基于探地雷达测量的青藏公路多年冻土区热棒路基降温效果分析  

Cooling effect analysis of thermosyphons used in Qinghai-Xizang Highway in permafrost regions based on GPR measurement

作　　者：景晶晶 吴志坚 丁万鹏 张晓华 马巍 JING Jingjing;WU Zhijian;DING Wanpeng;ZHANG Xiaohua;MA Wei(School of Transportation Engineering,Nanjing Tech University,Nanjing 211816,China;School of Architectural Engineering,Jiangsu Open University,Nanjing 210036,China;Jiangsu Province Engineering Research Center of Transportation Infrastructure Security Technology,Nanjing 211816,China)

机构地区：[1]南京工业大学交通运输工程学院,江苏南京211816 [2]江苏开放大学建筑工程学院,江苏南京210036 [3]江苏省交通基础设施安全保障技术工程研究中心,江苏南京211816

出　　处：《冰川冻土》2024年第6期1728-1740,共13页Journal of Glaciology and Geocryology

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0905);国家自然科学基金项目(42330704);江苏省高等学校自然科学研究面上项目(22KJB560013)资助。

摘　　要：青藏高原气候暖湿化加剧了多年冻土退化速率,影响公路、铁路等基础设施稳定性。热棒技术具有主动单向降温特点,已广泛应用于我国青藏高原和东北部的多年冻土地区。现有研究多采用数值仿真或钻孔测温方式分析热棒技术的降温效果,随着地球物理探测技术的发展,探地雷达技术为冻土工程领域提供了一种连续且无损的新研究方法。本文以青藏公路沱沱河至唐古拉山垭口段为研究区,采用探地雷达技术研究热棒技术对路基的降温效果。在道路病害调查的基础上,选取双侧单排直插热棒路基、单侧单排斜插热棒路基和相邻未处治冻土路基三处典型路段,采用探地雷达技术探测分析路基结构损伤和下伏冻土分布情况,结合现场考察评价不同热棒布设方式对冻土路基降温效果的影响。结果表明降温效果:双侧单排直插热棒路基>单侧单排斜插热棒路基>未处治路基。双侧单排直插热棒路基下伏多年冻土层分布具有良好的连续性,与路侧天然地表相比冻土上限提升0.47 m,其上路基结构完整;单侧单排斜插热棒路基下伏多年冻土层连续性一般,冻土上限与路侧天然地表相比较为接近,其上路基结构存在结构疏松和裂隙区域;未处治路基下伏多年冻土层分布连续性较差,冻土退化明显,冻土上限较路侧天然地表退化0.80 m,其上路基结构存在大面积疏松和局部积水。同时,冻土退化会诱发道路工程病害,对比发现单侧单排斜插热棒路基和未处治路基冻土退化路段,路基结构疏松和裂隙发育,不均匀沉降和路面裂缝、坑槽等病害多发。探地雷达测试能够较好地呈现道路下伏多年冻土的分布情况和路基结构损伤特征,分析路面病害机理,为公路大中修方案提供科学依据。分析表明热棒技术可以有效减缓路基下伏多年冻土的退化速率,但不同的布设方式对热棒的降温效果有一定�The warming and humidifying climate on the Qinghai-Xizang Plateau of China is causing permafrost degradation at a faster rate,which is affecting the stability of infrastructure such as highways and railways on it.To resolve this problem,thermosyphons have been widely applied to protect the degrading permafrost in Northeast China and the Qinghai-Xizang Plateau.The thermosyphon has the characteristic of active unidirectional cooling.Existing researches often use numerical simulation or borehole temperature measurement methods to analyze its cooling effect on permafrost foundations.With the development of geophysical exploration technology,ground penetrating radar(GPR) technology provides a new research method for frozen soil engineering,which can obtain continuous data without causing damage to structures.The section of the Qinghai-Xizang Highway from Tuotuo River to Tanggula Mountain Pass was selected as the research area,and GPR technology is used to study the cooling effect of thermosyphons.Based on the investigation of road problems,three typical road sections were selected,where double-sided and single-row vertical thermosyphons,single-sided and single row oblique thermosyphons,and adjacent non-thermosyphons were placed,respectivley.GPR technology was used to detect and analyze structural damage and underlying permafrost distribution.Meanwhile,combined with onsite investigations,the impact of different thermosyphon placement methods on the cooling effect of frozen soil embankment was evaluated.The results indicate that the cooling effect is as follows:double-sided and single row vertical thermosyphons have better cooling effect,followed by single-sided and single row oblique thermosyphons and non-thermosyphon.The distribution of the permafrost layer beneath the double-sided and singlerow vertical thermosyphon embankment had good continuity,with an increase of 0.47 m in the upper limit of permafrost compared to the natural surface near the road,and the road structure was entire.The permafrost layer under the si

关 键 词：多年冻土 青藏公路 热棒 探地雷达 

分 类 号：U216.417[交通运输工程—道路与铁道工程] P642.14[天文地球—工程地质学]