CN111794732A - Method for estimating ground stress of soft rock in fault fracture zone - Google Patents

Method for estimating ground stress of soft rock in fault fracture zone Download PDF

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CN111794732A
CN111794732A CN202010439581.4A CN202010439581A CN111794732A CN 111794732 A CN111794732 A CN 111794732A CN 202010439581 A CN202010439581 A CN 202010439581A CN 111794732 A CN111794732 A CN 111794732A
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陈卫忠
李喆
田洪铭
张广泽
王栋
杨建平
田云
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Wuhan Institute of Rock and Soil Mechanics of CAS
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Abstract

The invention relates to a method for estimating the geostress of soft rock in a fault fracture zone, which comprises the following steps: obtaining geostress test results of three main stresses of the hard rock area so as to determine a stress matrix of an original coordinate system of the hard rock area; converting the stress matrix of the original coordinate system of the hard rock area into a stress matrix of a geodetic coordinate system of the hard rock area; converting the stress matrix of the geodetic coordinate system of the hard rock area into a stress matrix of a fault coordinate system of the hard rock area; converting the stress matrix of the fault coordinate system of the hard rock area into the stress matrix of the fault coordinate system of the soft rock area; converting the stress matrix of the fault coordinate system of the soft rock area into a stress matrix of a geodetic coordinate system of the soft rock area; and converting the stress matrix of the geodetic coordinate system of the soft rock area into the stress matrix of the tunnel coordinate system of the soft rock area. The stress estimation method carries out estimation on the soft rock ground stress of the fault fracture zone based on the complete rock ground stress test result, so that the large deformation prediction result can well accord with the actual measurement result.

Description

Method for estimating ground stress of soft rock in fault fracture zone
Technical Field
The invention relates to the technical field of civil engineering, in particular to a method for estimating the ground stress of soft rock in a fault fracture zone.
Background
The soft rock in the fault fracture zone of the deeply buried long and large tunnel is easy to generate large deformation disasters, the ground stress is an important parameter for grading and predicting the large deformation disasters, and the reasonable value of the ground stress is very important. The existing common ground stress test methods comprise a hydraulic fracturing method and a stress relieving method, wherein the ground stress test of the two methods requires the rock to be relatively complete, and particularly the stress relieving method also requires drilling and coring to have higher requirements on the integrity of the rock.
Therefore, the existing ground stress test is mostly carried out in the complete rock mass, the ground stress test result of the existing ground stress test is difficult to reflect the real ground stress condition of the soft rock in the fault fracture zone, so that the large deformation prediction result and the actual measurement result have large difference, and a method for estimating the ground stress of the soft rock in the fault fracture zone based on the ground stress test result of the complete rock mass is required.
Disclosure of Invention
The application provides a method for estimating the ground stress of soft rock in a fault fracture zone, which solves the technical problems that the ground stress test of the existing deep-buried long and large tunnel is mostly carried out in a complete rock mass, the ground stress test result of the existing deep-buried long and large tunnel is difficult to reflect the real ground stress condition of the soft rock in the fault fracture zone, and the large deformation prediction result and the actual measurement result have large difference, and achieves the technical effect of estimating the ground stress of the soft rock in the fault fracture zone based on the ground stress test result of the complete rock mass.
