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Basic modeling concept for coupled

analysis using GTS.

Perform: Seepage Analysis (Steady-State) – Stage 1

Perform: Construction – Stage 2

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Determination of Hydraulic Head

Reference Height @ (0,0)

Height: 50 cm

Pressure head = 450 cm

Elevation head = 50 cm

Pressure head = 450 cm

Units

Force: NLength:cm

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Determination of Hydraulic

Head: Stage 1Stage Type

- Seepage Analysis (SS)

Activated Data

- Element: 50 cm- Boundary: pressure head = 450 cm

Elevation head = 50 cm

Pressure head = 450 cm

Total head = 500 cm

Define Construction Stage

**Once a defined construction stage has been

properly defined for seepage analysis, the user

must define an analysis case to instruct the

solver to consider construction stage.

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Results

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Extracting Results

440

450

460

470

480

490

500

510

0 20 40 60

Pressure Head (cm)

Pressure Head

(cm)

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Stage 2 Define Construction Stage :

Stress Analysis

Since one stage has been

defined for seepage analysis,

the user must add a “New”

stage.

In this case, the stage type will

be assigned as “Construction”

to consider the stress results.

Pore pressure results will be

automatically considered from

the previous seepage analysis

stage 1.

BC: boundary condition

SW: Self weight

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Pore Pressure Results

Pore pressure results from seepage analysis have transferred to Construction Stage.

The legend has flipped indicating that the solver has considered the results into stress analysis.

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Results

The pore pressure results from seepage analysis may not be exactly the same asthe pore pressure results that have been transferred to the stress stage. The reason

being is that the results for stress/strain values have been assigned as Center by default.

To get the exact solution, click the Center + node.

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Overview

Mesh sets

Ground

Excavation 9m, 8m,7m

Wall

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Presentation model

Wall

Several colored layers

representing

excavations

10m

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Construction Stage OverviewSemi-Coupled analysis can be modeled in GTS by interchanging the constructions

from seepage to construction stages. Interchanging the seepage stage and stress

stages can simulate the varying seepage flow and stress variations.

Semi-coupled analysis cannot consider the hydrostatic effects on the wall. In order

to simulate pressure acting on the face wall, users may consider modeling the

varying pressure loads or defining a water level function in construction stageanalysis.

**Semi-couple analysis cannot consider excess pore pressure. This can be done in

a consolidation analysis. Undrained and drained conditions can be considered.

See online help manual for instructions on defining these conditions.

Finally, a seepage face is defined along the length of the wall. This function acts as

a review boundary conditions where the solver review the total head difference

and redirects the flow path. In short, it is a boundary condition to simulate

impermeable surface. Nodal flux can also be used to simulate impermeable

permeable surfaces.

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Construction Stage 1

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Construction Stage 2

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Construction Stage 3

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Construction Stage 4

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Construction Stage 5

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Construction Stage 6

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Construction Stage 7

Total Head Stage 7

Seepage Pore pressure Stage 7

Deformation DXY

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Flow

Flow path VXY

Pore pressure last stageof excavation

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Deformation Results with and without

seepage analysis

DXY results for semi coupled analysis

: Max 6.0e-1m

DXY results for construction stage analysis

Only considering 9m water level:Max: 5.81e-1