Penetrating Soil Strength and Wave Velocity Combined Testing Device and Application Method

Abstract

The invention discloses a penetration type soil body strength and wave velocity combined testing device and a use method thereof, wherein the testing device is mainly composed of a probing rod, a cross beam, a pressure sensor and a displacement sensor. The probing rod can make bending element pieces go into a soil body with a certain depth, and does not make contact with the soil body in the process, so as to ensure the original state property of the test soil sample and the safety of the bending element pieces. The shear modulus of the soil body in various directions can be measured at the same time through the bending element pieces with different mounting directions and inserting of the device into the soil body in different directions, and the intrinsic anisotropy ratio of the soil body is obtained; the Poisson's ratio of the soil body can be obtained by testing of the shear wave velocity and the compression wave velocity; the undrained shear strength of the soil body is obtained through a change curve of the pressure along with the depth in the process of pressing the device into the soil body. The test device designed by the invention is simple in principle and easy to carryand can effectively guarantee the original state property of the test soil sample and the safety of a piezoelectric ceramic bending element pieces, and the intrinsic anisotropy, Poisson's ratio and undrained shear strength of the soil body can be obtained.

Description

technical field [0001] The invention relates to a penetrating soil strength and wave velocity combined testing device and its use method, in particular to a penetrating piezoelectric ceramic bending element soil anisotropic shear modulus, Poisson's ratio and different Drained Shear Strength Joint Test Apparatus. Background technique [0002] Small-strain shear modulus is a basic mechanical parameter of soil, which can be obtained through indoor geotechnical tests and field tests. Indoor tests mostly use resonant columns and piezoelectric ceramic bending elements, and indoor test soil samples must be obtained from the field, which will inevitably cause certain disturbance and damage to the soil during the process of soil extraction and transportation, which will lead to negative results in indoor test results. It often cannot reflect the real shear modulus of the soil, so the test of the shear modulus of the soil on site is particularly important. So far, only Zhejiang Univ...

AI Technical Summary

Problems solved by technology

So far, only Zhejiang University has developed a piezoelectric ceramic bending element soil shear wave velocity test device that can be used for field testing in 2008, but this device can only directly connect the transmitting and receiving piezoelectric ceramic bending elements It is inserted into the surface soil, and the surface soil is also greatly affected by the disturbance, so it cannot really effectively guarantee the original state of the tested soil sample, so it is particularly important that the test device can penetrate into the soil to a certain depth; and the device can only The measured soil particles vibrate in the horizontal direction, and the shear wave velocity V of the wave propagating in the horizontal direction hh , the shear wave velocity V at which soil particles vibrate in the vertical direction and the wave propagates in the horizontal direction cannot be measured vh and soil particles vibrate in the horizontal direction, the shear wave velocity V of the wave propagating in the vertical direction hv , so that the square ratio of each shear wave velocity of the on-site soil cannot be obtained, that is, the inherent anisotropy characteristics of the on-site soil cannot be obtained

At the same time, so far, there is no portable field test device in China that can simultaneously obtain soil shear modulus, Poisson's ratio and undrained shear strength.

Images