Design method of safe operation interval of compressed air energy storage cavern considering load sharing effect

Abstract

This invention discloses a design method for the safe operating range of a compressed air energy storage chamber considering load sharing, comprising the following steps: inputting the physical and mechanical parameters of the surrounding rock, excavation radius, and chamber burial depth; calculating the upper and lower limits of the surrounding rock wall pressure using limit equilibrium analysis and elastoplastic analysis; determining the final upper and lower limits of the surrounding rock wall pressure based on the calculation results; then, inputting the lining structure parameters to first obtain the calculated safe pressure range of the surrounding rock wall, and then obtain the calculated safe operating pressure range of the chamber; if the chamber design safe operating pressure range needs to be met, a condition judgment is performed; if the condition is met, the result is directly output; if not, the lining structure parameters are redesigned and recalculated until the chamber design conditions are met. This invention overcomes the limitations of previous research methods on the geostress field, broadens the applicability of analytical solutions, and improves the accuracy of the calculated safe operating pressure range.

Description

Technical Field

[0001] This invention belongs to the field of compressed air energy storage chamber construction and design technology, specifically involving a design method for the safe operation zone of a compressed air energy storage chamber that takes into account the load sharing effect. Background Technology

[0002] Against the backdrop of the global push for a green and low-carbon energy transition, the proportion of renewable energy sources, such as wind and solar power, in the power system continues to increase. However, the inherent intermittency and volatility of these renewable energy generation sources pose challenges to the stable operation of the power grid, necessitating the support of large-scale, long-duration energy storage technologies. Compressed air energy storage has attracted significant attention in this context due to its advantages such as large scale, long lifespan, and flexible site selection. This technology converts electrical energy into compressed air energy stored in underground chambers during off-peak hours and releases it to generate electricity during peak hours, providing crucial support for building new power systems.

[0003] To achieve commercial applications, compressed air energy storage requires large-scale underground gas storage spaces. Among these, artificial hard rock chambers, due to their advantages such as flexible site selection, strong adaptability, and moderate cost, have broader application prospects than salt cavern gas storage and have become an international research hotspot. These chambers typically employ a composite structural system of surrounding rock, lining, and sealing layer: the surrounding rock bears the main load, the lining transmits and distributes pressure, and the sealing layer primarily serves to prevent seepage. Under long-term high-pressure alternating loads, rationally determining the operating gas pressure range becomes the core issue for ensuring the safe and stable operation of the chamber, directly affecting gas storage efficiency and power plant economics.

[0004] Patent application CN118607155A discloses a method for calculating the structural stress of a gas storage facility. This method can obtain the load-sharing ratio of the inner lining gas storage facility, solving the problems of long numerical simulation time, slow analysis and calculation, and huge computational load, thus improving computational efficiency. However, this technology has the following drawbacks: it simplifies the geostress experienced by the chamber, while in reality, the geostress field of the original rock far from the chamber is usually in a biaxial non-isobaric state; it can only calculate the structural stress and deformation, and cannot calculate the safe burial depth based on the operating gas pressure.

[0005] Patent application CN119312572A discloses a semi-analytical method for analyzing the mechanical response of a circular underground compressed air energy storage cavern. This method considers a plastic analytical solution and can accurately determine the radius of the plastic zone and stress distribution of the lining-surrounding rock composite structure. However, this technique has the following drawbacks: the external radial stress of the surrounding rock is treated as uniformly distributed geostress, making it only applicable to biaxial isobaric geostress fields.

[0006] Patent application CN120611435A discloses a method and system for optimizing the design of underground lining caverns for compressed air energy storage. The method proposes a method for designing the burial depth of compressed air energy storage caverns: determining the initial burial depth range through numerical simulation and obtaining the mechanical parameters of the surrounding rock; quantifying the load distribution among structures based on the collaborative bearing mechanism of steel lining, concrete lining, and surrounding rock; and calculating the ultimate burial depth of the cavern using limit equilibrium analysis and verifying its stability. This technology has the following drawbacks: it does not consider the influence of the crack initiation angle, which is a key factor determining the location of crack initiation in the surrounding rock cavern wall; and while the combination of numerical simulation and analytical solutions yields relatively accurate results, it is not convenient for the safety design and verification of compressed air energy storage caverns.

