Application of drilled screw piles in Shanghai soft soils

The applicability of drilled screw pile in Shanghai soft soils is proved by the Expo Village (Block Ⅰ) project. Firstly, two design schemes, i.e., traditional drilled pile and drilled screw pile, are put forward according to the existing construction conditions. The bearing capacities of the two types of piles are predicted using the existing calculation methods. The predicted results show that the ultimate capacity of the drilled screw pile is 1.47 times larger than that of the traditional drilled pile. Then low-strain dynamic tests and static load tests are conducted on this type of pile. The result of the low-strain dynamic tests shows that the pile quality of the drilled screw pile is very reliable in Shanghai soft soils. The results of the static load tests demonstrate that the designed drilled screw pile has a high bearing capacity which is close to the predicted value, and the accuracy of the proposed method is validated. Finally by the scheme comparison, the drilled screw pile is chosen as the engineering pile of this project, and its application effect is good.