CN118246112A - Method and system for constructing dangerous area model of crust fault - Google Patents

Abstract

The invention provides a method and a system for constructing a dangerous area model of crust fault, which belong to the technical field of coal mine disaster prevention and control and comprise the following steps: acquiring an activating evaluation index of the crust fault under the influence of a single factor; determining different levels corresponding to different physical parameter values of each activity evaluation index, and determining membership functions corresponding to the different levels; establishing comparison matrixes of all factors, and determining the maximum eigenvector of each comparison matrix; weighting the comprehensive judgment matrix A and the weight vector X to obtain the activation degree of each fault and obtain a fault activation geologic structure model; constructing a coal seam roof lithology database of the crust fault, obtaining a maximum principal stress contour map, and constructing a stress partition model; and superposing the structural stress partition model and the fault activation geological structure model to obtain a structural dangerous area model. The prediction method introduces the influence of the broken layer on the structural stress, and improves the accuracy and rationality of the evaluation result.

Description

Method and system for constructing dangerous area model of crust fault

Technical Field

The invention belongs to the technical field of coal mine disaster prevention and control, and particularly relates to a method for constructing a dangerous area model of crust faults.

Background

The fault dislocation caused by mining is one of main reasons for inducing the mine earthquake and the fault impact mine pressure, and the stress state of the fault and the coal seam nearby the fault under the mining condition is closely related to whether the mine earthquake and the fault impact mine pressure occur or not, so that the method is very important for judging the activation of the fault and analyzing the stress state of the mine.

The dangerous area model of the crust fault is constructed according to the activation judgment of the fault and the stress state analysis of the mine, so that the potential occurrence areas of geological disasters such as earthquakes, ground subsidence and the like can be accurately predicted and estimated, and important scientific basis is provided for urban planning, mineral resource development, environmental protection and seismic research, so that the safety and the sustainability of human activities are ensured.

At present, china mainly researches from an indirect angle and a qualitative angle, reports of research from a direct angle and a quantitative angle are relatively few, and supportable data are insufficient. The dangerous area model of the crust fault cannot be constructed according to the fault activation and the common influence on the mine construction stress field.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a method for constructing a dangerous area model of a crust fault.

In order to achieve the above object, the present invention provides the following technical solutions:

a method of constructing a model of a hazard zone of a crust fault, comprising:

acquiring an activating evaluation index of the crust fault under the influence of a single factor;

determining different levels corresponding to different physical parameter values of each activation evaluation index by adopting a maximum membership criterion, and determining membership functions corresponding to the different levels; substituting the physical parameter values of the crust faults under the influence of a single factor into a membership function, and forming the values output by the membership function into a comprehensive judgment matrix A;

comparing the activeness evaluation indexes of each factor in pairs and constructing a comparison matrix; determining the maximum eigenvector of each comparison matrix, and taking each maximum eigenvector as a weight vector X of the current influence factor;

weighting the comprehensive judgment matrix A and the weight vector X to obtain the activation degree of each fault;

Constructing a coal seam roof lithology database of the crust faults by using lithology information of the crust faults, and respectively projecting the maximum main stress values of the ground stress to X, Y directions according to the actually measured results of the ground stress of the crust mine coal seam to obtain a maximum main stress contour map; dividing a maximum principal stress contour map into a low stress region, a normal stress region, a stress gradient region and a high stress region according to the stress of the original rock mass of the crust fault so as to construct a stress partition model;

Marking the activation degree of faults on the stress partition model to obtain a dangerous area model of the crust faults.

Further, the selected activated faults; comprising the following steps:

Judging whether the fault belongs to an activated fault or not according to the distance delta R between a stress circle on the fault plane and a tangential stress straight line based on Mohr-Coulomb intensity criterion;

when delta R is more than 0, separating a Mohr stress circle on the fault surface from a straight line represented by Mohr-Coulomb intensity criterion on the fault surface, and judging that the fault is in a stable equilibrium state;

When Δr=0, the Mohr stress circle on the fault plane is tangent to a straight line represented by the Mohr-Coulomb intensity criterion on the fault plane, and the fault is determined to be in a limit balance state;

When DeltaR is less than 0, the Mohr stress circle on the fault plane intersects with the straight line expressed by Mohr-Coulomb intensity criterion on the fault plane, and the fault is judged to be in an activated state, and is selected as an activated fault.

