Quantitative and rapid evaluation method, device and system for grade of ground stress of tunnel

Abstract

The invention discloses a tunnel ground stress grade quantitative rapid evaluation method, device and system, and relates to the technical field of geological survey. The method comprises the following steps: firstly, collecting field measuring point related information of a measuring point rock core, a surrounding rock secondary stress obtained by performing a stress recovery test on the measuring point rock core by a stress recovery test device, and a transverse compressive strength obtained by performing a transverse compressive strength test on the measuring point rock core; then, according to the data, calculating in sequence to obtain a vertical crustal stress, an initial crustal stress in the horizontal direction of a vertical hole axis and a modified strength stress ratio, and finally, according to the modified strength stress ratio and a known mapping relation between the crustal stress grade and the modified strength stress ratio, determining the crustal stress grade of an area where the measuring point is located. Therefore, only a small round hole needs to be drilled for stress relief during tunnel site construction, deep holes do not need to be drilled, and the method has the advantages that the testing cost is low, the method can be applied to high-crustal-stress hard rock tunnels, and a high-crustal-stress identification result can be quickly obtained on site.

Description

Technical Field

[0001] The invention belongs to the technical field of geological survey, and in particular relates to a method, a device and a system for quantitatively and quickly evaluating the ground stress level of a tunnel based on secondary stress and lateral compressive strength testing. Background Art

[0002] In recent years, with the construction of a large number of deep underground projects in my country, a series of major disasters caused by high ground stress are also increasing, such as geological disasters such as rock bursts. The occurrence of these disasters not only poses a great threat to on-site personnel, but also seriously causes delays in construction. Therefore, it is particularly important to timely and effectively evaluate the ground stress state during tunnel construction.

[0003] At present, the ground stress level of tunnels is mainly judged during tunnel construction by the size of initial ground stress, geological phenomena of high ground stress and strength-stress ratio.

[0004] In order to judge high geostress based on the size of initial geostress, it is necessary to measure the initial geostress of the rock mass. For example, if the hydraulic fracturing method is used to test the initial geostress, the drilling depth needs to reach hundreds of meters depending on the tunnel burial depth, the test time is as long as 10-30 days, and the cost of a drilling test is as high as 400,000 to 500,000 yuan. The test is generally carried out during the survey and design period. Although the hollow package triaxial strain gauge method can be used to measure the initial geostress during the construction period, the drilling depth needs to reach 20 to 30 meters, the drilling requires large-scale machinery, and the cost of a single test is about 300,000 yuan, which has a high economic cost. Due to economic cost and test time, the above two methods cannot be widely used in the measurement of initial geostress of all tunnels.

[0005] When judging high ground stress based on the geological surface phenomena of high ground stress, many high ground stress phenomena cannot be observed in the first time, and there is a time lag in the occurrence of disasters. In addition, it is a qualitative judgment, which requires high on-site experience of the judges and is greatly affected by human factors. In addition, it does not consider the relationship between the severity of the geological surface phenomena and the high ground stress level.

[0006] To identify high geostress based on the strength-stress ratio, it is also necessary to measure the maximum initial geostress value in the direction perpendicular to the tunnel axis, which also faces the problem of long test time and economic cost of hundreds of thousands of dollars. At the same time, it is also necessary to measure the uniaxial compressive strength of rock indoors. When measuring the uniaxial compressive strength of rock, it is necessary to sample the rock on site and send it back indoors for sample preparation, which takes a certain amount of time. In addition, certain disturbances will occur during the transportation and preparation of rock samples, resulting in a certain gap between the in-situ mechanical parameters of the rock mass under tunnel site conditions.

[0007] The above three existing technologies for determining the level of high ground stress all have problems to varying degrees, such as deep drilling depth, great difficulty in drilling, inability to quickly obtain reference data to provide guidance for on-site construction due to long testing time, and inability to carry out testing applications in all high ground stress tunnels due to high economic costs. Summary of the invention

[0008] The purpose of the present invention is to provide a method, device, system, computer equipment, computer readable storage medium and computer program product for quantitatively and rapidly assessing the ground stress level of a tunnel, so as to solve the problems of high cost and long time consumption in the existing high ground stress level identification scheme.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] In a first aspect, a method for quantitatively and rapidly assessing the ground stress level of a tunnel is provided, comprising:

[0011] Collecting on-site measuring point related information of the measuring point core and the secondary stress of the surrounding rock obtained by first performing a stress recovery test on the measuring point core by a stress recovery test device and then performing a transverse compressive strength test on the measuring point core, wherein the measuring point core refers to the core obtained by stress relief on the tunnel wall behind the tunnel face at the excavation site of the tunnel flat guide and taken out from the measuring point, the area where the measuring point is located is located between the tunnel flat guide and the tunnel main tunnel, and the on-site measuring point related information includes the rock deadweight of the measuring point core, the rock buried depth of the measuring point core, the tunnel surrounding rock grade of the tunnel flat guide and the distance that the tunnel flat guide leads the tunnel main tunnel;

[0012] According to the deadweight of the rock mass and the buried depth of the rock mass at the measuring point, the vertical ground stress S is calculated according to the following formula: Z :

[0013] S Z =γ×h

[0014] Wherein, γ represents the deadweight of the rock mass at the measuring point, and h represents the buried depth of the rock mass at the measuring point;

[0015] According to the vertical ground stress S Z and the vertical secondary stress S in the surrounding rock secondary stress zz The initial geostress S in the horizontal direction perpendicular to the tunnel axis is calculated according to the following formula: X :

[0016] S X =c 1 ×(m×S Z -n×e×S zz )

[0017] In the formula, c1 represents a first calculation parameter determined according to the tunnel surrounding rock grade and negatively correlated with the tunnel surrounding rock grade, m represents a preset second calculation parameter, n represents a preset third calculation parameter, and e represents a fourth calculation coefficient determined according to the distance and negatively correlated with the distance;

[0018] According to the transverse compressive strength, the vertical ground stress S Z and the initial geostress S X , the modified strength stress ratio CSSR is calculated according to the following formula:

[0019] CSSR=R b ÷max(S Z ,S X )

[0020] In the formula, R b represents the transverse compressive strength, and max() represents the maximum value function;

[0021] The ground stress level of the area where the measuring point is located is determined according to the corrected strength stress ratio CSSR and the known mapping relationship between the ground stress level and the corrected strength stress ratio.