[0007] Existing theories on the stability of compressed air energy storage chambers are mostly calculated based on safe burial depths, with less emphasis on designing safe operating pressure ranges. Furthermore, they often only consider the geostress field under biaxial isobaric conditions, while actual sites are usually not under hydrostatic pressure, thus limiting the application of analytical solutions. Summary of the Invention

[0008] The purpose of this invention is to provide a design method for the safe operating range of a compressed gas energy storage chamber that takes into account the load sharing effect, which breaks through the limitations of previous research methods on the geostress field, broadens the applicability of analytical solutions, and improves the accuracy of the calculation results of the safe operating pressure range.

[0009] To achieve the above objectives, this invention provides a design method for the safe operating range of a compressed gas energy storage chamber, taking into account load sharing, comprising the following steps: S1, input the physical and mechanical parameters of the surrounding rock, excavation radius, and chamber burial depth; S2, Calculate the upper limit of the surrounding rock wall pressure in the limit equilibrium analysis method (UEM). Upper limit of surrounding rock wall pressure in EPM (elastoplastic analysis method) Lower limit ; S3, based on the calculation results of S2, determines the final upper limit of the pressure on the surrounding rock tunnel wall. Lower limit ; S4, the final upper limit of the surrounding rock wall pressure obtained based on S3. Lower limit Input the lining structure parameters to first obtain the safe pressure range of the surrounding rock tunnel wall. Then, the safe operating pressure range for the chamber is obtained. ; S5, if the chamber is calculated to have a safe operating pressure range The chamber needs to meet the safe operating pressure range designed for its operation. If the condition is met, a conditional judgment is performed. If the condition is met, the result is output directly; otherwise, the input lining structure parameters are redesigned and recalculated until the condition is met. satisfy .

[0010] As a further aspect of the present invention: In S2, the upper limit of the surrounding rock wall pressure is calculated using the limit equilibrium analysis method (UEM). The formula is expressed as: ; in, This is the lateral pressure coefficient parameter. ; For cohesion parameters, ; For the geometric parameters of the earth arch, ; This is the lateral pressure coefficient, with a value range of 1 / 3 < <3; ρ is the weight of the surrounding rock; c is the cohesion of the surrounding rock. The angle between the fracture surfaces; The internal friction angle of the surrounding rock; To create a cracked corner; The outer radius of the lining; For safety factor; The chamber is buried deep.

[0011] As a further aspect of the present invention: the upper limit of the surrounding rock wall pressure using the elastoplastic analysis method (EPM). Lower limit The calculation process is divided into two stages according to the different stages of stress on the chamber during operation: (a) initial ground stress Surrounding rock cave wall pressure (b) Initial geostress Surrounding rock cave wall pressure The lateral pressure coefficient is taken as 1 as the limit: 1) : When the chamber is in the un-air-filled stage or the low-pressure stage, that is, when the pressure of the surrounding rock wall is... Initial geostress At that time, the formula for the lower limit of pressure on the surrounding rock wall of the arched tunnel. Represented as: ; When the chamber is in a high-pressure stage, that is, when the pressure on the surrounding rock walls is high... Initial geostress Formula for the upper limit of pressure on the tunnel wall surrounding the arch Represented as: ; 2) : When the chamber is in the un-air-filled stage or the low-pressure stage, that is, when the pressure of the surrounding rock wall is... Initial geostress At that time, the formula for the lower limit of the pressure on the surrounding rock wall of the arch is... Represented as: ; When the chamber is in a high-pressure stage, that is, when the pressure on the surrounding rock walls is high... Initial geostress Formula for the upper limit of pressure on the surrounding rock wall of an arched tunnel. Represented as: ; According to the lateral pressure coefficient The difference lies in the upper limit of the pressure on the surrounding rock of the EPM tunnel. EPM lower limit of surrounding rock wall pressure The values ​​of are also different; when , for , for ;when , for , for .

