基于NPR锚索监测的顺层岩质边坡多阶变形规律研究

Research on multistage deformation law of bedding rock slopes based on NPR anchor cable monitoring

山西煤系地层多发育砂泥岩互层的顺层岩质边坡,受降雨及地下水等影响,滑坡灾害较为频发。为研究含软弱夹层顺层岩质边坡在NPR锚索支护下的多阶变形规律,对于坡体受控于多条陡直贯通裂隙的边坡,基于极限平衡法,全面考虑坡脚临空面高度h、岩层倾角β、坡面倾角α、滑体重度γ、滑面长度L,滑带软岩强度(c,φ)力学参数,建立力学分析模型,通过公式推导确定滑带岩土在软化及蠕变过程中不同强度参数下NPR锚索支护边坡的2种类型:整体稳定型和局部稳定型,从机制上分析强降雨过程中2种类型边坡的多阶变形规律。且由公式推导对是否设置NPR锚索的同等条件边坡失稳时滑面长度变化进行定性分析,得到对滑坡规模变化的影响,并对影响滑坡规模变化的参数敏感度进行分析;此外对设置NPR锚索的同等条件边坡,是否考虑水力作用,定性分析其失稳时滑面长度变化,得到对滑坡规模变化的影响。最后利用何满潮团队研发的滑坡地质灾害牛顿力远程监测预警系统在山西省柳林县禄聚茆滑坡的应用,得到监测数据所反映的实际预警结果与理论推导的边坡失稳模式相符,而进一步佐证相关理论研究。

The bedding rock slope with sand-mudstone interbeds is mostly developed in the coal-bearing strata of Shanxi Province.Affected by rainfall and groundwater,landslide disasters are frequent.Based on the limit equilibrium method and considering the slope parameters such as the height h of the free surface at the foot of the slope,the slope anglea,the strata inclinationb,the weightgof the sliding mass,the length L of the slip surface,and the mechanical parameters(c,f)of the soft rock strength of the slip zone,a mechanical analysis model is established to study the multi-stage deformation law of bedding rock slopes with weak interlayers under the support of NPR anchor cables.Through formula derivation,two types of NPR anchor cable-supported slopes under different strength parameters in the softening and creep process of the rock and soil in the slip zone are determined:the overall stable type and the local stable type,and the multi-stage deformation laws of the two types of slopes during strong rainfall are analyzed from the mechanism.The formula is derived to qualitatively analyze the change of the length of the sliding surface when the slope is unstable under the same condition of whether the NPR anchor cable is set,and the influence on the change of the landslide scale is obtained,for the same condition slope with NPR anchor cable whether considering the hydraulic action or not,the change of slip surface length is qualitatively analyzed when the slope is unstable,and the influence on the change of landslide scale is obtained.Finally,the application of the remote monitoring and early warning system of Newtonian force of landslide geological disaster developed by He Manchao's team in the Lujumao landslide in Liulin County,Shanxi Province is used.The actual early warning results reflected by the monitoring data are consistent with the theoretical derivation of the slope instability model.