[0022] Based on the above invention content, a new solution for quickly identifying the ground stress level of a tunnel based on the test results of secondary stress and transverse compressive strength is provided, that is, firstly collect the field measuring point related information of the measuring point core and the surrounding rock secondary stress obtained by stress recovery test equipment on the measuring point core and the transverse compressive strength obtained by transverse compressive strength test, then calculate the vertical ground stress, the initial ground stress in the horizontal direction of the vertical tunnel axis and the modified strength stress ratio in sequence according to these data, finally determine the ground stress level of the area where the measuring point is located according to the modified strength stress ratio and the known mapping relationship between the ground stress level and the modified strength stress ratio, so that only a small circular hole needs to be drilled for stress relief during the tunnel construction, without the need to drill a deep hole, and all the test data can be obtained on site, so that the process is simple and fast, and the normal construction is not affected due to the short time consumption on site, and the test has the advantages of low testing cost, application in high ground stress hard rock tunnels, and rapid acquisition of high ground stress identification results on site, which is convenient for practical application and promotion.

[0023] In a possible design, the secondary stress of the surrounding rock is measured as follows:

[0024] A plug-type stress recovery test device is used to perform stress recovery on the core of the measuring point at the tunnel site, and the stress recovery process is automatically controlled by the strain difference before and after the stress is released, and finally the recovery load in the vertical direction is obtained;

[0025] The vertical secondary stress S is calculated according to the following stress calculation formula: zz As the secondary stress of surrounding rock:

[0026] S zz =λ×α×β×F Z ÷A

[0027] Wherein, λ represents the size influence coefficient determined according to the diameter of the core at the measuring point and positively correlated with the diameter, α represents the stress equivalent coefficient determined according to the quantification level of the equivalent elastic modulus of the core at the measuring point and positively correlated with the quantification level, β represents the confining pressure influence coefficient determined according to the confining pressure of the core at the measuring point and positively correlated with the confining pressure, and F Z It represents the recovery load in the vertical direction when the stress recovery is automatically controlled based on the strain difference to reach the preset strain difference, A represents the compressive area of ​​the measuring point core when it is horizontally compressed and A=L×H, L represents the contact width between the saddle-shaped pad of the gate plug type stress recovery test equipment and the measuring point core and the unit is mm, H represents the contact height between the saddle-shaped pad and the measuring point core and the unit is mm.

[0028] In one possible design, the transverse compressive strength is measured as follows:

[0029] Placing the measuring point core in a saddle-shaped pad of a gate plug type stress recovery test device, and controlling the gate plug type stress recovery test device to pressurize the measuring point core;

[0030] Record the load F of the core at the measuring point during transverse fracturing, and calculate the transverse compressive strength R of the core at the measuring point based on the load F. b :

[0031] R b =F÷A

[0032] In the formula, A represents the compression area of ​​the measuring point core when it is subjected to transverse compression, and A=L×H, L represents the contact width between the saddle-shaped pad of the gate plug type stress recovery test equipment and the measuring point core, and the unit is mm, and H represents the contact height between the saddle-shaped pad and the measuring point core, and the unit is mm.

[0033] In one possible design, the first calculated parameter c 1 It is determined as follows: when the tunnel surrounding rock grade is grade II, the first calculation parameter c is determined in the value range [1.02, 1.14]. 1 When the tunnel surrounding rock grade is grade III, the first calculation parameter c is selected within the numerical range [0.97, 1.02] 1When the tunnel surrounding rock grade is IV, the first calculation parameter c is selected within the value range [0.89, 0.94] 1 When the tunnel surrounding rock grade is grade V, the first calculation parameter c is selected within the numerical range [0.83, 0.88] 1 ;

[0034] And / or, the second calculation parameter m is preset to 2.91;

[0035] And / or, the third calculation parameter n is preset to 1.12;

[0036] And / or, the fourth calculation coefficient e is determined in the following manner: when the distance is less than 20 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.96, 1.0]; when the distance is greater than or equal to 20 meters and less than 40 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.94, 0.96]; when the distance is greater than or equal to 40 meters and less than 60 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.90, 0.94]; when the distance is greater than or equal to 60 meters and less than 80 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.87, 0.90]; when the distance is greater than or equal to 80 meters and less than 100 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.81, 0.87].

[0037] In a possible design, according to the modified strength stress ratio CSSR and a known mapping relationship between the ground stress level and the modified strength stress ratio, determining the ground stress level of the area where the measuring point is located includes:

[0038] Obtain the known mapping relationship between the in-situ stress level and the modified strength-stress ratio: the modified strength-stress ratio corresponding to the general in-situ stress level is greater than 4.5; the modified strength-stress ratio corresponding to the high in-situ stress level is greater than 2.5 and less than or equal to 4.5; the modified strength-stress ratio corresponding to the extremely high in-situ stress level is less than or equal to 2.5;

[0039] According to the known mapping relationship, if the corrected strength stress ratio CSSR is greater than 4.5, it is determined that the ground stress level of the area where the measuring point is located is a general ground stress level; if the corrected strength stress ratio CSSR is greater than 2.5 and less than or equal to 4.5, it is determined that the ground stress level of the area where the measuring point is located is a high ground stress level; and if the corrected strength stress ratio CSSR is less than or equal to 2.5, it is determined that the ground stress level of the area where the measuring point is located is an extremely high ground stress level.