[0012] As a further aspect of the present invention: the upper limit of the final surrounding rock wall pressure in S3 The formula is expressed as: The lower limit of the final surrounding rock wall pressure The formula is expressed as: .

[0013] As a further aspect of the present invention: calculating the safe operating pressure range for the chamber. Based on the pressure of the surrounding rock tunnel wall Operating air pressure of the chamber The relationship and the ultimate upper limit of the pressure on the surrounding rock tunnel wall Lower limit Calculations determined that the pressure on the surrounding rock tunnel walls... Operating air pressure of the chamber The relational formula is expressed as: ; in, The inner radius of the lining; The elastic modulus of the lining; Poisson's ratio for the lining; Let be the elastic modulus of the surrounding rock. is the Poisson's ratio of the surrounding rock.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. For biaxial unequal pressure geostress fields, analytical solutions for surrounding rock and structures under hydrostatic pressure and non-hydrostatic pressure states are derived respectively, breaking through the limitations of previous research methods on geostress fields and broadening the applicability of analytical solutions.

[0015] 2. Based on the thick-walled cylinder theory and Kirsch solution, a quantitative relationship between the pressure of the surrounding rock tunnel wall and the operating air pressure of the tunnel was established. Simultaneously, the model considers the load transfer and sharing mechanism of the lining structure, accurately reflecting the conversion process from the operating air pressure of the tunnel to the pressure of the surrounding rock tunnel wall, thus improving the accuracy of the calculation results for the safe operating air pressure range.

[0016] 3. Based on the elastoplastic analysis method and the limit equilibrium analysis method, the analytical solution of the safe operating pressure range of the chamber under theoretical analysis is clarified. Attached Figure Description

[0017] Figure 1 This is a flowchart of the design method for the safe operation zone of a compressed gas energy storage chamber, taking into account the load-sharing effect, according to the present invention.

[0018] Figure 2 This invention is a failure model of a chamber cone that considers the structural load sharing effect.

[0019] Figure 3 This is the force analysis diagram of block ABC of the present invention.

[0020] Figure 4 This is a stress diagram of the surrounding rock-lining structure of the compressed air energy storage chamber of the present invention.

[0021] Figure 5 This is the biaxial unequal pressure geostress calculation diagram of the present invention.

[0022] Figure 6 These are the upper and lower limits of the EPM surrounding rock wall pressure during the operation of the chamber in this invention, as shown in the figure: (a) (b) .

[0023] Figure 7 This is a stress diagram of the lining structure of the present invention.

[0024] Figure 8 This is a curve showing the safe surrounding rock pressure range of the tunnel wall under the limit equilibrium analysis method of this invention.

[0025] Figure 9 This is a curve showing the safe surrounding rock pressure range of the tunnel wall under the elastoplastic analysis method of this invention.

[0026] Figure 10 This is a curve showing the safe surrounding rock pressure range of the tunnel wall, which combines the two methods of this invention. Detailed Implementation

[0027] The present invention will be further illustrated by the following examples.

[0028] like Figure 1 As shown, the design method for the safe operating range of a compressed gas energy storage chamber considering load sharing includes the following steps: S1, input the physical and mechanical parameters of the surrounding rock, excavation radius, and burial depth of the chamber.

[0029] S2, Calculate the upper limit of the pressure on the surrounding rock wall using the Limit Equilibrium Analysis (UEM) method. Upper limit of pressure on the surrounding rock tunnel wall using elastoplastic analysis (EPM) Lower limit .

[0030] The rigid cone analysis model based on the limit equilibrium analysis method is as follows: Figure 2 As shown, the fracture initiation point extends from point A (point F) in the surrounding rock along fracture surface AB (surface EF) to point B (point E) on the ground surface. Fracture surfaces AB and EF are symmetrical about the central axis of the chamber. The fracture angle is the angle formed by the fracture surface in the vertical direction. The EB surface is the earth's surface and is not subject to external forces. The upward force resisting the high internal air pressure of the chamber includes the weight of the cone itself. Pressure 2N and shear resistance 2T, chamber burial depth is h The inner radius of the lining is The outer radius of the lining is .

