摘要
以某黄土公路隧道为对象,基于室内试验和数值分析方法,研究隧道所处黄土地层的地下水位不同抬升高度、地层不同增湿程度对衬砌结构的力学响应。主要结果与结论:地层地下水位抬升及增湿期间,降低了隧道地层的成拱效应,衬砌应力均呈增大趋势,拱脚及拱顶处衬砌受力趋于不安全状态,水位抬升高度每增加70%,拱脚部位衬砌拉、压应力分别提高20%和10%;地层含水率每增加30%,拱脚部位衬砌拉、压应力提高50%和12%;采取修正的围岩压力计算公式,能更合理的反映黄土地层增湿效应下“围岩压力放大效应”,应从加强支护力度、改善围岩条件和增强防排水措施三个角度来改善黄土隧道在施工期成洞条件和增强工后期的长期稳定性。
Taking a highway tunnel in loess region as the research object,based on laboratory tests and numerical method,the mechanical response of lining under different elevation of underground water level and wetting degree of surrounding soil to lining was tested.The results are as follows.During the rise of underground water level and wettiing condition of tunnel surrounding loess,the arching effects of tunnel decreased and the stress at different positions of the lining all showed a increase trend,the foot and vault of lining tend to be unsafe.When the height of water level increased by 70%,the maximum tensile stress of lining foot increases by about 20%on average,the average compressive stress increases by about 10%.The maximum tensile stress and compressive stress of the lining foot increased by about 50%and 12%on average for every 30%increase in water content.The modified calculation formula for surrounding soil pressure can more reasonably reflect the amplification effect of surrounding soil pressure under the wetting effect of loess stratum,which is safer and more reliable for the design.Strengthening the support strength and the surrounding soil,strengthening the waterproof and drainage measures,from the above three aspects,the tunnel forming conditions during the construction period and the long-term stability during the post-construction period should be improved.
作者
李玉波
朱才辉
段宇
吴宏
王振林
LI Yubo;ZHU Caihui;DUAN Yu;WU Hong;Wang Zhenlin(China Railway First Survey And Design Institute Group Co.,Ltd.,Xi’an,Shaanxi 710043,China;Institute of Geotechnical Engineering,Xi’an University of Technology,Xi’an,Shaanxi 710048,China;Shaanxi Han River-Wei River Diversion Project Construction Co.,Ltd.,Xi’an,Shaanxi 710010,China)
出处
《水利与建筑工程学报》
2020年第6期33-38,共6页
Journal of Water Resources and Architectural Engineering
基金
国家自然科学基金资助项目(51678484)
陕西省自然科学基金资助项目(2019JLP-22)。
关键词
黄土隧道
衬砌结构
力学响应
增湿效应
loess tunnel
lining construction
mechanical response
wetting effect