[0040] In a second aspect, a device for quantitatively and rapidly assessing the ground stress level of a tunnel is provided, comprising a field information collection unit, a vertical ground stress calculation unit, an initial ground stress calculation unit, a stress ratio calculation unit and a ground stress level determination unit;

[0041] The field information collection unit is used to collect field measurement point related information of the measurement point core and the secondary stress of the surrounding rock obtained by first performing a stress recovery test on the measurement point core by a stress recovery test device and then performing a transverse compressive strength test on the measurement point core, wherein the measurement point core refers to the core obtained by stress relief on the tunnel wall behind the tunnel face at the excavation site of the tunnel flat guide and taken out from the measurement point, the area where the measurement point is located is located between the tunnel flat guide and the tunnel main tunnel, and the field measurement point related information includes the rock body deadweight of the measurement point core, the rock body burial depth of the measurement point core, the tunnel surrounding rock grade of the tunnel flat guide and the distance by which the tunnel flat guide leads the tunnel main tunnel;

[0042] The vertical geostress calculation unit is communicatively connected to the on-site information collection unit and is used to calculate the vertical geostress S according to the following formula based on the deadweight of the rock mass and the buried depth of the rock mass at the measuring point core: Z :

[0043] S Z =γ×h

[0044] Wherein, γ represents the deadweight of the rock mass at the measuring point, and h represents the buried depth of the rock mass at the measuring point;

[0045] The initial geostress calculation unit is respectively connected to the field information collection unit and the vertical geostress calculation unit for calculating the vertical geostress according to the vertical geostress S Z and the vertical secondary stress S in the surrounding rock secondary stress zz The initial geostress S in the horizontal direction perpendicular to the tunnel axis is calculated according to the following formula: X :

[0046] S X =c 1 ×(m×S Z -n×e×S zz )

[0047] In the formula, c 1 represents a first calculation parameter determined according to the tunnel surrounding rock grade and negatively correlated with the tunnel surrounding rock grade, m represents a preset second calculation parameter, n represents a preset third calculation parameter, and e represents a fourth calculation coefficient determined according to the distance and negatively correlated with the distance;

[0048] The stress ratio calculation unit is respectively connected to the field information collection unit and the initial ground stress calculation unit for calculating the vertical ground stress according to the lateral compressive strength and the vertical ground stress S Z and the initial geostress S X , the modified strength stress ratio CSSR is calculated according to the following formula:

[0049] CSSR=R b ÷max(S Z ,S X )

[0050] In the formula, R b represents the transverse compressive strength, and max() represents the maximum value function;

[0051] The geostress level determination unit is communicatively connected to the stress ratio calculation unit, and is used to determine the geostress level of the area where the measuring point is located according to the corrected strength stress ratio CSSR and a known mapping relationship between the geostress level and the corrected strength stress ratio.

[0052] In a third aspect, a system for quantitatively and rapidly assessing the ground stress level of a tunnel is provided, comprising a stress recovery test device and a host computer device connected in communication;

[0053] The stress recovery test equipment is used to perform stress recovery test on the measuring point core to obtain the secondary stress of the surrounding rock and to perform transverse compressive strength test to obtain the transverse compressive strength, and transmit the secondary stress of the surrounding rock and the transverse compressive strength to the host computer equipment, wherein the measuring point core refers to the core obtained by stress relief on the tunnel wall behind the tunnel face at the excavation site of the tunnel flat guide and taken out from the measuring point, and the area where the measuring point is located is between the tunnel flat guide and the tunnel main tunnel;

[0054] The host computer device is used to execute the method for quantitatively and quickly assessing the tunnel ground stress level as described in the first aspect or any possible design of the first aspect.

[0055] In a fourth aspect, the present invention provides a computer device comprising a memory, a processor and a transceiver which are communicatively connected in sequence, wherein the memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program to execute the method for quantitatively and rapidly assessing the ground stress level of a tunnel as described in the first aspect or any possible design of the first aspect.

[0056] In a fifth aspect, the present invention provides a computer-readable storage medium having instructions stored thereon, which, when executed on a computer, executes a method for quantitatively and rapidly assessing tunnel geostress levels as described in the first aspect or any possible design of the first aspect.

[0057] In a sixth aspect, the present invention provides a computer program product, comprising a computer program or instructions, which, when executed by a computer, implements the method for quantitatively and rapidly assessing the ground stress level of a tunnel as described in the first aspect or any possible design of the first aspect.

[0058] Beneficial effects of the above scheme:

[0059] (1) The invention provides a new solution for quickly identifying the in-situ stress level of a tunnel based on the test results of secondary stress and transverse compressive strength, that is, firstly collecting the relevant information of the in-situ measuring point of the measuring point core and the secondary stress of the surrounding rock obtained by the stress recovery test equipment on the measuring point core and the transverse compressive strength obtained by the transverse compressive strength test, then calculating the vertical in-situ stress, the initial in-situ stress in the horizontal direction of the vertical tunnel axis and the modified strength-stress ratio in turn according to these data, and finally determining the in-situ stress level of the area where the measuring point is located according to the modified strength-stress ratio and the known mapping relationship between the in-situ stress level and the modified strength-stress ratio. In this way, only a small circular hole needs to be drilled for stress relief during the in-situ construction of the tunnel, without the need to drill a deep hole, and all the test data can be obtained on-site, making the process simple and fast, and the short on-site time consumption does not affect the normal construction. The invention has the advantages of low testing cost, application in high-stress hard rock tunnels, and rapid acquisition of high-stress identification results on-site, which is convenient for practical application and promotion;

[0060] (2) This scheme can also provide a modified strength-stress ratio for rapid identification of tunnel geostress levels, so that the magnitude of tunnel geostress can be rapidly evaluated quantitatively, providing accurate guidance for on-site construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0062] Figure 1 A schematic flow chart of a method for quantitatively and rapidly assessing tunnel geostress level provided in an embodiment of the present application.

[0063] Figure 2 This is an example diagram of the positional relationship between the measuring points and the tunnel guide and tunnel main tunnel provided in the embodiment of the present application.

[0064] Figure 3 Schematic diagram of the structural principle of measuring the secondary stress of surrounding rock through a stress recovery test provided in an embodiment of the present application.

