Device and method for measuring crustal stress through single drill hole

Abstract

The invention provides a device and method for measuring crustal stress through a single drill hole. The accurate size and direction information of crustal stress at a measure point can be obtained through a single drill hole. The device comprises a hole interior core positioning photographing device and a core ground redirecting device. The method comprises the steps that the hole interior core positioning photographing device is utilized for carrying out positioning photographing on a non-broken core located in a primary rock stress area in the drill hole, a fracture surface feature point clear image of the core in place is obtained, a core ground redirecting device is utilized for accurately simulating and reproducing the space position of parameters such as an azimuth angle and an inclination angle on the ground, graphic feature points are used for comparison and restoration to obtain the actual space position state of the core in underground place, direction marking lines are marked, a sound emission sub-standard specimen is machined and manufactured in the marking line direction, and finally by carrying out all-direction rock specimen sound emission signal testing, a corresponding Kaiser effect point is obtained, and an underground rock actual three-dimensional crustal stress value is calculated.

Description

technical field [0001] The invention belongs to the technical field of ground stress testing in underground rock mass engineering, and in particular relates to a device and a measuring method for measuring ground stress through a single borehole. Background technique [0002] In-situ stress refers to the internal stress of the rock mass in the earth's crust in its natural state. It is the fundamental force that causes deformation and destruction of mining, water conservancy and hydropower, civil construction, roads and various underground geotechnical excavation projects. A scientific and accurate grasp of its distribution in the crust is a necessary prerequisite for determining the mechanical properties of engineering rock mass, analyzing the stability of surrounding rock, and realizing scientific decision-making, design, and excavation of geotechnical engineering. The natural in-situ stress field existing in the rock mass can only be obtained by means of actual testing at...

AI Technical Summary

Problems solved by technology

At present, both at home and abroad are trying to push the geostress measurement technology of AE method to a deeper and wider practical stage, but the problem of core orientation has not been solved well, that is, if the traditional AE method wants to obtain the real three-dimensional geostress information of underground rock mass (including size and direction), it is necessary to use multiple oriented cores with a certain angle at the measuring point as the test material (usually a vertical drill hole and three horizontal drill holes with an included angle of 45°), so it takes a lot of energy Use special directional coring tools to drill downhole or rock formations to drill directional cores. The high cost, low efficiency, and time-consuming process of directional cores makes this method unable to be effectively promoted.

However, the paleomagnetic orientation method, in-hole television and rock formation scanning orientation method developed in recent years cannot be effectively promoted due to the engineering applicability in actual use.

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