降雨诱发滑坡的NPR锚索控制机理及临滑预警
Control Mechanism and Early Warning of Rainfall-Induced Landslide Based on NPR Anchor Cable
陶志刚 1史广诚 1杨晓杰 1何满潮1
作者信息
- 1. 中国矿业大学(北京)隧道工程灾变防控与智能建养全国重点实验室,北京 100083;中国矿业大学(北京)力学与土木工程学院,北京 100083
- 折叠
摘要
为研究降雨滑坡的控制及临滑预警技术,以熊家山滑坡为原型,通过分析边坡变形的时空特征,设计了相似模型试验.以普通预应力锚索(简称PR锚索)和NPR锚索为加固材料,运用高速摄像机、孔压、土压和锚索力传感器,分析了降雨诱发的滑坡规律和锚索控制机理,并结合现场试验探究了滑坡牛顿力变化规律.结果表明:孔隙水压力突降与边坡局部滑塌近似同步;NPR锚索力突降,边坡内部产生局部变形;PR锚索因无法承受大变形被拉断失效,而NPR锚索凭借恒阻大变形特性产生高应力吸能控制功能,促使边坡达到二次平衡状态;NPR锚索在滑坡前表现出明显的"先突增,后突降"的变形-临滑动力学规律;现场试验揭示了滑坡全过程牛顿力演变规律,提前7.5 h发出临滑预警.
Abstract
In order to study the control and the early-warning prediction technology for rainfall-induced landslide,the similar model test was designed by analyzing the spatial and temporal characteristics of slope deformation of Xiongjia Mountain landslide.Using ordinary Poisson's ratio(PR)anchor cable and negative Poisson's ratio(NPR)anchor cable as reinforcement materials,the law of rainfall-induced landslide and control mechanism of anchor cable were analyzed by using high-speed photography,pore pressure,earth pressure and anchor cable force sensors,and the evolution law of the Newtonian force during landslide was explored based on field tests.The results show that the sudden drop in pore water pressure is approximately synchronized with the local collapse of slope.NPR anchor force drop abruptly,causing local deformation in slope.The PR anchor cables fail because they cannot withstand large deformation,while the NPR anchor cables have high-stress energy absorption control functions due to the constant resistance and large deformation characteristics,enabling the slope to reach a secondary equilibrium state.The NPR anchor cable exhibits a significant deformation-slip dynamic law characterized by a first sudden increase followed by a sudden drop before the landslide.The field test revealed the Newtonian force evolution law in the whole process of the landslide,and obtained the early-warning time parameters of the Xiongjia Mountain landslide 7.5 h in advance.
关键词
滑坡/降雨/NPR锚索/控制机理/监测预警Key words
landslide/rainfall/negative Poisson's ratio(NPR)anchor cable/control mechanism/monitoring and early-warning引用本文复制引用
基金项目
中国博士后科学基金(2022M713385)
国家自然科学基金(41941018)
出版年
2024
NETL
NSTL
万方数据