click

1 3

2

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4

5

6

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7

8

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SoilWorks

Ground05. Analysis


10. Stage: select Level 2 Excavation

11. Drag & drop Level 2 Excavation Top Weathered Soil & Level 2 Excavation

Lower Weathered Soil into Deactivated Data at the Current Stage and Level 2

Free-stress Length & Level 2 Anchorage Bond Length Mesh Sets & Level 2

Prestress into Activated Data at the Current Stage.

SoilWorks provides

Tree Style & Table

Style for data input for

12. Click

13. Stage: select Level 3 Excavation

14. Drag & drop Level 3 Excavation Lower Weathered soil~Soft rock Mesh Sets into

Deactivated Data at the Current Stage

15. Click

16. Click

.

10

11

12

ls

13

14

15

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[Define Construction Stage Models]


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SoilWorks

Ground05. Analysis

3. Define Analysis Cases

From the Main Menu, selectAnalysis | Design > Analysis Control > Analysis Case

(command: ac)

1. Click in Define Analysis Case.

2. Enter Shoring Wall Construction Stage Analysis in Name.

.

4. Select Analysis Control Data

5. Check on Initial Stage for Stress Analysis & select Original Ground

6. Check on K0 Condition

7. Click

8. Click

.

1

5

6

2

3

4

9

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SoilWorks

Ground05. Analysis

4. Define Design Options

Define the design options to be used for report generation.

From the Main Menu, selectAnalysis | Design > Design and Report Control > Design

Option

1. Under the Adjacent Structure tab, select User Defined for the allowable displacement

management standard.

2. Select the Allowable Angular Displacement and enter 750 in the input box.

3. Click

1

2

[Define Design Option]

3

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Ground05. Analysis

5. Define Design Members & Adjacent Structures

Define the adjacent structures to be used in the report.

From the Main Menu, selectAnalysis | Design > Design and Report Cont rol > Adjacent

Structures

1. Under the Adjacent Structure tab, enter Pipe 1 in Name.

2. Construction Stage: select Level 3 Excavation

3. Below Construction Stage: select Curve

4. Select Curve representing Pipe 1.

5. Check on Flexural-Axial Stress, Shear Stress & Axial Force

6. Click

7. Under the Adjacent Structure tab, enter Pipe 2 in Name.

8. Select Curve representing Pipe 2.

9. Check on Flexural-Axial Stress & Shear Stress

10. Click

11. Click

1

5

3

2

4

ls

6

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[Define Design Option]

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SoilWorks

Ground05. Analysis

6. Analysis

Using the analysis cases, perform analysis and report generation.

From the Main Menu, selectAnalysis | Design > Run > Analysis / Report

(command: ra)

1. Check on Shoring Wall Construction Stage Analysis & Report for Structures

Adjacent to Tunnel

Any data generated

during the process of

2. Click analysis is displayed at

the bottom of Analysis &

Report Execution

Manager. Especially,

use caution when

Warnings appear as theanalysis results may be

erroneous. Analysis

1

data is saved in a text

f ile format in .OUT file in

the same folder as Save

file.

2

ls

na ys s epor

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Ground06. Results Analysis & Report Generation


Check the deformed shape of the ground due to construction stages.

From the Post Tree, select Shoring Wall Construction Stage Analysis > Level 3

Excavation > Displacement > Vertical Displacement (DX(V))

1. From the Main Menu, select Results > View Results > Table

2. In order to check the top point of shoring wall, enter the node number of the left side of

Node numbers can be

checked in WorksTree,

the top point of shoring wall.

3. Stage/Step: select all the stages.

4. Click

5. Check the ground settlements by stages in a table. (Can be exported to Excel)

6. Check the horizontal displacement with construction stages by Export To Graph

Mesh Set > View

Labels > Node ID.

2

[Vertical Displacement at the last stage]1

3

5

ls

2

46

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[Check the Table Results of ground settlements and Export To Graph]


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Check the forces and relative displacements of the interface elements.

1. From the Post Tree, select Shoring Wall Construction Stage Analysis > Level 3

Excavation > Interface > Interface 1D Element Normal Traction (Tx)

2. From the Post Tree, select Shoring Wall Construction Stage Analysis > Level 3

Excavation > Interface > Relative Displacement of Interface 1D Element in the

Normal Direction (dDx)

1

n er ace orces n orma

Direction at the last stage]

2

[Relative Displacements in

Normal Direction at the last stage]

ls [Interface at the last stage]

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2. Report Generation

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[ Check Stress of Neighboring Structure ]


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SoilWorks

Ground07. Analysis Guide

This tutorial has reviewed the effects on existing adjacent structures and shoring wall member

forces as the ground excavation advanced.

In order to predict the behavior of shoring wall and secure its stability, elasto-plastic methods

have been developed and commercialized. Such methods however have limitations to accurately

simulate the interaction among shoring wall, ground and adjacent structures. As an alternative,

the use of the finite element method is now becoming important.

For shoring wall analysis, SoilWorks enables the user to closely reflect the physical state of the

ground, material nonlinearity, anisotropy and the state of the original ground stress in conjunction

with the use of various material models and higher order elements. In addition, interface

elements between the shoring wall and the ground are inserted in the analytical model to closely

reflect the true behavior of excavation.

Through the tutorials related to the Ground module including construction stage analysis, the

following is composed to understand the workflow of shoring wall analysis and tunnel numerical

analysis:

1) Effects on Adjacent Structures due to Tunnel Excavation

2) Parallel Tunnel Analysis using the K0 parametric variable

3) Main Tunnel Lining Analysis

4) Seepage-stress coupled analysis

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construction stage analysis of shored excavation

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