Currently, knowledge of the failure mechanisms of narrow backfills with retaining walls rotating about the top (RT mode) is still lacking which leads to inaccurate estimations of the earth pressure. Numerical simulations using finite element limit analysis find that under the effects of backfill geometries, interface strengths, and soil properties, the upper soil layer supported by soil arching retains its integrity and the lower soil layer is sheared by multiple curved sliding surfaces in the limit state. Based on the failure mechanisms of narrow backfills, a calculation model is established which considers the soil arching effect, curved sliding surface, and cohesive soils. Analytical solutions for the earth pressure of narrow cohesive backfills with retaining walls rotating about the top are derived by using the limit equilibrium horizontal slice method. Compared with previous studies, the present method predicts the earth pressure distribution with higher accuracy. Several extensive parametric studies have also been conducted. Thus, decreasing the aspect ratio of backfills, increasing the inclined angle of natural slopes, interface strengths, and soil cohesion are beneficial for maintaining backfill integrity and reducing earth pressure against retaining walls.

目前，仍然缺乏对狭窄的回填土的失效机理的了解，其中挡土墙绕顶部旋转（RT模式），这导致对土压力的估计不准确。使用有限元极限分析的数值模拟发现，在回填几何形状，界面强度和土壤特性的影响下，由土拱形成的上部土层保持其完整性，并且下部土层在极限状态下被多个弯曲滑动面剪切。根据狭窄回填土的破坏机理，建立了考虑土拱效应，弯曲滑动面和粘性土的计算模型。采用极限平衡水平切片法，推导了围护墙绕顶部旋转的窄粘性回填土的土压力解析解。与以前的研究相比，本方法可以更准确地预测土压力分布。还进行了一些广泛的参数研究。因此，降低回填的长宽比，增加自然坡度的倾斜角，界面强度和土壤粘聚力对于保持回填的完整性和减少土方对挡土墙的压力是有益的。