2010年7月 施工技术 第39卷第7期 CONSTRUCTION TECHNOLOGY 99 天津市土地交易市场工程防空洞拆除施工新技术 焦文秀,张俊红,班永表 (天津市地质基工程公司,天津300191) [摘要]为实现天津市土地交易市场工程桩基础施工和基坑支护方案,需要将原办公大楼北侧历史遗留的防空润 拆除.拆除防空洞过程中,果用水泥土高压旋喷桩进行止水,在高压旋喷桩体内插无缝钢管,在体外内插工字钢进 行挡土的施工方法,保护原有建筑天然地基安全.通过监测发现原有建筑最大沉降为24.8mm 不影响结构安全. .[关键词]基坑支护;防空润;拆除;支护 [中图分类号]TU746.5 【文献标识码]A [文章编号]1002-8498(2010)07-0099-03 New Construction Technology on Demolishing the Air-raid Shelter of Tianjin Land Exchange Center Jiao Wenxiu Zhang Junhong Ban Yongbiao (Tianjin Geological Foundation Engineering Company Tianjin 300191 China) Abstract:In order to achieve construction of pile foundation and excavation foundation support program of Tianjin Land Exchange Center project it's necessary to demolish the air-raid shelter at the north side of the existing office building.During demolishing cement soil high pressure jet grouting piles are used as water seal measure these piles with internal seamless steel tube and outer I-steel are used as earth- retaining measure which can protect nature basement safety of the existing building.By on-site monitoring the maximum settlement of the existing building is about 24.8mm to have no influence on structure safety. Key words:excavation support;air-raid shelter;demolishing;support 天津市建筑工程基坑支护多采用水泥土搅拌桩对撑的形式,支撑桩采用灌注桩内插钢格构柱的形式, 钢筋混凝土藩注桩即排桩.该方法工艺成熟、经济合布2道支撑.靠近老楼一侧另布置密排800mm灌注 理,应用较广泛.对于超深基坑也采用地下连接墙桩78根,防止地下连续墙施工时原有办公楼侧向位移 高压旋喷桩(封堵槽段接头缝隙)的方法.但支护方及减少开挖时地下连续墙的变形.基坑支护排桩、地 法的选择除根据建筑物本身特点外,还须考虑建筑物 下连续墙轴线与原有办公楼的位置关系如图1所示. 周边环境的客观条件影响.往往每个工程都有自...