Further, the distance Δr between the stress circle and the tangential stress line is:

wherein c is a fault cohesion; Is an internal friction angle; σ1 is the maximum principal stress; σ3 is the minimum principal stress; pi is fracture fluid pressure.

Further, the tomographic activation evaluation index includes:

fault throw, fault dip angle, fault-to-maximum principal stress angle, fault-to-maximum shear stress angle, and fault lithology compressive strength.

Further, determining membership functions corresponding to different grades; comprising the following steps:

Determining membership functions of all single factors, wherein the calculation formula is as follows:

For the critical value between the single factor evaluation index grades belonging to two grades at the same time, the membership degree of the two grades is equal according to the formula (3), and 0.5 is taken, so that the value of the single factor undetermined parameter b is determined: equation (3) is

Meanwhile, as the single factor evaluation index has no upper bound in the same grade range, when the single factor evaluation index exceeds the lower bound, the membership degree is in an increasing trend, and the calculation is carried out by adopting a formula (4), so that the parameters a and b of each membership function are finally determined; the formula (4) is:

wherein alpha is an average value in a range corresponding to each single factor parameter, xb is a boundary value of a single evaluation index in a certain class range;

And determining the membership degree of each evaluation index at different grades by adopting a maximum membership degree criterion, thereby forming a membership function of the evaluation index.

Further, after determining the maximum feature vector of each comparison matrix, carrying out consistency test on the maximum feature vector, and taking the maximum feature vector passing the consistency test as a weight vector X of the current influencing factor;

in the consistency test, the random consistency index of the n-order comparison matrix is as follows:

wherein CR is a random consistency index of the matrix, and when CR is less than 0.1, the consistency requirement is met; CI is a generally consistent index of the matrix, CI= (λmax-m)/(m-1); RI is the average random consensus index of the matrix.

Further, according to the fuzzy mathematical theory, determining a fault activation evaluation index under the influence of a single factor.

A system for constructing a model of a hazard zone of a crust fault, comprising:

the evaluation index construction module is used for acquiring an activation evaluation index of the crust fault under the influence of a single factor;

The fault activation degree construction module is used for determining different levels corresponding to different physical parameter values of each activation evaluation index by adopting a maximum membership criterion and determining membership functions corresponding to the different levels; substituting the physical parameter values of the crust faults under the influence of a single factor into a membership function, and forming the values output by the membership function into a comprehensive judgment matrix A;

comparing the activeness evaluation indexes of each factor in pairs and constructing a comparison matrix; determining the maximum eigenvector of each comparison matrix, and taking each maximum eigenvector as a weight vector X of the current influence factor;

weighting the comprehensive judgment matrix A and the weight vector X to obtain the activation degree of each fault;

The construction stress partition model construction module is used for constructing a coal seam roof lithology database of the crust fault by using lithology information of the crust fault, and respectively projecting the maximum principal stress value of the crust stress to the direction X, Y according to the actual measurement result of the ground stress of the crust mine coal seam to obtain a maximum principal stress contour map; dividing a maximum principal stress contour map into a low stress region, a normal stress region, a stress gradient region and a high stress region according to the stress of the original rock mass of the crust fault so as to construct a stress partition model;

And the dangerous area model construction module is used for marking the activation degree of the faults on the stress partition model to obtain a dangerous area model of the crust faults.

