Project Behavior Of Disk Pile Under Repeated Loading

Disk pile is a new type pile developed in recent years. Comparing with the constant diameter pile, it has higher bearing capacity and lower settlement deformation. If it could be applied in various areas of Civil Engineering, that will gain good economic and social benefits. But as a new technology, the system and sophisticated theory about the disk pile has not been formed, which restricts the widely use of it. The article based on the existing research achievement, studies the bearing capacity, loading transfer behavior, stress distribution about the disk pile under vertical static load by model test and finite element analysis, especially studies the bearing mechanism and settlement of the pile under repeated loading.First, according to the dates of model test, make Q-S curve and axial force curve, which shows the better bearing capacity of the pile. Under the disk, axial force reduces drastically, that is to say the disk takes the more load, reduce the end resistance effectively. And because of the disk, the friction around the pile body will be affected in a certain extent up and down the disk, there will even be negative friction, which increase the axial force of pile body up the disk. Second, take repeated loading test, and compare the results of the tests in different soil and under different loads. It shows the higher bearing capacity and lower deformation of the pile and the deformation curve convergences sooner in silt with lower moisture than in clay with higher moisture. In the same soil, the deformation curve convergences sooner as the load smaller.In addition, take the comparison test under repeated loading and sustained loading. The result indicates that settlement of the pile under repeated loading is bigger than under sustained loading. And the settlement gap will be bigger as the load increase.At last, obtain the displacement and stress distribution fig of pile body and the soil around pile by finite element simulation. The displacement is ring distributed, and reduces gradually. The main pressure area is under disk and end of pile, the stress will reduce up the disk because of arches effect. Generally speaking, the simulation result and the model test are in agreement.