Estimation method for horizontal ground stress in alpine canyon area
By establishing a numerical model and revising the horizontal geostress calculation formula in the high mountain canyon area, the problems of difficult implementation of traditional methods and insufficient numerical simulation data were solved, and efficient and extensive geostress estimation was achieved.
Patent Information
- Application Number
- CN202510753628.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-06
- Publication Date
- 2025-09-09
AI Technical Summary
In high mountain canyon areas, traditional geostress estimation methods are difficult and costly to implement, and numerical simulation methods lack geological data, resulting in a limited estimation range and time-consuming and labor-intensive calculations.
By establishing a numerical model, the horizontal geostress changes under different terrain conditions are obtained, the horizontal geostress calculation formula is corrected using the equivalent mountain height, and the correction is made in combination with the tectonic stress, and the applicable scope is determined and calculated.
It reduces the amount of calculation, improves the estimation efficiency and scope, saves manpower, material resources and time costs, and provides a wider range of ground stress estimation data.
Smart Images
Figure CN120611513A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of geostress estimation, and in particular to a method for estimating horizontal geostress in a high mountain canyon area. Background Art
[0002] The distribution characteristics of the geostress field are key factors in controlling the stability of tunnel surrounding rock. Topography has a significant impact on the distribution of shallow geostress fields, especially in high mountain canyon areas. Previous studies have provided qualitative understanding of this. Currently, traditional methods rely on field testing, such as stress relief and hydraulic fracturing, but these methods may be difficult to implement in high mountain canyon areas, are costly, or are restricted by topography. In addition, numerical simulation methods require a large amount of geological data, which may be difficult to obtain anytime and anywhere in complex terrain. The density of measured geostress data points is low, making it difficult to support regional stress field inversion, resulting in a limited estimation range and time-consuming and labor-intensive calculations. Summary of the Invention
[0003] In order to reduce the amount of calculation and improve the estimation range, this application provides a method for estimating horizontal ground stress in high mountain canyon areas.
[0004] The technical solution adopted by the present invention to solve the above problems is: Methods for estimating horizontal ground stress in alpine canyon areas include: Step 1: Build a numerical model based on actual test data to obtain the horizontal stress changes at different locations under different terrain conditions; terrain conditions refer to: mountain height h, slope and valley width W; location refers to: valley bottom, slope foot and ridge; Step 2: Obtain the equivalent mountain heights at different locations under different terrain conditions based on the changes in horizontal ground stress; Step 3: Calculate the horizontal ground stress in the formula based on the equivalent mountain height Correction is made, where the calculation formula for horizontal ground stress is: , , where is the horizontal ground stress, H is the depth of the measuring point from the ground surface, is the equivalent mountain height, is the rock density, g is the acceleration of gravity, and v is the Poisson's ratio of the rock; Step 4: Determine the applicable range of the revised horizontal in-situ stress calculation formula based on the simulated value obtained by the numerical model. The determining condition is that the relative error between the estimated value calculated by the revised horizontal in-situ stress calculation formula and the simulated value is less than a threshold value. Step 5: Use the revised horizontal geostress calculation formula to complete the horizontal geostress calculation of other measuring points within the applicable range.
[0005] Furthermore, step 2 is specifically as follows: Step 21: Obtain the horizontal ground stress distribution under the same slope, the same valley width and different mountain heights, the same mountain height, the same valley width and different slopes, and the same slope, the same mountain height and different valley widths; Step 22: Based on the horizontal stress distribution and the equivalent burial depth principle, obtain the equivalent mountain height under different terrain conditions.
[0006] Furthermore, the equivalent mountain height under different terrain conditions Expressed as: Along the valley floor: ; Along the slope foot: ; Along the ridge: .
[0007] Furthermore, in step 4, the threshold is 10%.
[0008] Furthermore, step 4 is specifically as follows: determining whether there is an applicable range calculation formula, If it exists, the applicable scope of the horizontal ground stress calculation formula is determined according to the applicable scope calculation formula; If it does not exist, the applicable scope of the revised horizontal geostress calculation formula is determined based on the relative error between the estimated value calculated by the revised horizontal geostress calculation formula and the simulated value being less than the threshold; when the obtained applicable scope meets the regression analysis condition, a regression analysis is performed on the applicable scope of the horizontal geostress calculation formula under different terrain conditions to obtain the applicable scope calculation formula.
[0009] Furthermore, the calculation formula for the applicable scope is expressed as: Along the valley floor: ; Along the slope foot: ; Along the ridge: ; is the minimum value of the formula applicable range, .
[0010] Furthermore, step 3 also includes using tectonic stress to correct the horizontal ground stress calculation formula.
