Design verification of driven piles in soft ground using maintain load test and high strain dynamic load test

Abstract

In Malaysia, piling activities are very active due to the numerous development projects that are on-going now. Types of piles used for these development projects can broadly be divided into displacement and replacement piles. Given many uncertainties inherent in the design and construction of piles, it is difficult to predict the performance of a pile. In order to mitigate and prevent such occurrence, a comprehensive pile-testing program must be conducted. Load testing can be carried out on preliminary piles to confirm the pile data and design. Although pile load tests add to the cost of foundation, the saving can be substantial in the event that the improvement of the foundation design can be materialized. Pile test can be generally be divided into three (3) main categories, which are Static Load Test such as Maintain Load Test, Dynamic Load Test such as High Strain Dynamic Load Test and Statnamic Load Test which is the combination of the latter. For pile foundation projects, it is usually necessary to confirm the capacity and to verify the behavior of the piles agrees with the assumptions of the design. The foundations design requires a good knowledge of the soil behavior, the methods of pile testing and the analysis of piles used. In this study, the methods employed for Maintain Load Test are such as Davisson’s Method, Chin’s Method, Mazurkiewicz’s Method and De Beer’s Method. Meanwhile, CAPWAP analysis is employed for High Strain Dynamic Load Test. Based from the comparison it was found that De Beer’s Method provide best capability to predict ultimate pile capacity. From the CAPWAP analysis, it shows that the mobilised capacity is approximately 30% to 60% higher than the ultimate pile capacity from Maintain Load Test