Influence of degree of saturation in the dynamic stress transmission to a deep foundation

¹ LabUnsat, Civil Engineering Department, University of Costa Rica, Costa Rica
² Construction Engineering, Costa Rica Institute of Technology, Costa Rica

^* Corresponding author: rafael.baltodanogoulding@ucr.ac.cr

Abstract

The structural design of deep foundations depends on both the applied loads and the soil that will support them. However, during an earthquake this process reverses, and the seismic stresses are transmitted towards the structure through the soil. Proper design of deep foundations must account for the lateral loads imposed on the foundations by the dynamic loading. In order to assess the influence of soil saturation in the transmission of a dynamic load to a foundation, a dynamic lateral load pile design was performed using Reese’s p-y curve method. A series of suction-controlled dynamic triaxial tests were performed to obtain the Modulus of subgrade reaction at different matric suctions and seismic coefficients were back-calculated to perform structural designs. In general terms, it was observed that contemplating a saturated soil in the dynamic lateral load pile design does not represent the critical load case for seismic analysis.