青藏公路多年冻土区路基融化槽发育特征

Development characteristeristics of subgrade thawing trough in permafrost regions along Qinghai-Tibet highway

融化槽在青藏公路多年冻土区路基中是普遍存在的,它是导致路基产生不均匀沉陷、坑槽、翻浆、纵(横)向裂缝、路肩坍塌等病害的主要原因。通过整理青藏公路沿线多年冻土路基的大量钻孔资料,分析3次地质雷达探测成果,确定了青藏公路沿线连续多年冻土区南北界、典型河流融区边界,并提出了一种利用"n系数"法来确定高山越岭区不发育融化槽路段边界的计算方法。利用以上手段,进一步明确了青藏公路多年冻土区沥青路面路基融化槽的分布区域及边界、变化规律和形态特征,可为多年冻土区沥青公路路基的设计和运营维护提供理论支持和技术服务。

Studies have shown that thawing trough is widespread under subgrade of Qinghai -Tibet Highway in permafrost regions .Thawing trough is the main reason of causing differential settlement , pothole , pumping , longitudinal or transverse cracks , road shoulder collapse .By sorting borehole data of Qinghai-Tibet Highway in permafrost regions , analyzing the results of three times GPR detections , comprehensively determines the south and north boundary of permafrost regions along Qinghai-Tibet Highway and the boundary of typical river taliks . Furthermore, a calculation method of “n coefficient” for determining the boundary of mountainous highway where subgrade did not develop the thawing trough is proposed .Using the above comprehensive means , this subject further defined the distribution area and its boundary, change rule, morphological characteristics of the thawing trough.The research results can provide theoretical support and technical services for roadbed design , operation and maintenance of Qinghai-Tibet Highway .