[0031] Figure 3 Here is the force analysis diagram for soil mass ABC, and the weight of the soil mass is... Since soil mass DEF is equivalent to ABC, the self-weight of soil mass DEF is also considered as... BC is the Earth's surface and is not subjected to any external forces. AB is subjected to pressure N and shear resistance T. AC is subjected to at-rest earth pressure. and shear force effect.

[0032] Earth pressure at rest on surface AC The formula is expressed as: ; In the formula, This is the lateral pressure coefficient; The weight of the soil in the surrounding rock. For burial depth variables.

[0033] The mechanical equilibrium of block ABC in the horizontal direction is as follows: ; ; In the formula, The angle between the fracture surfaces; The internal friction angle of the surrounding rock is denoted as .

[0034] If the pressure N and shear resistance T on surface AB satisfy the Mohr-Coulomb strength criterion, then the formula for the total shear resistance T on surface AB is as follows: ; In the formula, c represents the cohesion of the surrounding rock.

[0035] Combining equations (1) to (4), we can obtain the formula for pressure N as follows: ; Considering the influence of the lining's self-weight and load bearing, a vertical force analysis of the entire rigid cone ABEF yields the following results: ; ; ; ; In the formula: This is the total self-weight of the overlying rock mass; The self-weight of soil mass ABC or soil mass DEF; The self-weight of the ACDF soil mass; To create a cracked corner; This represents the upper limit of the pressure on the surrounding rock wall of the UEM tunnel. For safety margin, it is generally taken as 1.3 to 1.5.

[0036] Combining equations (4) to (9), we can obtain the upper limit of the pressure on the surrounding rock wall of the UEM tunnel. The formula is expressed as: ; In the formula: This is the lateral pressure coefficient parameter. ; For cohesion parameters, ; For the geometric parameters of the earth arch, .

[0037] The calculation formula under the analytical solution method is expressed as follows: ; like Figure 4 As shown, in the surrounding rock-lining structure of a compressed air energy storage chamber under a biaxial unequal compressive stress field, the stress in the surrounding rock will redistribute as the operating gas pressure is applied. Whether the surrounding rock enters the plastic stage mainly depends on the ultimate equilibrium condition of rock mass yielding. Initial in-situ stress As a distant load, the lateral pressure coefficient is Operating air pressure in the chamber After the lining bears the load, the pressure on the surrounding rock wall is ,like Figure 5 As shown. This invention is based on the design concept of preventing the structure from entering a plastic state, and derives analytical solutions for the radial stress, circumferential stress, and radial displacement of each structure.

[0038] Based on the Kirsch solution, the stress in the surrounding rock under a biaxial unequal pressure stress state can be obtained: ; ; in, Let be the radial stress at any point in the surrounding rock; Let be the circumferential stress at any point in the surrounding rock, and r represent the radius at that point. when At that time, the radial stress of the surrounding rock tunnel wall can be obtained. Circumferential stress of the surrounding rock tunnel wall : ; ; Specifically, assuming the polar axis is horizontal to the right, the circumferential stress in the arch waist is... Circumferential stress at the crown They are respectively: ; ; When the chamber is under construction, that is ,when When the value is greater than 3, it can be seen from equation (9) that tensile stress appears at the arch waist of the chamber; when When the lateral pressure coefficient is less than 1 / 3, it can be seen from equation (10) that tensile stress occurs at the arch of the chamber. Therefore, in order to prevent tensile stress from occurring in the chamber, the lateral pressure coefficient should be taken as 1 / 3. 3.