The method for constructing the dangerous area model of the crust fault has the following beneficial effects:

The invention provides a method for constructing stress partition based on dual actions of fault activation and original rock stress, which comprises the steps of firstly selecting a fault activation evaluation index under the influence of a single factor and determining the activation degree of a fault according to the evaluation index, thereby obtaining the fault activation degree; the invention uses membership functions to judge different levels corresponding to different physical parameter values of each evaluation index so as to obtain a standard for judging the activation degree; and then, establishing a comparison matrix according to the relative influence degree of different factors to determine different weights for different standards so as to obtain a numerical value capable of accurately reflecting the activation degree. And constructing a stress partition model by using rock mass stress analysis system software, and marking the activation degree of faults on the stress partition model so as to obtain a dangerous area model of the crust faults constructed according to the fault activation and the common influence on the mine construction stress field.

Drawings

In order to more clearly illustrate the embodiments of the present invention and the design thereof, the drawings required for the embodiments will be briefly described below. The drawings in the following description are only some of the embodiments of the present invention and other drawings may be made by those skilled in the art without the exercise of inventive faculty.

FIG. 1 is a schematic diagram of a method of constructing a model of a hazard zone of a crust fault according to the present invention.

Detailed Description

The present invention will be described in detail below with reference to the drawings and the embodiments, so that those skilled in the art can better understand the technical scheme of the present invention and can implement the same. The following examples are only for more clearly illustrating the technical aspects of the present invention, and are not intended to limit the scope of the present invention.

Examples:

the invention provides a method for constructing a dangerous area model of crust fault, which is shown in fig. 1 in particular and comprises the following steps:

The first step:

according to the Mohr-Coulomb intensity criterion, assuming that the vertical distance between a Mohr stress circle on the fault surface and a straight line represented by the Mohr-Coulomb intensity criterion on the fault surface under the mining influence is delta R, judging the fault activation according to a formula (1), and when delta R is more than 0, judging that the fault is in a stable equilibrium state by separating the Mohr stress circle on the fault surface from the straight line represented by the Mohr-Coulomb intensity criterion on the fault surface; when Δr=0, the Mohr stress circle on the fault plane is tangent to a straight line represented by the Mohr-Coulomb intensity criterion on the fault plane, and the fault is determined to be in a limit balance state; when the delta R is less than 0, the Mohr stress circle on the fault surface is intersected with a straight line represented by Mohr-Coulomb intensity criterion on the fault surface, and the fault is judged to be in an activated state.

Wherein c is a fault cohesion; Is an internal friction angle; σ1 is the maximum principal stress; σ3 is the minimum principal stress; pi is fracture fluid pressure.

And a second step of:

Selecting a representative fault activation index, namely: fault head H, fault inclination angle alpha, fault and angle of maximum principal stress Included angle between fault and maximum shear stress/>And determining fault activeness evaluation indexes under the influence of single factors according to fault lithology compressive strength Rc.

And a third step of:

The membership function of each single factor is determined according to the formula (2), and the critical value between the evaluation index grades for the single factor should belong to two grades at the same time, so that the membership degrees of the two grades are equal and approximately equal to 0.5 according to the formula (3), thereby determining the value of the single factor undetermined parameter b. Meanwhile, as the single factor evaluation index has no upper bound in the same grade range, according to the membership criterion, the membership degree shows an increasing trend when exceeding the lower bound, and the calculation is carried out by adopting a formula (4), so that the parameters a and b of each membership function are finally determined.

Wherein alpha is an average value in a range corresponding to each single factor parameter, and Xb is a boundary value of a single evaluation index in a certain class range.

And determining the membership degree of each evaluation index at different grades by adopting a maximum membership degree criterion according to the characteristics and the actual conditions of each evaluation index, thereby forming a membership function of the evaluation index.

Fourth step:

Determining the number of faults in a well field according to geological data such as geological exploration of the well Tian Sanwei, deep exploration and the like, extracting parameters of 5 evaluation indexes, and taking different physical parameter values of each factor into membership functions to establish a fault comprehensive judgment matrix A;

Fifth step: and (5) adopting a chromatographic analysis method to clarify the fuzzy concept and determining the grade weight of the evaluation index. And 5 evaluation indexes form a 5-order comparison matrix, and the maximum eigenvalue lambda max and the maximum eigenvector Xmax of the matrix are solved. If the feature vector passes the consistency test, that is, if the result of the formula (5) is smaller than 0.1, the vector is considered as a weight vector X, and if the feature vector cannot pass the test, the grade weight of the evaluation index is redefined until the feature vector passes the consistency test.

