Geological energy-based deep underground engineering disaster discrimination method and system

Abstract

This invention relates to the field of underground engineering data processing technology, and discloses a method and system for identifying hazards in deep underground engineering based on geological energy. It aims to solve the problem that existing methods cannot effectively reveal the multi-hazard coupling mechanism and accurately identify hazards. The solution mainly includes: acquiring multi-source data of the underground engineering; calculating energy field components and energy density; dividing the engineering area into shallow or deep engineering zones based on energy density; for shallow engineering zones, calculating surrounding rock deformation based on a surrounding rock mechanics model and comparing it with a deformation threshold to determine the collapse risk; for deep engineering zones, calculating the failure index through uniaxial test energy analysis to determine the risk of rockburst or large deformation; determining the risk of thermal damage through chamber heat balance analysis; determining the risk of sudden water inrush through a preset energy rule; and performing multi-field coupling correction for composite hazards. This invention improves the accuracy of hazard identification and is applicable to deep underground engineering.

Description

Technical Field

[0001] This invention relates to the field of underground engineering data processing technology, specifically to a method and system for identifying deep underground engineering hazards based on geological energy. Background Technology

[0002] As water conservancy and hydropower projects continue to expand into areas with high mountains, deep valleys, and complex geological conditions, the burial depth of underground powerhouses, water diversion tunnels, transportation tunnels, and ancillary chambers has significantly increased. The surrounding rock environment of these projects exhibits significant characteristics such as high ground stress, high ground temperature, high water pressure, and heterogeneous strata. Against this backdrop, the mechanisms and evolution patterns of underground engineering disasters are significantly different from those in shallow-buried engineering stages, posing a more severe challenge to engineering safety.

[0003] Extensive engineering practice has shown that underground engineering disasters are not caused by a single mechanical factor, but rather by the long-term coupling effect of the geostress field, thermal field, and seepage field. Under the combined influence of excavation disturbance and time effects, various forms of geological energy continuously accumulate and transform within the surrounding rock, including rock mass deformation energy, intra-earth thermal energy, and groundwater potential energy. When the accumulation, transfer, or release of energy exceeds the bearing capacity of the rock mass and support system, it often induces engineering disasters such as collapse, large deformation, rock burst, thermal damage, or sudden water inrush. In severe cases, it can even manifest as multiple disasters superimposed or in a chain-like evolution.

[0004] Existing methods for identifying underground engineering hazards are mostly based on single physical fields or empirical indicators. For example, they use the deformation or stress concentration of surrounding rock to judge the risk of collapse and large deformation, temperature or ventilation conditions to assess thermal hazards, and water pressure or permeability coefficient to analyze the possibility of sudden water inrush. These methods have certain practical value in the early stages of engineering, but they generally have the following shortcomings: First, they are difficult to reflect the intrinsic connections and mutual transformation relationships between different types of geological energy; second, they lack a unified energy scale, making it difficult to comprehensively identify and compare different hazards; third, their applicability to the evolution of hazards under deep-buried, high-temperature, and high-pressure conditions is limited; and fourth, they are difficult to systematically identify and quantitatively analyze complex-controlled hazards.

[0005] From the perspective of energy conservation and transformation, the surrounding rock of underground engineering is essentially an open system with multiple coupled energies. The energy stored in the surrounding rock under long-term geological processes is continuously redistributed and transformed under engineering disturbance conditions: deformation energy can be released during failure and partially converted into thermal and fluid energy; thermal energy can alter the mechanical properties of the rock mass through thermo-mechanical coupling, promoting surrounding rock deformation; and water potential energy can be rapidly released after structural rupture, triggering sudden water inrushes or even amplifying the scale of rock mass failure. Therefore, analyzing only from the perspective of a single hazard is insufficient to fully reveal the essential mechanisms of underground engineering disasters. Summary of the Invention

[0006] This invention aims to address the problem that existing methods for identifying disasters in underground engineering cannot effectively reveal the mechanisms of multi-hazard coupling and accurately identify disasters. It proposes a method and system for identifying disasters in deep underground engineering based on geological energy.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0008] In a first aspect, the present invention provides a method for identifying deep underground engineering hazards based on geological energy, the method comprising:

[0009] Acquire multi-source data for underground engineering, including engineering geometric parameters, rock mass physical and mechanical parameters, thermophysical parameters, hydrogeological parameters, construction support parameters, and test and monitoring data;

[0010] The energy field components are calculated based on the multi-source data. The energy field components include stratum deformation energy, intra-earth thermal energy, and groundwater potential energy. The stratum deformation energy, intra-earth thermal energy, and groundwater potential energy are algebraically superimposed to obtain the total stratum energy. The energy density of the engineering area is then calculated based on the total stratum energy.

[0011] Based on the comparison results between the energy density and the preset threshold, the engineering area is divided into a shallow engineering area or a deep engineering area, and then enters the corresponding disaster identification process respectively.

[0012] For shallow engineering areas, the deformation of the surrounding rock is calculated based on the surrounding rock mechanics model and compared with the deformation threshold to determine the risk of collapse.

[0013] For deep engineering areas, potential stress-controlled, thermally controlled, seepage-controlled, and combined-controllable hazard types are identified. For stress-controlled hazards, based on rock mechanics test data, energy analysis is used to calculate indices characterizing the tendency to fail, thereby determining the risk of rockburst or large deformation. For thermally controlled hazards, the heat budget of the chamber is calculated, and the relationship between the amount of heat entering and the amount of heat dissipating is compared to determine the risk of heat damage. For seepage-controlled hazards, based on formation energy and groundwater dynamic parameters, a pre-defined energy rule is applied to determine the risk of sudden water inrush. For combined-controllable hazards, the coupling effect between different energy fields is analyzed, and the single hazard criteria are coupled and corrected. Based on the corrected coupled criteria, a comprehensive hazard assessment is performed.

