“三柳”高速公路典型路堑高边坡稳定性分析

发布时间：2018-04-05 19:00

本文选题：高速公路　切入点：路堑边坡　出处：《石家庄铁道大学》2015年硕士论文

【摘要】：我国是一个多山的国家,山地占总面积的60%以上,尤其是西部地区,高山峡谷等复杂的地形给工程建设带来了众多的难题。为加快西部地区的发展,2000年国家制定了西部大开发战略,近年来,随着西部大开发战略的推进,越来越多的高速公路开工建设,而这些高等级公路的建设不可避免地面临着深挖路堑高边坡。广西三江至柳州高速公路是广西壮族自治区高速公路网“4纵6横3支线”的重要组成部分,是三江到北海高速公路的起始段。以三柳高速公路典型路堑高边坡为研究对象,先根据现场地质调查及室内岩土物理力学试验、原位测试,定性评价天然边坡的整体稳定性,提出开挖的合理建议,然后基于FLAC3D有限差分软件,采用有限差分强度折减法对天然边坡和路堑开挖边坡进行数值模拟分析,得到边坡在不同状态下的剪应变、塑性区和变形特征,为边坡开挖和支护提供依据。通过理论分析、稳定性定性分析和数值模拟,结果表明:(1)根据现场工程地质情况调查,天然状态下该边坡处于稳定状态,主要岩土体从上至下依次为粉质粘土、全风化黑色绢云千枚岩夹砂岩、强风化黑色绢云千枚岩夹设宴、微风化黑色绢云千枚岩夹砂岩;(2)采用有限差分强度折减法对天然边坡的FLAC3D数值分析表明,边坡稳定性系数为1.22,处于稳定状态,坡体位移较小,塑性区没有贯通,没有出现明显的滑动面;(3)路堑开挖后,边坡的稳定性系数降至0.81,边坡失稳,公路内侧高边坡塑性区贯通,形成圆弧形滑面,坡脚挤压隆起,坡顶向下滑动,产生滑坡;(4)建议对边坡采取分级放坡开挖,公路内侧边坡采用锚杆框架梁支护,外侧边坡采用植被护坡。
[Abstract]:China is a mountainous country, which accounts for more than 60% of the total area, especially in the western region, mountain canyons and other complex terrain has brought a lot of problems to the engineering construction.In order to speed up the development of the western region, the state formulated the strategy for the large-scale development of the western region in 2000. In recent years, with the development of the western region strategy, more and more highways have started to build.The construction of these high-grade highways is inevitably faced with deep excavation cutting high slope.Guangxi Sanjiang to Liuzhou expressway is an important part of Guangxi Zhuang Autonomous region highway network "4 longitudinal 6 horizontal 3 branch line", is the beginning section of Sanjiang to Beihai Expressway.Taking the typical cutting high slope of Sanliu Expressway as the research object, according to the field geological investigation and the indoor geotechnical physical and mechanical test, in situ test, the overall stability of the natural slope is evaluated qualitatively, and the reasonable suggestion of excavation is put forward.Based on the FLAC3D software, the shear strain, plastic zone and deformation characteristics of the natural slope and the cut excavation slope are obtained by using the finite difference strength reduction method, and the shear strain, plastic zone and deformation characteristics of the slope under different conditions are obtained.It provides basis for slope excavation and support.Through theoretical analysis, qualitative stability analysis and numerical simulation, the results show that according to field engineering geological investigation, the slope is in a stable state in natural state, and the main rock and soil mass is silty clay from top to bottom.Fully weathered black sericite phyllite intercalated sandstone, strongly weathered black sericite phyllite intercalated with banquet, breeze black sericite phyllite intercalated sandstone Kuo 2) the FLAC3D numerical analysis of natural slope by finite difference strength reduction method shows that,The stability coefficient of the slope is 1.22. The slope is in a stable state, the displacement of the slope is small, the plastic zone is not through, and there is no obvious slip surface. After excavation, the stability coefficient of the slope decreases to 0.81, the slope is unstable and the plastic zone of the high slope inside the highway is through.It is suggested that the slope should be excavated by stages, the inside side of the highway should be supported by anchor frame beam, and the outside slope should be protected by vegetation.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.14

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