[0065] Figure 4 A schematic diagram of the structural principle of measuring the transverse compressive strength through a transverse compressive strength test provided in an embodiment of the present application, wherein: Figure 4 (a) shows the schematic diagram of the main structure principle of the transverse compressive strength test. Figure 4 (b) in the figure shows a schematic diagram of the side view structural principle of the transverse compressive strength test.

[0066] Figure 5 A schematic diagram of the structure of a device for quantitatively and quickly assessing tunnel geostress level provided in an embodiment of the present application.

[0067] Figure 6 A schematic diagram of the structure of a system for quantitatively and rapidly assessing tunnel geostress level provided in an embodiment of the present application.

[0068] Figure 7 A schematic diagram of the structure of a computer device provided in an embodiment of the present application.

[0069] In the above drawings: 100-tunnel pilot hole; 200-tunnel main hole; 300-on-site heading face; 400-measuring point; 500-the area where the measuring point is located. DETAILED DESCRIPTION

[0070] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structures of the drawings is only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these embodiments without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0071] It should be understood that although the terms first and second, etc. may be used herein to describe various objects, these objects should not be limited by these terms. These terms are only used to distinguish one object from another object. For example, a first object can be referred to as a second object, and similarly, a second object can be referred to as a first object without departing from the scope of the exemplary embodiments of the present invention.

[0072] It should be understood that the term "and / or" that may appear in this document is merely a description of the association relationship between associated objects, indicating that there may be three relationships. For example, A and / or B can indicate three situations: A exists alone, B exists alone, or A and B exist at the same time. For another example, A, B and / or C can indicate the existence of any one of A, B and C or any combination of them. The term " / and" that may appear in this document describes another type of association object relationship, indicating that there may be two relationships. For example, A / and B can indicate two situations: A exists alone or A and B exist at the same time. In addition, the character " / " that may appear in this document generally indicates that the previous and next associated objects are in an "or" relationship.

[0073] Example

[0074] like Figures 1 to 4 As shown, the method for quantitatively and rapidly assessing the tunnel ground stress level provided in the first aspect of this embodiment can be, but is not limited to, executed by a computer device with certain computing resources, such as a platform server, a personal computer (PC, which refers to a multi-purpose computer with a size, price and performance suitable for personal use; desktops, laptops, small laptops, tablets and ultrabooks are all personal computers), smart phones, personal digital assistants (PDA) or wearable devices. Figure 1 As shown, the method for quantitatively and quickly assessing the tunnel geostress level may include, but is not limited to, the following steps S1 to S5.

[0075] S1. Collecting on-site measuring point related information of measuring point cores and the secondary stress of the surrounding rock obtained by first performing a stress recovery test on the measuring point cores by a stress recovery test device and then performing a transverse compressive strength test on the transverse compressive strength obtained, wherein the measuring point cores refer to the cores obtained by stress relief on the tunnel wall behind the heading face at the excavation site of the tunnel pilot and taken out from the measuring point, and the area where the measuring point is located is between the tunnel pilot and the tunnel main tunnel. The on-site measuring point related information includes but is not limited to the deadweight of the rock mass of the measuring point cores, the buried depth of the rock mass of the measuring point cores, the tunnel surrounding rock grade of the tunnel pilot, and the distance by which the tunnel pilot leads the tunnel main tunnel.

[0076] In step S1, the positional relationship between the measuring point and the tunnel parallel guide (i.e., the parallel guide tunnel of the tunnel main tunnel, which serves as an auxiliary, and the relationship between the two is like that between the main tunnel and the auxiliary tunnel arranged in parallel) and the tunnel main tunnel is as follows: Figure 2As shown; the sampling parameters of the measuring point core include but are not limited to: diameter 50mm and sampling depth 50mm. The measuring point core is obtained on site and needs to be tested on site to obtain the surrounding rock secondary stress and the transverse compressive strength (in order to meet the needs of on-site testing, the stress recovery test equipment can be but is not limited to conventional improvements based on the existing gate plug stress recovery test equipment). The surrounding rock secondary stress and the transverse compressive strength can be obtained by input by on-site personnel, or by transmission from the stress recovery test equipment, and the on-site measuring point related information can be input by on-site personnel. In addition, the on-site measuring point related information can also include but is not limited to another distance from the measuring point to the on-site face.

[0077] In the step S1, specifically, the secondary stress of the surrounding rock can be measured in the following manner, but is not limited to: firstly, a plug-type stress recovery test device is used to perform stress recovery on the core of the measuring point at the tunnel site, and the stress recovery process is automatically controlled by the strain difference before and after the stress is released, and finally the recovery load in the vertical direction is obtained; then, the secondary stress S in the vertical direction is calculated according to the following stress calculation formula: zz As the secondary stress of surrounding rock:

[0078] S zz =λ×α×β×F Z ÷A

[0079] Wherein, λ represents the size influence coefficient determined according to the diameter of the core at the measuring point and positively correlated with the diameter, α represents the stress equivalent coefficient determined according to the quantification level of the equivalent elastic modulus of the core at the measuring point and positively correlated with the quantification level, β represents the confining pressure influence coefficient determined according to the confining pressure of the core at the measuring point and positively correlated with the confining pressure, and F Z It represents the recovery load in the vertical direction when the stress recovery is automatically controlled based on the strain difference to reach the preset strain difference, A represents the compression area of ​​the measuring point core when it is horizontally compressed and A=L×H, L represents the contact width between the saddle-shaped pad of the gate plug stress recovery test equipment and the measuring point core and the unit is mm, H represents the contact height between the saddle-shaped pad and the measuring point core and the unit is mm. The structural principle of measuring the secondary stress of the surrounding rock through the stress recovery test is the principle of the prior art, such as Figure 3 shown.