The application provides a fault fracture zone soft rock ground stress estimation method, which comprises the following steps:
step 1: obtaining geostress test results for three principal stresses in a hard rock region, the three principal stresses comprising: horizontal large main stress, horizontal small main stress and vertical stress; establishing an original coordinate system by taking the horizontal large principal stress direction as an X axis, the horizontal small principal stress direction as a Y axis and the vertical stress direction as a Z axis so as to determine a stress matrix of the original coordinate system of the hard rock area;
step 2: determining a first conversion matrix of coordinate conversion according to a conversion matrix formula, and converting a stress matrix of an original coordinate system of the hard rock area into a stress matrix of a geodetic coordinate system of the hard rock area according to the first conversion matrix and a stress component conversion formula;
and step 3: determining a second conversion matrix of coordinate conversion according to a conversion matrix formula, and converting a stress matrix of a geodetic coordinate system of the hard rock area into a stress matrix of a fault coordinate system of the hard rock area according to the second conversion matrix and the stress component conversion formula; converting the stress matrix of the fault coordinate system of the hard rock area into the stress matrix of the fault coordinate system of the soft rock area according to the generalized Hooke's law;
and 4, step 4: applying the inverse operation of the stress component conversion formula through a third conversion matrix, wherein the third conversion matrix is a transposed matrix of the second conversion matrix, and converting the stress matrix of the fault coordinate system of the soft rock area into the stress matrix of the geodetic coordinate system of the soft rock area;
and 5: and applying the inverse operation of the stress component conversion formula through a fourth conversion matrix, wherein the fourth conversion matrix is a transposed matrix of the first conversion matrix, and converting the stress matrix of the geodetic coordinate system of the soft rock area into the stress matrix of the tunnel coordinate system of the soft rock area.
Preferably, the method further comprises the step 6:
and converting the stress matrix of the geodetic coordinate system of the hard rock area into the stress matrix of the tunnel coordinate system of the hard rock area according to the fourth conversion matrix and the stress component conversion formula.
Preferably, the method for estimating the crustal stress of the fault fracture zone soft rock has the following assumed preconditions:
the dimension of the rock layer parallel to the xoy plane in the horizontal direction is larger than the dimension in the vertical direction;
the rock stratum is isotropic;
the material satisfies the elastic assumption.
Preferably, the matrix expression of the stress component conversion formula for the same point in different coordinate systems is as follows:
[σ']＝[β][σ][β]T；
Figure BDA0002503583020000031
wherein [ sigma' ] is the stress matrix of the new coordinate system, [ beta ] is the transformation matrix, and [ sigma ] is the stress matrix of the original coordinate system.
Preferably, the transformation matrix formula under different coordinate systems for the same point is as follows:
Figure BDA0002503583020000032
the method comprises the following steps of setting x, y and z as coordinate axes of an original coordinate system, setting x ', y' and z 'as coordinate axes of a new coordinate system, setting lij to cos (Ai, Bj), i to 1-3, and j to 1-3, setting A1-A3 to be x', y 'and z', setting B1-B3 to be x, y and z, and setting lij to be cosine of an included angle between an Ai axis and a Bj axis.
Preferably, the maximum horizontal principal stress direction of the geodetic coordinate system of the hard rock area is set to be X ' axial north, the minimum horizontal principal stress direction is Y ' axial east, and the vertical stress is Z ' axial downward; the azimuth angle of the maximum horizontal principal stress of the geodetic coordinate system is alpha;
the first conversion matrix formula in step 2 is:
Figure BDA0002503583020000033
preferably, the vertical fault plane of the fault coordinate system of the hard rock region is a z ' axis, the direction of the fault plane intersecting with the horizontal plane in the geodetic coordinate system is an x ' axis, and the direction perpendicular to the x ' axis and the z ' axis is a y ' axis; setting the tendency of the fault of the hard rock area as alpha and the inclination angle as beta;
then the z' axis unit vector direction is (cos α sin β, sin α sin β, cos β); the unit vector direction of the x' axis is (sin α, -cos α, 0); the y' axis unit vector direction is (cos α cos β, sin α cos β, -sin β); the unit vector directions of the x axis, the y axis and the z axis of the geodetic coordinate system are (1, 0, 0), (0, 1, 0) and (0, 0, 1) respectively;
the second conversion matrix formula in step 3 is:
Figure BDA0002503583020000041
preferably, the solving formula of the analytic solution of the generalized hooke's law is as follows:
Figure BDA0002503583020000042
Figure BDA0002503583020000043
Figure BDA0002503583020000044
the stress in the soft rock area is
Figure BDA0002503583020000045
The stress of the hard rock area is
Figure BDA0002503583020000046
The strain of the soft rock area and the strain of the hard rock area are equally substituted into the generalized Hooke's law to obtain:
Figure BDA0002503583020000047
Figure BDA0002503583020000048
Figure BDA0002503583020000049
one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
according to the method and the device, the soft rock ground stress of the fault fracture zone is estimated based on the complete rock ground stress test result, so that the large deformation prediction result can well accord with the actual measurement result.
