中文摘要：

考虑基坑的安全性和经济性，采取“人工挖孔桩＋钢筋混凝土内支撑”与原支护形成延伸开挖后的复合支护结构。采用Plaxis2D软件对复合支护结构进行有限元数值模拟，分析复合基坑支护结构的受力变形情况．结果表明：支护加固体系的受力和变形均符合延伸开挖的要求，Plaxis2D软件分析的结果反映出支护结构的薄弱点．

英文摘要：

Considering the safety and economy, the composite supporting structure of the ＇pile -1- reinforced concrete interior support＇ reinforcement form and the original supporting system were adopted. The software Plaxis 2D was used to simulate the deformation of the composite foundation pit supporting structure, The results show that both stress and deformation of the reinforced system meet the requirement of deepening excavation, and the vulnerable points are also pointed out.