用地震折射法探测沥青路面的季节融化深度及其变化

Survey of Seasonally Thawing Layer and Its ChangeBeneath Asphalt-paved Road with SeismicRefraction Method

试验结果表明,用经过数字化改造后的地震仪测出的路心融化深度,与钻孔测温确定的融化深度相比,其解释误差小于7％。路基和涵洞横剖面的探测结果能反映出融化层变化的主要趋势。不同路堤高度的路基形成的融化横剖面均呈下凹形,而涵洞下形成的融化横剖面则是涵洞中心的融化深度小于两端洞口处的融化深度。因此,地震折射法将为多年冻土地区路基的修筑和稳定性研究提供一种简捷、可靠的探测手段。

The test results prospecting seasonally thawing depth in the asphalt-paved road of Qinghai-Xizang Highway with refraction method in 1983-1984 have been summarized. Because there is an evident difference in elastic velocity between thawed and frozen soils, and active layer on permafrost with lower elastic velocity, it is easy to delineate their boundary with refraction method. Comparing with seasonally thawing depth determined by temperature monitoring in bore holes of the roadbed, prospecting errors with converted engineering seismograph of model DZG6-1 for seasonally thawing layer along the road center are less than 7%, while traveltime plots on cross sections of roadbed and culvert could indicate general change of thawing layer. According to test results, the seasonally thawing depth at the center of asphalt-paved road is deeper than that at both sides, whereas the seasonally thawing depth in culvert center is shallower than that in both exits of the culvert.