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In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.
FIG. 1 is a schematic flow chart of a method for estimating the crustal stress of soft rock in a fault fracture zone according to an embodiment of the application;
FIG. 2 is a schematic diagram of coordinate transformation from an original coordinate system to a geodetic coordinate system provided in an embodiment of the present application;
fig. 3 is a schematic diagram of coordinate transformation from a geodetic coordinate system to a fault coordinate system according to an embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Referring to fig. 1, the application provides a method for estimating the geostress of soft rock in a fault fracture zone, which includes:
s1: geostress test results were obtained for three principal stresses in a hard rock region, including: horizontal large main stress, horizontal small main stress and vertical stress; and establishing an original coordinate system by taking the horizontal large main stress direction as an X axis, the horizontal small main stress direction as a Y axis and the vertical stress direction as a Z axis so as to determine a stress matrix of the original coordinate system of the hard rock area.
S2: and according to the first conversion matrix and the stress component conversion formula, converting the stress matrix of the original coordinate system of the hard rock area into the stress matrix of the geodetic coordinate system of the hard rock area.
S3: determining a second conversion matrix of coordinate conversion according to the conversion matrix formula, and converting the stress matrix of the geodetic coordinate system of the hard rock area into the stress matrix of the fault coordinate system of the hard rock area according to the second conversion matrix and the stress component conversion formula; and converting the stress matrix of the fault coordinate system of the hard rock area into the stress matrix of the fault coordinate system of the soft rock area according to the generalized Hooke's law.
S4: converting the stress matrix of the fault coordinate system of the soft rock area into the stress matrix of the geodetic coordinate system of the soft rock area by applying inverse operation of a stress component conversion formula through a third conversion matrix, wherein the third conversion matrix is a transposed matrix of the second conversion matrix; that is, the step S4 is the inverse operation of the step S3, so the conversion matrix of this time is the transpose of the conversion matrix of the step S3.
S5: the stress matrix of the earth coordinate system of the soft rock area is converted into the stress matrix of the tunnel coordinate system of the soft rock area by applying the inverse operation of a stress component conversion formula through a fourth conversion matrix, wherein the fourth conversion matrix is a transposed matrix of the first conversion matrix; if the tunnel azimuth is regarded as the maximum horizontal principal stress direction angle, step S5 is the inverse operation of step 2, so the conversion matrix of this time is the transpose matrix of the conversion matrix of step 2.
Further, the method also comprises the step 6: and converting the stress matrix of the geodetic coordinate system of the hard rock area into the stress matrix of the tunnel coordinate system of the hard rock area according to the fourth conversion matrix and the stress component conversion formula.
Further, the fault fracture zone soft rock ground stress estimation method has the following assumed preconditions:
1) the size of the rock stratum parallel to the xoy plane in the horizontal direction is larger than that in the vertical direction;
2) the rock stratum is isotropic;
3) the material satisfies the elastic assumption.
Further, the matrix expression of the stress component conversion formula for the same point under different coordinate systems is as follows:
[σ']＝[β][σ][β]T；
Figure BDA0002503583020000071
wherein [ sigma' ] is the stress matrix of the new coordinate system, [ beta ] is the transformation matrix, and [ sigma ] is the stress matrix of the original coordinate system.
