Full waveform information test method for joint stiffness of rock mass

Abstract

The invention relates to a full-waveform information test method for the joint rigidity of rock mass. The method comprises data test and data analysis. The test comprises the following two steps: (1) testing the physical mechanics parameter of the rock mass within a test region, and (2) testing the normal rigidity and the tangential rigidity of the joint in the field; the data analysis comprises the following five steps: (1) building a time-domain analysis model when wavelet is propagated within the joint, (2) decomposing transmitted wave by the wavelet, (3) computing a wavelet system of incident wave and reflected wave, (4) computing time-domain wave form at an incident side which is in parallel with the joint trend and is vertical to the joint trend, and (5) computing the normal rigidity and the tangential rigidity of the joint. The test method is used for analyzing the rigidity of the joint based on the full-waveform information, a structural surface has the function of controlling the mechanical property of the rock mass, the exact acquisition of the normal rigidity and the tangential rigidity of the joint of the rock mass has important meaning on the design, the construction, the stability evaluation and the rock mass reinforcement of the rock mass engineering, According to the method, the operation is simple and quick, and the test cost is low, and a test result comprehensively reflects the complexity of the mechanical property.

Description

technical field [0001] The invention relates to rock mass joint rigidity testing technology, and proposes a testing method for calculating rock mass joint rigidity with full waveform information in the time domain on the basis of in-depth research on the law of amplitude and phase change of wavelets caused by joints. Background technique [0002] During the long geological process, structural planes of different scales are formed in the rock mass, and these structural planes lead to the discontinuous, heterogeneous and anisotropic mechanical properties of the rock mass. These structural surfaces with different scales, shapes and intricate distribution strongly affect the mechanical properties and stability of engineering rock mass, play a role in controlling the deformation and destruction of rock mass, and accurately obtain the mechanical parameters of rock mass structural surfaces It is an important and difficult problem in rock mechanics. [0003] The test methods of joi...

AI Technical Summary

Problems solved by technology

(1) Indoor testing, through on-site sampling, or making test samples that meet the same or similar ratio requirements for certain parameters, and using indoor measurement methods to obtain joint deformation parameters, this method has the advantages of low cost and simple operation, but there are problems It is difficult to comprehensively consider geological environmental factors such as in-situ stress and groundwater, and the sampling process is easily disturbed, especially joints, whose thickness is only a few millimeters to several centimeters, and it is difficult to sample on-site for indoor measurement

(2) On-site test, the test results of this method are accurate and reliable, but limited by the long on-site test period and high test cost, the test points must have strong representativeness

(3) Parameter inversion. This method has the advantage of low cost, but it depends on the accuracy of the input parameters. Before the macroscopic failure of the rock mass, the contribution of the joints to the overall deformation of the rock mass is very small. When adjusting the deformation mechanical parameters of the joints, The overall deformation of the rock mass is not obvious, so when performing parameter inversion, the reliability of the inversion results is greatly affected

(4) Engineering geophysical prospecting, this method has the advantages of low test cost, simple operation and convenient on-site test, but the data processing is difficult. At present, the test method is mainly proposed based on wave velocity and impedance parameters

However, rock mass joints have the characteristics of small scale and complex mechanical properties, and conventional testing techniques need to be improved

There are many factors that affect the propagation of stress waves in rock mass joints, such as the material composition of joints, grain size distribution, water content, void ratio, dry density, etc. In addition, they are also affected by the macro and micro fabrics of interlayers, in-situ stress, and groundwater. Due to the influence of the environment, it is difficult to reflect the rock mass joints with complex mechanical properties based on a certain waveform parameter

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