基于弯曲元的剪切波扁铲侧胀技术可行性试验研究

Feasibility study on flat shovel bulging technique with shear wave based on bending elements

扁铲侧胀技术由于其对土体扰动小,试验简单,可以真实地反映土体的实际状态,已被广泛用于各种工程的岩土勘察与测试中。本文提出了将侧装式弯曲元应用于扁铲侧胀技术的设想,并对其可行性进行了探讨。通过搭建侧装式弯曲元测试系统,分别对三种土类在不同上覆压力和含水率条件下土体的剪切波速进行了测试,可以看出,土样的剪切波速与上覆压力基本符合线性关系,且土中细砂含量越高,其剪切波速越大。在相同上覆压力条件下,砂土的剪切波速随着含水率的增大呈现先增大后减小的趋势,当含水率为6.8%时,砂土的剪切波速达到极值。试验结果表明,基于弯曲元的剪切波扁铲侧胀技术是可行的,在常规扁铲侧胀测试的基础上,可以实现对不同深度土体相关物理力学参数的原位测试。

Because of the small disturbance to the soil,the simple test and to truly reflect the actual state of the soil,the flat shovel expansion technique has been widely used in engineering geotechnical survey and testing. In this paper,the idea to apply the side mounted bending element to flat shovel expansion technique is put forward,and its feasibility is discussed. The shear wave velocities of the soil under different overburden pressure and water content are tested by constructing the side-mounted bending element testing system. It can be seen that the shear wave velocities of the soil samples are in accordance with the overburden pressure linear relationship,and the higher the sand content of soil is,the greater the shear wave velocity is. Under the same overburden pressure,the shear wave velocity of the sand increases firstly and then decreases with the increase of water content. When the water content is 6. 8%,the shear wave velocity of the sand reaches the extreme value. The experimental results show that the side bulging technique based on the bending element is feasible,and the physical and mechanical parameters of the soils with different depth could be tested in situ.