Further, the transformation matrix formula for the same point under different coordinate systems is as follows:
Figure BDA0002503583020000072
the method comprises the following steps of setting x, y and z as coordinate axes of an original coordinate system, setting x ', y' and z 'as coordinate axes of a new coordinate system, setting lij to cos (Ai, Bj), i to 1-3, and j to 1-3, setting A1-A3 to be x', y 'and z', setting B1-B3 to be x, y and z, and setting lij to be cosine of an included angle between an Ai axis and a Bj axis; such as l12＝cos(x′，y)，l32＝cos(z′，y)。
Further, setting the maximum horizontal principal stress direction of the geodetic coordinate system of the hard rock area as X ' axial north, the minimum horizontal principal stress direction as Y ' axial east and the vertical stress as Z ' axial down; the azimuth of the maximum horizontal principal stress of the geodetic coordinate system is α (azimuth: north is 0 °, east is 90 °), as shown in fig. 2;
the first conversion matrix formula in S2 is:
Figure BDA0002503583020000073
furthermore, the vertical fault plane of the fault coordinate system in the hard rock region is a z ' axis, the direction of the fault plane in the geodetic coordinate system intersecting with the horizontal plane is an x ' axis, and the direction vertical to the x ' axis and the z ' axis is a y ' axis; setting the tendency of the fault of the hard rock area as alpha and the inclination angle as beta; as shown in fig. 3, a horizontal plane XOY of a fault plane BCD is perpendicular to CD, which is a fault plane trend and is set as an x' axis direction; b is processed to be BA T CD, AB is the y' axis direction; the projection AO of the angle-adjustable magnetic field on the horizontal plane is a tendency, the angle BAO is an inclination angle, and the z' axis is an inverted T layer BCD.
Then the z' axis unit vector direction is (cos α sin β, sin α sin β, cos β); the unit vector direction of the x' axis is (sin α, -cos α, 0); the y' axis unit vector direction is (cos α cos β, sin α cos β, -sin β); the unit vector directions of the x axis, the y axis and the z axis of the geodetic coordinate system are (1, 0, 0), (0, 1, 0) and (0, 0, 1) respectively;
the second transformation matrix formula in S3 is:
Figure BDA0002503583020000081
further, since the coordinate system has been converted into the tomographic coordinate system, the x 'oy' plane is parallel to the slice plane at this time. The forces F borne by the unit body in any direction parallel to the horizontal plane in both hard rock areas and soft rock areasX、FY、FZAre equal. Thus τXZ，τYZAnd σZZAre equal. And τXY，σXXAnd σYYAre not equal. But due to its strain in the XOY planeXX、XY、YYEquality, so the solution of the analytical solution can be performed according to generalized hooke's law:
Figure BDA0002503583020000082
Figure BDA0002503583020000083
Figure BDA0002503583020000084
stress in soft rock regions of
Figure BDA0002503583020000085
The stress of the hard rock area is
Figure BDA0002503583020000086
The strain of the soft rock area and the strain of the hard rock area are equally substituted into the generalized Hooke's law to obtain:
Figure BDA0002503583020000091
Figure BDA0002503583020000092
Figure BDA0002503583020000093
by the estimation method, the ground stress test of the deep-buried long tunnel is not required to be carried out in the complete rock mass, and the ground stress of the soft rock of the fault fracture zone can be accurately estimated based on the ground stress test result of the complete rock mass.
The estimation method of the present application is described in detail by the following specific examples (estimation of fault fracture zone stress of a tunnel in tibetan railway):
the proposed railway tunnel adopts a hydraulic fracturing method to carry out a ground stress test in the complete sandstone, and the ground stress test result is shown in table 1.
Table 1 summary of fracture ground stress test results
Figure BDA0002503583020000094
Wherein, Shmin: formation minimum horizontal principal stress; shmax: maximum horizontal principal stress of the formation; sv: vertical stress (rock volume weight 2.60g/cm 3).