[0011] Compared with the existing technology, the present invention has the following advantages: by studying the distribution characteristics of geostress in different terrains, combining three-dimensional modeling, and based on the equivalent burial depth, a horizontal geostress calculation formula corresponding to the slope height, slope foot and valley width in high mountain canyon areas is proposed, so as to achieve the purpose of quickly estimating horizontal geostress. This method reduces the calculation amount of geostress estimation, improves the estimation efficiency and estimation range, and is conducive to saving manpower, material resources and time costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 This is a flow chart of the horizontal ground stress estimation method in high mountain canyon areas; Figure 2 Schematic diagram for parameter settings. DETAILED DESCRIPTION
[0013] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0014] like Figure 1 As shown in Figure 2, the method for estimating horizontal ground stress in high mountain canyon areas includes: Step 1: Build a numerical model based on actual test data to obtain the horizontal stress changes at different locations under different terrain conditions; terrain conditions refer to: mountain height h, slope And the valley width W; the parts refer to: valley bottom, slope foot and ridge.
[0015] In this embodiment, the simulation results are presented in the form of horizontal geostress variation curves at different locations with burial depth. The L1 line reflects the geostress variation below the valley bottom under different terrain conditions, the L2 line mainly reflects the geostress variation below the slope foot, and the L3 line reflects the geostress variation below the ridge. Figure 2 shown.
[0016] By comparing the stress changes in different parts, we can obtain the general rules of the influence of mountains and valleys on ground stress. By comparing the stress changes in the same part under different terrains, we can obtain the degree of influence of different terrain parameters on ground stress.
[0017] Step 2: Obtain the equivalent mountain heights at different locations under different terrain conditions based on the changes in ground stress.
[0018] The horizontal stress versus burial depth curves were drawn for the same slope and valley width but different mountain heights, and the distribution patterns of horizontal ground stress along L1, L2, and L3 at different mountain heights were obtained.
[0019] The horizontal stress versus burial depth curves were drawn for the same mountain height and valley width but different slopes, and the distribution patterns of horizontal ground stress along L1, L2, and L3 under different slopes were obtained.
[0020] The horizontal stress versus burial depth curves were drawn for the same slope and mountain height but different valley widths, and the distribution patterns of horizontal ground stress along L1, L2, and L3 for different valley widths were obtained.
[0021] Take a horizontal stress value in the straight line segment of the horizontal stress versus burial depth curve, and compare the burial depth with the burial depth when the horizontal stress is equal to the burial depth when the surface is flat. The difference is the equivalent mountain height above the surface under the corresponding terrain. By regression analysis of the equivalent mountain height under different terrain parameters, the equivalent mountain height regression equation for different parts can be obtained. In this embodiment, the equivalent mountain height under different terrain conditions is Expressed as: Along the valley floor: ; Along the slope foot: ; Along the ridge: .
[0022] Step 3: Calculate the horizontal ground stress in the formula based on the equivalent mountain height Correction is made, where the calculation formula for horizontal ground stress is: , , where is the horizontal ground stress, H is the depth of the measuring point from the ground surface, is the equivalent mountain height, is the rock density, g is the acceleration due to gravity, and v is the Poisson's ratio of the rock.
[0023] The calculation formula of horizontal ground stress is based on propose, is the horizontal stress, is the vertical stress, = .
[0024] Since the original horizontal geostress calculation formula does not take into account tectonic movements, such as plate compression and additional stress generated by fault activity, the horizontal geostress calculation formula can also be corrected by using tectonic stress to improve the calculation accuracy.
[0025] In this embodiment, the revised horizontal in-situ stress calculation formula is: , where is the horizontal ground stress, is the tectonic stress in the x direction, MPa; is the corrected deadweight horizontal stress, H is the depth of the measuring point from the ground surface, m; is the equivalent mountain height, m; is the rock density, ; g is the acceleration due to gravity, ; v is the Poisson's ratio of rock.
[0026] Step 4: Determine the applicable scope of the revised horizontal geostress calculation formula based on the simulation value obtained from the numerical model. The determination condition is that the relative error between the estimated value calculated by the revised horizontal geostress calculation formula and the simulation value is less than a threshold. In this embodiment, the threshold is 10%, and other values can also be set according to actual needs.
[0027] Step 5: Use the revised horizontal geostress calculation formula to complete the horizontal geostress calculation of other measuring points within the applicable range.
[0028] Furthermore, in order to quickly determine the applicable scope of the horizontal geostress calculation formula, a regression analysis can be performed on the applicable scope of the horizontal geostress calculation formula under different terrain conditions to obtain an applicable scope calculation formula, and the applicable scope calculation formula is used in subsequent calculations to determine the applicable scope.
