Evaluation of Existing p-y Models for Caliche Based on Numerical Analysis of Raiders Stadium Lateral Load Tests

Numerical lateral load analysis based on the beam on Winkler foundation (BNWF) model (i.e., the p-y
method) is a simple, and widely used tool to predict lateral responses of drilled shafts from field load
tests. The lack of a site-specific p-y model for cemented soil layers such as caliche is one of the major
limitations of simulating lateral load tests conducted in Las Vegas Valley. In this study, some of the
existing p-y models for rock materials, such as Florida Limestone and Vuggy Limestone have been
evaluated to simulate the lateral resistance of caliche. This has been done in the context of four lateral
load tests in caliche-dominant sites from the recently constructed Raiders Stadium project in Las Vegas
(NV). The uncertainty in characterizing the material properties of caliche has been addressed. The p-y
analyses were performed using NVShaft, a MATLAB-based, comprehensive load analysis program. The
applicability of the considered p-y models for caliche material was evaluated by quantifying the
normalized error margins between measured and predicted lateral responses from the simulations of the
mentioned load tests. Correlations between such errors and the depth and thickness of caliche in soil
layers affecting numerical predictions were established, for both up to and beyond design load levels.