摘要
以中国一带一路重点项目西藏自治区羊八井至大竹卡段公路改建工程为依托,研究了高原冻土地区公路边坡冻融稳定性及施工技术.采用有限元软件MIDAS-GTS NX建立边坡模型,运用强度折减法计算、分析了冻融循环前后公路边坡位移、应力及应变等力学特性的变化规律,并与施工现场检测数据进行对比分析.结果表明:边坡水平方向上的最大位移发生在坡趾位置,竖直方向上的最大位移发生在坡肩位置;经历冻融循环后,边坡水平位移、竖向位移分别增加1.91 cm和7.5 cm,且坡面破坏以竖向沉降为主;边坡水平和竖直方向上的最大应力均发生在坡底,并出现应力集中现象.结合工程特点及模拟分析结果提出减小冻土开挖深度、锥形坡面砌筑、拱式防护、仰斜式路肩墙、浸水路肩墙以及主动防护系统等防护措施,后期现场观测表明,冻融引起公路边坡失稳问题治理效果明显.将建模理论计算值和工程实测值进行比较分析,验证了本文方法的正确性.
Based on the reconstruction project of the Yangbajing to Dazhuka section of the Tibet Autonomous Region,as a key project of China’s Belt and Road Initiative,the freeze-thaw stability and construction technology of highway slopes in plateau frozen soil areas were studied.The finite element software MIDAS-GTS NX was used to establish the slope model,and the strength reduction method was used to calculate and analyze the changes of the mechanical characteristics of the highway slope displacement,stress and strain before and after the freeze-thaw cycle,and compared with the construction site test data.The results show that the maximum displacement in the horizontal direction of the slope occurs at the position of the toe,and the maximum displacement in the vertical direction occurs at the position of the slope shoulder.After the freeze-thaw cycle,the horizontal and vertical displacements of the slope increase by 1.91 cm and 7.5 cm,respectively,and the slope failure is dominated by vertical settlement.The maximum stress in both the horizontal and vertical directions of the slope occurs at the bottom of the slope,and stress concentration occurs.Combining engineering characteristics and simulation analysis results,protective measures such as reduction of the excavation depth of frozen soil,conical slope masonry,arch protection,inclined shoulder wall,flooded shoulder wall,and active protection system are proposed.Later field observations show that freezing the treatment effect of road slope instability caused by melting is obvious.The comparison and analysis between the theoretical calculation value of the modeling and the actual engineering measurement verify the correctness of the method in this paper.
作者
丁姣月
程伟峰
于英霞
梁斌
DING Jiaoyue;CHENG Weifeng;YU Yingxia;LIANG Bin(School of Civil Engineering,Henan University of Science and Technology,Henan Luoyang471023,China;CCCC-SHEC Forth Engineering Co.Ltd.,Henan Luoyang471013,China)
出处
《河南大学学报（自然科学版）》
CAS
2021年第3期329-338,共10页
Journal of Henan University:Natural Science
基金
国家自然科学基金资助项目(U1604135)
中交第二公路局有限公司重点科研项目(2017-1-1)
河南省科技厅产学研合作项目(2015HNCXY011)。
关键词
高原冻土地区
冻融
公路边坡稳定性
施工技术
强度折减法
lateau frozen land
freeze-thaw
highway slope stability
construction technology
strength reduction method