[0014] Furthermore, calculating the energy field components based on the multi-source data specifically includes:

[0015] Calculate formation deformation energy :

[0016] ;

[0017] in, Represents the stress tensor. Represents the strain tensor. This represents the inner product operation of tensors. This indicates the volume of the disturbed area from the underground engineering project;

[0018] Calculate the geothermal energy :

[0019] ;

[0020] in, This indicates the specific heat capacity of the surrounding rock. Indicates the density of the surrounding rock. This indicates the permissible air temperature for underground engineering construction. This indicates the temperature of the undisturbed original rock. This indicates the volume of the area affected by the temperature of the surrounding rock during construction.

[0021] Calculate groundwater potential energy :

[0022] ;

[0023] in, This indicates the density of water. Represents gravitational acceleration. This indicates the height of the groundwater level relative to the foundation slab of the project. Indicates the pressure of the pressurized water. Indicates the groundwater flow velocity. Indicates the first The total volume of groundwater storage space in hydrogeological structures. These correspond to the fissure type, fault type, karst cave type, and conduit and underground river type, respectively.

[0024] Furthermore, the volume of the area affected by the surrounding rock temperature during the construction process. The methods for determining this include:

[0025] The radius of temperature influence is determined using a heat conduction model. According to the radius of temperature influence With the length of the chamber Calculate the volume of the area affected by the temperature of the surrounding rock during construction. For circular chambers, ;

[0026] The governing equations of the heat conduction model are:

[0027] ;

[0028] in, Indicates radial distance. Indicates time, Indicates the thermal conductivity coefficient of the surrounding rock;

[0029] The far-field boundary conditions of the heat conduction model are:

[0030] ;

[0031] in, This indicates the radial distance from the center of the chamber is... The temperature of the surrounding rock at that location It represents the radial distance originating from the center of the circular chamber;

[0032] The near-field boundary conditions of the heat conduction model are as follows:

[0033] ;

[0034] in, Indicates the heat transfer coefficient. Indicates the temperature of the cave wall rock. Indicates the radius of the chamber;

[0035] The radius of temperature influence The approximate solution is:

[0036] ;

[0037] in, This represents the thermal diffusivity.

[0038] Furthermore, the formula for calculating the total energy of the formation is as follows:

[0039] ;

[0040] The formula for calculating the energy density is as follows:

[0041] ;

[0042] in, Represents the total energy of the formation. Indicates the deformation energy of the strata. Indicates geothermal energy. Represents the potential energy of groundwater. Indicates energy density, It represents the total volume of the rock mass within the engineering area.

[0043] Furthermore, for shallow engineering areas, methods for determining collapse risk include:

[0044] An elastoplastic mechanical model of the surrounding rock is established based on the Mohr-Coulomb criterion, the characteristic curve of the surrounding rock is determined, and the displacement around the surrounding rock is calculated; when the displacement around the surrounding rock is greater than 40 mm, it is determined that there is a risk of collapse.

[0045] Based on the aforementioned surrounding rock characteristic curve, the methods for determining the surrounding rock displacement at each stage include:

[0046] For the elastic stage, the displacement of the surrounding rock The calculation formula is:

[0047] ;

[0048] in, Indicates the radius of the tunnel excavation. Indicates the initial ground stress. Indicates support strength. Represents Poisson's ratio. Indicates the elastic modulus of the rock mass;

[0049] For the plastic stage, the displacement of the surrounding rock The calculation formula is:

[0050] ;

[0051] in, Indicates the shear strength of the rock mass. Indicates the friction angle within the rock mass. The radius of the plastic zone is represented by the following formula:

[0052] ;

[0053] in, This represents the extreme value of shear strength after the surrounding rock has been weakened. This represents the extreme value of the internal friction angle after the surrounding rock has been weakened;

[0054] For the loosening stage, the displacement of the surrounding rock The calculation formula is:

[0055] ;

[0056] in, Indicates the internal friction angle of the rock mass in the loosened zone. The stress in the loosened zone is represented by the following formula:

[0057] ;

[0058] in, Indicates the cohesion of the rock mass in the loosened area. Indicates the weight of the rock mass.

[0059] Furthermore, for stress-controlled disasters, methods for assessing the risk of rockbursts or large deformations include:

[0060] Calculate the cross-sectional area of ​​the specimen based on uniaxial compression test data. Axial stress Axial strain Uniaxial compressive strength and elastic modulus The calculation formulas are as follows:

[0061] ; ; ; ; ;

[0062] in, Indicates the diameter of the sample. Indicates axial load. Indicates the amount of axial deformation. Indicates the initial height of the sample. Indicates the maximum load at which the specimen fails. and These represent the stress increment and the corresponding strain increment during the linear elastic stage, respectively.

[0063] Stress-strain curves were plotted based on the uniaxial compression test data, and energy analysis was performed on the stress-strain curves to calculate the total energy absorbed by the specimen during loading. Releaseable elastic strain energy With dissipated energy The calculation formula is as follows:

[0064] ; ; ;

[0065] in, This indicates that the specimen has reached uniaxial compressive strength. The corresponding axial strain at that time, This represents the strain when the load is unloaded to zero. Represents the unloading stress function;

[0066] Calculate the energy release rate Energy dissipation rate and destruction index :

[0067] ; ; ;

[0068] According to the damage index The value is used to determine: when At that time, it was determined that the tendency was mainly towards large deformation; when At that time, it was determined that both large deformation and rockburst were prominent; when At that time, it was determined that the tendency was mainly rockburst.

