柔性拉筋式重力墙地震土压力计算方法研究

Study on Calculation Method of Seismic Earth Pressure on Flexible Tensioned Gravity Wall

为有效确定地震荷载作用下柔性拉筋式重力墙的土压力,基于塑性极限分析上限法及拟静力法,采用对数螺旋面作为滑裂面,通过对挡墙后填土进行内能耗散功率与外力功率的计算,建立了拉筋式重力墙地震土压力分析模型。通过算例分析,对比数值模拟与研究提出的算法结果,验证了所提出算法的合理性,并就填土及拉筋的相关参数对地震土压力的影响进行了讨论。结果表明:随着填土强度参数的增加,地震土压力呈非线性减小;土压力随着土工格栅间距的增大而呈非线性增大;随着顶层拉筋长度的增加,土压力呈非线性减小趋势;当顶层拉筋长度大于10 m时,土压力值基本不变。

In order to effectively determine the earth pressure of flexible tensioned gravity walls under seismic loads, based on the upper bound method of plastic limit analysis and quasi-static method, logarithmic helical surface as the slip surface, through the calculation of internal energy dissipation power and the external power of the backfill behind the retaining wall, the calculation and analysis model of seismic earth pressure of tensioned gravity wall is established. Through the analysis of an example, combined with the numerical simulation method and the results of this algorithm, the rationality of the proposed method is verified. The influence of the parameters of filling and reinforcement on seismic earth pressure is also discussed. The results show that the seismic earth pressure decreases nonlinearly with the increase of filling strength parameters;the earth pressure increases nonlinearly with the increase of geogrid spacing;the earth pressure decreases nonlinearly with the increase of the length of the top reinforcement. When the length of the top reinforcement is longer than 10 m, the earth pressure value remains unchanged.