GTS NX INTERFACES AUTOCAD MIDAS GEN FOR TUNNEL SOIL PILE INTERACTION ANALYSIS

Transcription

1 INTERFACES AUTOCAD MIDAS GEN FOR TUNNEL SOIL PILE INTERACTION ANALYSIS Angel F. Martinez Civil Engineer MIDASOFT Integrated Solver Optimized for the next generation 64-bit platform Finite Element Solutions for Geotechnical Engineering

2 Procedure This tutorial identifies the soil structure interaction by analyzing construction stage of 3D tunnel excavation and comparing differential settlement of adjacent building. Part 1: 3D Terrain Generation How to import DXF files and excel ta bles to make accurate 3D terrain. Excel Part 2: Tunnel Collapse Analysis Import 3D solid tunnel and loads for tunnel failure analysis. Part 3: Soil Pile Tunnel Interaction Import MXT files of a building from midas GEN to analyze the differential settlement during the excavation of a tunnel.

3 Training Course Part 1 3D Terrain Generation Import Topographic DXF file and combine with bore hole strata information 3

4 Export DXF from AUTOCAD 1. Set coordinates to origin (0,0,0) 2. All Polylines 3. Save as DXF 4

5 Import Terrain DXF 1. Set model to 3D 2. Import DXF 3D 3. Select Boring DXF file 5

6 Import Strata Data 1. Geometry > Bedding Plane 2. Import Excel data 3. Set dimensions X:200 Y:200 6

7 Import Topography 1. Import DXF file 2. Select all layers 3. Select all contours, set Zone 4. Export.tms file 7

8 Create 3D Terrain Geometry 1. Import terrain.tms file 2. Create 3D box 3. Divide box by 2D planes 8

9 Export 3D Terrain to AUTOCAD 1. Export CAD file as Parasolid 2. Import to Autocad for modification 3. Export CAD after changes Training Course 9

10 Training Course Part 2 Tunnel Collapse Analysis

11 Import tunnel CAD 1. Options > Import > Unit > mm 2. Import SAT file 3. Measure dimensions

12 Import terrain CAD 1. Options > Import > Unit > m 2. Import X_T file 3. Check tunnel and terrain

13 Move Tunnel CAD 1. Geometry Translate 2. Move tunnel 30 m down 3. Preview. Apply

14 Create 2D face 1. Move Work Plane 2. Select 3 points of left face 3. Draw Face over tunnel

15 Copy 2D face 1. Geometry > Translate 2. Copy face to opposite parallel face of terrain 3. Preview. Apply

16 Divide tunnel by faces 1. Geometry > Divide > Solid 2. Divide tunnel by 2 faces 3. Delete extra tunnel sections

17 Connect geometries 1. Geometry > Surface & Solid > Auto Connect 2. Method Boolean > Select All 3. Geometry > Tools > Check Duplicates

18 Import Materials 1. Import Property from part 2 file 2. Inspect Materials Tunnel Concrete Max Yield Stress 7500kN/m^2 18

19 Mesh structures 1. Mesh > Generate > 3D 2. Mesh Raft Size: 5m Property: Concrete 3. Mesh Tunnel Size: 1m Property: Concrete 19

20 Mesh soil layers 1. Mesh Top Soil Layer Size: 10m Property: Top Soil 2. Mesh 2nd Soil Layer Size: 10m Property: Mid Soil 3. Mesh 3 rd Soil Layer Size: 10m Property: Bot Soil 4. Mesh 4 th Soil Layer Size: 10m Property: Soft Rock 20

21 Apply boundary 1. Static / Slope Analysis > Boundary > Constraint 2. Auto > Apply 21

22 Import building loads from excel 1. Static / Slope Analysis > Load 2. Apply Gravity 3. Import point loads from excel table 22

23 Create Analysis Case 1. Analysis Case > General 2. Type: Nonlinear static Activate all except excavations 3. Analysis Control > Activate options as shown 23

24 Inspect results 1. Results > Displacement > Total Translation Use Clipping Plane 2. Deactivate all sets except tunnels 24