Wherein CR is a random consistency index of the matrix, and when CR is less than 0.1, the consistency requirement is met; CI is a generally consistent index of the matrix, CI= (λmax-m)/(m-1); RI is the average random concordance index of the matrix, and the values are shown in Table 1.

Table 1RI values

Order of	1	2	3	4	5	6	7	8	9	10
											RI	0	0	0.58	0.90	1.12	1.24	1.32	1.41	1.45	1.49

Sixth step:

Multiplying the comprehensive evaluation matrix A by the weight vector X to obtain the activation degree of each fault, carrying out normalization processing, determining the comprehensive evaluation result of the fault activation and constructing a mine fault activation geological structure model.

Seventh step:

And constructing a mine coal seam roof lithology database by utilizing the lithology information disclosed by the exploration line drilling lithology and the mining, and measuring the result according to the ground stress. And respectively projecting the maximum principal stress values to X, Y directions, obtaining a maximum principal stress contour map by using rock mass stress analysis system software, and dividing the contour map into a low stress region, a normal stress region, a stress gradient region and a high stress region according to the stress of the original rock, thereby establishing a structural stress partition model.

Eighth step:

and constructing a dangerous area division comparison matrix according to a geological power division theory and an analytic hierarchy process, and determining a stress dangerous area division under the dual actions of fault activation and original rock stress according to the superposition effect of the two models.

The invention introduces the influence of faults on structural stress distribution characteristics, and quantitatively researches the fault activation characteristics, thereby determining structural stress partition under double functions. And a new thought is provided for the characteristic research of the mine construction stress field.

The above embodiments are merely preferred embodiments of the present invention, the protection scope of the present invention is not limited thereto, and any simple changes or equivalent substitutions of technical solutions that can be obviously obtained by those skilled in the art within the technical scope of the present invention disclosed in the present invention belong to the protection scope of the present invention.

Claims (8)

1. A method of constructing a model of a hazard zone of a crust fault, comprising:

acquiring an activating evaluation index of the crust fault under the influence of a single factor;

determining different levels corresponding to different physical parameter values of each activation evaluation index by adopting a maximum membership criterion, and determining membership functions corresponding to the different levels; substituting the physical parameter values of the crust faults under the influence of a single factor into a membership function, and forming the values output by the membership function into a comprehensive judgment matrix A;

comparing the activeness evaluation indexes of each factor in pairs and constructing a comparison matrix; determining the maximum eigenvector of each comparison matrix, and taking each maximum eigenvector as a weight vector X of the current influence factor;

weighting the comprehensive judgment matrix A and the weight vector X to obtain the activation degree of each fault;

Constructing a coal seam roof lithology database of the crust faults by using lithology information of the crust faults, and respectively projecting the maximum main stress values of the ground stress to X, Y directions according to the actually measured results of the ground stress of the crust mine coal seam to obtain a maximum main stress contour map; dividing a maximum principal stress contour map into a low stress region, a normal stress region, a stress gradient region and a high stress region according to the stress of the original rock mass of the crust fault so as to construct a stress partition model;

Marking the activation degree of faults on the stress partition model to obtain a dangerous area model of the crust faults.

2. A method of constructing a model of a hazard zone of a crust fault as claimed in claim 1, wherein said selecting an activated fault; comprising the following steps:

Judging whether the fault belongs to an activated fault or not according to the distance delta R between a stress circle on the fault plane and a tangential stress straight line based on Mohr-Coulomb intensity criterion;

when delta R is more than 0, separating a Mohr stress circle on the fault surface from a straight line represented by Mohr-Coulomb intensity criterion on the fault surface, and judging that the fault is in a stable equilibrium state;

When Δr=0, the Mohr stress circle on the fault plane is tangent to a straight line represented by the Mohr-Coulomb intensity criterion on the fault plane, and the fault is determined to be in a limit balance state;

When DeltaR is less than 0, the Mohr stress circle on the fault plane intersects with the straight line expressed by Mohr-Coulomb intensity criterion on the fault plane, and the fault is judged to be in an activated state, and is selected as an activated fault.

