Continuous Flight Auger Pile Bridge Foundations (Phase II): Technical Report

摘要

This report discusses the behavior of augered cast-in-place (ACIP) piles in very dense sand and hard clay. Full-scale load testing was conducted on instrumented ACIP piles that were designed to support highway bridges on Texas SH7 at East Cochino Bayou (ECB) and Cochino Bayou (CB) with a design capacity of 92 tons and 128 tons, respectively. Construction quality control techniques for ACIP piles were reviewed and the installations of two piles were monitored and evaluated. Load tests were performed on ACIP piles that measured 30 in. diameter and 33.1 feet (ECB) and 39.1 feet (CB) in length to verify design capacity. Each pile was loaded over 350% of its design load. The loading frame was supported on eight reaction piles with a diameter of 18 inches. The test pile was instrumented using load cell and axial vibrating wire strain gages at four levels and lateral vibrating wire strain gages at two levels. The reaction pile was instrumented using vibrating wire strain gages at three levels. The load-settlement and load-transfer relationships of the piles were investigated based on the load test. The long-term behavior of six service piles was studied for more than a year. Load on the service piles was 70 tons for ECB and 60 to 86 tons for the CB piles after 600 days.