[0029] Since the actual burial depth is used in the numerical simulation ,and The result is the equivalent burial depth. The two are slightly different in value but are actually the same point, that is, Therefore, this embodiment uses the actual burial depth Fitting is performed to determine the applicable scope of the horizontal ground stress calculation formula.
[0030] In this embodiment, the calculation formula for the applicable range is expressed as: Along the valley floor: ; Along the slope foot: ; Along the ridge: .
[0031] The present invention modifies the horizontal geostress calculation formula based on the equivalent mountain height and equivalent burial depth, and uses a numerical model to obtain the horizontal geostress of a certain number of measuring points to determine the scope of application of the modified horizontal geostress calculation formula. The horizontal geostress calculation of other measuring points within the applicable range can be completed using the modified horizontal geostress calculation formula. Compared with the method of using numerical models to calculate the horizontal geostress of all measuring points, the amount of calculation is significantly reduced, the calculation efficiency is effectively improved, and a large amount of time and computing resources are saved. At the same time, based on the horizontal geostress calculation formula, the horizontal geostress at some special measuring points that are difficult to directly calculate using numerical models can also be reasonably inferred. For example, in areas with complex geological conditions, difficult model construction, or excessively high calculation costs, this formula can provide valuable geostress estimation data for engineering design and geological research by virtue of its simplicity and practicality, thereby broadening the estimation range of horizontal geostress.
Claims
1. A method for estimating horizontal ground stress in high mountain canyon areas, characterized by: include: Step 1: Based on the actual test data, a numerical model is established to obtain the horizontal stress changes at different locations under different terrain conditions; Conditions refer to: mountain height h, slope and valley width W; location refers to: valley bottom, slope foot and ridge; Step 2: Obtain the equivalent mountain heights at different locations under different terrain conditions based on the changes in horizontal ground stress; Step 3: Calculate the horizontal ground stress in the formula based on the equivalent mountain height Correction is made, where the calculation formula for horizontal ground stress is: , , where is the horizontal ground stress, H is the depth of the measuring point from the ground surface, is the equivalent mountain height, is the rock density, g is the acceleration of gravity, and v is the Poisson's ratio of the rock; Step 4: Determine the applicable range of the revised horizontal in-situ stress calculation formula based on the simulated value obtained by the numerical model. The determining condition is that the relative error between the estimated value calculated by the revised horizontal in-situ stress calculation formula and the simulated value is less than a threshold value. Step 5: Use the revised horizontal geostress calculation formula to complete the horizontal geostress calculation of other measuring points within the applicable range.
2. The method for estimating horizontal ground stress in a high mountain canyon area according to claim 1, characterized in that: Step 2 is as follows: Step 21: Obtain the horizontal ground stress distribution under the same slope, the same valley width and different mountain heights, the same mountain height, the same valley width and different slopes, and the same slope, the same mountain height and different valley widths; Step 22: Based on the horizontal stress distribution and the equivalent burial depth principle, obtain the equivalent mountain height under different terrain conditions.
3. The method for estimating horizontal ground stress in a high mountain canyon area according to claim 2, characterized in that: Equivalent mountain height under different terrain conditions Expressed as: Along the valley floor: ; Along the slope foot: ; Along the ridge: .
4. The method for estimating horizontal ground stress in a high mountain canyon area according to claim 1, characterized in that: In step 4, the threshold is 10%.
5. The method for estimating horizontal ground stress in a high mountain canyon area according to claim 1, characterized in that: Step 4 is specifically: determine whether there is an applicable scope calculation formula, If it exists, the applicable scope of the horizontal ground stress calculation formula is determined according to the applicable scope calculation formula; If it does not exist, the applicable scope of the revised horizontal geostress calculation formula is determined based on the relative error between the estimated value calculated by the revised horizontal geostress calculation formula and the simulated value being less than the threshold; when the obtained applicable scope meets the regression analysis condition, a regression analysis is performed on the applicable scope of the horizontal geostress calculation formula under different terrain conditions to obtain the applicable scope calculation formula.
6. The method for estimating horizontal ground stress in a high mountain canyon area according to claim 5, characterized in that: The calculation formula for the applicable scope is expressed as: Along the valley floor: ; Along the slope foot: ; Along the ridge: ; is the minimum value of the formula applicable range, .
7. The method for estimating horizontal ground stress in a high mountain canyon area according to any one of claims 1 to 6, characterized in that: Step 3 also includes using tectonic stress to correct the horizontal ground stress calculation formula.