3. A method of constructing a model of a hazard zone of a crust fault according to claim 2, wherein the distance Δr between the stress circle and the tangent stress line is:

wherein c is a fault cohesion; Is an internal friction angle; σ1 is the maximum principal stress; σ3 is the minimum principal stress; pi is fracture fluid pressure.

4. The method of constructing a model of a hazardous area for a crust fault as claimed in claim 1, wherein the fault activation assessment indicator comprises:

fault throw, fault dip angle, fault-to-maximum principal stress angle, fault-to-maximum shear stress angle, and fault lithology compressive strength.

5. The method of constructing a model of a hazardous area for a crust fault as claimed in claim 1, wherein said determining membership functions for different classes; comprising the following steps:

Determining membership functions of all single factors, wherein the calculation formula is as follows:

For the critical value between the single factor evaluation index grades belonging to two grades at the same time, the membership degree of the two grades is equal according to the formula (3), and 0.5 is taken, so that the value of the single factor undetermined parameter b is determined: equation (3) is

Meanwhile, as the single factor evaluation index has no upper bound in the same grade range, when the single factor evaluation index exceeds the lower bound, the membership degree is in an increasing trend, and the calculation is carried out by adopting a formula (4), so that the parameters a and b of each membership function are finally determined; the formula (4) is:

wherein alpha is an average value in a range corresponding to each single factor parameter, xb is a boundary value of a single evaluation index in a certain class range;

And determining the membership degree of each evaluation index at different grades by adopting a maximum membership degree criterion, thereby forming a membership function of the evaluation index.

6. The method for constructing a dangerous area model of a crust fault according to claim 1, wherein after determining the maximum eigenvector of each comparison matrix, performing consistency check on the maximum eigenvector, and taking the maximum eigenvector passing the consistency check as a weight vector X of the current influencing factor;

in the consistency test, the random consistency index of the n-order comparison matrix is as follows:

wherein CR is a random consistency index of the matrix, and when CR is less than 0.1, the consistency requirement is met; CI is a generally consistent index of the matrix, CI= (λmax-m)/(m-1); RI is the average random consensus index of the matrix.

7. The method for constructing a model of a dangerous area of a crust fault according to claim 1, wherein the fault activation evaluation index under the influence of a single factor is determined according to a fuzzy mathematical theory.

8. A system for constructing a model of a hazard zone of a crust fault, comprising:

the evaluation index construction module is used for acquiring an activation evaluation index of the crust fault under the influence of a single factor;

The fault activation degree construction module is used for determining different levels corresponding to different physical parameter values of each activation evaluation index by adopting a maximum membership criterion and determining membership functions corresponding to the different levels; substituting the physical parameter values of the crust faults under the influence of a single factor into a membership function, and forming the values output by the membership function into a comprehensive judgment matrix A;

comparing the activeness evaluation indexes of each factor in pairs and constructing a comparison matrix; determining the maximum eigenvector of each comparison matrix, and taking each maximum eigenvector as a weight vector X of the current influence factor;

weighting the comprehensive judgment matrix A and the weight vector X to obtain the activation degree of each fault;

The construction stress partition model construction module is used for constructing a coal seam roof lithology database of the crust fault by using lithology information of the crust fault, and respectively projecting the maximum principal stress value of the crust stress to the direction X, Y according to the actual measurement result of the ground stress of the crust mine coal seam to obtain a maximum principal stress contour map; dividing a maximum principal stress contour map into a low stress region, a normal stress region, a stress gradient region and a high stress region according to the stress of the original rock mass of the crust fault so as to construct a stress partition model;

And the dangerous area model construction module is used for marking the activation degree of the faults on the stress partition model to obtain a dangerous area model of the crust faults.