既有高边坡下深基坑支护设计与施工监测分析
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（1南华大学城建学院， 衡阳 421001； 2 湖南核工业岩土工程勘察设计研究院， 长沙 410001）［摘要］某既有高陡边坡下深基坑采用了桩锚支护结构，介绍了支护结构设计。在基坑支护结构施工和开挖过程中，对支护结构位移、锚索拉力以及周边建筑物沉降进行了监测，并结合施工工况对监测数据进行了分析。分析结果表明：基坑顶支护结构的水平位移受基坑旁既有高边坡的影响，其与边坡的高度、基坑顶上的荷载大小有关；锚索拉力突然出现先降后升的异常现象，是锚索失效的征兆；基坑周边房屋沉降与距基坑的距离有关，邻近基坑一侧沉降大，远侧沉降小。最后介绍了当基坑周边房屋沉降过大而成为危房时所采用的加固措施。［关键词］既有高边坡; 深基坑; 支护结构; 监测中图分类号：TU473 文献标识码：A 文章编号：1002-848X(2013)24-0068-04Supporting design and construction monitoring analysis of deep foundation pit under an existing high-steep slopeDai Wenkui1, Xiong Zhibiao1, Gong He1, Wang Renjie1, Song Shihao2(1 College of Urban Construction, University of South China, Hengyang 421001, China; 2 Institute of Nuclear Industry Geotechnical and Engineering Investigation Design and Research, Changsha 410001, China)Abstract: The pile-anchor supporting structure is applied in a deep foundation pit under an existing high-steep slope, and the design of the supporting structure was introduced. The displacement of the supporting structure, the tension of anchor rope, and the settlement of the surrounding buildings were monitored when the supporting structure of the excavation was being constructed and excavated. Combining construction state, the monitoring data was analyzed. The analysis results show that the horizontal displacement of the supporting structure at the top of the foundation pit is affected by the existing high-steep slope, its value is relative to height of the slope and the magnitude of load at the top of the foundation pit. It can be judged a symptom of the failure anchors that anchor cable tension suddenly appears abnormal phenomenon which decreases first and then increases. The settlement of the buildings surrounding the foundation pit is relative to the distance from the foundation pit, the settlement is large nearby the foundation pit and small far away from it. Reinforcement measures were introduced when the buildings surrounding the foundation become dangerous buildings due to too large settlement of the buildings.Keywords: existing high-steep slope; deep foundation pit; supporting structure; monitor作者简介：戴文奎, 硕士研究生， Email:554105720@qq.com。参考文献［1］孙凯，方宗新，苏魁聪. 高陡边坡下基坑边坡的稳定与变形控制设计［C］//中国岩石力学与工程学会第七次学术大会论文集.西安，2002：477-481.［2］熊智彪，王启云. 某复杂平面基坑支护结构水平位移监测及加固［J］. 岩土力学, 2009, 30(2)：572-576.［3］赵忠岩，石汉生，刘翔，等.南京联强国际大厦深基坑支护设计与监测［J］. 建筑结构, 2007，37(9)：115-117.［4］房师军，付拥军，姚爱军.某地铁工程深基坑排桩围护结构变形规律分析［J］. 岩土工程学报, 2011, 33(1)：216-219.［5］JGJ 125—99 危险房屋鉴定标准［S］.北京：中国建筑工业出版社，2000.
