CN-121997415-A - Deep rock stress state characterization method based on dimensionless rock strength

CN121997415ACN 121997415 ACN121997415 ACN 121997415ACN-121997415-A

Abstract

The invention provides a method for representing stress state of a deep rock mass based on dimensionless rock strength, and belongs to the field of rock mechanical engineering. According to the method, the real three-dimensional stress of the rock body and the basic mechanical parameters of the rock are firstly obtained, then the main stress is subjected to dimensionless treatment through the ratio of the stress to the rock strength parameters, and a stress difference coefficient based on dimensionless stress difference is constructed to represent the three-dimensional stress non-uniformity. The invention can embody the absolute magnitude of stress, the intensity approximation degree and the three-dimensional stress non-uniformity at the same time, and provides a universal and scientific evaluation system for deep rock health evaluation, dynamic disaster prediction and underground engineering design.

Inventors

ZHANG FENGPENG
SUN YUFU
YANG GUODONG
XU HONGPENG
WANG XIULONG
ZHOU YUANHANG
LIU CHUANYI

Assignees

东北大学

Dates

Publication Date: 20260508
Application Date: 20251230

Claims (9)

1. The method for representing the stress state of the deep rock mass based on the dimensionless rock strength is characterized by comprising the following steps of: S1, acquiring three-dimensional original rock stress and rock basic mechanical parameters of a target rock body; S2, carrying out dimensionless treatment on each main stress based on the ratio of the stress to the corresponding rock strength parameter, constructing a main stress strength ratio, and calculating a stress difference coefficient according to the main stress strength ratio; s3, re-expressing generalized Hooke 'S law under a dimensionless stress frame, so that the generalized Hooke' S law can reflect the approaching degree of the stress level relative to the rock strength, and comprehensive characterization of the stress state of the deep rock mass is realized.
2. The method for characterizing the stress state of the deep rock mass based on dimensionless rock strength according to claim 1, wherein the step of obtaining the basic mechanical parameters and the stress state of the rock comprises the steps of sampling according to the specification requirements on site, processing and manufacturing standard rock test pieces according to the related test specifications, and respectively carrying out a uniaxial compression test, a Brazilian split test and a direct shear test to obtain the strength parameters of the rock.
3. The method for characterizing the stress state of the deep rock mass based on the dimensionless rock strength according to claim 1, wherein the ratio of the stress to the corresponding rock strength parameter characterizes the stress in each direction, and the stress difference coefficient is calculated; by the stress of the rock and the uniaxial compressive strength of the rock The stress level and the stress difference degree are characterized together, wherein the maximum principal stress for the stress state is The intermediate principal stress is The minimum principal stress is 。
4. The method for characterizing stress states of a deep rock mass based on dimensionless rock strength according to claim 1, wherein the step of characterizing each principal stress based on a ratio of stress to a corresponding rock strength parameter and calculating a stress difference coefficient comprises employing a magnitude of principal stress at a point of the rock mass and a uniaxial compressive strength of the rock And simultaneously characterize the stress level and the degree of stress variability of the test point.
5. The method for characterizing stress states of a deep rock mass based on dimensionless representation of rock strength according to claim 1, wherein the stress difference coefficient is based on a ratio of a dimensionless principal stress difference to a maximum principal stress.
6. The method for characterizing the stress state of a deep rock mass based on dimensionless rock strength according to claim 1, wherein the value of the stress difference coefficient is normalized to be within 0-1.
7. The method for characterizing stress states of a deep rock mass based on dimensionless representation of rock strength according to claim 1, wherein the reformulation of the generalized hooke's law takes dimensionless principal stress as an input variable.
8. The method for characterizing stress states of a deep rock mass based on dimensionless representation of rock strength according to claim 1, wherein the dimensionless principal stress intensity ratio is used to construct a rock mass health index.
9. The method for characterizing the stress state of a deep rock mass based on dimensionless rock strength according to claim 8, wherein the health index is used for rock burst risk prediction and roadway support optimization design.

Description

Deep rock stress state characterization method based on dimensionless rock strength Technical Field The invention relates to the technical field of rock mechanical engineering, in particular to a method for representing stress state of a deep rock body based on dimensionless rock strength. Background As mining and underground space development rapidly advances to deep, deep engineered rock mass is commonly in a high three-way stress environment. Conventional stress state description methods typically employ maximum principal stressIntermediate principal stressAnd minimum principal stressIs characterized by the absolute value of (a). Although this approach is intuitive in form, there are significant limitations under deep high stress conditions. First, the absolute stress value can only reflect the stress itself, and the relation between the stress level and the rock strength cannot be represented. Under different lithologic conditions, even the same absolute values of stress, their corresponding risk of failure and steady state may be quite different, resulting in difficulty in accurately assessing the stability or proximity of failure of a rock mass depending only on the absolute values of principal stress. Therefore, a new method capable of reflecting the absolute stress magnitude, the relative rock strength approaching degree and the three-dimensional stress difference simultaneously is needed, the rock breaking approaching degree is simply and clearly reflected, and the scientificity and the applicability of stress characterization are remarkably improved so as to meet the evaluation requirement of the high stress condition of deep engineering. Disclosure of Invention According to the technical problems mentioned in the background art, a method for representing the stress state of a deep rock body based on dimensionless rock strength is provided. When the method is used for describing the stress state of any point in the rock mass, the obtained stress parameters have the advantages that unified quantification and comparability of the stress state can be realized under different lithology conditions, the absolute size of stress of the rock mass can be reflected, the approaching degree of the stress level of the point relative to the rock breaking strength can be accurately reflected, so that the asymptotic characteristic of the breaking risk is reflected, the three-dimensional stress nonuniformity commonly existing in deep engineering can be quantitatively represented, the strength control effect can be reflected in the rock constitutive relation, and a stress index with more physical significance is provided for revealing the intrinsic mechanism of the mechanical response of the deep rock mass. The invention adopts the following technical means: a method for representing stress state of deep rock mass based on dimensionless rock strength comprises the following steps: S1, acquiring three-dimensional original rock stress and rock basic mechanical parameters of a target rock body; S2, carrying out dimensionless treatment on each main stress based on the ratio of the stress to the corresponding rock strength parameter, constructing a main stress strength ratio, and calculating a stress difference coefficient according to the main stress strength ratio; s3, re-expressing generalized Hooke 'S law under a dimensionless stress frame, so that the generalized Hooke' S law can reflect the approaching degree of the stress level relative to the rock strength, and comprehensive characterization of the stress state of the deep rock mass is realized. Further, the step of obtaining the basic mechanical parameters and stress state of the rock comprises the steps of sampling according to the standard requirements on site, processing and manufacturing a standard rock test piece according to the related test standard, and respectively carrying out a uniaxial compression test, a Brazilian split test and a direct shear test to obtain the strength parameters of the rock. Further, the ratio of the stress to the corresponding rock strength parameter characterizes the stress in each direction, and the stress difference coefficient is calculated; by the stress of the rock and the uniaxial compressive strength of the rock The stress level and the stress difference degree are characterized together, wherein the maximum principal stress for the stress state isThe intermediate principal stress isThe minimum principal stress is。 Further, the step of characterizing each principal stress based on the ratio of the stress to the corresponding rock strength parameter and calculating the stress difference coefficient includes employing the magnitude of the principal stress at a point of the rock mass to the uniaxial compressive strength of the rockAnd simultaneously characterize the stress level and the degree of stress variability of the test point. Further, the stress variability factor is based on a ratio of the dimensionless principal s