摘要
为明确青藏高原多年冻土区在役公路路基变形的主要驱动因素及其对气候变化的适应能力,选取了穿越青藏高原多年冻土区的两大工程走廊——格尔木至那曲、共和至玉树的3条在役公路进行研究,分析了路基变形状况指标与气候环境参数、交通荷载差异、路基工程本体参数、路基工程所在场地参数的空间相关性;提出了青藏高原多年冻土区公路路基气候韧性的概念。分析结果表明:海拔高度与最大冻结深度、植被覆盖率与年累计降水量是影响路表国际平整度指数、跳车指标变化最主要的驱动因素,相关系数绝对值均超过0.4,明显区别于其他因素;季节冻土带无论年累计降水量高低,路面行驶质量指数(RQI)均保持良好以上;而多年冻土带的年累计降水量在220~370 mm区间时,RQI几乎全为差;多年冻土带的累计降水量达到370 mm以上时,多年冻土含冰量、地下水、土质类型和路侧积水侵蚀沿路线方向的跳跃性分布是其变形的主要驱动因素;此外,年降水量超过370 mm及路侧积水产生的热积累效应导致融区与多年冻土岛状交替发育,成为该区域无法明确强相关驱动因素的主要原因;路基总体随天然大地发生长周期沉降和季节性冻胀融沉,特殊结构路基可减缓形变速率,桩筏地基处理方式可有效终止沉降趋势;建议通过增强路面-路基-地基体系结构韧性及削弱气候环境对场地参数的不利影响等路径,提升多年冻土区公路路基的气候韧性,为该区域的公路工程维养改造提供理论指导和实践参考。
To identify the main driving factors of deformation for inservice highway subgrades in the permafrost region of the Qinghai-Xizang Plateau and their adaptability to climate change,three inservice highways crossing the two major engineering corridors—Golmud to Nagqu and Gonghe to Yushu in the permafrost region of the Qinghai-Xizang Plateau were selected.The spatial correlations between indicators of subgrade deformation and a range of factors,including climate environment parameters,traffic loading differences,inherent parameters of subgrade engineering,and parameters of the site where the subgrade engineering was located were examined.The concept of climate resilience for highway subgrades in the permafrost region of the Qinghai-Xizang Plateau was proposed.Analysis results show that elevation and maximum frozen depth,as well as vegetation coverage and annual cumulative precipitation,are the predominant driving factors influencing the variation of the international roughness index and bumpiness index,with absolute correlation coefficients exceeding 0.4,significantly distinguishing them from other factors.In the seasonal frozen zone,regardless of the annual cumulative precipitation,the road quality index(RQI)remains above good level.In the permafrost zone,when the annual cumulative precipitation is in the range of 220-370 mm,the RQI is mostly poor.However,when the annual cumulative precipitation exceeds 370 mm,the main driving factors of subgrade deformation are the ice content of permafrost,groundwater,soil type,and the jump-like distribution of roadside accumulated water erosion along the route.Furthermore,the heat accumulation effect caused by annual precipitation exceeding 370 mm and roadside water accumulation leads to the alternating development of thaw zones and permafrost islands,which is the main reason for the lack of clear strong correlation with the driving factors in this region.The subgrade overall follows the long-cycle subsidence and seasonal frost heave-thaw collapse of the natural terrain,and the use of subgrades with special structures can slow down the subsidence rate,while pile-raft foundation can effectively terminate the subsidence trend.It is recommended to enhance the structural resilience of the pavement-subgrade-foundation system and reduce the adverse impact of climate environment on site parameters to improve the climate resilience of highway subgrades in permafrost regions.This study provides theoretical guidance and practical reference for the maintenance and renovation of highway engineering in this region.
作者
权磊
田波
李思李
李立辉
张盼盼
犹铄森
彭智鑫
符敏仪
QUAN Lei;TIAN Bo;LI Si-li;LI Li-hui;ZHANG Pan-pan;YOU Shuo-sen;PENG Zhi-xin;FU Min-yi(Fundamental Research Innovation Center,Research Institute of Highway Ministry of Transport,Beijing 100088,China)
出处
《交通运输工程学报》
北大核心
2025年第5期38-52,共15页
Journal of Traffic and Transportation Engineering
基金
国家重点研发计划(2023YFB2604800)
西藏自治区重点研发项目(XZ202501ZY0062)。
关键词
道路工程
气候韧性
相关性分析
多年冻土
路基变形
驱动因素
road engineering
climate resilience
correlation analysis
permafrost
subgrade deformation
driving factor
