摘要
在我国公路路线建设过程中,不可避免地会遇到地形起伏较大的地质环境,一般采取以深挖路堑形式通过,这可能会形成含球状风化体混合花岗岩边坡。混合花岗岩边坡坡体中球状风化体的存在易形成落石及崩塌,为此开展此类边坡的稳定性分析及加固措施研究显得十分重要。以某拟建公路K248+640标段含球状风化体混合花岗岩边坡实际工程为案例,根据现场勘察得到的球状风化体含量,采用随机程序生成半径1 m的球状风化体数据,并导入PLAXIS2D中构建相应边坡数值模型;利用有限元强度折减法开展边坡稳定性研究,探究不同工况下边坡的稳定性,并提出了3种不同的边坡加固方案;通过该类边坡不同加固方案位移、剪应变、稳定性系数等方面的数值模拟分析,并经过现场实测数据的印证,揭示了锚索格构梁方案加固该类边坡的可行性。结果表明:(1)含球状风化体混合花岗岩边坡稳定性变化规律表现为,最大剪应力随开挖步数逐渐增多整体上呈现出前期缓增、中期陡增、后期缓增的阶段性发展特征;(2)被动支护与主动施加反压力支护对含球状风化体混合花岗岩边坡支护效果有明显的不同,总结出被动支护与主动施加反压力支护的区别;(3)数值模拟与现场验证相结合,监测数据显示该类边坡采取锚索格构梁方案可以取得较好的支护效果。该研究可为锚索格构梁方案在此类含球状风化体混合花岗岩边坡加固中的应用提供借鉴。
In the process of highway construction in our country,it is inevitable to encounter geological environments with large terrain undulations.Generally,deep excavation of road cuts is adopted to pass through,which may form a mixture of spherical weathering granite.The presence of spherical weathering body in mixed granite slope can easily lead to rockfall and collapse,making it important to conduct stability analysis and reinforcement measures research on such slope.Taking the K248+640 section of a proposed highway as a case study,based on the content of spherical weathering body obtained from on-site investigation,in this paper a random program is used to generate spherical weathering body data with a radius of 1 m,and the corresponding slope model is constructed by importing it into PLAXIS2D.Using the finite element strength reduction method to conduct slope stability research,the paper explores the slope stability under different working conditions,and proposes three different slope reinforcement schemes.Through numerical simulation analysis of displacement,shear strain,stability coefficient,and other aspects of different reinforcement schemes for this type of slope,and confirmed by on-site measured data,the feasibility of using anchor cable lattice beam scheme to reinforce this type of slope is revealed.The results are as follows:①The stability variation law of the mixed granite slope containing spherical weathering body shows that the maximum shear stress gradually increases with the number of excavation steps,and overall shows a phased development feature of gradual increase in the early stage,sudden increase in the middle stage,and gradual increase in the later stage;②There is a significant difference in the support effect of passive support and active application of counter pressure support on mixed granite slopes containing spherical weathering body.The differences between passive support and active application of counter pressure support are summarized;③Combining numerical simulation with on-site ver
作者
董高一
周春梅
许方党
高鹏
DONG Gaoyi;ZHOU Chunmei;XU Fangdang;GAO Peng(School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430073,China;Zhejiang Geology and Mineral Technology Co.,Ltd.,Hangzhou 310007,China)
出处
《安全与环境工程》
CAS
CSCD
北大核心
2024年第2期180-192,共13页
Safety and Environmental Engineering
基金
国家自然科学基金项目(52174085、52174086)。
关键词
球状风化体
混合花岗岩边坡
稳定性
加固方案
数值模拟
spherical weathering body
mixed granite slope
stability
reinforcement scheme
numerical simulation
