2D Tutorial Coupled Analysis Non Linear Time History With Slope Stability Analysis

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Integrated Solver Optimized for the next generation 64-bit platform

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2 Geometry Import

Geometry Import

Import Materials

Mesh generation

Boundary Conditions

Dynamic Load Conditions

Eigen

Eigenvalue

value Analys

Analysis

is

STEP 01

STEP 02

STEP 03

STEP 04

STEP 05

STEP 06

TH + SRM Analysis Case

STEP 07

STEP 08

Perform analysis and check result

Overview

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Overview

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01 2D Slope

•2D nonlinear time history analysis coupled with slope stability

•Plane strain elements are used to model ground condition.

•Free Field boundary conditions used for time history analysis.

•Ground Acceleration used as dynamic load.

For performing slope stability analysis using the finite element method (FEM), use higher order

elements and triangle shaped elements.

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02 Material for Soil

Name

Ground

Material

Isotropic

Model Type

Mohr-Coulomb

General

Elastic Modulus (E) (kN/m^2)

50,000

Poisson’s Ratio(v)

0.4 Unit

Weight(r)

(kN/m^3)

19 K0

1 Porous

Unit Weight(Saturated) (kN/m^3)

19 Non-Linear

Friction

Angle

5 Cohesion

(kN/m^2)

30

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03 Property for Soil

Name

Ground

Property

2D

Model Type

Plain

Strain

Material

Ground

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Integrated Solver Optimized for the next generation 64-bit platform

Finite Element Solution s f or Geotechnic al Engineering

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Procedure

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01 Create New Project

1

Main Menu > New Analysis Setting > Model Type > 2D

Set units to kN / m / sec

2

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Procedure

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02

1 1

Main Menu > Open

Select NTH with SRM > DXF> Open Select OK 2 2 3 3

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Procedure

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03 Define Material / Property for Soil & Structures

1 _{Mesh > Prop. > Property}

•Import Materials and Properties from finished file (Refer to Project Overview > Material / Property). Import All

1 1

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Procedure

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04 Generate Mesh (2D Element)

1 _{Mesh > Generate > 2D > Auto}

-Area

Select Edge(s) > Select 6 edges highlighted in figure.

Input element Size : 1 (1m between two nodes) Select Property : Ground Input Mesh Set Name : Ground Click on the ‘>>’ icon to open the Advanced Option Window Select Triangle as Element Type Activate Higher Order Elements Click OK > OK 2 2 2 3 4 5 3 4 5  6 6 1 7 8 9 8 1 9 7

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Procedure

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05 Define Free Field Boundary

1 Mesh > Element > Free Field

Line: Select the left and right vertical edges of the mode’s boundary as shown in the image.

Create Free Field Property > Free field type: Line

Width Factor : 10e15 Press Ok>OK 1 2 2 3 3 4 4

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Procedure

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06 Define Boundary Condition (Ground)

1 Static / Slope Analysis >

Boundary > Constraint > Advanced

Select all the bottom nodes and the bottom free field as shown in the images. Restrict DOF Tx and Ty Press OK 1 2 3 2 3 4 4

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Procedure

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06 Define Boundary Condition (Ground)

Mesh > Create > Other > Ground Surface Sprind Select mesh set Press OK

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Procedure

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07 Load Condition (Self Weight)

1

1 Static / Slope Analysis >

Load > Self Weight

Load Set Name : Self weight

2

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Procedure

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08 Dynamic Load > Gravity

Create Dynamic Load Case for gravity to be considered in dynamic analysis

Dynamic Analysis > Load > Time Varying Static

Select load set and click ADD Dynamic Load Set : gravity Press OK 1 2 1 3 4 2 3 4

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Procedure

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08 Dynamic Load > Ground Acceleration

Create Time History Load Funcition for dynamic analysis

Dynamic Analysis > Load > Ground Acceleration

Activate X direction, Scale Factor: -1 and click in the icon to define the function

Click ADD Time Function Click EARTHQUAKE to select function from out data base Select 1940 El Centro, 270 degree Press OK, > OK > CLOSE > OK

1 2 1 3 4 2 3 4 1 2 5 6 3 4 5 6 6 6 6

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Procedure

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09 Analysis Case

1

Create EigenValue Analysis Cases 1. Analysis > Analysisi Case >

General > Eigenvalue 2. Activate Sets as shown 3. Analysis Control > 30 Modes 4. Press OK > OK 2 3 1 2 3 4 4

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Procedure

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10 Perform Analysis and Check Results

1 Analysis > Analysis > Perform

Select OK

1

2

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Procedure

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11 Post Processing (Results)

* After analysis, model view will be converted to Post-Mode automatically, can back to Pre-Mode to change model information.

1 1

Results can be Viewed in table format.

Find the 2 highest mass participation modes and write

down their corresponding periods. MODE 1: 1.2222 sec

MODE 4: 0.7152 sec

3 2

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Procedure

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12 Analysis Case (Nonlinear Time History + SRM )

1

Create Nonlinear Time History & SRM analysis Cases

1. Analysis > General > Nonlinear Time History & SRM

2. Ac tivate all sets 3. Define Time Step Name: time

Time Duration: 2 sec Time Increment:: 0.02 sec Intermediate Output:: 10 Press Add > OK > CLOSE

4. Analysis Control > Dynamic > Damping Method

-Select > Calculate from Modal Damping > Period

-Type in the 2 periods from Eigenvalue results -Damping Ratio : 0.05 -Press OK 5. Analysis Control > SRM -Time: 1.68 sec Press Add > OK Press OK 2 3 1 2 3 3 4 4 4 4 5 5 6 6

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Procedure

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13 Perform Analysis and Check Results

1 Analysis > Analysis > Perform

Select Nonlinear Time History with SRM Select OK 1 3 2 3 2

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Procedure

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1 Inspect the FOS or the SRM analysis case.

FOS: 1.01

SRM>Plane Strain Strains>E-Equivalent

14 Post Processing (Post mode)

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