西安建筑科技大学学报(自然科学版)

隧道下穿运营高速公路路基边坡施工扰动造成既有路基边坡的松动和变形,降雨入渗引起的下滑力增加和滑面抗剪强度的降低进一步加剧了边坡的变形,考虑降雨入渗和隧道下穿施工影响的路基边坡稳定性分析及确定合理、可行的加固方案对确保路基边坡的稳定性尤为重要.以贵阳轨道交通1号线下麦西地铁隧道下穿运营高速公路路基边坡工程为背景,考虑雨水入渗条件下隧道施工扰动对边坡稳定的影响,基于路基边坡土体的土 - 水特征曲线特性构建非饱和土体的流固耦合计算模型,分析雨水入渗条件下扰动路堤边坡的位移、塑性区特性和路堤边坡的安全性,分析结果表明降雨入渗对含软弱夹层的路基边坡稳定性影响显著,造成路堤边坡沿该弱面的塑性区贯通; 考虑降雨的影响,经历降雨影响后的边坡安全系数降低,低于原边坡的安全系数,因此对受临近施工扰动的边坡需要考虑不同降雨次数后边坡安全性的累积作用.考虑降雨对扰动路堤边坡的影响,对比分析了锚索和抗滑桩加固措施对边坡滑移的控制效果,建议并实施了路堤边坡的施工,取得了良好效果.

Rainfall has important influence on slope stability, it has been a hot and difficult topic to study the mechanical knowledge of unsaturated soil for simulating the deformation of unsaturated soil roadbed slope under the condition of rainfall infiltration. This paper adopted the unsaturated soil fluid-solid coupling calculation model which considering hydraulic permeability coefficient and soil-water characteristic curve for the numerical analysis about the seepage field and stress field coupling of unsaturated roadbed slope under the condition of rainfall infiltration to calculate the stability about the interaction between roadbed slope and tunnel. The results show that rainfall infiltration has a significant influence on the stability of roadbed slope with weak interlayer, meanwhile the slope safety factor and potential sliding surface position are different under the condition of same rainfall intensity with different rainfall duration, which is based on the project of Guiyang No.1 rail transit line underpass the roadbed slope of existing expressway. At the same time, this paper also discusses the control effects of different reinforcement measures to reduce the slope slippage, and it is concluded that the anchorage cable reinforcement can effectively reduce the slope slippage.

引言
1 模型计算理论
2 非饱和土边坡的稳定性分析
3 考虑降雨影响的稳定性分析
4 基于数值分析的边坡加固建议
5 结论

图1 路基边坡三维模型<br/>Fig.1 Three-dimensional model of the roadbed slope

图1 路基边坡三维模型
Fig.1 Three-dimensional model of the roadbed slope

表1 土体参数
Tab.1 The soil parameter

图2 降雨与位移约束边界<br/>Fig.2 Rainfall and displacement constraint boundary

图2 降雨与位移约束边界
Fig.2 Rainfall and displacement constraint boundary

图3 雨量为200 mm/d时孔隙水压力变化云图<br/>Fig.3 The variational cloud diagram of pore water pressure when rainfall intensity is 200 mm/d

图3 雨量为200 mm/d时孔隙水压力变化云图
Fig.3 The variational cloud diagram of pore water pressure when rainfall intensity is 200 mm/d

图4 持续降雨时边坡塑性区变化云图<br/>Fig.4 The variational cloud diagram of roadbed slop plastic zone during continuous rainfall

图4 持续降雨时边坡塑性区变化云图
Fig.4 The variational cloud diagram of roadbed slop plastic zone during continuous rainfall

图5 边坡总位移云图<br/>Fig.5 Total displacement cloud diagram of roadbed slop

图5 边坡总位移云图
Fig.5 Total displacement cloud diagram of roadbed slop

表2 边坡安全系数变化情况<br/>Tab.2 The changing of the slop safety factor

表2 边坡安全系数变化情况
Tab.2 The changing of the slop safety factor

图6 加固措施布置图<br/>Fig.6 Reinforcement measures plan

图6 加固措施布置图
Fig.6 Reinforcement measures plan

图7 边坡加固模型<br/>Fig.7 Slope reinforcement model

图7 边坡加固模型
Fig.7 Slope reinforcement model

表3 锚索、抗滑桩力学参数<br/>Tab.3 The mechanics parameter of anchor cable and anti-slide piles

表3 锚索、抗滑桩力学参数
Tab.3 The mechanics parameter of anchor cable and anti-slide piles

表4 各工况下边坡位移值比较分析<br/>Tab.4 Analysis of the displacement values of the slope under three conditions

表4 各工况下边坡位移值比较分析
Tab.4 Analysis of the displacement values of the slope under three conditions

图8 各工况下边坡总位移、水平位移变化情况比较<br/>Fig.8 Comparison of total displacement、horizontai displacement of slope under three working conditions

图8 各工况下边坡总位移、水平位移变化情况比较
Fig.8 Comparison of total displacement、horizontai displacement of slope under three working conditions

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备注

引言

1 模型计算理论

2 非饱和土边坡的稳定性分析

3 考虑降雨影响的稳定性分析

4 基于数值分析的边坡加固建议

5 结论

期刊信息