Diamond Engineer: Tunnel Series Training 2

Transcription

1 Diamond Engineer: Tunnel Series Training 2 Angel Francisco Martinez Application Engineer MIDAS NY

2 Content 01 Introduction 02 Construction Stages 03 Demo 04 Post - Processing

3 Introduction

4 About MIDAS No. 1 in software for civil engineering 650 Developers and Engineers 120 Distribute in 120 countries 10,000 Clients 30,000 Licenses

5 2D vs 3D tunnels with soil springs Structural analysis gives importance to the uncertainty of load, acting on the structure. Hence, it conducts the member design for the largest member force obtained by combining various results systematically

6 2D vs 3D tunnels w/ ground elements Ground analysis focuses more on the uncertainty of construction step and material itself, it is important to understand physical state inside the ground. As a result, solid elements need to be used in modeling to reflect the ground shape and construction situation; and non-linear anisotropic materials and in-situ stress states need to be considered to reflect the actual on-site conditions as much as possible.

7 WHY model Tunnels in 3D FEM? Ground displacements associated with tunnel excavations occur in vector directions X-Y-Z, thus to accurately represent ground behavior during tunnel excavation processes, detailed 3D numerical analysis is vital. Modeling tunnels in 3D is becoming more attractive because of limitations of the 2D modeling and because it captures the response of tunnel excavations more accurately.

8 Work flow for FEM analysis Automatic generation of shared surfaces function [Import or automatically generate 3D layers through actual field data] Modeling Analysis section 자동요소망생성 Check shared surfaces Check results Define analysis conditions and run the high performance analysis Hybrid Mesh generation 1-8

9 Construction stage analysis 3D Analysis considering construction stages when constructing Open Cut Tunnel Stability during construction stages applying SIG placing method for reviewing the appropriateness and stability of foundation Construction Stages Stage2 Excavation Analysis Results Stage1 Original ground Stage3 SIG placing Y-dir. Displacement diagram Failure Diagram Section Stage4 Box Construction Vertical Stress Diagram Stage6 Additional Load Stage5 Banking Axial Force Diagram

10 Model from Training 1

11 Static to Sequential Excavations Open static model Terrain and strata w/tunnel 4 tunnel lining segments and rock bolts

12 Static Results for ground and support structures Total Ground Displacements Total Tunnel Displacements Axial forces on rock bolts Axial forces on lining 1-12

13 Show CS stages of model

14 Show CS stages of model The LDF keeps track of the Internal Forces of a deactivated element and loads it in stages according to the factor assigned for each construction stage, rather than loading it all at once.

15 Show CS stages of model The ground stress from the non-linear analysis results in the previous stage is coupled and slope stability analysis is conducted.

16 CS Analysis Case

17 Construction stage analysis Excavation 1 Excavation 2 Final Stage Excavation 1 Excavation 2 Final Stage

18 Wizards (Modeling Assistants)

19 Wizard Wizard for easy construction stages set up

20 Wizard Use CS wizard to efficiently define the construction stages. Remove and Activate sets in sequence. 1 2

21 Wizard

22 Wizard Stage Simulator Check the defined construction stage as a video. It can be used in analyses that incorporate construction stages (Static/Slope analysis, Seepage/Consolidation analysis).

23 Tunnel Wizard

24 Tunnel Wizard

25 Tunnel Wizard Input Mesh Size and soil properties.

26 Tunnel Wizard Results

27 Demo

28 3D tunnel connection

29 Post-Processing

30 Results Total Tunnel Displacements Mirror Image Total Ground Displacements

31 Results Iso- Volume- Max Displacements Stresses on lining Axial forces on lining

32 Results Material Status Plastic Status of Ground Element Safety Result (Mohr-Coulomb) Calculate Factor of Safety for each element based on MC failure criteria. In case that Safety Factor is less than 1.2, it can be identical with plastic failure region.

33 Results

34 Results

35 Results 3D-2D Wizard When checking the results after 3D analysis, use the cut section & clipping function to check the arbitrary section result contours. Multi-Stage Animation

36 Results Flight Simulation The Perspective view function from the View toolset below can be used to check the interior information and results of a 3D model.

37 Time History Probe

38 Results Dynamic Report Save the model information before analysis and the result information after analysis as a 3-dimensional PDF document. Adjusting the 3D view on the PDF document and checking the cross-section information, similar to the operations in the program, is possible. Hence, the 3D model/analysis result information can all be checked on one PDF document without the model/result files.

39 Conclusions Tunnels have wide range of analysis and excavation methods. FEM allows for more accurate representation of all local conditions and coupling of multiple types of analysis. 2D is advantageous when terrain is simple and tunnel segment is straight only. The 3D FEM allows for accurate simulation of terrain and sequential construction process. Modeling in 3D can be more time consuming and should be carried out after it was determined 2D model has hit limit.

40 Assignment 2

41 Tunnel Wizard Start File

42 Tunnel Wizard General

43 Tunnel Wizard Shotcrete and Rock Bolts

44 Tunnel Wizard Excavation

45 Tunnel Wizard Mesh

46 Tunnel Wizard Mesh

47 Tunnel Wizard Analysis Case

48 Tunnel Wizard Results

49 3D CS Tunnel Send to: Review for training 2: Post Processor & Wizards

50 Thanks! Integrated Solver Optimized for the next generation 64-bit platform Finite Element Solutions for Geotechnical Engineering