An Innovative Method of Load Testing Deep Foundations

摘要

Current procedures for high strain dynamic testing of piles require estimation of the dynamic resistance. This paper presents an innovative method of load testing deep foundations that estimates the pile capacity directly. By placing and monitoring sensitive force sensors near a pile head, a force-time curve can be generated when an impact load is applied. The unique stages of the impact event are captured in a force-time plot from which the ultimate pile capacity is estimated directly. Similar sensors can be placed at the pile toe to estimate end bearing. Ancillary equipment, consisting of the same force sensors sandwiched between two thin plywood boards, can be placed on top of production piles during driving for capacity estimates. Pile capacities derived have been found to be in reasonably good agreement with values from two static load tests. It also provides information on pile integrity during driving.