Theory And Practice Of No-Root-Pile In Foundation Pit Supporting

Along with the reform and open policy spring breeze, high-rise buildings have sprung up in great river north and south of China, the development and utilization of underground space makes the deep foundation pit engineering also gradually come into the mind of the engineer.Foundation pit supporting method has got unprecedented development, economy and safety become a beacon of foundation pit supporting design.No-Root-Pile is put forward by professor Mr.Jia in2002,during cast-in-place pile in the rock foundation pit, sometimes because of the above part of the rock and the pit bottom rock is hard, under construction machinery to or affected by the economic benefits, which lead to deep foundation pit at the bottom of the pile,then form no root pile. Because of no root, the stability of the supporting structure is greatly reduced, and easy to cause the pile engineering accidents occurring topple. As a result, when the pile into the hole to stop after hard formation drilling, To the small diameter of pore forming equipment (such as rock anchor rod drilling machine) can be in the pile bottom is very convenient for small diameter into a hole, then put in the hole of steel reinforcement and pouring concrete with fine stones will no root pile anchor into hard rock, which can greatly improve the stability of the retaining piles and the shear capacity, the formation of the real No-Root-Pile.In this paper, No-root-pile basic structure and construction method has carried on the detailed introduction, analysis of the advantages of no arm guard piles and the applicable scope, and limitations of no root arm guard piles is discussed.Through introducing the design theory of No-root-pile, plus dalian some living engineering example of calculation, prove that No-Root-Pile reliability in theory and in practice is feasible.Finally, using the finite element analysis software of ABAQUS combined with related engineering example, the application of No-Root-Pile foundation has carried on the simple numerical simulation, analyzed the foundation pit when using No-Root-Pile and ordinary reinforced concrete pile in both cases the horizontal displacement and vertical displacement.Prove the feasibility of No-Root-Pile in theory, No-Root-Pile design provides a theoretical reference.