Reasonable Design Method for Reinforced Slope Cutting

为建立合理的加筋路堑边坡设计方法，通过试验和分析研究加筋路堑边坡的加筋机理和稳定性特征，提出了加筋路堑边坡稳定性混合设计方法。该方法是一种有限元法与极限平衡法相结合的方法，将边坡的潜在破坏面定义为破坏剪应变区，根据应变破坏准则，采用强度折减技术从坡脚向坡顶逐层展开，将边坡的安全系数定义为平均应力水平的倒数，根据应力破坏准则。分析结果表明，混合法得到的安全系数和破坏模式与Bishop法相当接近。为了验证混合法用于加筋路堑边坡稳定性分析的有效性，进行了两个残积土加筋路堑边坡的现场试验。混合法预测的加筋路堑边坡性状与现场试验数据和现场观测结果吻合较好。根据分析结果和现场实测，提出了一种适用于加筋边坡的修正Fellenius法。混合方法和改进的Fellenius方法之间的一致性是令人满意的。结果表明，该方法在实际的原位加固边坡加固工程中是可行的。此外，修正的Fellenius方法也可作为一种简化方法应用。

Reinforcement mechanism and stability characteristics of reinforced slope cutting were studied both experimentally and analytically to establish a reasonable design method for reinforced slope cutting.A hybrid slope stability design method for reinforced slope cutting was proposed. The proposed method is a kind of hybrid method of the finite element method and limit equilibrium method, in which the potential failure slip surface of a slope is defined as the failure shear strain zone, according to strain failure criterion, being developed from the toe to the top of the slope tracing by shear strength reduction technique, and the safety factor of the slope is defined as the invert of the average stress level, according to stress failure criterion. Analytical results showed that the safety factor and the failure pattern obtained from the proposed hybrid method were quite close to those from the Bishop's method.In order to verify the hybrid method for reinforced cut slope stability analysis, two full scale field tests on reinforced cut slopes in residual soil were performed. The predicted behavior of the reinforced slope cutting by the hybrid method agreed with the field test data and site observation. Based on the analytical results and field measurements, a modified Fellenius' method for reinforced slope was also proposed. Agreement between the hybrid method and the modified Fellenius' was found to be satisfactory. Consequently, applicability of the hybrid method to the practical in-situ reinforcement slope stabilization was demonstrated in success. Also, the modified Fellenius' method can be applied as a simplified method.