青藏工程走廊道路工程阴阳坡效应研究现状及展望

青藏工程走廊整体呈东北-西南走向,加之青藏高原强烈的太阳辐射及大气透明度高,导致廊内路基工程存在显著的"阴阳坡"效应。在阴阳坡热效应作用下,路基阳坡路肩沉降变形普遍大于阴坡路肩,由此引发包括路基倾斜、边坡滑塌、纵向裂缝等一系列路基路面病害问题,严重影响了路基工程的长期稳定性,大幅增加了工程后期运营维护成本。针对这一问题,从青藏工程走廊阴阳坡效应的成因、阴阳坡效应作用下路基体冻融过程及地基温度场分布、路基的横向差异沉降变形、阴阳坡效应相关路基路面病害以及防控措施5个方面系统论述了目前的研究和工程实践现状,并结合阴阳坡效应的量化研究、防治措施的有效性等方面就未来需要开展的研究工作进行了展望,以期为青藏工程走廊内路基工程的建设与维护提供参考。

Recent Research Progress and Prospect of the South and North-facing Slope Effect in the Roadway Engineering along the Qinghai-Tibet Engineering Corridor

The Qinghai-Tibet Engineering Corridor runs from the northeast to southwest. Because of the strong solar radiation and high atmospheric transparency in the Qinghai-Tibet Plateau, south-facing and north-facing slopes widely exist along the corridor. Due to the south-and north-facing slope effect, embankment settlement was generally greater for the south-facing slope than the north-facing slope, which triggered a series of embankment and pavement damages, including roadbed inclination, slope failure, and longitudinal cracks. These damages seriously undermined the stability of the embankments, and greatly increased the operation and maintenance cost during the latter period of the project. To address this issue, the causes of the south-and north-facing slope effect, the differential freezing-thawing process of the embankment, the asymmetrical distribution of temperature field beneath the embankment, the lateral differential embankment settlement, the related embankment and pavement damages, and the prevention measures of this effect were systematically reviewed and discussed in this paper. Some development trends regarding the quantitative research of this effect and the effectiveness of related prevention and control measures were also outlined. The review and prospect in this paper will provide reference for future constructions and maintenance of embankment engineering in the Qinghai-Tibet Engineering Corridor.