Why test pile should be used for spiral pile

　　At the construction site of spiral pile foundation, in order to ensure that the spiral pile may have high stability and reliability, before construction, it is necessary to select the parts that may represent the geological premise of the foundation, and screw in at most two spiral piles to stop the test. The goal of this is to check the plan through the test, so as to confirm the technical plan of pile driving and ensure the quality step 。

　　Through the test penetration, we may know the geological strength and the bearing capacity of the spiral ground pile. The stress of the test pile and the spiral ground pile should be close to each other to facilitate the accurate test of the penetration of the test pile. If the weak soil layer is very thick and the end of the spiral ground pile cannot reach the superior layer, we should consider the settlement of the pile foundation and other issues, and transfer the load to the next layer through the better soil layer The weak layer, on the contrary, increases the settlement of pile foundation.

　　In a word, the plan of spiral ground pile should pay attention to satisfying the two basic requirements of foundation bearing capacity and deformation. In engineering practice, because of the reasons of plan or construction, it is not uncommon for the different requests of spiral ground pile to become serious disorder. Therefore, it is necessary for the construction of spiral ground pile to do a good job in foundation exploration, make a serious choice of plan, plan and construction Principles to be followed.