[0080] In the step S1, specifically, the transverse compressive strength can be measured but is not limited to the following method: first, the measuring point core is placed in a saddle-shaped pad of a gate plug type stress recovery test device, and the gate plug type stress recovery test device is controlled to pressurize the measuring point core; then, the load F of the measuring point core during transverse fracturing is recorded, and the transverse compressive strength R of the measuring point core is calculated according to the load F. b:

[0081] R b =F÷A

[0082] In the formula, A represents the compression area of ​​the measuring point core when it is subjected to transverse compression and A=L×H, L represents the contact width between the saddle-shaped pad of the gate plug stress recovery test equipment and the measuring point core and the unit is mm, and H represents the contact height between the saddle-shaped pad and the measuring point core and the unit is mm. The structural principle of measuring the transverse compressive strength through the transverse compressive strength test is an existing principle, such as Figure 4 shown.

[0083] S2. According to the deadweight of the rock mass and the buried depth of the rock mass at the measuring point, the vertical ground stress S is calculated according to the following formula Z :

[0084] S Z =γ×h

[0085] Wherein, γ represents the deadweight of the rock mass of the core at the measuring point, and h represents the buried depth of the rock mass of the core at the measuring point.

[0086] S3. According to the vertical ground stress S Z and the vertical secondary stress S in the surrounding rock secondary stress zz The initial ground stress S in the horizontal direction vertical to the tunnel axis is calculated according to the following formula: X :

[0087] S X =c 1 ×(m×S Z -n×e×S zz )

[0088] In the formula, c 1 represents a first calculation parameter determined according to the tunnel surrounding rock grade and negatively correlated with the tunnel surrounding rock grade, m represents a preset second calculation parameter, n represents a preset third calculation parameter, and e represents a fourth calculation coefficient determined according to the distance and negatively correlated with the distance.

[0089] In step S3, the initial geostress S X The calculation formula and multiple calculation parameters are obtained based on the survey data fitting. Specifically, the first calculation parameter c 1 It is determined as follows: when the tunnel surrounding rock grade is grade II, the first calculation parameter c is determined in the value range [1.02, 1.14]. 1 When the tunnel surrounding rock grade is grade III, the first calculation parameter c is selected within the numerical range [0.97, 1.02] 1When the tunnel surrounding rock grade is IV, the first calculation parameter c is selected within the value range [0.89, 0.94] 1 When the tunnel surrounding rock grade is grade V, the first calculation parameter c is selected within the numerical range [0.83, 0.88] 1 ; The second calculation parameter m is preset to 2.91; The third calculation parameter n is preset to 1.12; The fourth calculation coefficient e is determined as follows: when the distance is less than 20 meters, the fourth calculation coefficient e is selected to be determined in the numerical range (0.96, 1.0]; when the distance is greater than or equal to 20 meters and less than 40 meters, the fourth calculation coefficient e is selected to be determined in the numerical range (0.94, 0.96]; when the distance is greater than or equal to 40 meters and less than 60 meters, the fourth calculation coefficient e is selected to be determined in the numerical range (0.90, 0.94]; when the distance is greater than or equal to 60 meters and less than 80 meters, the fourth calculation coefficient e is selected to be determined in the numerical range (0.87, 0.90]; when the distance is greater than or equal to 80 meters and less than 100 meters, the fourth calculation coefficient e is selected to be determined in the numerical range (0.81, 0.87]. In addition, considering the initial ground stress S in the direction of the tunnel axis Y It also provides a certain reference for the identification of tunnel high ground stress. Therefore, the secondary stress S in the direction of the tunnel axis in the secondary stress of the surrounding rock can also be used. yy The initial geostress S in the tunnel axis direction is calculated according to the following formula: Y To identify applications:

[0090] S Y =c 5 ×a'×(d×S yy ) b

[0091] In the formula, c 5 represents a fifth calculation parameter determined according to the tunnel surrounding rock grade and positively correlated with the tunnel surrounding rock grade, a' represents a preset sixth calculation parameter, d represents a seventh calculation coefficient determined according to another distance from the measuring point to the on-site tunnel face and positively correlated with the another distance, and b represents a preset eighth calculation parameter; the aforementioned initial geostress S Y The calculation formula and multiple calculation parameters are also obtained based on the survey data fitting. The specific value table of all calculation parameters can be shown in Table 1 below:

[0092] Table 1. Value table of all calculation parameters

[0093]

[0094] S4. According to the lateral compressive strength, the vertical stress S Zand the initial geostress S X , the modified strength stress ratio CSSR is calculated according to the following formula:

[0095] CSSR=R b ÷max(S Z ,S X )

[0096] In the formula, R b represents the transverse compressive strength, and max() represents the maximum value function.

[0097] S5. Determine the ground stress level of the area where the measuring point is located according to the corrected strength stress ratio CSSR and the known mapping relationship between the ground stress level and the corrected strength stress ratio.

[0098] In the step S5, specifically, according to the corrected strength stress ratio CSSR and the known mapping relationship between the ground stress level and the corrected strength stress ratio, the ground stress level of the area where the measuring point is located is determined, including but not limited to: first obtaining a known mapping relationship between the ground stress level and the corrected strength stress ratio: the corrected strength stress ratio corresponding to the general ground stress level is greater than 4.5; the corrected strength stress ratio corresponding to the high ground stress level is greater than 2.5 and less than or equal to 4.5; the corrected strength stress ratio corresponding to the extremely high ground stress level is less than or equal to 2.5; then according to the known mapping relationship, if the corrected strength stress ratio CSSR is greater than 4.5, it is determined that the ground stress level of the area where the measuring point is located is the general ground stress level, if the corrected strength stress ratio CSSR is greater than 2.5 and less than or equal to 4.5, it is determined that the ground stress level of the area where the measuring point is located is the high ground stress level, and if the corrected strength stress ratio CSSR is less than or equal to 2.5, it is determined that the ground stress level of the area where the measuring point is located is the extremely high ground stress level.

