（1 天津城建学院土木工程系，天津 300384； 2 中铁一局天津公司，天津 300250）

［摘要］超深基坑在逆作法开挖过程中立柱的受力和变形异常复杂，而立柱之间的差异竖向位移过大会对作为永久结构的水平梁板体系产生不利影响。某超深基坑盖挖逆作盆式开挖过程中，选取具代表性的立柱进行监测，对其竖向位移以及相邻地下连续墙的竖向位移作对比分析。研究表明，立柱的上浮与土体开挖深度有关，开挖第三层土体时为立柱竖向位移的最不利状态；中间立柱上浮量最大，向两边依次减小。

［关键词］软土；超深基坑；逆作法；竖向位移；工程实测

Analysis on-vertical displacement of pillars under top-down construction method in soft-soil area

Wang Wencan¹, Zhong Xiaomei¹, Zhan Xuezhi²（1 Civil Engineering Department, Tianjin Institute of Urban Construction, Tianjin 300384, China；2 Tianjin Branch of China Railway First Group Co.,Ltd., Tianjin 300250,China)

Abstract:The bearing capacity and deformation of pillars in super-deep foundation pit under top-down construction method are very complicated. If the differential vertical displacement between pillars is too large, it will exert an adverse impact on horizontal beam-slab structure which is taken as permanent construction. The analysis on monitoring data of vertical displacement of pillars and diaphragm walls was carried out under basin-excavation method in the excavation of super-deep foundation pit,considering the correlative factors which influence the vertical displacement of pillars. The results show that the ascents of pillars are in connection with the depth of excavation, excavation of the third layer is the most hazardous status, and the ascent of intermediary pillar is maximal, less in turns from middle to sideward.

Keywords:soft soil; super-deep foundation pit; top-down construction method; vertical displacement; construction monitoring

参考文献

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［2］陈立生.超深长条形基坑立柱上浮规律及其对钢筋混凝土支撑附加弯矩的影响［J］.城市道桥与防洪，2008（8）：193-198.

［3］DBJ08—61—1997基坑工程设计规程［S］.上海，1997．