[0069] Furthermore, for heat-controlled disasters, methods for assessing heat hazard risk include:

[0070] Calculate the total heat entering the chamber per unit time. :

[0071] ;

[0072] ;

[0073] ;

[0074] ;

[0075] in, Indicates the heat transfer rate of the surrounding rock. Indicates the heat transfer rate of hot water. Indicates the heat-carrying capacity of hot gas. Indicates a unit of time. Indicates the thermal conductivity of the surrounding rock. This indicates the area of ​​exposed surrounding rock during tunnel excavation. Indicates the original rock temperature. Indicates the temperature of the tunnel wall. Indicates the calculated thickness of the heat-affected zone of the surrounding rock. This indicates the density of water. This indicates the specific heat capacity of water. This indicates the total flow rate of hot water entering the chamber. Indicates the temperature of the gushing water. Indicates the density of harmful gases. Indicates the specific heat capacity of a gas. This indicates the volumetric flow rate of the high-temperature gas entering the chamber. Indicates gas temperature;

[0076] Calculate the total heat dissipated by the chamber per unit time. :

[0077] ;

[0078] ;

[0079] ;

[0080] ;

[0081] in, Indicates the ventilation and heat dissipation rate. Indicates the heat transfer efficiency of the insulation layer. Indicates the unsteady-state heat absorption rate of the surrounding rock. Indicates air density, This indicates the specific heat capacity of air at constant pressure. This indicates the volumetric flow rate of ventilation within the chamber. This indicates the temperature of the fresh air supplied to the chamber. This indicates the surface area of ​​the insulation layer. t represents the temperature on the outside of the insulation layer. Indicates the thermal resistance of the insulation layer. Indicates the thickness of the insulation layer. This indicates the thermal conductivity of the insulation material. Indicates the density of the surrounding rock. Indicates the specific heat capacity of the surrounding rock. This indicates the volume of the heat-affected zone of the surrounding rock involved in heat exchange. This indicates that the surrounding rock in this area has a time... The average temperature rise inside;

[0082] When satisfied At that time, it was determined that there was a risk of heat damage.

[0083] Furthermore, for seepage-controlled disasters, methods for assessing the risk of sudden water inrush disasters include:

[0084] Establish the First Law of Energy:

[0085] ;

[0086] in, Indicates the deformation energy of the strata. Represents the potential energy of groundwater. This indicates the fracture energy of the water-resistant rock mass. This indicates the area of ​​the fracture surface of the water-impermeable rock mass;

[0087] Establish the Second Law of Energy:

[0088] ;

[0089] in, This indicates the density of water. This indicates the volumetric flow rate of the water after it surges into the chamber. This indicates the cross-sectional area of ​​the chamber through which water flows.

[0090] When the stratum deformation energy and groundwater potential energy simultaneously satisfy the first energy law and the second energy law, it is determined that a sudden water inrush disaster will occur.

[0091] Furthermore, for composite control-type disasters, the single disaster criteria are coupled and modified, including:

[0092] For situations where thermo-mechanical coupling affects seepage-controlled disasters, the first energy law used to identify seepage-controlled disasters is modified as follows:

[0093] ;

[0094] in, Indicates geothermal energy;

[0095] Using the modified first energy law to identify penetration-controlled disasters;

[0096] For situations where water-mechanical coupling affects thermally controlled disasters, the total heat entering the chamber per unit time will be used to calculate the total heat entering the chamber. Revised to The calculation formula is as follows:

[0097] ;

[0098] ;

[0099] in, This represents the heat energy generated by friction. This represents the average shear stress on the sliding surface. This represents the effective contact area where sliding occurs. Indicates the cumulative slip;

[0100] Using the corrected total heat The total heat dissipated by the chamber per unit time Compare, if satisfied If so, it is determined that there is a risk of heat damage;

[0101] To address the situation where stress-controlled disasters are influenced by thermal-water coupling, uniaxial compression tests of rocks are conducted under preset high-temperature and high-pressure conditions. The failure index is calculated based on the corresponding uniaxial compression test data to identify stress-controlled disasters.

[0102] Secondly, the present invention provides a deep underground engineering hazard identification system based on geological energy, used to implement the deep underground engineering hazard identification method based on geological energy as described in the first aspect, the system comprising:

[0103] The multi-source data acquisition module is used to acquire multi-source data of underground engineering, including engineering geometric parameters, rock mass physical and mechanical parameters, thermophysical parameters, hydrogeological parameters, construction support parameters, and test monitoring data.

[0104] The geological energy calculation module is used to calculate energy field components based on the multi-source data. The energy field components include stratum deformation energy, intra-earth thermal energy, and groundwater potential energy. The stratum deformation energy, intra-earth thermal energy, and groundwater potential energy are algebraically superimposed to obtain the total stratum energy, and the energy density of the engineering area is calculated based on the total stratum energy.

[0105] The engineering area division module is used to divide the engineering area into shallow engineering area or deep engineering area based on the comparison result of the energy density and the preset threshold, and then enter the corresponding disaster judgment process respectively.

[0106] The shallow engineering area disaster assessment module is used to calculate the surrounding rock deformation based on the surrounding rock mechanics model for shallow engineering areas and compare it with the deformation threshold to determine the collapse risk.

[0107] The deep engineering area hazard assessment module is used to identify potential stress-controlled, thermally controlled, seepage-controlled, and combined-controllable hazard types in deep engineering areas. For stress-controlled hazards, it calculates an index characterizing the failure tendency based on rock mechanics test data through energy analysis to assess the risk of rockburst or large deformation. For thermally controlled hazards, it calculates the heat budget of the chamber and assesses the risk of thermal damage by comparing the magnitude of incoming and outgoing heat. For seepage-controlled hazards, it applies a preset energy rule based on formation energy and groundwater dynamic parameters to assess the risk of sudden water inrush. For combined-controllable hazards, it analyzes the coupling effect between different energy fields, performs coupling correction on individual hazard criteria, and performs comprehensive hazard assessment based on the corrected coupling criteria.

[0108] The beneficial effects of this invention are as follows: The method and system for identifying deep underground engineering hazards based on geological energy provided by this invention calculates energy density and scientifically divides the engineering area into shallow or deep engineering zones, solving the problem of traditional methods being difficult to comprehensively compare due to inconsistent criteria; for the divided areas, a refined identification path for stress-controlled, thermally controlled, seepage-controlled, and combined hazards is established, significantly improving the early identification accuracy and reliability of rockburst, large deformation, thermal hazards, and sudden water inrush hazards; this invention forms a complete technical chain from data acquisition, energy calculation, preliminary zoning assessment to precise hazard assessment and matching of prevention and control measures, providing a systematic and quantitative decision-making basis for hazard early warning and prevention and control of underground engineering under deep and complex geological conditions. Attached Figure Description

[0109] Figure 1 A flowchart illustrating a method for identifying hazards in deep underground engineering based on geological energy, provided as an example.