[0099] Therefore, based on the method for quantitatively and rapidly assessing the tunnel geostress level described in the aforementioned steps S1 to S5, a new scheme for rapidly identifying the tunnel geostress level based on the secondary stress and transverse compressive strength test results is provided, that is, firstly collecting the on-site measuring point related information of the measuring point core and the surrounding rock secondary stress obtained by stress recovery test of the measuring point core by the stress recovery test equipment and the transverse compressive strength obtained by transverse compressive strength test, then calculating the vertical geostress, the initial geostress in the horizontal direction of the vertical tunnel axis and the modified strength stress ratio in sequence according to these data, and finally determining the geostress level of the area where the measuring point is located according to the modified strength stress ratio and the known mapping relationship between the geostress level and the modified strength stress ratio, so that only a small circular hole needs to be drilled for stress relief during the on-site construction of the tunnel without drilling a deep hole, and all the test data can be obtained on-site, so that the process is simple and fast, and the normal construction is not affected due to the short on-site time consumption, and the test has the advantages of low testing cost, application in high geostress hard rock tunnels, and rapid acquisition of high geostress identification results on-site, which is convenient for practical application and promotion.

[0100] like Figure 5 As shown, the second aspect of this embodiment provides a virtual device for implementing the method for quantitatively and quickly assessing the tunnel ground stress level described in the first aspect, comprising a field information collection unit, a vertical ground stress calculation unit, an initial ground stress calculation unit, a stress ratio calculation unit and a ground stress level determination unit;

[0101] The field information collection unit is used to collect field measurement point related information of the measurement point core and the secondary stress of the surrounding rock obtained by first performing a stress recovery test on the measurement point core by a stress recovery test device and then performing a transverse compressive strength test on the measurement point core, wherein the measurement point core refers to the core obtained by stress relief on the tunnel wall behind the tunnel face at the excavation site of the tunnel flat guide and taken out from the measurement point, the area where the measurement point is located is located between the tunnel flat guide and the tunnel main tunnel, and the field measurement point related information includes the rock body deadweight of the measurement point core, the rock body burial depth of the measurement point core, the tunnel surrounding rock grade of the tunnel flat guide and the distance by which the tunnel flat guide leads the tunnel main tunnel;

[0102] The vertical geostress calculation unit is communicatively connected to the on-site information collection unit and is used to calculate the vertical geostress S according to the following formula based on the deadweight of the rock mass and the buried depth of the rock mass at the measuring point core: Z :

[0103] S Z =γ×h

[0104] Wherein, γ represents the deadweight of the rock mass at the measuring point, and h represents the buried depth of the rock mass at the measuring point;

[0105] The initial geostress calculation unit is respectively connected to the field information collection unit and the vertical geostress calculation unit for calculating the vertical geostress according to the vertical geostress S Z and the vertical secondary stress S in the surrounding rock secondary stress zz The initial geostress S in the horizontal direction perpendicular to the tunnel axis is calculated according to the following formula: X :

[0106] S X =c 1 ×(m×S Z -n×e×S zz )

[0107] In the formula, c 1 represents a first calculation parameter determined according to the tunnel surrounding rock grade and negatively correlated with the tunnel surrounding rock grade, m represents a preset second calculation parameter, n represents a preset third calculation parameter, and e represents a fourth calculation coefficient determined according to the distance and negatively correlated with the distance;

[0108] The stress ratio calculation unit is respectively connected to the field information collection unit and the initial ground stress calculation unit for calculating the vertical ground stress according to the lateral compressive strength and the vertical ground stress S Z and the initial geostress S X , the modified strength stress ratio CSSR is calculated according to the following formula:

[0109] CSSR=R b ÷max(S Z ,S X )

[0110] In the formula, R b represents the transverse compressive strength, and max() represents the maximum value function;

[0111] The geostress level determination unit is communicatively connected to the stress ratio calculation unit, and is used to determine the geostress level of the area where the measuring point is located according to the corrected strength stress ratio CSSR and a known mapping relationship between the geostress level and the corrected strength stress ratio.

[0112] The working process, working details and technical effects of the aforementioned device provided in the second aspect of this embodiment can be referred to the method for quantitatively and rapidly assessing the tunnel ground stress level described in the first aspect, and will not be described in detail here.

[0113] like Figure 6 As shown, the third aspect of this embodiment provides a physical system for implementing the method for quantitatively and quickly assessing the tunnel ground stress level described in the first aspect, including but not limited to a stress recovery test device and a host computer device connected in communication;

[0114] The stress recovery test equipment is used to perform stress recovery test on the measuring point core to obtain the secondary stress of the surrounding rock and to perform transverse compressive strength test to obtain the transverse compressive strength, and transmit the secondary stress of the surrounding rock and the transverse compressive strength to the host computer equipment, wherein the measuring point core refers to the core obtained by stress relief on the tunnel wall behind the tunnel face at the excavation site of the tunnel flat guide and taken out from the measuring point, and the area where the measuring point is located is between the tunnel flat guide and the tunnel main tunnel;

[0115] The host computer device is used to execute the method for quantitatively and quickly assessing the tunnel ground stress level as described in the first aspect.

[0116] The working process, working details and technical effects of the aforementioned system provided in the third aspect of this embodiment can be referred to the method for quantitatively and rapidly assessing the tunnel ground stress level described in the first aspect, and will not be described in detail here.

[0117] like Figure 7 As shown, the fourth aspect of this embodiment provides a computer device for executing the method for quantitatively and quickly assessing the tunnel ground stress level as described in the first aspect, including a memory, a processor and a transceiver that are sequentially connected in communication, wherein the memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program to execute the method for quantitatively and quickly assessing the tunnel ground stress level as described in the first aspect. Specifically, the memory may include, but is not limited to, a random access memory (Random-Access Memory, RAM), a read-only memory (Read-Only Memory, ROM), a flash memory (Flash Memory), a first-in-first-out memory (First Input First Output, FIFO) and / or a first-in-last-out memory (First Input Last Output, FILO), etc.; the processor may include, but is not limited to, a microprocessor of the STM32F105 series. In addition, the computer device may also include, but is not limited to, a power module, a display screen and other necessary components.