[0039] If a compressed air energy storage chamber operates under high internal pressure cyclic filling and discharging conditions, the surrounding rock will enter a plastic state, and the plastic deformation will continuously accumulate under long-term cyclic alternating loads, which is detrimental to the stability of the chamber. Therefore, based on the Mohr-Coulomb strength yield criterion and with the design concept of preventing the surrounding rock from entering a plastic state, this paper derives analytical solutions for the critical wall pressures of the surrounding rock entering the low-pressure plastic zone and the high-pressure plastic zone. Simultaneously, combining the elastic theory of thick-walled cylinders and the Kirsch solution, the operating air pressure of the chamber is established. Pressure on the surrounding rock and cave walls The quantitative relationship. The principal stresses at the yield point of the surrounding rock should satisfy: ; In the formula: , These are the first principal stress and the third principal stress, respectively.

[0040] Based on the load characteristics of the compressed air energy storage chamber during operation, the corresponding Mohr-Coulomb yield criterion can be divided into two stages according to the different stages of stress during chamber operation: (a) initial ground stress Surrounding rock cave wall pressure (b) Initial geostress Surrounding rock cave wall pressure The following is in order The boundary when it is 1 is explained.

[0041] 1) : When the chamber is in the un-air-filled stage or the low-pressure stage, that is, when the pressure of the surrounding rock wall is... Initial geostress At that time, we can obtain: ; Therefore, the lower limit of pressure on the surrounding rock wall of the arched cave is... for: ; If the chamber is damaged at this time, it will first occur at the waist of the arch, and then extend to the top and bottom of the arch.

[0042] When the chamber is in a high-pressure stage, that is, when the pressure on the surrounding rock walls is high... Initial geostress At that time, we can obtain: ; Therefore, the upper limit of pressure on the surrounding rock wall of the arched cave is... for: ; If the chamber is damaged at this time, it will first occur at the top and bottom of the arch, and then extend to the sides of the arch.

[0043] 2) : When the chamber is in the un-air-filled stage or the low-pressure stage, that is, when the pressure of the surrounding rock wall is... Initial geostress At that time, we can obtain: ; Therefore, the lower limit of the pressure on the surrounding rock wall of the arch is... for: ; If the chamber is damaged at this time, it will first occur at the top and bottom of the arch, and then extend to the sides of the arch.

[0044] When the chamber is in a high-pressure stage, that is, when the pressure on the surrounding rock walls is high... Initial geostress At that time, we can obtain: ; Therefore, the upper limit of pressure on the arched rock wall of the cave. for: ; If the chamber is damaged at this time, it will first occur at the waist of the arch, and then extend to the top and bottom of the arch.

[0045] In summary, for the elastoplastic analysis method, based on the lateral pressure coefficient... The difference lies in the upper limit of the pressure on the surrounding rock of the EPM tunnel. EPM lower limit of surrounding rock wall pressure The values ​​of are also different; when , for , for ;when , for , for .

[0046] Based on the above theoretical derivation, the upper and lower limits of the surrounding rock wall pressure during the operation of the tunnel under different lateral pressure coefficients are as follows: Figure 6 As shown. Among them, (1) the red area is the high-pressure plastic zone of the surrounding rock, indicating At that time, the operating air pressure of the chamber (2) The blue area represents the low-pressure plastic zone of the surrounding rock, indicating that the surrounding rock will enter a plastic state under high pressure; Operating air pressure in the chamber When the pressure is relatively low, the surrounding rock will enter a plastic state under the action of low air pressure; (3) Green represents the elastic zone of the surrounding rock, indicating At that time, the operating air pressure of the chamber This ensures that the surrounding rock remains in an elastic state throughout the chamber's operation. Furthermore, the magnitude of the principal stresses in the surrounding rock also changes with the operating air pressure within the chamber. Changes with the changes. When Less than When the chamber is not filled with gas or is under low pressure, the circumferential stress in the compressed gas storage chamber is greater than the radial stress. At this time, the circumferential stress is the first principal stress, and the radial stress is the third principal stress. The surrounding rock may enter the low-pressure plastic zone. Greater than When the chamber is under high pressure, the radial stress is greater than the circumferential stress. At this point, the order of the principal stresses in the surrounding rock changes; the radial stress becomes the first principal stress, and the circumferential stress becomes the third principal stress. The surrounding rock may enter a high-pressure plastic zone. and At the same time, the surrounding rock is in the elastic zone. When Within the elastic zone ( This is beneficial for the long-term operation of the chamber.