The details of a fault fracture zone to be evaluated are shown in table 2,
TABLE 2 fault fracture zone detailed information
Figure BDA0002503583020000095
The specific process of fault fracture zone stress estimation is as follows:
(1) and according to the ground stress test result of the complete sandstone area, establishing a coordinate system by taking the horizontal large main stress direction as an x axis, the horizontal small main stress direction as a y axis and the vertical stress direction as a z axis. Therefore, the stresses of the x-axis, the y-axis and the z-axis are respectively 8.40MPa, 5.58MPa and 5.30 MPa.
(2) The direction of maximum stress is known as N55 ° W, so that the angle α of the transformation matrix of the original coordinate system to the hard rock region geodetic coordinate system is 305 °. Thus, the stress state of the geodetic coordinate system in the hard rock region is obtained as follows:
Figure BDA0002503583020000101
(3) according to the fact that the occurrence of the F27 fault is N52 degrees W & lt 55 degrees SW, angles alpha and beta of a conversion matrix from a ground coordinate system to a fault coordinate system are 308 degrees and 55 degrees respectively. Substituting the transformation matrix to obtain the stress state of the fault coordinate system of the hard rock area:
Figure BDA0002503583020000102
(4) substituting the rock mass parameters of the soft and hard rock area into the stress state of the soft rock area fault coordinate system:
Figure BDA0002503583020000103
(5) and (3) converting the fault coordinate system of the soft rock area into a geodetic coordinate system, wherein the step is the inverse operation of the step (3), and the conversion matrix is the inverse matrix of the step (3), so that the fault coordinate system of the soft rock area is obtained:
Figure BDA0002503583020000104
(6) the direction of the tunnel axis is about N15 degrees E, so that the angle alpha of a conversion matrix from a fault coordinate system of the soft rock area to a geodetic coordinate system of the soft rock area is 105 degrees
The obtained stress state of the tunnel coordinate system in the soft rock area is as follows:
Figure BDA0002503583020000111
(7) and (3) obtaining the stress state of the tunnel coordinate system of the hard rock area by the transformation matrix of the step (6) and the stress state of the earth coordinate system of the hard rock area obtained in the step (3):
Figure BDA0002503583020000112
the values of the principal stress of the tunnel coordinate system in soft and hard rock areas are shown in Table 3 below
Figure BDA0002503583020000113
It can be seen that the stress in soft rock areas is lower than in hard rock areas in the same area.
The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. A method for estimating the geostress of soft rock in a fault fracture zone is characterized by comprising the following steps:
step 1: obtaining geostress test results for three principal stresses in a hard rock region, the three principal stresses comprising: horizontal large main stress, horizontal small main stress and vertical stress; establishing an original coordinate system by taking the horizontal large principal stress direction as an X axis, the horizontal small principal stress direction as a Y axis and the vertical stress direction as a Z axis so as to determine a stress matrix of the original coordinate system of the hard rock area;
step 2: determining a first conversion matrix of coordinate conversion according to a conversion matrix formula, and converting a stress matrix of an original coordinate system of the hard rock area into a stress matrix of a geodetic coordinate system of the hard rock area according to the first conversion matrix and a stress component conversion formula;
and step 3: determining a second conversion matrix of coordinate conversion according to the conversion matrix formula, and converting the stress matrix of the geodetic coordinate system of the hard rock area into the stress matrix of the fault coordinate system of the hard rock area according to the second conversion matrix and the stress component conversion formula; converting the stress matrix of the fault coordinate system of the hard rock area into the stress matrix of the fault coordinate system of the soft rock area according to the generalized Hooke's law;
and 4, step 4: applying the inverse operation of the stress component conversion formula through a third conversion matrix, wherein the third conversion matrix is a transposed matrix of the second conversion matrix, and converting the stress matrix of the fault coordinate system of the soft rock area into the stress matrix of the geodetic coordinate system of the soft rock area;
and 5: and applying the inverse operation of the stress component conversion formula through a fourth conversion matrix, wherein the fourth conversion matrix is a transposed matrix of the first conversion matrix, and converting the stress matrix of the geodetic coordinate system of the soft rock area into the stress matrix of the tunnel coordinate system of the soft rock area.