[0110] Figure 2A flowchart illustrating another method for identifying deep underground engineering hazards based on geological energy, provided as an example;

[0111] Figure 3 A schematic diagram of the structure of the circular chamber heat conduction model provided for the embodiment;

[0112] Figure 4 A schematic diagram of the disaster assessment process for shallow engineering areas provided in this embodiment;

[0113] Figure 5 A schematic diagram of the stress-controlled disaster identification process provided in the embodiment;

[0114] Figure 6 A schematic diagram of stress-strain curves provided for an embodiment;

[0115] Figure 7 This is a schematic diagram of the process for identifying thermal control-type disasters provided in the embodiments;

[0116] Figure 8 A schematic diagram of the process for identifying penetration-controlled disasters provided in this embodiment;

[0117] Figure 9 A schematic diagram of the structure of a deep underground engineering disaster identification system based on geological energy provided for an embodiment. Detailed Implementation

[0118] Existing methods for identifying underground engineering hazards struggle to quantify and comprehensively assess deformation energy, thermal energy, and water potential energy in deep, multi-field coupled geological environments. This results in an inability to effectively reveal the mechanisms of multi-hazard coupling and to conduct systematic risk classification. Therefore, the technical solution of this invention is proposed.

[0119] In this invention, firstly, the energy density is obtained by calculating the formation deformation energy, intra-earth thermal energy, and groundwater potential energy, and then superimposing them into the total formation energy. This energy density serves as a unified standard to scientifically divide the engineering area into shallow or deep engineering zones, solving the problem of traditional methods being difficult to comprehensively compare due to inconsistent criteria. Then, differentiated discrimination paths are adopted for the divided areas: for shallow engineering zones, deformation is calculated using a surrounding rock mechanics model and compared with a threshold to determine the collapse risk; for deep engineering zones, specific criteria are established for stress-controlled, heat-controlled, seepage-controlled, and combined-controlled disasters. For example, the failure index is calculated using experimental data to determine the risk of rockburst or large deformation; the relationship between incoming and outgoing heat is calculated to determine the risk of thermal damage; and the energy law is applied to determine the risk of sudden water inrush disasters. Combined corrections are also applied to combined disasters, thereby significantly improving the early identification accuracy and classification reliability of multiple disasters in deep, complex environments.

[0120] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0121] Figure 1 A flowchart illustrating a method for identifying hazards in deep underground engineering based on geological energy is shown. Please refer to [link / reference]. Figure 1 The method includes the following steps:

[0122] Step 1: Multi-source data acquisition:

[0123] Acquire multi-source data for underground engineering, including engineering geometric parameters, rock mass physical and mechanical parameters, thermophysical parameters, hydrogeological parameters, construction support parameters, and test and monitoring data.

[0124] This step is used to provide comprehensive and accurate input parameters for subsequent geological energy calculations and hazard identification.

[0125] In practical applications, the acquired data includes: engineering geometric parameters describing the basic state of the project (such as the project depth and the excavation dimensions of the chamber) and original rock environment parameters (such as the original rock temperature and ground stress); rock mass physical and mechanical parameters characterizing the basic properties of the rock mass (such as density, elastic modulus, Poisson's ratio, and shear strength) and thermophysical parameters (such as specific heat capacity and thermal conductivity); hydrogeological parameters reflecting groundwater conditions (such as groundwater pressure, flow velocity, and aquifer volume); construction support parameters defining engineering measures (such as support force and ventilation parameters); and experimental monitoring data obtained through tests and field methods (such as load-displacement curves of uniaxial compression tests of rock, hot water outflow and temperature, and surrounding rock deformation monitoring data).

[0126] Step 2, Geological Energy Calculation:

[0127] The energy field components are calculated based on the multi-source data. The energy field components include stratum deformation energy, intra-earth thermal energy, and groundwater potential energy. The stratum deformation energy, intra-earth thermal energy, and groundwater potential energy are algebraically superimposed to obtain the total stratum energy. The energy density of the engineering area is then calculated based on the total stratum energy.

[0128] Specifically, stratum deformation energy is used to characterize the mechanical energy stored in the surrounding rock due to stress and strain, intra-earth thermal energy is used to characterize the thermal energy stored in the stratum due to the temperature field, and groundwater potential energy is used to characterize the potential and kinetic energy of groundwater due to its location, pressure, and flow.

[0129] In this embodiment, the method for calculating energy field components based on the multi-source data specifically includes:

[0130] (1) Calculate the deformation energy of the formation :

[0131] ;

[0132] in, Represents the stress tensor. Represents the strain tensor. This represents the inner product operation of tensors. This indicates the volume of the area disturbed by underground engineering.

[0133] The above formula reflects the volume in the disturbed area of ​​underground engineering. (Typically, within a range of 5 times the radius of the chamber) the elastic mechanical energy stored in the surrounding rock due to stress and strain, including the stress tensor. With strain tensor It is determined by in-situ stress and excavation mechanical response.

[0134] (2) Calculate the geothermal energy :

[0135] ;

[0136] in, This indicates the specific heat capacity of the surrounding rock. Indicates the density of the surrounding rock. This indicates the permissible air temperature for underground engineering construction. This indicates the temperature of the undisturbed original rock. This indicates the volume of the area affected by the temperature of the surrounding rock during construction.

[0137] The above formula reflects the volume of the area affected by the temperature of the surrounding rock during construction. Inside, the surrounding rock from its original temperature Reduced to the allowable air temperature for engineering The released heat energy, volume It is obtained by solving a heat conduction model that includes the thermophysical parameters of the surrounding rock. Specific methods for determining this include:

[0138] The radius of temperature influence is determined using a heat conduction model. According to the radius of temperature influence With the length of the chamber Calculate the volume of the area affected by the temperature of the surrounding rock during construction. For circular chambers, .

