土钉加固边坡稳定性分析的等效参数提高方法

摘要

The reinforcement of the slopes by using soil nails was embodied in the equivalent increasing parameter method of soil shear strength based on the principle of Mohr-Coulomb .Accordingly ,the relationship between the reinforcement parameters of soil nails and soil mass mechanics was identified .Through the sensitivity analysis of nail length ,drilling angle and spacing between nails ,it was found that the spacing and nail length have a significant impact on the stability of the slopes ,whereas the angle showed no obvious effects .Finally the equivalent increasing parameter method was used to analyze the stability of Xianshuihe Hydropower Station reinforced slopes and then the results were compared with that of e-quivalent concentration method .Simulated results showed that the position for the most dangerous sliding surface and its safety factor of equivalent increasing parameter method was very close to that of the equivalent concentration method ,thus the reasonability of the presented method was validated .Effect of soil nails on the shear strength parameters of slope rock-soil is taken into account in the equivalent increasing parameter method ,and the calculation process is simple with good convergence ,therefore it is highly applicable in engineering projects .%基于Mohr-Coulomb准则，通过等效提高岩土体抗剪强度参数的方法来体现土钉对边坡的加固作用，明确了土钉加固参数和土体力学参数之间的关系。通过对土钉长度、角度以及间距进行敏感性分析发现，土钉间距、长度对边坡稳定性有较大影响，而钻孔角度的影响不明显。最后将该方法应用于鲜水河水电站边坡治理工程的稳定性分析，并与等效集中力法进行对比，计算结果表明：等效参数提高法与经典的集中力法计算得到边坡最危险滑动面位置及安全系数比较接近，验证了等效参数提高法的合理性；等效参数提高法考虑了土钉对边坡岩土体抗剪强度参数的影响，计算简便且收敛性好，具有较高的工程应用价值。