Hu Weidong, Zhu Xinnian, Zeng Yongqing, Liu Xiaohong, Peng Chucai
College of Civil Engineering and Architecture, Hunan Institute of Science and Technology, Yueyang, 414000, China.
Sci Rep. 2022 Jan 11;12(1):497. doi: 10.1038/s41598-021-04411-4.
A reasonable method is proposed to calculate the active earth pressure of finite soils based on the drum deformation mode of the flexible retaining wall close to the basement's outer wall. The flexible retaining wall with cohesionless sand is studied, and the ultimate failure angle of finite soils close to the basement's outer wall is obtained using the Coulomb theory. Soil arch theory is led to get the earth pressure coefficient in the subarea using the trace line of minor principal stress of circular arc after stress deflection. The soil layers at the top and bottom part of the retaining wall are restrained when the drum deformation occurs, and the soil layers are in a non-limit state. The linear relationship between the wall movement's magnitude and the mobilization of the internal friction angle and the wall friction anger is presented. The level layer analysis method is modified to propose the resultant force of active earth pressure, the action point's height, and the pressure distribution. Model tests are carried out to emulate the process of drum deformation and soil rupture with limited width. Through image analysis, it is found that the failure angle of soil within the limited width is larger than that of infinite soil. With the increase of the aspect ratio, the failure angle gradually reduces and tends to be constant. Compared with the test results, it is shown that the horizontal earth pressure reduces with the reduction of the aspect ratio within critical width, and the resultant force decreases with the increase of the limit state region under the same ratio. The middle part of the distribution curve is concave. The active earth pressure strength decreases less than Coulomb's value, the upper and lower soil layers are in the non-limit state, and the active earth pressure strength is more than Coulomb's value.
提出了一种基于靠近地下室外墙的柔性挡土墙鼓形变形模式来计算有限土体主动土压力的合理方法。对无粘性砂土的柔性挡土墙进行了研究,利用库仑理论得到了靠近地下室外墙有限土体的极限破坏角。引入土拱理论,利用应力偏转后圆弧小主应力迹线得到分区土压力系数。鼓形变形发生时,挡土墙顶部和底部的土层受到约束,土层处于非极限状态。给出了墙体位移大小与内摩擦角和墙摩擦角发挥程度之间的线性关系。对水平层分析法进行了修正,提出了主动土压力合力、作用点高度及压力分布。进行了模型试验,模拟有限宽度下鼓形变形和土体破裂的过程。通过图像分析发现,有限宽度内土体的破坏角大于无限土体的破坏角。随着宽高比的增加,破坏角逐渐减小并趋于恒定。与试验结果相比,结果表明在临界宽度内,水平土压力随宽高比的减小而减小,在相同比例下,合力随极限状态区域的增加而减小。分布曲线中部呈凹形。主动土压力强度减小量小于库仑值,上下土层处于非极限状态,主动土压力强度大于库仑值。