2. The method for estimating the geostress of soft rocks in a fractured zone of claim 1, further comprising the step 6 of:
and converting the stress matrix of the geodetic coordinate system of the hard rock area into the stress matrix of the tunnel coordinate system of the hard rock area according to the fourth conversion matrix and the stress component conversion formula.
3. The method for estimating the geostress of the soft rock of the fractured zone of claim 1, wherein the method for estimating the geostress of the soft rock of the fractured zone has the following assumed preconditions:
the dimension of the rock layer parallel to the xoy plane in the horizontal direction is larger than the dimension in the vertical direction;
the rock stratum is isotropic;
the material satisfies the elastic assumption.
4. The method of estimating geostress of soft rock in a fractured zone of claim 1,
the matrix expression of the stress component conversion formula for the same point in different coordinate systems is as follows:
[σ']＝[β][σ][β]T；
Figure FDA0002503583010000021
wherein [ sigma' ] is the stress matrix of the new coordinate system, [ beta ] is the transformation matrix, and [ sigma ] is the stress matrix of the original coordinate system.
5. The method of estimating geostress of soft rock in a fractured zone of claim 1,
the transformation matrix formula under different coordinate systems for the same point is as follows:
Figure FDA0002503583010000022
the method comprises the following steps of setting x, y and z as coordinate axes of an original coordinate system, setting x ', y' and z 'as coordinate axes of a new coordinate system, setting lij to cos (Ai, Bj), i to 1-3, and j to 1-3, setting A1-A3 to be x', y 'and z', setting B1-B3 to be x, y and z, and setting lij to be cosine of an included angle between an Ai axis and a Bj axis.
6. The method of estimating geostress of soft rock in a fractured zone of claim 5,
setting the maximum horizontal principal stress direction of the geodetic coordinate system of the hard rock area as an X ' axial north direction, the minimum horizontal principal stress direction as a Y ' axial east direction, and the vertical stress as a Z ' axial down direction; the azimuth angle of the maximum horizontal principal stress of the geodetic coordinate system is alpha;
the first conversion matrix formula in step 2 is:
Figure FDA0002503583010000031
7. the method of estimating geostress of soft rock in a fractured zone of claim 5,
the vertical fault plane of the fault coordinate system of the hard rock region is a z ' axis, the direction of the fault plane intersection horizontal plane in the geodetic coordinate system is an x ' axis, and the direction vertical to the x ' axis and the z ' axis is a y ' axis; setting the tendency of the fault of the hard rock area as alpha and the inclination angle as beta;
then the z' axis unit vector direction is (cos α sin β, sin α sin β, cos β); the unit vector direction of the x' axis is (sin α, -cos α, 0); the y' axis unit vector direction is (cos α cos β, sin α cos β, -sin β); the unit vector directions of the x axis, the y axis and the z axis of the geodetic coordinate system are (1, 0, 0), (0, 1, 0) and (0, 0, 1) respectively;
the second conversion matrix formula in step 3 is:
Figure FDA0002503583010000032
8. the method for estimating the crustal stress of the soft rock in the fault fracture zone according to claim 7, wherein the analytic solution of the generalized hooke's law is solved by the following formula:
Figure FDA0002503583010000033
the stress in the soft rock area is
Figure FDA0002503583010000034
The stress of the hard rock area is
Figure FDA0002503583010000035
The strain of the soft rock area and the strain of the hard rock area are equally substituted into the generalized Hooke's law to obtain:
Figure FDA0002503583010000041
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112528543A (en) * 2020-12-14 2021-03-19 中国科学院武汉岩土力学研究所 Method and device for analyzing ground stress and processing equipment
