AN ALTERNATIVE SOLUTION FOR LARGE LOAD PILE FOUNDATIONS-DX PILES

The DX pile is a newly developed variable cross-section pile which has multi bells on the shaft. After 10-year applications, DX pile has been applied to many projects covered varied fields. Many researches have been conducted on both bearing mechanism and load transfer mechanism, and some cheerful results are achieved. This paper mainly reviews the previous studies on DX pile and then illustrates the characteristics of DX pile based on load test of a bridge foundation piles. The details of this test including the site geology, soil properties, pile design and load test are provided. Then, according to the test results, the developments of the total capacity, settlement and bell capacity are analyzed and discussed. In this case, compared with conventional straight bored pile, DX pile increases the load capacity significantly and reduces the settlement. When the load capacity of 15400kN is reached, the settlements of two DX piles are only about 30% of straight pile. The bells on the pile shaft begin to perform at an early stage, and share about 35% of the total load capacity. As a result, it can be concluded that DX piles is an alternative way of large load pile foundations, which has profound meaning on future projects.