复杂平面基坑支护结构失稳原因与加固技术.pdfVIP

第4卷 第3期 地下空间与工程学报 V01．4 2008年6月 Chinese Journal of Underground Space and Engineering Jan．2008 复杂平面基坑支护结构失稳原因与加固技术 熊智彪 ，王启云 (南华大学城市建设学院，湖南衡阳 421001) 摘 要：衡阳某大型商城基坑平面形状复杂，支护结构采用桩锚体系。在基坑开挖后出现 了支护结构顶部水平位移监测结果超过了报警值且持续增加的情况，施工在没有进行深入分 析的基础上采用了增加预应力锚杆和局部反压的措施，没有有效控制支护结构的水平位移，支 护结构出现失稳现象。文章介绍了该基坑基本情况以及水平位移监测成果，着重分析了失稳 发生的机理，考虑周边环境的变化采用弹性支点法对支护结构进行了复核计算，在此基础上提 出了卸栽、砖墙填土反压等加固措施，取得了良好效果。 关键词：基坑支护；水平位移；弹性支点法；加固技术 中图分类号：TU753．1 文献标识码：A 文章编号：1673-0836(20o8)03-0504-04 The Cause of Instability and Reinforcing Measures of Retaining System for Complicated Planar Foundation Pit X10NG Zhi—biao。WANG Qi—yun (Urban Construction College，South China University，ttengyang 421001，China) Abstra~：A Pile·ancbor is applied as the support system for the foundation pit of a large·-scale commercial building in HengYang．After excavation-the horizontal displacement monitoring results show that the pile’S top de— formation of retaining structure exceeds the warning value and continue increase in the process of excavation．The pre— stressed anchor bolt and earth berm were added in local area without deep consideration and the displacement Was not controlled effectively and the retaining structure is in a dangerous state．This paper introduces the foundation pit and horizontal displacement monitoring results，stresses on analysis of mechanism for instability and a check is carried out on retaining structure by elastic subgrade method in view of changes in surroundings around foundation pit．This paper presents some reinforcing measure based on analysis-for example，unloading and brick masonry wall witll earth berm， and good effect has been