[0139] The governing equations of the heat conduction model describe the evolution of temperature within the surrounding rock with time and radial distance, as follows:

[0140] ;

[0141] in, Indicates radial distance. Indicates time, Indicates the thermal conductivity coefficient of the surrounding rock;

[0142] Please see Figure 3 The far-field and near-field boundary conditions of the heat conduction model respectively characterize the far-field state of the undisturbed original rock temperature and the convective heat transfer process between the tunnel wall and the air.

[0143] The far-field boundary conditions are:

[0144] ;

[0145] in, This indicates the radial distance from the center of the chamber is... The temperature of the surrounding rock at that location It represents the radial distance originating from the center of the circular chamber;

[0146] The near-field boundary conditions are:

[0147] ;

[0148] in, Indicates the heat transfer coefficient. Indicates the temperature of the cave wall rock. This indicates the radius of the chamber.

[0149] Based on the above heat conduction model, the radius of temperature influence The approximate solution is:

[0150] ;

[0151] in, This represents the thermal diffusivity.

[0152] (3) Calculate the groundwater potential energy :

[0153] ;

[0154] in, This indicates the density of water. Represents gravitational acceleration. This indicates the height of the groundwater level relative to the foundation slab of the project. Indicates the pressure of the pressurized water. Indicates the groundwater flow velocity. Indicates the first The total volume of groundwater storage space in hydrogeological structures. These correspond to the fissure type, fault type, karst cave type, and conduit and underground river type, respectively.

[0155] The above formula integrates the results for four types of hydrogeological structures: fissure type, fault type, karst cave type, and conduit and underground river type, and summarizes the total mechanical energy contained in the groundwater in these structures due to location head, pressure head, and velocity head.

[0156] In this embodiment, the formula for calculating the total formation energy is as follows:

[0157] ;

[0158] The formula for calculating the energy density is as follows:

[0159] ;

[0160] in, Represents the total energy of the formation. Indicates the deformation energy of the strata. Indicates geothermal energy. Represents the potential energy of groundwater. Indicates energy density, It represents the total volume of the rock mass within the engineering area.

[0161] Specifically, after separately calculating the formation deformation energy, intra-earth thermal energy, and groundwater potential energy, these are algebraically superimposed to obtain the total formation energy within the evaluation area. Finally, the energy density, i.e., the geological energy contained in a unit volume of rock mass, is calculated based on the total formation energy.

[0162] Step 3: Division of Engineering Areas

[0163] Based on the comparison results between the energy density and the preset threshold, the engineering area is divided into shallow engineering area or deep engineering area, and then enters the corresponding disaster identification process.

[0164] It is understandable that the concept of "deep" cannot be defined solely by absolute depth, as this would lack scientific rigor. The unique geophysical environment of deep engineering projects creates a high-energy environment in deep strata. Therefore, a quantitative expression for "deep" is proposed, using the stratum energy field as an indicator. When the energy in deep strata reaches a certain level, nonlinear mechanical phenomena not present in shallow engineering will occur; if engineering measures are not properly implemented, disasters such as large deformation of surrounding rock, high ground temperature, and water and mud inrush will occur. Therefore, deep underground engineering is defined as: when the energy density in the rock strata within a certain underground range where the project is located exceeds a critical threshold. When nonlinear mechanical effects are triggered, it is called deep underground engineering. Redefining deep engineering from an energy perspective enables precise quantitative analysis and has significant engineering practicality; at the same time, the physical connotation of geological energy is clear, possessing scientific validity. Based on this, if the calculated energy density is greater than... If the area is large enough, it is considered a deep engineering area; otherwise, it is considered a shallow engineering area.

[0165] Step 4: Disaster assessment in shallow engineering areas:

[0166] For shallow engineering areas, the deformation of the surrounding rock is calculated based on the surrounding rock mechanics model and compared with the deformation threshold to determine the risk of collapse.

[0167] Please see Figure 4 In this embodiment, the method for determining the collapse risk in shallow engineering areas includes:

[0168] An elastoplastic mechanical model of the surrounding rock is established based on the Mohr-Coulomb criterion, the characteristic curve of the surrounding rock is determined, and the displacement around the surrounding rock is calculated; when the displacement around the surrounding rock is greater than 40 mm, it is determined that there is a risk of collapse.

[0169] Based on the aforementioned surrounding rock characteristic curve, the methods for determining the surrounding rock displacement at each stage include:

[0170] For the elastic stage, the displacement of the surrounding rock The calculation formula is:

[0171] ;

[0172] in, Indicates the radius of the tunnel excavation. Indicates the initial ground stress. Indicates support strength. Represents Poisson's ratio. Indicates the elastic modulus of the rock mass;

[0173] For the plastic stage, the displacement of the surrounding rock The calculation formula is:

[0174] ;

[0175] in, Indicates the shear strength of the rock mass. Indicates the friction angle within the rock mass. The radius of the plastic zone is represented by the following formula:

[0176] ;

[0177] in, This represents the extreme value of shear strength after the surrounding rock has been weakened. This represents the extreme value of the internal friction angle after the surrounding rock has been weakened;

[0178] For the loosening stage, the displacement of the surrounding rock The calculation formula is:

[0179] ;

[0180] in, Indicates the internal friction angle of the rock mass in the loosened zone. The stress in the loosened zone is represented by the following formula:

[0181] ;

[0182] in, Indicates the cohesion of the rock mass in the loosened area. Indicates the weight of the rock mass.

[0183] Specifically, for areas where energy density is determined to be shallow engineering zones, the main disaster risk is collapse. This step quantitatively evaluates the stability of the surrounding rock based on a surrounding rock mechanics model, specifically determining the characteristic curve of the surrounding rock through analytical methods. The characteristic curve, based on the Mohr-Coulomb criterion, describes the mechanical behavior of the surrounding rock in segments during the elastic, plastic, and loosening stages, and calculates the displacement around the surrounding rock accordingly. (i.e., surrounding rock deformation). The calculated displacement around the surrounding rock... The deformation is compared with a preset deformation threshold (e.g., 40 mm): if the deformation exceeds the threshold, a collapse risk is identified; otherwise, the surrounding rock is considered to be in a stable state. This method enables rapid quantitative identification of collapse hazards in shallow engineering areas, providing a direct basis for engineering support design.

