The Analysis of Instrumented Piles Under Lateral Load

For a large pile foundation in China, four 1.0 m diameter 15 m long reinforced concrete bored piles are laterally jacked to their ultimate condition. The lateral deflections and bending moments of the piles under different horizontal loads as well as the failure pattern at 'Ground' level are measured. The moment distribution, the maximum moment and its location determined from several Winkler's models are compared with the in-situ measurements. Based on the full-scale measurements, the lateral stress-strain relationship for the soil is back-calculated. It is found that no single set of parameters is applicable to every load level if a simple stress-strain relationship is adopted. 3D finite element analysis was also performed for the test piles, and the predictions of the deflections and moments by 3D finite element analysis are found to be only slightly better than those of the simple Winkler's models. The failure pattern at Ground level predicted by 3D finite element analysis is basically similar to the failure mechanism as measured on site.