CN115983052A (en) * 2023-03-21 2023-04-18 中国矿业大学(北京) Initial stress generation method suitable for FLAC3D medium-density rock stratum condition

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4781062A (en) * 1987-10-23 1988-11-01 Amoco Corporation Conjugate fracture systems and formation stresses in subterranean formations
US20080201079A1 (en) * 2007-02-21 2008-08-21 Castillo David A Method and apparatus for remote characterization of faults in the vicinity of boreholes
CN105350972A (en) * 2015-10-26 2016-02-24 中铁二十局集团有限公司 High-ground-stress weak surrounding rock tunnel excavation construction method
CN106021840A (en) * 2016-02-03 2016-10-12 中原工学院 Method for inverting transverse isotropic rock mass ground stress
US20170009575A1 (en) * 2015-07-09 2017-01-12 Conocophillips Company Rock strength and in-situ stresses from drilling response
WO2017136208A1 (en) * 2016-02-03 2017-08-10 Schlumberger Technology Corporation Downhole modeling using inverted pressure and regional stress
CN107633146A (en) * 2017-09-28 2018-01-26 国家电网公司 A kind of method that crustal stress result of calculation is changed in high precision between different scale model
CN108798662A (en) * 2018-06-23 2018-11-13 东北石油大学 Coal seam directional well borehole wall Fracturing Pressure Prediction method
CN109583116A (en) * 2018-12-10 2019-04-05 西南交通大学 Underground engineering primary stress field dynamic playback method based on multi-source real measured data
CN110514342A (en) * 2019-09-18 2019-11-29 长江水利委员会长江科学院 The quickly measuring device and method of measurement soft rock strata crustal stress

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4781062A (en) * 1987-10-23 1988-11-01 Amoco Corporation Conjugate fracture systems and formation stresses in subterranean formations
US20080201079A1 (en) * 2007-02-21 2008-08-21 Castillo David A Method and apparatus for remote characterization of faults in the vicinity of boreholes
US20170009575A1 (en) * 2015-07-09 2017-01-12 Conocophillips Company Rock strength and in-situ stresses from drilling response
CN105350972A (en) * 2015-10-26 2016-02-24 中铁二十局集团有限公司 High-ground-stress weak surrounding rock tunnel excavation construction method
CN106021840A (en) * 2016-02-03 2016-10-12 中原工学院 Method for inverting transverse isotropic rock mass ground stress
WO2017136208A1 (en) * 2016-02-03 2017-08-10 Schlumberger Technology Corporation Downhole modeling using inverted pressure and regional stress
US20180372911A1 (en) * 2016-02-03 2018-12-27 Schlumberger Technology Corporation Downhole Modeling Using Inverted Pressure and Regional Stress
CN107633146A (en) * 2017-09-28 2018-01-26 国家电网公司 A kind of method that crustal stress result of calculation is changed in high precision between different scale model
CN108798662A (en) * 2018-06-23 2018-11-13 东北石油大学 Coal seam directional well borehole wall Fracturing Pressure Prediction method
CN109583116A (en) * 2018-12-10 2019-04-05 西南交通大学 Underground engineering primary stress field dynamic playback method based on multi-source real measured data
CN110514342A (en) * 2019-09-18 2019-11-29 长江水利委员会长江科学院 The quickly measuring device and method of measurement soft rock strata crustal stress

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
WEN-PING LI;XIAO-QIN LI;RU-HUA SUN: "An Estimation Method of Stress in Soft Rock Based on In-situ Measured Stress in Hard Rock", 《JOURNAL OF CHINA UNIVERSITY OF MINING & TECHNOLOGY》 *
朱光仪，郭小红，陈卫忠，邱祥波，李术才: "雪峰山公路隧道地应力场反演及工程应用", 《中南公路工程》 *
李文平: "煤及软岩层中地应力值的初步估算方法", 《岩石力学与工程学报》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112528543A (en) * 2020-12-14 2021-03-19 中国科学院武汉岩土力学研究所 Method and device for analyzing ground stress and processing equipment
CN115983052A (en) * 2023-03-21 2023-04-18 中国矿业大学(北京) Initial stress generation method suitable for FLAC3D medium-density rock stratum condition

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