Rock mass structure surface roughness evaluation method overcoming size effect

Abstract

The invention relates to a rock mass structure surface roughness evaluation method overcoming a size effect. Operation steps are characterized by selecting a large size profile which possesses representativeness and whose length is L on a natural rock mass structure surface and marking the profile; a measuring instrument is erected along a selected profile and collecting n small-size profiles whose lengths are l on the profile; ensuring that an acquisition quantity n is greater than an effective acquisition quantity ne; digitizing the acquired n profiles; using a variable diagram method to calculate fractal dimensions D of the n profiles so as to obtain the n values of the fractal dimensions D; averaging the n values of the fractal dimensions D so as to acquire an average value of the fractal dimensions, using the average value of the fractal dimensions to describe roughness of the large size profile whose the selected length is the L so that roughness of a small-size rock mass structure surface is used to represent roughness of a large-size rock mass structure surface and an error brought by the size effect is eliminated. According to the method of the invention, through measuring the roughness of parts of the rock mass structure surfaces, the roughness of the overall rock mass structure surface is evaluated; an evaluation result is real and reliable and high precision is possessed.

Description

technical field [0001] The invention relates to a method for evaluating the roughness of a rock mass structural surface which overcomes the size effect, and is especially suitable for the occasion where the measuring range of the adopted instrument is smaller than the effective measurement length, can eliminate the error introduced by the size effect, and realize the accurate evaluation of the roughness of the rock mass structural surface. Background technique [0002] Rock mass in nature is an extremely complex geological body. It is not a homogeneous isotropic and complete object. There are many structural planes developed inside, such as faults, layers, joints, schistoses, and fissures. The existence of these weak structural planes greatly reduces the integrity of the rock mass and plays a controlling role in the destruction of the rock mass. Therefore, it is extremely important to carry out research on structural planes of rock mass to understand the failure mechanism of...

AI Technical Summary

Problems solved by technology

However, it is not feasible to use this traditional method to eliminate or reduce the error caused by the size effect, and there are still some problems:

For rock structural surfaces with particularly large effective dimensions, it is necessary to design a large-scale measuring instrument, which will greatly increase the manufacturing, portability, test cost, measurement time, and work intensity of the instrument, which is obviously not very realistic.

[0007] 2. Although the current 3D laser measurement technology can realize large-area rock mass structural surface roughness data collection, this technology is easily affected by external factors (temperature, humidity, electromagnetic interference, vehicle shock, etc.), and the cost is extremely expensive

The roughness measurement of the rock mass structural surface is carried out in the field, and the measuring instruments with large geometric dimensions are very inconvenient to carry

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