【作者】 王杨；

【导师】 王海涛； 张世春；

【作者基本信息】 大连交通大学 ， 交通运输工程（专业学位）， 2021， 硕士

【摘要】 随着我国基础设施建设的发展,在工程建设时对地表岩土体的开挖、堆填会破坏原有植被覆盖层,造成滑坡等次生灾害,严重危害公共安全。因此如何在确保边坡稳定性的前提下进行水土保持和植被恢复,是我国工程建设中的关键问题。本文以大连市某边坡工程为依托,建立锚杆联合植物根系护坡的边坡支护模式,对该护坡模式的边坡进行稳定性评价及效益评价,以期为工程设计提供技术支持。主要研究内容及成果如下:(1)归纳并整理了边坡的主要破坏模式,并筛选控制边坡稳定性的主要因素,通过对锚杆锚固机理、植物浅层护坡机理的分析研究,提出锚杆联合植物根系护坡的联合支护方式以期减轻坡面变形、提高边坡稳定性。(2)通过有限差分软件模拟不同工况下的大连某边坡变形情况,基于强度折减法和弹塑性法对边坡水平变形、土体沉降、塑性区贯通情况及安全系数进行对比分析。再根据不同边坡运用条件下的边坡变形量及安全系数计算结果对该生态护坡边坡进行稳定性评价。结果表明:锚杆联合植物根系护坡方式大大提高了边坡稳定性,边坡安全系数从1.189的不稳定状态提升至1.777的稳定状态,并通过对比支护前后的边坡模型分析得知边坡最大变形发生在边坡坡面中部,应对其采取集中支护,支护后边坡最大变形移至坡脚处,对实际工程具有一定指导意义。(3)研究了各参数对锚杆联合植根支护的边坡稳定性的影响。通过对边坡稳定性影响因素的分析和辨识,模拟出不同参数条件下边坡安全系数变化规律。计算结果表明,边坡安全系数随边坡岩土体粘聚力和内摩擦角的增大而提高,且粘聚力在边坡坡面角较大时对边坡稳定性的影响更大,内摩擦角与之相反;安全系数随锚杆长度、植物主根长度及植生层密度的增加而提高并呈线性关系,且当锚杆长度超过有效锚固长度时,边坡稳定性不会继续提升,此时滑移面会往坡面移动,降低边坡稳定性。(4)构建了锚杆联合植物根系护坡的边坡效益评价体系。首先,筛选并优化了锚杆联合植根护坡的边坡效益评价指标体系;然后,分别采用相容矩阵法和熵权法计算各评价指标权重,并基于相对熵综合赋权法优化了评价指标权重;最后,构建了基于优度评价法的锚杆联合植根护坡的边坡效益评价模型,并确定了整个锚杆联合植物根系护坡的边坡系统的效益等级为第四等级效益较好状态。更多还原

【Abstract】 With the development of infrastructure construction in China,excavation and filling of ground rock and soil during engineering construction will destroy the original vegetation cover layer,cause secondary disasters such as landslides,and seriously endanger public safety.Therefore,how to carry out soil and water conservation and vegetation restoration on the premise of ensuring slope stability is the key problem in engineering construction in China.In this paper,based on a slope engineering in Dalian City,a slope supporting mode of bolt combined with plant root protection is established,and the slope stability and benefit evaluation of the slope protection mode are carried out,in order to provide technical support for engineering design.The main research contents and results are as follows:(1)The main failure modes of the slope are summarized and sorted out,and the main factors controlling the stability of the slope are screened.Through the analysis and study of the mechanism of bolt anchoring and shallow slope protection mechanism of plants,the combined support mode of bolt combined with plant root slope protection is proposed to reduce slope deformation and improve slope stability.(2)The finite difference software was used to simulate the deformation of a slope in Dalian under different working conditions.Based on the strength reduction method and the elastoplastic method,the horizontal deformation of the slope,soil settlement,penetration of the plastic zone and the safety factor were compared and analyzed.Then the stability of the ecological slope protection is evaluated according to the calculation results of slope deformation and safety factor under different slope operation conditions.The results showed that: Bolt joint has greatly increased the plant roots slope protection method of slope stability,safety factor of slope unstable state up to 1.777 from 1.189 the stability of the state,and through the analysis of the slope model before and after contrast to support that slope deformation occurred in the middle,can create biggest deal with its focus their support,support after the maximum deformation of slope to the slope toe,It has certain guiding significance to actual engineering.(3)The influence of various parameters on the slope stability of bolt-combined root support is studied.Through the analysis and identification of the influencing factors of slope stability,the variation law of slope safety factor under different parameters is simulated.The results show that the safety factor of the slope increases with the increase of the cohesion force and the internal friction Angle of the rock mass,and the cohesion force has a greater effect on the slope stability when the slope Angle is larger,while the internal friction Angle is opposite.The safety factor increases linearly with the increase of bolt length,plant main root length and planting layer density.When the bolt length exceeds the effective anchoring length,the slope stability will not continue to improve,and the slip surface will move to the slope surface and reduce the slope stability.(4)The slope benefit evaluation system of bolting combined with plant root protection was constructed.Firstly,the evaluation index system of slope benefit of bolt-combined root protection is screened and optimized.Then,the weight of each evaluation index is calculated by using the compatible matrix method and entropy weight method respectively,and the weight of evaluation index is optimized based on the relative entropy comprehensive weighting method.Finally,the slope benefit evaluation model based on the goodness evaluation method was established,and the benefit grade of the whole slope system with bolt combined root protection was determined to be the fourth grade with better benefit status.更多还原