面波测试在汶川强震区土体损伤调查中的应用

汶川地震后,确定地震对岩土体扰动的范围和损伤程度,是预测震后次生山地灾害演化趋势,以及制定道路修复加固工程对策的重要依据。面波勘察是通过获取剪切波速变化情况,推断土体扰动范围的快捷手段。本文在位于汶川地震强震区的213国道都汶段内的2个边坡工点和3个路堤工点,布设6个测段进行了高精度面波浅层地震勘查。结果表明：①9度和10度地震烈度区土体扰动的深度无明显差别;②在汶川地震强震区,人工填筑的路堤工程所造成的强扰动区深度不小于5 m,自然土体造成的强扰动区深度为0-5 m;③路堤工程表面填、挖交界处的损伤明显。上述结论可供灾后道路修复工程设计中确定边坡加固深度和路堤翻挖深度时参考。

Application of Surface Wave Testing in Survey of Mountain Soil Damage in Wenchuan Strong Earthquake Area

After the Wenchuan earthquake,to determine the scope of soil disturbance and the degree of soil damage is a significant basis for road repair and reinforcement works as well as for predicting the evolution of mountain post-earthquake hazard trends. It＇s a quick means to obtain the change of shear wave velocity through surface wave survey in order to infer the scope of soil disturbance. In this paper, we introduce the high-precision surface wave shallow seismic exploration of six sites respectively located in two slope con- struction points and three embankment construction points aside the Duwen segment of National Highway 213 in strong earthquake zones. The following test results are obtained： （1）The disturbance depth of the soil in IX and X seismic intensity area is not significantly different; （2） In the Wenchuan strong earthquake zones, the soil disturbance depth of manual filling of the embankment projects is more than or equal to 5 m, while the natural soil of slope is less than or equal to 5 m; （3） Between filling and digging section in the surface of the embankment construction, the junction injury is obvious. The above conclusions are important for road rehabilitation to determine the depth of both embankment repair digging and slope reinforcement during the Wenchuan reconstruction.