预应力锚索加固岩质边坡及锚索参数优化数值分析  

Numerical Analysis on Reinforcement of Rock Slope with Prestressed Anchor Cable and Optimization of Anchor Cable Parameters

作　　者：杨朝震 YANG Chao-zhen(China Railway 18th Bureau Group 5Engineering Co Ltd,Tianjin 300451,China)

机构地区：[1]中铁十八局集团第五工程有限公司,天津300451

出　　处：《武汉理工大学学报》2021年第12期64-68,共5页Journal of Wuhan University of Technology

摘　　要：以某岩质边坡开挖支护为研究对象,采用数值模拟手段重点分析了预应力锚索加固岩质边坡效果并进行参数影响分析。结果表明,边坡采用预应力锚索加固之前极易发生失稳滑塌现象,采用预应力锚索加固之后安全系数为1.67,此时边坡属于永久性预应力锚索加固边坡,符合规范和安全要求;边坡安全系数随锚索倾角的增大先增大后减小,可以通过合理的设计锚索倾角,使得锚索最大程度地提供抗滑力。增大锚索预应力可以增大边坡的稳定性,但随着锚索预应力的持续增大,边坡安全系数增加变得缓慢,且预应力增大会导致施工成本和难度增大,故应合理地设计锚索的预应力值;锚固段剪应力随锚固段长度的增大先增大后减小,且锚固段发挥剪应力作用的部位主要分布在其前端1~5m范围内,锚固段的长度不宜过长,一般以8m为宜。Taking the excavation and support of a rock slope as the research object,the effect of prestressed anchor cable reinforcement of rock slope was emphatically analyzed by means of numerical simulation,and the influence of parameters was analyzed.The results show that the slope is prone to instability and collapse before prestressed anchor cable reinforcement,and the safety factor after prestressed anchor cable reinforcement is 1.67.At this time,the slope belongs to the slope reinforced by permanent prestressed anchor cable,which meets the specifications and safety requirements.The slope safety factor first increases and then decreases with the increase of anchor cable inclination.Through the reasonable design of anchor cable inclination,the anchor cable can provide anti sliding force to the greatest extent.Increasing the prestress of anchor cable can increase the stability of slope,but with the continuous increase of prestress of anchor cable,the increase of slope safety factor becomes slow,and the increase of prestress will increase the construction cost and difficulty,so the prestress value of anchor cable should be designed reasonably.The shear stress of the anchorage section first increases and then decreases with the increase of the length of the anchorage section,and the parts where the anchorage section plays the role of shear stress are mainly distributed in the range of 1~5mat the front end.The length of the anchorage section should not be too long,generally 8m.

关 键 词：岩质边坡 预应力锚索 边坡稳定性 参数分析 数值模拟 

分 类 号：TU476[建筑科学—结构工程]