[0118] The working process, working details and technical effects of the aforementioned computer equipment provided in the fourth aspect of this embodiment can be found in the method for quantitatively and rapidly assessing the tunnel ground stress level described in the first aspect, and will not be described in detail here.

[0119] In a fifth aspect of this embodiment, there is provided a computer-readable storage medium storing instructions including the method for quantitatively and rapidly assessing the ground stress level of a tunnel as described in the first aspect, that is, the computer-readable storage medium stores instructions, and when the instructions are executed on a computer, the method for quantitatively and rapidly assessing the ground stress level of a tunnel as described in the first aspect is executed. The computer-readable storage medium refers to a carrier for storing data, which may include, but is not limited to, computer-readable storage media such as floppy disks, optical disks, hard disks, flash memories, USB flash drives, and / or memory sticks, and the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0120] The working process, working details and technical effects of the aforementioned computer-readable storage medium provided in the fifth aspect of this embodiment can be referred to the method for quantitatively and rapidly assessing the ground stress level of a tunnel as described in the first aspect, and will not be described in detail here.

[0121] A sixth aspect of this embodiment provides a computer program product, including a computer program or an instruction, which, when executed by a computer, implements the method for quantitatively and rapidly assessing the tunnel ground stress level as described in the first aspect. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device.

[0122] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for quantitatively and rapidly assessing tunnel geostress level, characterized in that: include: Collecting on-site measuring point related information of the measuring point core and the secondary stress of the surrounding rock obtained by first performing a stress recovery test on the measuring point core by a stress recovery test device and then performing a transverse compressive strength test on the measuring point core, wherein the measuring point core refers to the core obtained by stress relief on the tunnel wall behind the tunnel face at the excavation site of the tunnel flat guide and taken out from the measuring point, the area where the measuring point is located is located between the tunnel flat guide and the tunnel main tunnel, and the on-site measuring point related information includes the rock deadweight of the measuring point core, the rock buried depth of the measuring point core, the tunnel surrounding rock grade of the tunnel flat guide and the distance that the tunnel flat guide leads the tunnel main tunnel; According to the deadweight of the rock mass and the buried depth of the rock mass at the measuring point, the vertical ground stress S is calculated according to the following formula: Z : S Z =γ×h Wherein, γ represents the deadweight of the rock mass at the measuring point, and h represents the buried depth of the rock mass at the measuring point; According to the vertical ground stress S Z and the vertical secondary stress S in the surrounding rock secondary stress zz The initial geostress S in the horizontal direction perpendicular to the tunnel axis is calculated according to the following formula: X : S X =c1×(m×S Z -n×e×S zz ) In the formula, c1 represents a first calculation parameter determined according to the tunnel surrounding rock grade and negatively correlated with the tunnel surrounding rock grade, m represents a preset second calculation parameter, n represents a preset third calculation parameter, and e represents a fourth calculation coefficient determined according to the distance and negatively correlated with the distance; According to the transverse compressive strength, the vertical ground stress S Z and the initial geostress S X , the modified strength stress ratio CSSR is calculated according to the following formula: CSSR=R b ÷max(S Z ,S X ) In the formula, R b represents the transverse compressive strength, and max() represents the maximum value function; The ground stress level of the area where the measuring point is located is determined according to the corrected strength stress ratio CSSR and the known mapping relationship between the ground stress level and the corrected strength stress ratio.

2. The method for quantitatively and rapidly assessing tunnel geostress level according to claim 1, characterized in that: The secondary stress of the surrounding rock is measured as follows: A plug-type stress recovery test device is used to perform stress recovery on the core of the measuring point at the tunnel site, and the stress recovery process is automatically controlled by the strain difference before and after the stress is released, and finally the recovery load in the vertical direction is obtained; The vertical secondary stress S is calculated according to the following stress calculation formula: zz As the secondary stress of surrounding rock: S zz =λ×α×β×F Z ÷A Wherein, λ represents the size influence coefficient determined according to the diameter of the core at the measuring point and positively correlated with the diameter, α represents the stress equivalent coefficient determined according to the quantification level of the equivalent elastic modulus of the core at the measuring point and positively correlated with the quantification level, β represents the confining pressure influence coefficient determined according to the confining pressure of the core at the measuring point and positively correlated with the confining pressure, and F Z It represents the recovery load in the vertical direction when the stress recovery is automatically controlled based on the strain difference to reach the preset strain difference, A represents the compressive area of ​​the measuring point core when it is horizontally compressed and A=L×H, L represents the contact width between the saddle-shaped pad of the gate plug type stress recovery test equipment and the measuring point core and the unit is mm, H represents the contact height between the saddle-shaped pad and the measuring point core and the unit is mm.

3. The method for quantitatively and rapidly assessing tunnel geostress level according to claim 1, characterized in that: The transverse compressive strength is measured as follows: Placing the measuring point core in a saddle-shaped pad of a gate plug type stress recovery test device, and controlling the gate plug type stress recovery test device to pressurize the measuring point core; Record the load F of the core at the measuring point during transverse fracturing, and calculate the transverse compressive strength R of the core at the measuring point based on the load F. b : R b =F÷A In the formula, A represents the compression area of ​​the measuring point core when it is subjected to transverse compression, and A=L×H, L represents the contact width between the saddle-shaped pad of the gate plug type stress recovery test equipment and the measuring point core, and the unit is mm, and H represents the contact height between the saddle-shaped pad and the measuring point core, and the unit is mm.

