【摘要】 椭圆形深基坑支护结构在土压力作用下,为空间受力体系,主要承受环向压应力,能充分发挥混凝土材料的抗压性能。本文采用有限元方法建立椭圆形深基坑支护结构的三维数值分析模型,模拟分析了椭圆形深基坑支护结构各主要构件在施工过程中的受力变形规律。结果表明,支护桩侧向位移沿环向逐渐变化,大圆弧处支护桩的侧向位移大于小圆弧处支护桩的侧向位移。相应地在大圆弧处和小圆环处的支护桩所受土压力和所产生弯矩剪力分布也发生较大变化。椭圆形环梁控制内力为轴力,自上而下各环梁轴力逐渐增大,各环梁轴力在环梁施加完成后的两个开挖工况增加迅速,继续开挖施工轴力增大速率则明显变缓。更多还原

【Abstract】 The support structure of oval deep foundation pit is the space stress system under the action of soil pressure, which mainly bears the annular pressure stress and can give full play to the compressive performance of concrete materials. In this paper, finite element method is used to establish a three-dimensional numerical analysis model of the support structure of oval deep foundation pit. The results show that the lateral displacement of the supporting pile changes gradually along the annular direction, and the lateral displacement of the supporting pile at the greater circular arc is greater than that at the smaller circular arc. Correspondingly, the soil pressure and the shear force distribution of bending moment produced by the retaining piles in large arc and small ring also changed significantly. The internal force of the oval girder is the axial force, and the axial force of each girder increases gradually from top to bottom. The axial force of each girder increases rapidly in the two excavation conditions after the application of girder, while the increasing rate of axial force increases obviously slow in the continuous excavation.更多还原