考虑不同土压力模式的水泥土重力式围护墙抗倾覆稳定性分析
Anti-overturning stability analysis of cement-soil gravity retaining wall under different earth pressure modes
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摘要: 墙前开挖区土压力和墙后土压力模式的确定是水泥土重力式挡土墙抗倾覆稳定性验算的关键,不同土压力模式下抗倾覆系数曲线形态有一定的差异。根据墙体竖向力的平衡确定抗倾覆验算点位置,根据墙体的变形特征,同时考虑由于基坑开挖引起的上覆有效土压力变化引入修正系数α修正墙前后土压力,推导了修正土压力模式下墙体的抗倾覆稳定计算公式,对比分析三种不同土压力模式下Kq曲线的形态特征及其影响因素,结果表明墙前后土压力修正模式更能反映实际状态下墙的倾覆失稳形态,其抗倾覆稳定系数也更加合理。Abstract: The mode of earth pressures acting on the front wall and behind the wall plays a key role in checking the anti-overturning stability of cement-soil gravity retaining wall after excavation. The curve of anti-overturning safety factor somewhat varies under different earth pressure modes. The turning point can be determined according to the balance of vertical force. In order to consider the characteristics of wall deformation and the change of effective vertical earth pressure, a coefficient is introduced to modify the earth pressure on the wall, meanwhile a formula for calculating the safety factor is proposed under the new mode. Through analysis of the morphological characteristics of the curve and the influencing factor under three different earth pressure modes, the calculated results show that the anti-overturning safety factor is more reasonable, and the modified method can better reveal the real state of wall overturning.