论文部分内容阅读
剪切波速和相对密度是评价无黏性土力学性能的重要参数指标。以砾性土的剪切波速测试技术为出发点,通过在特制的钢制承模筒上整合弯曲元的剪切波速测试技术,利用竖向振动台的驱动以改变筒内试样的相对密度,自主研发一套无黏性土剪切波速与相对密度联合测试系统,并对弯曲元剪切波速测试中的初至时间进行修正。该系统用于测试最大粒径小于50 mm的无黏性土的剪切波速,建立无黏性土剪切波速与相对密度的关系。针对标准砂试样、花岗岩圆砾试样、两者按含砾量60%配制的砾性土试样及根据汶川地震中液化砾性土平均级配配制的砾性土试样进行了剪切波速与相对密度联合测试,并与GDS大三轴剪切波速系统的测试结果进行对比。试验结果显示,所研发的系统与GDS系统对土样的测试结果相似,但适用范围更广,测试更简便;相同相对密度下,砾性土的剪切波速比砂土大;试样的剪切波速随相对密度的增加而呈现幂函数形式增长。
Shear wave velocity and relative density are important parameters to evaluate the mechanical properties of non-cohesive soil. Taking the shear wave velocity testing technology of gravelly soil as the starting point, the shear wave velocity testing technology of bending element integrated on the special steel bearing mold cylinder was used to change the relative density of the sample in the cylinder by using the vertical vibration table. Independently developed a joint test system of cohesion-free soil shear wave velocity and relative density, and corrected the first arrival time in bending element shear wave velocity test. The system is used to test the shear wave velocity of clayey soils with a maximum particle size of less than 50 mm and to establish the relationship between shear wave velocity and relative density of clayey soils. For the standard sand samples, granite boulder samples, the two gravel soil samples prepared according to gravel content of 60% and gravelly soil samples prepared according to the average grade of liquefied gravel soil in the Wenchuan earthquake were cut Wave velocity and relative density of the joint test, and GDS large triaxial shear wave velocity system test results were compared. The test results show that the developed system and the GDS system are similar to the soil samples, but the scope of application is more extensive and the testing is more simple. The shear wave velocity of the gravelly soil is larger than that of the sand under the same relative density. The shear wave velocity shows a power function form increase with the increase of relative density.