[0047] To ensure that the surrounding rock tunnel walls do not enter a state of tensile stress, the range of the lateral pressure coefficient should be [range missing]. During the high-pressure operation phase of the chamber, when When the value is less than 1, tensile failure will occur first at the arch crown and arch bottom of the chamber; when When the value is greater than 1, tensile failure will occur first at the two waists of the chamber.

[0048] S3, based on the calculation results of S2, determines the final upper limit of the pressure on the surrounding rock tunnel wall. Lower limit .

[0049] Based on the preceding theoretical derivation and analysis, the limit equilibrium analysis method can only obtain the upper limit of the pressure on the surrounding rock wall of the UEM tunnel. Elastoplastic analysis can be used to obtain the upper limit of the pressure on the surrounding rock wall of the EPM tunnel. Lower limit From formula (10), we can see that and h The relationship is basically a quadratic function; it can be seen from formulas (20), (22), (24) and (26) that... , and h The relationship is linear. Therefore, when h When smaller, Relatively small; when the burial depth of the chamber is relatively large, Relatively small. Considering both UEM and EPM, the upper limit pressure of the surrounding rock wall for both UEM and EPM is taken. and The minimum value is the upper limit of the final surrounding rock cave wall pressure. ,Pick The lower limit of the final surrounding rock wall pressure Therefore, the upper limit of the final surrounding rock wall pressure of the compressed air energy storage chamber. Lower limit They are respectively: ; ; in, for or ; for or .

[0050] S4, the final upper limit of the surrounding rock wall pressure obtained based on S3. Lower limit Input the lining structure parameters to first obtain the safe pressure range of the surrounding rock tunnel wall. Then, the safe operating pressure range for the chamber is obtained. .

[0051] S5, if the chamber is calculated to have a safe operating pressure range The chamber needs to meet the safe operating pressure range designed for its operation. If the condition is met, a conditional judgment is performed. If the condition is met, the result is output directly; otherwise, the input lining structure parameters are redesigned and recalculated until the condition is met. satisfy .

[0052] Based on the thick-walled cylinder theory and the theoretical derivation of the Kirsch solution above, the pressure on the surrounding rock tunnel wall can be obtained. Operating air pressure of the chamber The relational expression is given. For the theoretical model of the lining's stress, the outer radius of the lining is... The inner radius of the lining is The pressure inside the lining is the operating air pressure of the chamber. The pressure on the outside of the lining is the pressure of the surrounding rock tunnel wall. The stress calculation model of the lining is as follows Figure 7 As shown, this model analysis can be considered as being composed of and The problem of axisymmetric plane strain in a thick-walled cylindrical lining under combined action means that the radial stress at any point in the lining is... Circumferential stress radial displacement With circumferential displacement They are respectively: ; ; ; ; In the formula, A , C For undetermined coefficients, A Indicates the degree to which radial / circumferential stress varies with radial distance. C This indicates the degree to which radial / circumferential stress remains constant with radial distance. r Represents the radius at any point. To represent the Poisson's ratio of any material, It represents the elastic modulus of any material.

[0053] And because the inner radius of the lining is The outer radius of the lining is Operating air pressure of the chamber and the pressure of the surrounding rock tunnel walls The function and boundary conditions are: ; ; in, For lining Radial stress in the lining at the location; For lining Radial stress in the lining at the location.

[0054] Substituting equations (33) to (34) into equations (29) to (32), the radial stress at any point of the lining can be obtained by solving the equations. Circumferential stress radial displacement and circumferential displacement for: ; ; ; ; In the formula, The elastic modulus of the lining. Poisson's ratio for the lining.

[0055] From the polar coordinate geometric equations of the plane problem, we can obtain: ; ; in, Radial strain of the surrounding rock; This is the partial differential of the radial displacement of the surrounding rock; For the partial differential of the radius at any point; For the circumferential strain of the surrounding rock; This represents the circumferential displacement of the surrounding rock. This is the partial derivative of the circumferential displacement of the surrounding rock; For the partial derivative of the angle; This represents the radial displacement of the surrounding rock. Let be the elastic modulus of the surrounding rock. is the Poisson's ratio of the surrounding rock.

