钻孔灌注桩因其承载力高、施工干扰小、技术成熟等优点被广泛用于各类建筑工程中。本文探讨的是钻孔灌注桩中的一个特例,即在深孔(50 m以上)、砂层(土体中含粘粒在3%以下),且深基坑中进行钻孔灌注桩的施工。通过对该工程实例的分析,来说明这类灌注桩施工应特别注意的问题。1工程概况工程是位于江苏省昆山市内的一座桥梁,全桥共5个墩台,均采用钻孔灌注桩施工,其中,2号、3 Bored piles are widely used in various construction projects due to their high bearing capacity, small construction interference and mature technology. This article discusses a special case of bored piles, that is, in the deep hole (50 m above), the sand layer (containing clay in the soil below 3%), and the construction of bored piles in deep excavation . Through the analysis of the project example to illustrate the construction of such bored pile should pay particular attention to the problem. 1 Project Overview Project is located in Kunshan City, Jiangsu Province, a bridge, the bridge a total of five piers, are used bored pile construction, of which 2, 3