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目前关于临近地下室外墙影响的挡土墙空间土压力的计算理论的研究还比较少,原有的平面应变条件下的理论不能满足挡土墙的长高比B/H较小时的挡土墙土压力计算要求。通过将土拱效应原理引入顾慰慈~([8])建立的空间土压力计算模型,建立了考虑土拱效应的临近地下室外墙影响的空间土压力计算模型,根据挡土墙和地下室外墙的间距与土体破裂面状态的关系将该模型分为3种情况,并将各模型划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ四个区域,通过在各个区域内取水平微分单元体,建立各微分单元体的水平和竖向静力平衡方程,推导出了各区相应的挡土墙空间主动土压力计算公式,该公式可以计算出墙背任意位置的主动土压力;并提出了空间土压力合力及其合力作用点的计算方法。通过算例计算可以直观地看出挡土墙后主动土压力的空间分布,由此可以看出,当空间效应存在时,考虑土拱效应的挡土墙主动土压力沿墙长的分布与平面应变条件时有很大的不同,此时挡土墙两端附近区域的主动土压力远小于平面应变条件下计算出的主动土压力,同时可以看出,考虑空间效应的挡土墙主动土压力合力作用点要比平面应变条件下的位置要高,挡土墙长高比B/H越小,空间效应对主动土压力沿墙长的分布和主动土压力合力作用点位置的影响越大。
At present, there is still little research on the calculation theory of earth pressure in the retaining wall near the influence of the external wall of the basement. The theory under the original plane strain condition can not meet the requirement of retaining wall with aspect ratio lower than B / H Earth pressure calculation requirements. By introducing the principle of soil arching into the earth pressure calculation model established by Gu Weici ~ ([8]), a space earth pressure calculation model considering the influence of soil arching near the basement wall is established. According to the calculation model of earth pressure, The relationship between the distance and the state of soil rupture surface The model is divided into three kinds of situations, and each model is divided into four areas of Ⅰ, Ⅱ, Ⅲ, Ⅳ. By taking horizontal differential elements in each area, The formula of active earth pressure of corresponding retaining wall space in each area is deduced. The formula can calculate the active earth pressure at any position on the back of the wall. The calculation of synergy point. Through the example calculation, the spatial distribution of active earth pressure behind the retaining wall can be visually observed. It can be seen that when the spatial effect exists, the distribution of the active earth pressure along the wall length and the plane There are great differences in the strain conditions. At this moment, the active earth pressure near the both ends of the retaining wall is much smaller than the active earth pressure calculated under the plane strain. At the same time, it can be seen that the active earth pressure of the retaining wall considering the space effect The effect point is higher than that under plane strain condition. The smaller the ratio of length to height of retaining wall B / H, the greater the effect of space effect on the distribution of active earth pressure along the length of the wall and the position of active earth pressure.