[0056] Considering that the initial displacement caused by the initial ground stress is completed after the excavation of the chamber and before the construction of the lining structure, the displacement of the surrounding rock under the action of internal pressure is not included in the present invention. By combining equations (12), (13), (39) and (40), the radial displacement of the surrounding rock can be obtained. for: ; Furthermore, due to the radial displacement of the surrounding rock lining radial displacement exist Since the time is continuous, by combining equations (38) and (41), the pressure of the surrounding rock tunnel wall can be obtained. Operating air pressure of the chamber The relational formula is expressed as: ; By combining equations (27) and (28) with equation (42), the safe operating pressure range for the chamber, taking into account both UEM and EPM, can be obtained. .

[0057] The specific implementation is as follows: The design and calculation of the safe operating pressure range of the compressed air storage chamber are carried out using Class I surrounding rock with different lateral pressure coefficients. The elastic modulus of the surrounding rock under Class I surrounding rock grade is... Poisson's ratio of the surrounding rock The weight of the surrounding rock soil internal friction angle of surrounding rock Cohesion of surrounding rock c The selection was made in accordance with the "Engineering Rock Mass Classification Standard" GB / T 50218–2014, as shown in Table 1. , The lining thicknesses are 8m and 8.5m respectively. The lining depth is 0.5m, the concrete grade used for the lining is C30, and the elastic modulus of the lining is... The Pa is 30 GPa, and the Poisson's ratio of the lining is... It is 0.2. The values ​​are 0.8, 1.0, and 1.5. For and In terms of the expression, the burial depth of the chamber h The operating air pressure in the chamber ranges from 0 to 200 meters. The initial ground stress is 10 MPa. It is 5.6 MPa.

[0058] Table 1 Physical and mechanical calculation parameters of Class I surrounding rock under different lateral pressure coefficients

[0059] Figure 8The pressure on the tunnel wall under different lateral pressure coefficients of UEM Class I surrounding rock. Among them, the green public areas P Zone 1 (PP1Z) represents the range of safe tunnel wall pressures under the same surrounding rock grade and three variations of lateral pressure coefficients, ensuring that the overlying surrounding rock will not become unstable or fail.

[0060] Figure 9 This indicates different lateral pressure coefficients under EPM Class I surrounding rock. , The variation range, where the green public-elastic zone (PEZ) represents the range of safe tunnel wall pressure that prevents the surrounding rock from entering a plastic state under the same surrounding rock grade and three variations of lateral pressure coefficients; when Higher than At this time, the surrounding rock will enter the high-plastic zone (HPZ); when Below When the surrounding rock enters the low-plastic zone (LPZ), whether it enters the HPZ or LPZ, it is detrimental to the long-term operational stability of the compressed gas storage chamber.

[0061] Figure 10 The public-P range of the tunnel wall pressure, representing Class I surrounding rock and different lateral pressure coefficients, is calculated using UEM and EPM. 1safe zone (PP1SZ). As can be seen from the figure, under different surrounding rock grades, when the chamber burial depth is relatively small... It should be determined according to UEM. Determined according to EPM. When the burial depth of the chamber is large, The method used remains unchanged, and the determination is made. The method is to replace UEM with EPM.

[0062] based on Figure 1 The process uses the parameter benchmark value of Class I surrounding rock with a lateral pressure coefficient of 1 as the calculation parameter, and finally obtains the safe operating air pressure range of the chamber when the burial depth is 200m. The calculation results are shown in Table 2.

[0063] Table 2 shows the calculated safe operating pressure range for chambers with a surrounding rock grade of I at a burial depth of 200m. (Unit: MPa) .

