Maximum Envelope of Lateral Resistance through Dynamic Increasing Energy Test in Piles

R.M. Valverde, F. Massad

Article

Soils and Rocks, São Paulo, 41(1): 75-88, January-April, 2018 | PDF


Abstract

The traditional dynamic load test, based on the one-dimensional wave propagation theory consists in applying a sequence of constant energy blows and making measurements using deformation and acceleration sensors installed on top of the pile, as a function of time. The traditional method has evolved with the development of a numerical model that simulates the Static Load Test (SLT) of a pile dynamically tested. Another evolution was the introduction of the Dynamic Increasing Energy Test (DIET) created and proposed by Aoki (1997). The present study is an initiative to deepen the increasing energy method focusing on the definition of the maximum lateral resistance envelope, allowing the recovery of the mobilized resistance along the shaft, lost in blows prior to the maximum applied energy, especially in layers close to the top of the pile. This procedure is called the Maximum Envelope of Lateral Resistance. Two case studies are presented, in which static and dynamic tests were performed on the same pile. The application of the Maximum Envelope of Lateral Resistance, also referred to as Maximum Envelope Method, led to a definition of higher load capacities through the CAPWAP analysis, with simulated load-displacement curves with good correlations in comparison with the Static Load Tests (SLT). When performed after several rest periods, the Maximum Envelope Method allows an assessment of the “setup” development over time.


Submitted on September 26, 2017; Final Acceptance on March 21, 2018; Discussion open until August 31, 2018. DOI: 10.28927/SR.411075