Instrumented Pile Load Test: Analysing Measurement Anomaly at the Pile Head

Abstract

Loading activity during Distributed Optical Fibre Strain Sensor (DOFS) instrumented pile load test prevails the strain disparity within the pile’s initial depth and converges at a certain depth. This work aims to determine the strain convergence (SC) depth: investigate the influence factor of the SC and propose a standard empirical model for SC depth determination. The strain profile variation at any point within the pile diameter is examined using PLAXIS 2D. A set of test cases are simulated starting with defining influence factors of SC depth and further analysis of the cogent factor. The proposed model is validated to a few real field projects. This work is significant to determine the real start (RS) depth of the plotted strain profile and will improve data processing for the pile load transfer analysis of the DOFS instrumented pile load test. The cogent factor that influences the SC depth is the jack area coverage to pile area and an empirical model is proposed to determine the SC depth. The model is validated to a few real field projects with nominal differences of SC by the model to the field measured at ±0.05 sensitivity, comply the model goodness of fit at 0.9492 (R-square).