Claims

1. A method for designing a safe operation interval of a compressed air energy storage cavern considering load sharing, characterized in that, Includes the following steps: S1, input the physical and mechanical parameters of the surrounding rock, excavation radius, and chamber burial depth; S2, calculating the upper limit of the surrounding rock tunnel wall pressure of the limit equilibrium method UEM and the upper limit of the surrounding rock tunnel wall pressure of the elastic-plastic method EPM , lower limit ; S3, based on the result of S2, determine the upper limit of the final surrounding rock wall pressure , lower limit ; S4, upper limit of final surrounding rock pressure obtained based on S3 , lower limit , input lining structure parameters, first obtain surrounding rock calculation tunnel wall safety pressure interval , then obtain chamber calculation safety operation gas pressure interval ; S5, if the chamber calculates the safe operation pressure interval Need to meet the chamber design safe operation pressure interval , then the conditional judgment, meet the conditions directly output results, not meet then re-design calculation input lining structure parameters, until Meet .

2. The design method for the safe operating zone of a compressed gas energy storage chamber considering load sharing as described in claim 1, characterized in that, The upper limit of the surrounding rock wall pressure calculated by the UEM in S2 is expressed by the formula: The upper limit of the surrounding rock wall pressure calculated by the UEM in S2 is expressed by the formula: ； in, This is the lateral pressure coefficient parameter. ; For cohesion parameters, ; For the geometric parameters of the soil arch, ; This is the lateral pressure coefficient, with a value range of 1 / 3 < <3; ρ is the weight of the surrounding rock; c is the cohesion of the surrounding rock. The angle between the fracture surfaces; The internal friction angle of the surrounding rock; To create a cracked corner; The outer radius of the lining; For safety factor; The chamber is buried deep.

3. The design method for the safe operating zone of a compressed gas energy storage chamber considering load sharing as described in claim 2, characterized in that, Upper limit of surrounding rock wall pressure in EPM (Elastic-Plastic Analysis) Lower limit The calculation process is divided into two stages according to the different stages of stress on the chamber during operation: (a) initial ground stress Surrounding rock cave wall pressure (b) Initial geostress Surrounding rock cave wall pressure The lateral pressure coefficient is taken as 1 as the limit: 1） ： When the chamber is in the un-air-filled stage or the low-pressure stage, that is, when the pressure of the surrounding rock wall is... Initial geostress At that time, the formula for the lower limit of pressure on the surrounding rock wall of the arched tunnel. Represented as: ； When the chamber is in a high-pressure stage, that is, when the pressure on the surrounding rock walls is high... Initial geostress Formula for the upper limit of pressure on the tunnel wall surrounding the arch Represented as: ； 2） ： When the chamber is in the un-air-filled stage or the low-pressure stage, that is, when the pressure of the surrounding rock wall is... Initial geostress At that time, the formula for the lower limit of the pressure on the surrounding rock wall of the arch is... Represented as: ； When the chamber is in a high-pressure stage, that is, when the pressure on the surrounding rock walls is high... Initial geostress Formula for the upper limit of pressure on the surrounding rock wall of an arched tunnel. Represented as: ； According to the lateral pressure coefficient The difference lies in the upper limit of the pressure on the surrounding rock of the EPM tunnel. EPM lower limit of surrounding rock wall pressure The values ​​of are also different; when , for , for ;when , for , for .

4. The design method for the safe operating zone of a compressed gas energy storage chamber considering load sharing as described in claim 3, characterized in that, The final upper limit of the surrounding rock wall pressure in S3 The formula is expressed as: The lower limit of the final surrounding rock wall pressure The formula is expressed as: .

5. The design method for the safe operating zone of a compressed gas energy storage chamber considering load sharing as described in claim 4, characterized in that, Calculation of safe operating pressure range for the chamber Based on the pressure of the surrounding rock tunnel wall Operating air pressure of the chamber The relationship and the ultimate upper limit of the pressure on the surrounding rock tunnel wall Lower limit Calculations determined that the pressure on the surrounding rock tunnel walls... Operating air pressure of the chamber The relational formula is expressed as: ； in, The inner radius of the lining; The elastic modulus of the lining; Poisson's ratio for the lining; Let be the elastic modulus of the surrounding rock. is the Poisson's ratio of the surrounding rock.

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