关键词: 路基, 强度系数法, 抗剪强度, 稳定分析, 排水固结, 有效固结应力法, 有效应力法

Abstract: The effective stress method is seldom utilized due to the complexity of calculating effective stress along the sliding surface. The stability factor calculated by the effective consolidation-stress method is underestimated. A novel stability analysis method for consolidation embankments needs to be developed. The sliding body of a consolidation embankment was categorized into active shear zone, direct shear zone, and passive shear zone based on the sliding surfaces in the deformation fields of a model experiment on soft ground. The effective normal stress on the sliding surface in the active or passive zone was calculated using the Skempton equation and the Mohr-Coulomb strength criterion. The effective normal stress on the sliding surface in the direct shear zone was determined after considering the excess pore water pressure using the Skempton equation and following the principle that the increment of shear stress equals the shear strength on the failure surface. Equations for the shear strength on the failure surface, with the vertical consolidation stress as the variable and the strength coefficients composed of shear strength indexes and the coefficient of excess pore water pressure, were developed. Finally, the strength coefficient method was proposed as a new stability analysis approach for consolidation embankments based on the shear strength equations mentioned above. The study reveals that the average error in the coefficient of frictional shear strength across three zones, as determined in this paper compared to the method suggested by Shen Zhu-jiang, ranges from −7% to 7%. Furthermore, the coefficient obtained from the current code is 20% to 25% lower than that derived in this paper, and the coefficient from the vane test is 20% to 31% lower. The stability analysis of a consolidation embankment on an operational express highway demonstrates that the stability factor from the current code’s method is below 1. Both the strength coefficient method and the approach proposed by Shen Zhu-jiang align well with the engineering principles.

Key words: embankment, strength coefficient method, shear strength, stability analysis, consolidation, effective consolidation stress method, effective stress method