[0184] Step 5: Disaster assessment in deep engineering areas:

[0185] For deep engineering areas, potential stress-controlled, thermally controlled, seepage-controlled, and combined-controllable hazard types are identified. For stress-controlled hazards, based on rock mechanics test data, energy analysis is used to calculate indices characterizing the tendency to fail, thereby determining the risk of rockburst or large deformation. For thermally controlled hazards, the heat budget of the chamber is calculated, and the relationship between the amount of heat entering and the amount of heat dissipating is compared to determine the risk of heat damage. For seepage-controlled hazards, based on formation energy and groundwater dynamic parameters, a pre-defined energy rule is applied to determine the risk of sudden water inrush. For combined-controllable hazards, the coupling effect between different energy fields is analyzed, and the single hazard criteria are coupled and corrected. Based on the corrected coupled criteria, a comprehensive hazard assessment is performed.

[0186] Specifically, when assessing hazards in areas identified as deep engineering zones based on energy density, the first step is to identify potential hazard types. Because deep engineering projects operate in complex geological environments characterized by high ground stress, high ground temperature, and high water pressure, hazards are typically triggered by the coupling of multiple energy fields. Therefore, this step identifies potential hazard types into four categories based on the dominant energy field: stress-controlled hazards (such as rockbursts and large deformations) primarily driven by the accumulation and release of mechanical energy (deformation energy); heat-controlled hazards primarily driven by thermal equilibrium disruption and heat accumulation; seepage-controlled hazards (such as sudden water inrushes) primarily driven by the sudden release of groundwater energy (potential energy); and composite-controlled hazards (such as rockbursts induced by thermo-mechanical coupling and heat damage exacerbated by water-mechanical coupling) jointly controlled by the interaction of two or three of the above energy fields. Then, specific criteria are established for each type of controlled hazard to determine the hazard type.

[0187] Please see Figure 5 In this embodiment, the method for determining the risk of rockburst or large deformation for stress-controlled disasters includes:

[0188] Calculate the cross-sectional area of ​​the specimen based on uniaxial compression test data. Axial stress Axial strain Uniaxial compressive strength and elastic modulus The calculation formulas are as follows:

[0189] ; ; ; ; ;

[0190] in, Indicates the diameter of the sample. Indicates axial load. Indicates the amount of axial deformation. Indicates the initial height of the sample. Indicates the maximum load at which the specimen fails. and These represent the stress increment and the corresponding strain increment during the linear elastic stage, respectively.

[0191] Stress-strain curves were plotted based on the uniaxial compression test data, and energy analysis was performed on the stress-strain curves to calculate the total energy absorbed by the specimen during loading. Releaseable elastic strain energy With dissipated energy The calculation formula is as follows:

[0192] ; ; ;

[0193] in, This indicates that the specimen has reached uniaxial compressive strength. The corresponding axial strain at that time, This represents the strain when the load is unloaded to zero. Represents the unloading stress function;

[0194] Calculate the energy release rate Energy dissipation rate and destruction index :

[0195] ; ; ;

[0196] According to the damage index The value is used to determine: when At that time, it was determined that the tendency was mainly towards large deformation; when At that time, it was determined that both large deformation and rockburst were prominent; when At that time, it was determined that the tendency was mainly rockburst.

[0197] In practical applications, to establish quantitative criteria for stress-controlled disasters in deep engineering, it is necessary to conduct standard uniaxial compression tests on representative rock samples and perform energy analysis based on the test data. The specific implementation process is as follows:

[0198] First, sample preparation is carried out by processing the cored rocks from the field into standard cylindrical samples, and accurately measuring and recording their initial height. and diameter And based on this, the cross-sectional area of ​​its original sample was calculated. .

[0199] Next, complete the sample installation by placing the sample between the upper and lower pressure plates of the uniaxial compression testing machine and installing a high-precision displacement gauge or strain measuring device to monitor the deformation of the sample in real time during the axial loading process.

[0200] Subsequently, axial loading and data acquisition were performed. Under conditions without lateral constraints, axial compression was applied to the specimen at a constant displacement-controlled or load-controlled rate. The testing machine system synchronously and continuously recorded the axial load throughout the entire loading process. and the corresponding axial deformation The loading continued until the specimen underwent macroscopic fracture, at which point the maximum axial load at which the specimen failed was recorded. .

[0201] After obtaining the raw load-displacement data, the data processing and curve plotting stage begins. The raw data is converted into basic rock mechanics parameters using the following formula:

[0202] Axial stress: ;

[0203] Axial strain: ;

[0204] Uniaxial compressive strength (UCS): ;

[0205] Elastic modulus: .

[0206] Based on calculations Plot the complete axial stress-strain curve using the data pairs. Please refer to [link / reference]. Figure 6 A typical rock stress-strain curve can be divided into the compaction stage, elastic deformation stage, yielding stage, and post-peak strain softening stage.

[0207] Then, by integrating the stress-strain curves, the energy conversion and distribution of the specimen during the failure process are quantified:

[0208] Total energy absorbed by the specimen from the start of loading to the peak stress point By calculating the curve from the zero strain point ( ) to the strain corresponding to the peak stress ( The area enclosed by ) is obtained, that is .

[0209] Releaseable elastic strain energy stored in the specimen The calculation requires determining the unloading path: if the test includes an actual unloading curve, then the path is taken along that curve from the peak strain point ( Integrate to the point where the stress is zero. If no actual unloading curve is available, then a curve based on the elastic modulus will be used. The equivalent linear unloading path is calculated based on the defined parameters. .

[0210] Energy dissipated during loading in the form of plastic deformation, crack initiation and propagation, etc. This can be obtained from the law of conservation of energy: .

[0211] To further characterize the energy release characteristics of rock failure, the energy release rate was calculated. With energy dissipation rate , respectively defined as the rate of change of elastic strain energy and dissipated energy with respect to strain, i.e. ; .

