成都某地铁车站排桩支护结构受力变形规律研究

为了研究排桩支护结构的受力变形规律,指导基坑的信息化施工,针对成都某地铁车站基坑的地质条件较差、开挖深度较大(23 m)、支护形式较复杂(排桩+4道钢管支撑)的特点,对基坑的施工过程进行了精心监测,并建立了三维有限元模型,应用ABAQUS软件对基坑的开挖过程进行数值模拟。通过计算结果与监测结果的对比分析发现:1)多支点排桩支护结构的桩身水平位移曲线通常呈"弓形"分布,第1道支撑对减小桩顶位移有非常重要的作用;2)支撑的设置对减小桩身弯矩有重要作用;3)支撑轴力会受到相邻支撑设置的影响;4)计算桩后土压力与朗肯主动土压力、静止土压力均有差异。

Research on Displacement and Stress of Soldier Pile Structure in Foundation Pit of Metro Station in Chengdu

The geological condition of the foundation pit of a Metro station in Chengdu is very bad. The depth of the foundation pit is 23 m, and the supporting structure of the foundation pit is complex. The construction of the foundation pit is monitored. 3 D finite element models are established, and the excavation of the foundation pit is numerically simu- lated by means of ABAQUS software. The comparison and contrast between the calculation results and the monitoring re- suits shows that： 1 ） The horizontal displacement curves of the multi-point braced soldier piles generally present ＂C＂ shape, and the first-level bracing plays an important role in reducing the displacement of the pile head. 2） The bracing plays an important role in reducing the bending moment of the piles. 3 ） The axial force of the bracing can be affected by the neighboring bracing. 4） There are differences among the calculated lateral earth pressure, Rankine active earth pres- sure and static earth pressure.