Bi-directional Load Cell Testing of 1.5-Metre Diameter Bored Concrete Piles within Surficial Deposits Near the Darling Scarp: Insights from the METRONET, Byford Rail Extension Project in Perth

This paper presents the results of bi-directional load cell testing conducted on two pre-production 1.5-meter diameter bored concrete piles as part of the METRONET Byford Rail Extension project in Perth. The testing aimed to assess the geotechnical capacity, load–displacement response, and shaft friction parameters of the piles within surficial deposits near the Darling Scarp. The information obtained from the pre-production testing has been valuable in supporting the foundation design of a 46-span rail viaduct structure, which will comprise a total of 131 1.8-meter diameter piles. Bi-directional load cell testing involves the installation of load cells within piles, allowing for the direct measurement of load distribution along the pile length and determination of its ultimate pile capacity. The load–displacement response obtained through the testing provides insights into the pile-soil interaction and facilitates the establishment of shaft friction parameters. In Perth, bi-directional load cell testing of large diameter piles is not yet common practice. Increased utilization of bi-directional load cell testing in large diameter pre-production piles may provide economic value to future projects. The insights gained from the testing enhance the accuracy of shaft friction design parameters and contribute to improved safety in design, ensuring reliable and cost-effective foundation solutions. The successful application of bi-directional load cell testing in this study emphasizes its potential as a valuable tool for geotechnical engineering practices in Perth and beyond.