[0212] Finally, to clearly distinguish between hard rock bursts and soft rock large deformations, two typical stress-controlled disaster tendencies, a failure index was introduced. As a comprehensive criterion, its calculation formula is: Based on statistical analysis of extensive engineering practice and experimental data, the following discrimination criteria are established:

[0213] when When the time is right, it indicates that energy dissipation is dominant, the rock destruction process is relatively slow, and the disaster is mainly characterized by large deformation.

[0214] when At this time, it indicates that both energy release and dissipation are relatively significant, and it is determined that large deformation and rockburst are prominent, indicating a moderate risk of dynamic damage.

[0215] when When this occurs, it indicates that the rapid release of elastic strain energy dominates, indicating a strong tendency for rockburst and the potential for intense dynamic damage.

[0216] Through the above-mentioned systematic experimental operations, data calculations, and energy analysis, this embodiment achieves quantitative and refined identification of the types of stress-controlled disasters (rockbursts or large deformations) and their risk levels in deep engineering, providing a key basis for the formulation of targeted prevention and control measures.

[0217] Please see Figure 7 In this embodiment, the method for determining the risk of heat damage for heat-controlled disasters includes:

[0218] Calculate the total heat entering the chamber per unit time. :

[0219] ;

[0220] ;

[0221] ;

[0222] ;

[0223] in, Indicates the heat transfer rate of the surrounding rock. Indicates the heat transfer rate of hot water. Indicates the heat-carrying capacity of hot gas. Indicates a unit of time. Indicates the thermal conductivity of the surrounding rock. This indicates the area of ​​exposed surrounding rock during tunnel excavation. Indicates the original rock temperature. Indicates the temperature of the tunnel wall. Indicates the calculated thickness of the heat-affected zone of the surrounding rock. This indicates the density of water. This indicates the specific heat capacity of water. This indicates the total flow rate of hot water entering the chamber. Indicates the temperature of the gushing water. Indicates the density of harmful gases. Indicates the specific heat capacity of a gas. This indicates the volumetric flow rate of the high-temperature gas entering the chamber. Indicates gas temperature;

[0224] Calculate the total heat dissipated by the chamber per unit time. :

[0225] ;

[0226] ;

[0227] ;

[0228] ;

[0229] in, Indicates the ventilation and heat dissipation rate. Indicates the heat transfer efficiency of the insulation layer. Indicates the unsteady-state heat absorption rate of the surrounding rock. Indicates air density, This indicates the specific heat capacity of air at constant pressure. This indicates the volumetric flow rate of ventilation within the chamber. This indicates the temperature of the fresh air supplied to the chamber. This indicates the surface area of ​​the insulation layer. t represents the temperature on the outside of the insulation layer. Indicates the thermal resistance of the insulation layer. Indicates the thickness of the insulation layer. This indicates the thermal conductivity of the insulation material. Indicates the density of the surrounding rock. Indicates the specific heat capacity of the surrounding rock. This indicates the volume of the heat-affected zone of the surrounding rock involved in heat exchange. This indicates that the surrounding rock in this area has a time... The average temperature rise inside;

[0230] When satisfied At that time, it was determined that there was a risk of heat damage.

[0231] It is understandable that when underground engineering projects approach or enter geological bodies with high geothermal internal energy that can cause disasters, thermal phenomena such as rock temperature, water temperature, and concentration of harmful gases in the tunnel will develop from occurrence to development and eventually lead to disaster, forming a thermal hazard. Tunnel thermal hazard disasters encompass aspects such as the source of hot water and gas, transport channels, dynamic mechanisms, and engineering thermal signs, and are characterized by strong concealment, high suddenness, and complex disaster-causing mechanisms.

[0232] In practical applications, the first step is to calculate the total heat entering the chamber per unit time. The main factors affecting heat gain include three: the heat transfer rate of the surrounding rock. Hot water heat carrying capacity and heat carrying capacity of hot air The total heat entering per unit time is the sum of the three and the heat entering per unit time. The product of.

[0233] Secondly, calculate the total heat dissipated by the chamber per unit time. The main factors affecting heat expenditure include three: ventilation heat dissipation rate. Heat transfer rate of insulation layer and the unsteady heat absorption rate of the surrounding rock The total heat dissipated per unit time is the sum of the above three items and the heat dissipated per unit time. The product of.

[0234] Finally, the heat income-expenditure ratio is calculated by comparing heat income and expenditure. 2. Based on the principle of energy conservation and the aforementioned disaster-causing mechanisms, when When the ratio is greater than the heat capacity of the chamber, it indicates that the heat entering the chamber is consistently greater than its heat dissipation capacity, leading to an imbalance in the thermal environment inside the chamber and a continuous accumulation of heat energy, thus indicating a risk of heat hazard. The magnitude of this ratio can be further used to classify the severity level of heat hazard, providing a direct quantitative basis for taking corresponding cooling, ventilation, or insulation control measures.

[0235] Please see Figure 8 In this embodiment, the method for determining the risk of sudden water inrush disaster for seepage-controlled disasters includes:

[0236] Establish the First Law of Energy:

[0237] ;

[0238] in, Indicates the deformation energy of the strata. Represents the potential energy of groundwater. This indicates the fracture energy of the water-resistant rock mass. This indicates the area of ​​the fracture surface of the water-impermeable rock mass;

[0239] Establish the Second Law of Energy:

[0240] ;

[0241] in, This indicates the density of water. This indicates the volumetric flow rate of the water after it surges into the chamber. This indicates the cross-sectional area of ​​the chamber through which water flows.

[0242] When the stratum deformation energy and groundwater potential energy simultaneously satisfy the first energy law and the second energy law, it is determined that a sudden water inrush disaster will occur.

[0243] It is understandable that when the groundwater potential energy reaches a certain value and there is room for energy release, a sudden water inrush disaster occurs when the thickness of the impermeable rock mass is reduced to less than the minimum safe thickness due to the ongoing excavation of underground works. The occurrence of sudden water inrush satisfies two energy laws.

