圆砾地层地下连续墙成槽工法与施工接头技术

Trenching Technology and Construction Joint Technology of the Diaphragm Wall in the Round Gravel Stratum

本文总结分析了圆砾地层这一南宁地区常见地层的特殊的工程特性,圆砾层性质介于砂土与岩石之间,透水性极强且一般存在高承压水,因此基坑围护结构的防渗性能对基坑安全起到至关重要的作用,并分析了地下连续墙在圆砾地层中的适用性,采用地下连续墙不仅能满足受力需求且有效提高了圆砾地层基坑围护结构的止水性能。进一步针对圆砾层中地下连续墙施工中存在的主要问题进行了适用性研究,经过对各种成槽工法和施工接头优缺点分析,结合圆砾层的工程特点,提出了圆砾层中地下连续墙宜采用钻抓结合的成槽工法以及H型钢或十字钢板的施工接头技术。

This essay sums up the special engineering characteristics of the round gravel stratum which is common in Nanning district. Its property is between those of sandy soil and rock. The high permeability and the presence of high pressure water make seepage performance the key role for safety of retaining structure. The applicability of the diaphragm wall in the round gravel stratum is also analyzed. Using diaphragm wall can meet the demand of load requirement and sealing requirement. Then,considering the trenching and construction joint which are the important problems,it studies the applicability further. Through analyzing the merits and demerits of the kinds of trenching technologies and the construction joint technologies and in the light of the engineering characteristics of the round gravel stratum,it advances the trenching technologies with combination of drilling and grabing and the H shaped steel or cross plate construction joint technologies of the diaphragm wall in the round gravel stratum.