Why do spiral ground piles need to be tested before construction?

At the construction site of the spiral pile foundation, in order to ensure that the spiral pile can have a high degree of stability and reliability, it is necessary to choose a part that can represent the geological premise of the foundation before construction, and at most two spiral piles are screwed in to stop the test. The main goal of this is to check the plan through tests to confirm the piling skills plan and ensure quality steps.
Through the penetration of the test, it is possible to understand the strength of the geology and the bearing capacity of the spiral pile. The stress diagram of the test pile and the spiral pile are close, so as to accurately test the penetration of the test pile. If it is weak The soil layer is very thick, and the pile end of the spiral pile cannot reach the superior stratum. The settlement of the pile foundation should be considered. The load is transmitted to the weak layer underneath through the better soil layer, which will increase the settlement of the pile foundation.
In short, the spiral pile plan should pay attention to the two fundamental requirements of satisfying the foundation bearing capacity and deformation. In engineering practice, it is not uncommon for the spiral pile to diverge from the request due to planning or construction reasons, or even to become a serious disorder. Therefore, doing a good job of foundation exploration, solemnly choosing a plan, careful planning, and careful construction are also principles that must be observed in the construction of spiral pile projects.