台阶式格栅加筋挡墙潜在破裂面计算模式研究

基于自洽理论建立了筋土复合材料力学模型,对不同台阶宽度的格栅加筋土挡墙的塑性区进行了有限元分析。研究了其塑性区的发展和贯通过程,对台阶式格栅加筋土挡墙的塑性区分布规律进行了讨论。研究表明,加筋土直墙的塑性区分布接近于0.3H破裂面的假定,但台阶墙的塑性区分布与直墙有显著差异,且随着台阶宽度的变化而变化。提出了适合于不同台阶宽度的格栅加筋土挡墙潜在破裂面的计算模式,当上阶挡墙前趾位于下阶挡墙的主动区内时,该破裂面为一连续曲面;当上阶挡墙前趾位于下阶挡墙的过渡区内时,该破裂面为分段曲面;当台阶宽度为0时,该破裂面可退化为0.3H破裂面。该计算模式具有较好的通用性,能适用于具有不同台阶宽度的加筋土挡墙。

Study on Rational Model of Potential Fractured Surface for Stepped Geogrid Reinforced Soil Retaining Wall

Based on self-consistent theory,a mechanical model for soil-reinforcement composite material is built up,the plastic zone of geogrid reinforced soil retaining wall(RSRW) with different step widthes is analyzed by FEM,the development and run-through process of the plastic zone is studied,and its distribution pattern is discussed.The research findings show that the plastic zone of erective RSRW is close to the hypothesis of 0.3H fractured surface presented by criterion,but the plastic zone of stepped RSRW is observably different from that of erective RSRW,and mutative along with the step width.Therefore,a rational model of potential fractured surface for geogrid RSRW with different step widthes is advanced.When the leading adge of the upper retaining wall is located in the active-zone of the lower retaining wall,the fractured surface is a consecutive curved surface,when lacated in the transition-zone,it is a broken curved surface,and when the step width is equal to zero,it can be degraded into the 0.3H fractured surface.So the presented model provides with universal properties,it can be applied to the RSRW with different step widthes.