4. The method for quantitatively and rapidly assessing tunnel geostress level according to claim 1, characterized in that: The first calculation parameter c1 is determined as follows: when the tunnel surrounding rock grade is grade II, the first calculation parameter c1 is selected and determined within the numerical range of [1.02, 1.14]; when the tunnel surrounding rock grade is grade III, the first calculation parameter c1 is selected and determined within the numerical range of [0.97, 1.02]; when the tunnel surrounding rock grade is grade IV, the first calculation parameter c1 is selected and determined within the numerical range of [0.89, 0.94]; when the tunnel surrounding rock grade is grade V, the first calculation parameter c1 is selected and determined within the numerical range of [0.83, 0.88]; And / or, the second calculation parameter m is preset to 2.91; And / or, the third calculation parameter n is preset to 1.12; And / or, the fourth calculation coefficient e is determined in the following manner: when the distance is less than 20 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.96, 1.0]; when the distance is greater than or equal to 20 meters and less than 40 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.94, 0.96]; when the distance is greater than or equal to 40 meters and less than 60 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.90, 0.94]; when the distance is greater than or equal to 60 meters and less than 80 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.87, 0.90]; when the distance is greater than or equal to 80 meters and less than 100 meters, the fourth calculation coefficient e is selected to be determined in the numerical range of (0.81, 0.87].

5. The method for quantitatively and rapidly assessing tunnel geostress level according to claim 1, characterized in that: Determining the ground stress level of the area where the measuring point is located according to the corrected strength stress ratio CSSR and a known mapping relationship between the ground stress level and the corrected strength stress ratio includes: Obtain the known mapping relationship between the in-situ stress level and the modified strength-stress ratio: the modified strength-stress ratio corresponding to the general in-situ stress level is greater than 4.5; the modified strength-stress ratio corresponding to the high in-situ stress level is greater than 2.5 and less than or equal to 4.5; the modified strength-stress ratio corresponding to the extremely high in-situ stress level is less than or equal to 2.5; According to the known mapping relationship, if the corrected strength stress ratio CSSR is greater than 4.5, it is determined that the ground stress level of the area where the measuring point is located is a general ground stress level; if the corrected strength stress ratio CSSR is greater than 2.5 and less than or equal to 4.5, it is determined that the ground stress level of the area where the measuring point is located is a high ground stress level; and if the corrected strength stress ratio CSSR is less than or equal to 2.5, it is determined that the ground stress level of the area where the measuring point is located is an extremely high ground stress level.

6. A device for quantitatively and rapidly assessing tunnel ground stress level, characterized in that: It includes a field information collection unit, a vertical ground stress calculation unit, an initial ground stress calculation unit, a stress ratio calculation unit and a ground stress level determination unit; The field information collection unit is used to collect field measurement point related information of the measurement point core and the secondary stress of the surrounding rock obtained by first performing a stress recovery test on the measurement point core by a stress recovery test device and then performing a transverse compressive strength test on the measurement point core, wherein the measurement point core refers to the core obtained by stress relief on the tunnel wall behind the tunnel face at the excavation site of the tunnel flat guide and taken out from the measurement point, the area where the measurement point is located is located between the tunnel flat guide and the tunnel main tunnel, and the field measurement point related information includes the rock body deadweight of the measurement point core, the rock body burial depth of the measurement point core, the tunnel surrounding rock grade of the tunnel flat guide and the distance by which the tunnel flat guide leads the tunnel main tunnel; The vertical geostress calculation unit is communicatively connected to the on-site information collection unit and is used to calculate the vertical geostress S according to the following formula based on the deadweight of the rock mass and the buried depth of the rock mass at the measuring point core: Z : S Z =γ×h Wherein, γ represents the deadweight of the rock mass at the measuring point, and h represents the buried depth of the rock mass at the measuring point; The initial geostress calculation unit is respectively connected to the field information collection unit and the vertical geostress calculation unit for calculating the vertical geostress according to the vertical geostress S Z and the vertical secondary stress S in the surrounding rock secondary stress zz The initial geostress S in the horizontal direction perpendicular to the tunnel axis is calculated according to the following formula: X : S X =c1×(m×S Z -n×e×S zz ) In the formula, c1 represents a first calculation parameter determined according to the tunnel surrounding rock grade and negatively correlated with the tunnel surrounding rock grade, m represents a preset second calculation parameter, n represents a preset third calculation parameter, and e represents a fourth calculation coefficient determined according to the distance and negatively correlated with the distance; The stress ratio calculation unit is respectively connected to the field information collection unit and the initial ground stress calculation unit for calculating the vertical ground stress according to the lateral compressive strength and the vertical ground stress S Z and the initial geostress S X , the modified strength stress ratio CSSR is calculated according to the following formula: CSSR=R b ÷max(S Z ,S X ) In the formula, R b represents the transverse compressive strength, and max() represents the maximum value function; The geostress level determination unit is communicatively connected to the stress ratio calculation unit, and is used to determine the geostress level of the area where the measuring point is located according to the corrected strength stress ratio CSSR and a known mapping relationship between the geostress level and the corrected strength stress ratio.

7. A system for quantitatively and rapidly assessing tunnel geostress level, characterized in that: Including a stress recovery test device and a host computer device connected by communication; The stress recovery test equipment is used to perform stress recovery test on the measuring point core to obtain the secondary stress of the surrounding rock and to perform transverse compressive strength test to obtain the transverse compressive strength, and transmit the secondary stress of the surrounding rock and the transverse compressive strength to the host computer equipment, wherein the measuring point core refers to the core obtained by stress relief on the tunnel wall behind the tunnel face at the excavation site of the tunnel flat guide and taken out from the measuring point, and the area where the measuring point is located is between the tunnel flat guide and the tunnel main tunnel; The host computer device is used to execute the method for quantitatively and quickly assessing the tunnel ground stress level as described in any one of claims 1 to 5.

8. A computer device, characterized in that: It includes a memory, a processor and a transceiver which are communicatively connected in sequence, wherein the memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program to execute the method for quantitatively and quickly assessing the ground stress level of a tunnel as described in any one of claims 1 to 5.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores instructions, and when the instructions are executed on the computer, the method for quantitatively and quickly assessing the tunnel ground stress level as described in any one of claims 1 to 5 is executed.

10. A computer program product comprising a computer program or instructions, characterized in that The computer program or the instructions, when executed by a computer, implements the method for quantitatively and rapidly assessing tunnel geostress level as claimed in any one of claims 1 to 5.

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