大口径钻孔灌注桩的孔壁稳定研究分析

从钻孔灌注桩钻孔过程来看,由于地层土压力、孔隙水压力、地下水位及土体的蠕变等因素的影响,在成孔过程中或混凝土浇筑之前,孔壁处于不稳定状态之中,随时会出现滑裂或坍塌的危险。结合重阳大桥钻孔灌注桩工程,在分析孔壁稳定条件的基础上,进行不同土层的钻孔孔壁稳定性分析,同时分析孔内泥浆的稳定护壁作用及功能,建立孔壁稳定性数学分析模型,提出相应的护壁措施,防止孔壁的坍塌。

Analysis on the Stability of Hole Wall of Large Diameter Bored Pile

Viewed from the process of drilling cast-in-place piles,because of the influence of ground soil pressure,pore water pressure,underground water level,soil creep and so on,the hole walls of bored pile is not stable during the drilling process or before casting concrete under water.It may occur slip crack or collapse at any time.According to the foundation project of Chongyang bridge,the stability of hole wall of pile to different soil layers was analyzed on the analysis of condition of hole wall stability,at the same time the protection and function of the slurry to the hole wall stability was analyzed.The mathematic analysis model of the stability of hole walls was established.the measurement to protect the stability of hole wall from collapse was proposed.