Laterally-Loaded Pile Foundation
Example Provided by: Christopher McGann, University of Washington
This article describes the OpenSees implementation of a simple laterally-loaded pile example. The problem is modeled as a beam on a nonlinear Winkler foundation (BNWF), utilizing displacement-based beam elements for the pile and nonlinear spring elements which represent the vertical and lateral response of the surrounding soil.
Provided with this article are the files needed to execute this analysis in OpenSees;
- the main input file, staticBNWFpile.tcl
- three procedures to define the soil constitutive behavior, get_pyParam.tcl, get_tzParam.tcl, and get_qzParam.tcl
- a file to define the pile section behavior, elasticSection.tcl
To run this example, the user must download each of the above files and place them in a single directory. Once this has been done, the user can then type "source staticBNWFpile.tcl" into the interpreter of the OpenSees.exe application to run the analysis. Representative results are presented in this article to verify the correct implementation of this example. Additionally, the pile response obtained from this analysis is compared to a similar analysis conducted using the commercial program LPile (http://www.ensoftinc.com) to provide verification the results of the OpenSees analysis.
Model Description
The centrifuge model geometry that we need to simulate is shown below. The model consists of two blocks of dense sand. On top of this lies a layer of loose liquefiable sand and on the top there are two facing slopes of Yolo Loam. The right hand side is treated with earthquake drains (PV-Drains) to accelerate the dissipation of excess pore pressure. An acceleration pattern is applied on the bottom of the model.