25 Inspect results 1. Results > Solid Stresses > S- Von Mises Shows Critical State of Tunnel Walls (Yield Stresses) 2. Results > Solid Stresses > Plastic Status Shows material that had plastic failure 25

26 Training Course Part 3 Soil Pile Tunnel Interaction

27 Import building from midas GEN 1. Export structure from MIDAS Gen (MXT text file). 2. Import building into 27

28 Import terrain geometry 1. Import CAD of terrain 2. Use imprint command on building footing for mesh connection with raft. 28

29 Import materials 1. Import Property from Steel Structure with soil and tunnel final 2. Inspect Materials 29

30 Mesh structures 1. Mesh > Generate > 3D 2. Mesh raft Size: 10m Property: Raft 3. Mesh Tunnel Excavations Size: 5m Property Mid Soil

31 Mesh soil layers 1. Mesh Top Soil Layer Size: 10m Property: Top Soil 2. Mesh 2nd Soil Layer Size: 10m Property: Mid Soil 3. Mesh 3 rd Soil Layer Size: 10m Property: Bot Soil 4. Mesh 4 th Soil Layer Size: 10m Property: Soft Rock 31

32 Extract tunnel walls 1. Mesh > Element > Extract 2. Select Tunnel Excavation geometries Activate: Skip Duplicate Faces Register Based on Owner 32

33 Mesh piles 1. Mesh > Generate > 1D > Pile 2. Mesh > Element > Pile Interface & Pile Tip 33

34 Apply boundary conditions 1. Static / Slope Analysis > Boundary > Constraint >Auto > Apply 2. Advance > Rz Restrict rotation in Z axis of piles for stability 34

35 Create Construction Stages 1. Static / Slope Analysis > Construction Stage > Stage Set 2. Stress > Add > Define CS 3. Stage 1: Initial Activate only Soil Layers, gravity and BC - Clear Displacements Save > New 35

36 Create Construction Stages 1. Stage 2: Foundation Activate foundation and building sets and BC Save > New 36

37 Create Construction Stages 1. Stage 3: Exca 1 Deactivate Tunnel Excavation 1 Save > New 2. Stage 4: Exca 2 Activate Tunnel Wall 1 Deactivate Tunnel Excavation 2 Save > New 37

38 Create Construction Stages 1. Stage 5: Exca 3 Activate Tunnel Wall 2 Deactivate Tunnel Excavation 3 Save > New 2. Stage 6: Exca 4 Activate Tunnel Wall 3 Deactivate Tunnel Excavation 4 Save > New 38

39 Create Construction Stages 1. Stage 7: Exca 5 Activate Tunnel Wall 4 Deactivate Tunnel Excavation 5 Save > New 2. Stage 8: Exca 6 Activate Tunnel Wall 5&6 Deactivate Tunnel Excavation 6 Save > Close 39

40 Create Construction Stages 1. Make Copy of Stage Set. Change name to No Piles > Define CS 2. Go to stage 2, modify case by removing piles Save > Close 40

41 Create Analysis Cases 1. Make Analysis Case for Construction Set with Piles 2. Make Analysis Case for Construction Set No Piles 3. Click Analysis Control Set up as shown for both. 41

42 Run Analysis 1. Perform Analysis on both cases. 42

43 Inspect Results 1. Check Total Translation for case with No Piles 2. Compare to Case with Piles 3. Use Clipping Plane to see tunnel better 43

44 Inspect Results Deactivate all mesh sets except building and raft 1. Check Total Translation for case with No Piles 2. Compare to Case with Piles 3. Use Probe to get table values of building nodes 44

45 Inspect Results 1. Check Axial Forces for Case with Piles 2. Check Moments Y 3. Check Shear Forces Z 45

46 Export Results 1. Results > Advanced > Extract Select Piles Analysis Case Select Displacements > Total Translation Select top corner node of building #615 Click TABLE Repeat for No Piles Analysis Case 2. Select columns and Export to Excel to Graph results 46

47 END 47