1、 1 摘摘 要要 *广场基坑工程位于南京市河西新区，基坑挖深 14m，开挖面积 40000m2左右，四邻城市主干道，建成后将成为河西地区地标性建筑。本 工程从可行性研究阶段一直到工程竣工阶段都会受到社会的广泛关注，其 自身的重要性不言而喻。保障本工程的施工安全成为关键性问题之一。 首先，对基坑及支护结构进行了分析并选择了钻孔灌注桩加钢筋混凝 土支撑的围护形式，然后根据 Rankine 土压力理论确定了土压力大小，采 用力不变等值梁法确定了支撑轴力大小及嵌固深度，根据结构力学相关知 识计算了桩身弯矩分布，然后基于正截面承载力计算理论与最大弯矩值确 定了桩身配筋，最后根据相关规范及工程特点确定了排
2、桩尺寸，冠梁尺寸 等细部结构尺寸。内支撑方面根据规范与偏心受压构件配筋理论确定了支 撑尺寸与配筋。稳定性验算方面，根据规范说明的方法，对整理抗滑稳定 性、坑底抗隆起稳定性、抗渗流稳定性、抗倾覆稳定性进行了验算。最后 根据规范及工程特点进行了施工组织、监测设计与安全对策制定。 关键词：软土基坑；基坑支护结构；基坑稳定验算；基坑施工组织；基坑 监测设计；施工安全对策 2 Abstract GREEN square excavation engineering is located in Hexi new district, Naning city. Excavation depth is abou
3、t 14 meters and it also covers an area of 40000 square meters. This engineering is surrounded by fours roads, which are main roads in Hexi. GREEN square would be an important landmark building in Hexi area of Naning. So it must widely attract the focus of the society since it is established and it i
4、s very important obviously. The key problem is to keep the safety of construction. Firstly, the form of supporting structure was analyzed and selected. Bored piles and concrete supporting were applied to this engineering in the end. Then soil pressure was calculated by Rankine earth pressure theory.
5、 The axial force of supporting structure and embedded depth were calculated by equivalent beam theory. According to related knowledge of structural mechanics, the distribution of the bending moment in the piles was calculated. Then based on the theory of the normal section bearing capacity and the v
6、alue of maximum bending moment, steel bars were assembled into piles and support. Finally, according to the revelant industry regulation and the engineering characteristics, some detailed sizes of structures formed. At the end of the project, the construction organization, the design of monitor and the safety countermeasures were determined. Key words: foundation pit in soft soil; supporting structure; the stability of foundation pit; construction organization; monitoring system; emergency pla
