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Method for inverting transverse isotropic rock mass ground stress

A transversely isotropic and in-situ stress technology is applied in the field of inversion of transversely isotropic rock mass in-situ stress, which can solve the problems of high cost of measurement equipment, limited application range of measurement results, and damage to rock mass structure and properties. Achieve the effect of avoiding complex equipment layout and simple and fast calculation method

Inactive Publication Date: 2016-10-12
ZHONGYUAN ENGINEERING COLLEGE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, most of the in-situ stress measurement is currently only for isotropic rock mass, and the cost of the measurement equipment is high, and the layout and installation are often very complicated, which will consume a lot of manpower and material resources, and improper layout will cause large measurement errors
Moreover, the structure and properties of the rock mass in the measurement area are often destroyed during the field test, which also makes the measurement results inaccurate, and the scope of application of the measurement results is also limited to a certain extent.

Method used

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  • Method for inverting transverse isotropic rock mass ground stress
  • Method for inverting transverse isotropic rock mass ground stress
  • Method for inverting transverse isotropic rock mass ground stress

Examples

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Embodiment 1

[0045] The invention relates to a method for inverting the in-situ stress of transversely isotropic rock mass, which inverts the in-situ stress of transversely isotropic rock mass through the displacement of rock mass in the roadway, comprising the following steps:

[0046] (1) Establish a transversely isotropic rock mass model in the x-y-z coordinate system. The cross section of the roadway is parallel to the xoy plane, and the roadway is excavated along the oz axis, where the xoy plane is the transversely isotropic plane, and the oz axis is Symmetry axis;

[0047] (2) Determine the direction of the in-situ stress of the transversely isotropic rock mass, the initial in-situ stress in the vertical direction is p along the y-axis direction, and the initial in-situ stress in the horizontal direction is q along the x-axis direction;

[0048](3) Take the rock mass sample in the roadway, measure the elastic modulus E, Poisson's ratio μ of the rock mass sample in the transverse isot...

Embodiment 2

[0070] Such as image 3 As shown, the difference between this implementation and Embodiment 1 is that when the roadway is a complex shape roadway, according to the displacement analysis formula

[0071]

[0072] Through the theory of uniqueness of displacement back analysis, it is proved that the in-situ stress of rock mass can be uniquely inverted through the displacement of rock mass in the roadway, and the expressions of in-situ stress p and q are obtained.

[0073] f 1 (z) to F 4 (z)(z=x+iy) is a complex variable function, their specific form depends on the shape of the roadway, r o [F j (z)] and I m [F j (z)] (j=1, 2, 3, 4) respectively represent the real part and the imaginary part of the corresponding complex variable function, θ is the order angle under the polar coordinate system, z=x+iy, point (x, y) Represents the coordinates of a point in the xoy plane, point (z, θ) represents the coordinates of a point in the polar coordinate system, u 1 and u 2 respect...

Embodiment 3

[0087] In the following, an example of inversion of in-situ stress in a circular roadway in a transversely isotropic rock mass is given by means of theoretical calculation and numerical simulation.

[0088] The radius of a roadway is a=2m, and the rock mass parameters are as follows: E=1Gpa, E′=0.8Gpa, μ=0.25, μ′=0.3. Pick two points (2, 0) and (2, 45), that is, let r 1 = 2m, θ 1 = 0°; r 2 = 2m, θ 2 =45°, the measured displacement values ​​of these two points are u 1 = 5.89cm and u 2 =3.68cm, put them and rock mass parameters into the formulas (1) and (2), after unifying the measurement units, the calculated ground stress values ​​are p=9.92Mpa, q=19.52Mpa.

[0089] Then use computer software FLAC3D to verify, the specific process is as follows: first adopt the numerical calculation software FLAC3D to establish a circular roadway model in a transversely isotropic rock mass, the specific parameters are as follows: roadway radius a=2m, rock mass parameters are as follows: E...

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Abstract

The invention relates to a method for inverting transverse isotropic rock mass ground stress. Through rock mass displacement in a roadway, transverse isotropic rock mass ground stress is inverted. The method comprises the following steps: establishing a transverse isotropic rock mass model in an x-y-z coordinate system, a roadway cross section being parallel to an isotropic plane; determining the direction of ground stress in the transverse isotropic rock mass; taking a rock mass sample in the roadway, measuring transverse isotropic rock mass parameters of the rock mass sample; measuring deformation displacement of the rock mass in the roadway; and according to a roadway displacement analytic formula, obtaining a ground stress expression. The method can obtain a set of specific formulas to calculate transverse isotropic rock mass ground stress just by substituting the rock mass parameter measured values and a displacement measured value into the displacement analytic formula. The method prevents problems of complex equipment arrangement, large errors, and limited application range caused by measuring ground stress on site. The calculation method is simple and fast, and the method is mainly used for calculating transverse isotropic rock mass ground stress.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering, in particular to a method for reversing the in-situ stress of transversely isotropic rock mass. Background technique [0002] At present, the method of determining the in-situ stress in geotechnical engineering is mainly to conduct field tests, arrange various testing instruments or equipment on the surface or inside of the rock mass, analyze and calculate the in-situ stress through the measured data, and obtain the distribution of in-situ stress rules and results. However, in-situ stress measurement is currently mostly only for isotropic rock mass, and the cost of measurement equipment is high, and the layout and installation are often very complicated, which will consume a lot of manpower and material resources, and improper layout will cause large measurement errors. Moreover, the structure and properties of the rock mass in the measurement area are often destroyed during the field tes...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F19/00
CPCG16Z99/00
Inventor 张志增李小昌袁振霞魏霖阳张欣
Owner ZHONGYUAN ENGINEERING COLLEGE
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