路基压实度剪切波测试新技术

对含砂低液限粘土、含砂低液限粉土与低液限粘土3种土样采用重型击实试验的方法进行了土的干密度与剪切波速的对比试验。大量试验结果表明,路基土干密度与剪切波速存在显著的相关性,各种土质的干密度与剪切波速的关系模型各不相同,但都可以利用4种典型回归模型来描述。论证了路基表层土压实度可以代表本层的压实度,提出了利用直达剪切波检测路基干密度的新方法。最后应用"振三压三"的压实方法对所得模型进行验证,将按照模型用剪切波速计算得到的数据与灌砂法所得数据进行了比较。现场试验表明:通过建立具体工程的干密度与剪切波速的关系模型,采用直达剪切波速检测技术,可以较好地实现路基压实度的无损检测。

Detecting Subgrade Compactness by Direct Shear Wave Method

The contrary experiment between the dry density of soil and the shear wave velocity was carried through compaction test of the sand clay of low liquid limit,sand silt of low liquid limit and clay of low liquid limit.The correlation between the dry density and the shear wave velocity of subgrade soils was studied using a large number of tests.The result shows that there is great difference among shear wave velocities of different soils with the same compactness.The correlation between the dry density and the shear wave velocity can be expressed using four-regression model.It was discussed that the compactness of the topsoil of subgrade can represent that of the whole layer of soil.The new direct shear wave method to test subgrade dry density was brought forward and then verified by the method of vibration three time and press three times.The in-situ test result show that the compactness of subgrades can be evaluated nondestructively by using the surface shear wave testing technique.