多年冻土区路桥过渡段路基优化结构稳定性研究  

Study on stability of optimized structure of subgrade in transition section of road and bridge in permafrost region

作　　者：牛玉川 吴亚平[2] 罗涛 燕波 NIU Yuchuan;WU Yaping;LUO Tao;YAN Bo(Shaanxi Railway Institute,Weinan 714000,Shaanxi,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]陕西铁路工程职业技术学院,陕西渭南714000 [2]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《冰川冻土》2024年第4期1279-1289,共11页Journal of Glaciology and Geocryology

基　　金：陕西铁路工程职业技术学院2022年科研基金项目(KY2022-24);国家自然科学基金重点项目(51236003);国家科技支撑计划课题(2014BAG05B05);中国铁路总公司科技研究开发计划课题(2015G005-C)资助。

摘　　要：由于冻胀融沉等病害导致青藏铁路路基问题较一般的地区更加严重且复杂多变。路桥过渡段作为道路与桥梁的重要衔接,路基与桥台的沉降差异严重影响铁路运营的安全性及行车的舒适性。结合一般地区的过渡段差异性沉降治理办法,从刚度差异入手,同时考虑冻土的活动层特性,提出桩基路桥过渡段优化结构,达到路基与桥台刚度的平缓过渡,同时对优化结构进行长期效果分析。结果表明:在过渡段路基处埋设双排四根混凝土桩基后,在持续外荷载以及循环温度荷载作用下,混凝土桩基对冻土温度场影响较小,能保证冻土良好的稳定性;路基与桥台差异性沉降和轨面折角大幅度降低;在全球气候变暖的环境下,通过ANSYS模拟分析温度场、位移场发现,混凝土桩基对过渡段处路基的温度场影响较小,对于差异性沉降治理效果十分显著。Since the Qinghai-Xizang Railway started operating,the subgrade problems caused by frost heave,thaw settlement and other diseases are more serious and complex than those in ordinary areas.As an important link between road and bridge,the settlement difference between subgrade and abutment seriously affects the safety of railway operation and driving comfort.Combined with the treatment methods of differential settlement in the transition section in general areas,starting from the stiffness difference,and considering the characteristics of the active layer of frozen soil,this paper puts forward the optimized structure of the transition section of pile foundation road and bridge,so as to achieve the smooth transition between the stiffness of subgrade and abutment,and analyzes the long-term effect of the optimized structure.The results show that after embedding two rows of four concrete pile foundations in the transition section subgrade,under the continuous external load and cyclic temperature load,the concrete pile foundation has little effect on the frozen soil temperature field,which can ensure the good stability of frozen soil.The differential settlement of subgrade and abutment and the rail surface angle are greatly reduced.In the global warming environment,through ANSYS simulation and analysis of temperature field and displacement field,it is found that the concrete pile foundation has little influence on the temperature field of subgrade at the transition section,and the treatment effect for differential settlement is very significant.

关 键 词：铁路路基 路桥过渡段 试验研究 青藏铁路 

分 类 号：U213.1[交通运输工程—道路与铁道工程]