桂南花岗岩残积土边坡稳定性分析及坡率优化建议OA

Based on the geological survey data of the Xinyi—Yulin(Guangxi section)expressway of the Cenxi—Daxin highway in the southern Guangxi region,the regularity and variability of the indoor test indicators of granite residual soil were statistically analyzed.Combined with field investigation,the stability of unsaturated seepage stress-coupled granite residual soil slope was simulated,the relationship between different slope ratios and stability coefficients under rainfall conditions was studied.The results show that the physical and mechanical indexes of granite residual soil have obvious variability,and the variability of cohesion index is the largest.When the slope ratio of granite residual soil is slow,rainfall infiltration and erosion increase,but it is too steep and easy to cause slope instability.When the slope ratio is 1∶0.75,the strength of granite residual soil can be fully utilized.It is recommended to set a reasonable slope ratio during the slope design,which the graded excavation scheme can be used to slow up and steep down,and the singe-stage side slope ratio should be 1∶0.75-1∶1.50(the upper side slope ratio can be slowed down appropriately).