钻孔咬合桩在软土深基坑围护施工中遇到的难题分析

全套管钻孔咬合桩即贝诺特(Benoto)灌注桩工法，是一种成熟的围护施工技术，在国内已经多次使用，但在南京地区长江漫滩淤泥质粉质粘土和饱和粉细砂层中施工尚属首次，由于地质条件等原因，实际施工时遇到了涌砂、超灌和拔桩等问题。介绍了南京地铁某车站钻孔咬合桩围护结构的施工情况，对在施工中遇到的具体技术难题和处理措施进行了总结。

Difficulties of Enclosure Construction in Soft Clay Deep Foundation Pit for Lock-joint Pile

Drilling lock-joint pile of full casing, i. e. Benoto cast-in-place pile method, is a kind of maturate enclosure construction technology, and put into use many times at home, but the first time in the construction in muddy and siltclay and fine sand layers of river beach in Nanjing. Because of the local geological conditions, sand pouring, over-placing and pile-drawing occurred during construction. The similar construction in a certain subway station is presented in the text, and the technical difficulties met in the course of the construction and their treatment are summarized by the author in the text. The experience can be served for reference to the projects of similar circumstances.