某坡前悬臂式支挡基坑开挖失稳案例分析
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摘要
对边坡前悬臂式支挡的基坑土体开挖导致的坡体和基坑坑壁失稳过程进行分析,建立滑坡体理论计算模型,通过理论计算分析基坑支挡结构受力状态,导出基坑开挖深度与基坑支护结构极限状态关系的公式,得出基坑支护结构失稳破坏的理论开挖深度为21. 45 m。综合滑坡后的现场勘查数据资料,此次基坑支护结构失稳的主要原因为滑体内部地下水的渗流作用以及实际滑动范围在抗滑桩后更远处产生的滑坡推力远大于两级支挡间的滑坡推力。
The instability process of slope and foundation pit wall caused by excavation of foundation pit soil with cantilever retaining in front of slope is analyzed. Based on the theoretical calculation model of landslide body,the stress state of foundation pit retaining structure is analyzed through theoretical calculation,and the formula of the relationship between the excavation depth of foundation pit and the ultimate state of foundation pit supporting structure is derived. The theoretical excavation depth of instability failure of foundation pit supporting structure is obtained to be 21. 45 m. Based on the field survey data after the landslide,the main reasons for the instability of the foundation pit support structure are the seepage of groundwater inside the sliding body and the fact that the actual sliding range is further behind the anti-slide pile,and the landslide thrust generated is far greater than that between the two levels of support.
The instability process of slope and foundation pit wall caused by excavation of foundation pit soil with cantilever retaining in front of slope is analyzed. Based on the theoretical calculation model of landslide body,the stress state of foundation pit retaining structure is analyzed through theoretical calculation,and the formula of the relationship between the excavation depth of foundation pit and the ultimate state of foundation pit supporting structure is derived. The theoretical excavation depth of instability failure of foundation pit supporting structure is obtained to be 21. 45 m. Based on the field survey data after the landslide,the main reasons for the instability of the foundation pit support structure are the seepage of groundwater inside the sliding body and the fact that the actual sliding range is further behind the anti-slide pile,and the landslide thrust generated is far greater than that between the two levels of support.
引文
[1]GB 50007-2011,建筑地基基础设计规范[S].
[2]JG 120-2012,建筑基坑支护技术规程[S].
[3]戴自航.抗滑桩滑坡推力和桩前滑体抗力分布规律的研究[J].岩石力学与工程学报,2002,21(4):517-521.
[4]安宏科.湿陷性黄土场地大型深基坑预应力锚杆与土钉联合支护结构失稳分析与研究[D].兰州:兰州交通大学硕士论文,2015.
[5]王晓峰,王铁行.考虑降雨入渗的黄土边坡稳定性分析[A].中国土木工程学会第九届土力学及岩土工程学术会议论文集[C].2003:995-997.
[6]边亦海.不同开挖深度下深基坑工程事故统计分析[J].地下空间与工程学报,2008,4(7):1378-1381.
[7]王念秦.黄土滑坡发育规律及其防治措施研究[D].成都:成都理工大学,2004.
[8]徐邦栋.滑坡分析与防治[M].北京:中国铁道出版社,2001.
[9]杨光华.深基坑支护结构的实用计算方法及其应用[M].北京:地质出版社,2004.
[2]JG 120-2012,建筑基坑支护技术规程[S].
[3]戴自航.抗滑桩滑坡推力和桩前滑体抗力分布规律的研究[J].岩石力学与工程学报,2002,21(4):517-521.
[4]安宏科.湿陷性黄土场地大型深基坑预应力锚杆与土钉联合支护结构失稳分析与研究[D].兰州:兰州交通大学硕士论文,2015.
[5]王晓峰,王铁行.考虑降雨入渗的黄土边坡稳定性分析[A].中国土木工程学会第九届土力学及岩土工程学术会议论文集[C].2003:995-997.
[6]边亦海.不同开挖深度下深基坑工程事故统计分析[J].地下空间与工程学报,2008,4(7):1378-1381.
[7]王念秦.黄土滑坡发育规律及其防治措施研究[D].成都:成都理工大学,2004.
[8]徐邦栋.滑坡分析与防治[M].北京:中国铁道出版社,2001.
[9]杨光华.深基坑支护结构的实用计算方法及其应用[M].北京:地质出版社,2004.