The sliding forms of weak sloped and horizontal subgrades during the sliding process differ. In addition, the sliding form of weakly sloped subgrades exhibits considerable slippage and asymmetry. The accuracy of traditional slice methods for computing the stability safety factor of weakly sloped subgrades is insufficient for a subgrade design. In this study, a novel modified Bishop method was developed to improve the accuracy of the stability safety factor for different inclination angles. The instability mechanism of the weakly sloped subgrade was considered in the proposed method using the “influential force” and “additional force” concepts. The “additional force” reflected the weight effect of the embankment fill, whereas the “influential force” reflected the effect of the potential energy difference. Numerical simulations and experimental tests were conducted to evaluate the advantages of the proposed modified Bishop method. Compared with the traditional slice method, the error between the proposed method and the exact value is less than 32.3% in calculating the safety factor.

滑移过程中弱坡路基和水平路基的滑移形式不同。此外，弱坡路基的滑动形式表现出相当大的滑动和不对称性。传统切片法计算弱坡路基稳定安全系数的精度不足以满足路基设计要求。在这项研究中，开发了一种新的改进 Bishop 方法，以提高不同倾角的稳定性安全系数的准确性。在所提出的方法中使用“影响力”和“附加力”概念考虑了弱坡路基的失稳机制。“附加力”反映了路堤填料的重量效应，而“影响力”反映了势能差的影响。进行了数值模拟和实验测试，以评估所提出的改进 Bishop 方法的优点。与传统切片法相比，所提方法在计算安全系数时与准确值的误差小于32.3%。