边坡破裂角分析

Analysis of rupture angle of slope

【目的】边坡破裂角是边坡稳定性分析和加固设计的重要参数。关于确定边坡破裂角的方法目前尚存在一些争议。【方法】运用摩尔-库伦强度理论、边坡稳定性评价和挡土墙土压力三种计算方法对边坡破裂角进行计算与分析。【结果】推导出直立边坡稳定安全系数所对应的破裂角计算公式。通过边坡稳定性计算得到边坡稳定安全系数所对应的破裂角,当边坡稳定安全系数大于1.00时,该破裂角为潜在破裂角;当边坡稳定安全系数等于1.00时,该破裂角为临界破裂角。【结论】运用挡土墙土压力计算方法得到的破裂角是土压力最大时所对应的破裂角,并不是边坡临界破裂角。《建筑边坡工程技术规范》(GB 50330—2013)基于挡土墙土压力计算思路确定的边坡破裂角是不合理的,建议修改。

[Purposes]The angle of rupture of slope is an important parameter for slope stability analysis and reinforcement design,At present,there are some controversies about the method of determining the rupture angle of slope.[Methods]In this paper,the rupture angle of slope is analyzed by three methods,namely,Moore′s Coulomb strength theory,slope stability and retaining wall earth pressure calculation.[Findings]It is pointed out that the rupture angle of slope is related to the stability of the slope,and the formula for calculating the angle rupture corresponding to the minimum stability coefficient of an upright slope is deduced.It is shown that the rupture angle obtained by stability calculation is the rupture angle corresponding to the safety factor of the slope,and when the stability factor of the slope is greater than 1.00,it is the potential rupture angle,and when the stability factor of the slope is just equal to 1.00,the rupture angle at this time is the critical angle of rupture.[Conclusions]The rupture angle obtained by using the soil pressure calculation method of the retaining wall is the rupture angle corresponding to the maximum soil pressure,and is not the critical rupture angle of the slope.Technical code for building slope engineering(GB 50330—2013)based on the idea of calculating soil pressure of retaining wall to determine the rupture angle of slope is unreasonable,and it is recommended to modify it.