水平旋喷技术在矿山法隧道下穿浅基础建筑物施工中的应用

摘要

在深圳地铁建设的全风化花岗片麻岩暗挖隧道施工中，常规施工方法极难控制，稍有不慎就会造成拱顶坍塌或者地面下沉，使得施工安全风险不断增大，同时也容易造成地面破坏。在深圳地铁某联络线区间段暗挖隧道施工中，由于采用了水平旋喷桩施工工艺，在暗挖隧道拱顶形成一个环状帷幕体，对原土体进行了改良，不仅克服了软弱围岩自稳性差的弱点，而且起到了抗变形、防流沙、防渗透的作用，成功地解决暗挖隧道在全风化花岗片麻岩层中近距离穿越浅基础建筑物的难题，充分显示了水平旋喷桩施工工艺在软弱地质条件下浅埋暗挖隧道开挖预支护工程应用上的优势。%During undermining completely decomposed granitic gneiss of Shenzhen Metro Project,controlling is quite diffi-cult by conventional method,and any carelessness may cause collapse or subsidence.It will increase risk and ground fail-ure.By using horizontal rotating jet grouting piles during the interval construction of a contact line for Shenzhen Metro Pro-ject,a ring curtain body mixed is formed in the tunnel vault.This kind of soil improvement technique not only overcomes the poor self-stability of the weak surrounding rocks,but also plays a role of anti-deformation,anti-quicksand,and anti-seepage,and then it successfully solves the problem of mined tunnel underpassing the existing buildings at close range in completely decomposed granitic gneiss,and fully illustrates its great efficiency of horizontal rotating jet grouting piles in weak geological condition of shallow buried tunnel excavation and pre-supporting engineering.