2004 OpenSees User Workshop. OpenSees. Geotechnical Capabilities and Applications. (U.C. San Diego) Roadmap

Transcription

1 P E E R 24 OpenSees User Workshop OpenSees Geotechnical Capabilities and Applications Ahmed Elgamal Jinchi Lu Zhaohui Yang Linjun Yan (U.C. San Diego) 1 Roadmap Soil materials and elements (manual and examples): -> Projects -> Geotechnical -> U.C. San Diego or OpenSeesTP (graphical user interface for SSI simulations with shallow foundation): For more information, please contact: Ahmed Elgamal Zhaohui Yang Jinchi Lu elgamal@ucsd.edu zhyang@ucsd.edu j3lu@ucsd.edu 2 1

2 Soil Materials and Elements in OpenSees ( 2D/3D solid-fluid fully coupled elements for simulating pore pressure generation/redistribution/dissipation (based on the u-p formulation of Zienkiewitz and Chan). 3D soil material models for simulating drained/undrained cyclic behavior, including liquefaction and liquefaction-induced permanent ground deformation. For user convenience, predefined soil material parameters are available for a wide range of soil types. We will constantly update these material parameters to incorporate latest research results. 3 Solid-Fluid Fully Coupled Elements Implemented in OpenSees ( Plane-strain elements 3D elements 4 2

3 Soil Material Model: Sand and Silt Multi-surface, non-associative plasticity model, incorporating soil dilatancy and liquefaction effects. 5 Soil Material: Clay and Silt Multi-surface, associative plasticity model. τ γ τ Failure surface P' 6 3

4 Soil Material: Undrained Model Coupled with sand/clay materials to simulate undrained soil response (e.g., soil below ground water table). 7 OpenSeesTP for shallow foundation simulation ( 8 4

5 OpenSeesTP Graphical User Interface: Model generation and simulation 9 OpenSeesTP Graphical User Interface: Visualizing simulation results 1 5

6 Sample Applications of Geotechnical Simulation Capabilities in SSI simulations 11 OpenSees Model of Humboldt Bay Bridge (UCSD) Prof. J. Conte, Prof. A. Elgamal, Mr. Y. Zhang, Mr. G. Acero, Dr. Z. Yang Water Table 12 6

7 Sand model response Soil Materials 2 1 Shear stress (kpa) Shear strain (%) Clay model response 6 4 Shear stress (kpa) Shear strain (%) 13 Concrete Piers (Conte, Acero, Zhang) Force-based nonlinear beam-column element with fiber cross section Stress Stress Stress Stress Strain Strain Concrete: Kent-Scott-Park Model Steel: Bilinear Model 12 x 14 1 x 15 Unconfined concrete Confined concrete 1 Moment [k-in] Moment (kips-in) Moment (kips-in) Reinforcing Steel Curvature (/in) x 1-3 Monotonic Pushover (Single Column on Fixed Base) x 1-3 Curvature (/in) Cyclic Pushover (Single Column on Fixed Base) 14 7

8 Precast, Prestressed Pile Groups (Conte, Acero, Zhang) OpenSees Model Response Nonlinear Fiber Beam-Column Element Unconfined concrete Confined concrete Reinforcing steel 15 Main Deformation Pattern: Settlement and Lateral Movement of Abutments 16 8

9 Observed Bridge Failure due to Abutment Deformation 17 Soil Shear Stress - Strain Response Soil Element 245 Soil Element Soil Element 1276 Soil Element Soil Element 315 Soil Element Soil Element 191 Soil Element 191 Shear Stress [kpa] Shear Stress [kpa] Shear Stress [kpa] Shear Stress [kpa] Shear Strain Shear Strain Shear Strain x Shear Strain x Shear Strain Shear Strain Shear Strain.5.1 Shear Strain 18 9

10 3D OpenSees Bridge Model 19 Defining Spatially Varying Ground Motion using Domain Reduction Method (Bielak et al. 23) Vertical wave 3 o Inclined wave 2 1

11 Defining Spatially Varying Ground Motion using Domain Reduction Method (Bielak et al. 23) Vertical wave 3 o Inclined wave 21 OpenSees Finite Element Simulation of Centrifuge SSI Tests (Boulanger, Wilson, Kutter, and Chang, 24) Free field soil (UCSD) Pile (UCB) p-y spring (UCD) 22 11

12 Computed and Recorded Responses of Soil Profile and Structure during a.49g Earthquake (Boulanger, Wilson, Kutter, and Chang, 24) 23 12