[0244] In practical applications, the first step is to apply the first energy law for judgment. The physical meaning of the first energy law is to assess whether the driving force causing the fracturing of the aquitard is sufficient. Among these factors is formation deformation energy. This reflects the mechanical energy accumulated in the impermeable rock mass due to factors such as excavation and unloading; groundwater potential energy. This represents the pressure energy and potential energy contained in the groundwater behind the impermeable rock mass; the sum of the two constitutes the driving energy that causes the rock mass to fracture. This inequality characterizes the intrinsic properties of rock mass materials in resisting fracture propagation. The validity of this inequality means that the total energy driving rock mass fracture exceeds the energy consumed by the rock mass itself to resist fracture, thus satisfying the first necessary condition for sudden water inrush: the impermeable rock mass possesses the energy to be hydraulically split or fractured.

[0245] Then, the second energy law is applied for judgment. The physical meaning of the second energy law is to verify whether the dynamic force of the water flow can be effectively contained after a sudden water inrush, avoiding continuous and uncontrolled catastrophic scouring. In the formula, Representing the volumetric flow rate of the inrush water The kinetic energy per unit volume of water after entering the chamber; the left side of the inequality represents the dynamic load energy of the sudden water flow impacting the chamber. The right side of the inequality... This refers to the potential energy of groundwater that can be released at the moment of fracturing of a water-impermeable rock mass. This rule requires that the impact energy of the water flow must not exceed the potential energy of the water body that can be released, thus ensuring that the surge process is energy-controllable rather than expanding indefinitely. This is the second necessary condition for the occurrence of a disaster.

[0246] Finally, a comprehensive disaster assessment is conducted. Only local strata deformation energy... With groundwater potential energy Only when both the first and second energy laws are met can it be determined that a sudden water inrush disaster will occur at the part of the project.

[0247] Based on the fundamental principle of energy conservation and transformation, the above-mentioned discrimination method achieves quantitative and systematic discrimination of the entire process of sudden water inrush disasters from "rupture initiation" to "continuous water inrush" through two interrelated energy criteria, which significantly improves the prediction accuracy and reliability of such seepage-controlled disasters that are highly concealed and sudden.

[0248] In this embodiment, for composite control-type disasters, the single disaster criterion is coupled and modified, including:

[0249] For situations where thermo-mechanical coupling affects seepage-controlled disasters, the first energy law used to identify seepage-controlled disasters is modified as follows:

[0250] ;

[0251] in, Indicates geothermal energy;

[0252] Using the modified first energy law to identify penetration-controlled disasters;

[0253] For situations where water-mechanical coupling affects thermally controlled disasters, the total heat entering the chamber per unit time will be used to calculate the total heat entering the chamber. Revised to The calculation formula is as follows:

[0254] ;

[0255] ;

[0256] in, This represents the heat energy generated by friction. This represents the average shear stress on the sliding surface. This represents the effective contact area where sliding occurs. Indicates the cumulative slip;

[0257] Using the corrected total heat The total heat dissipated by the chamber per unit time Compare, if satisfied If so, it is determined that there is a risk of heat damage;

[0258] To address the situation where stress-controlled disasters are influenced by thermal-water coupling, uniaxial compression tests of rocks are conducted under preset high-temperature and high-pressure conditions. The failure index is calculated based on the corresponding uniaxial compression test data to identify stress-controlled disasters.

[0259] It is understandable that disasters in deep underground engineering are often not isolated events, but rather a combination of multiple overlapping disasters. Such disasters are called complex-controlled disasters. While single-disaster criteria can be applied, it is crucial to analyze the energy conversion and interaction mechanisms among these multiple disasters. For example, the elastic strain energy accumulated during a rockburst can be partially converted into thermal and water potential energy upon release; underground thermal energy may be converted into surrounding rock deformation energy through thermo-mechanical coupling effects, or drive the abnormal accumulation of groundwater potential energy through thermo-water coupling. These energy conversion processes involve nonlinear coupling effects and multi-scale energy transfer paths, and their dynamic evolution is not yet fully understood. Therefore, it is urgent to construct a multi-disaster coupled energy conversion and interaction model to establish criteria for complex-controlled disasters.

[0260] In practical applications, by identifying and quantifying the interactions (coupling effects) between different energy fields, and by applying targeted coupling corrections to the aforementioned single disaster criteria, a more accurate comprehensive assessment of complex disasters can be achieved. This includes three typical scenarios:

[0261] (1) Corrections for the effects of thermo-mechanical coupling on seepage-controlled disasters:

[0262] In this situation, the high geothermal environment (earth's thermal energy) This will significantly reduce the mechanical strength of the water-resistant rock mass through thermal stress effects, and may also cause additional thermal fracturing, thereby affecting mechanical energy (formation deformation energy). These factors synergistically promote the occurrence of water inrush. Therefore, in determining this, the first energy law needs to be modified to include the thermal energy term in the driving energy. In the modified first energy law, the total driving energy that causes the fracturing of the impermeable rock mass is the sum of the intra-earth thermal energy, the stratum deformation energy, and the groundwater potential energy. Only when this combined energy exceeds the fracturing resistance of the rock mass is the modified condition for seepage disasters to occur under thermo-mechanical coupling satisfied.

[0263] (2) Corrections for the impact of water-mechanical coupling on thermally controlled disasters:

[0264] In this situation, groundwater seepage or rock deformation-induced structural sliding can generate significant frictional heat, becoming an additional and significant heat source within the chamber. Therefore, when assessing heat hazards, it is necessary to calculate the total heat entering the chamber. Make corrections. The corrected total heat... The heat energy generated by the original heat input and friction The sum. Using the corrected Total heat dissipated from the chamber Compare, if satisfied If so, it is determined that there is a risk of thermal damage under the influence of the water-mechanical coupling effect.

[0265] (3) Corrections for stress-controlled disasters caused by thermal-water coupling:

[0266] In this scenario, the high-temperature, high-pressure groundwater environment drastically alters the physical and mechanical properties of rocks (e.g., softening, dissolution, and accelerated fracture propagation), thus affecting their energy accumulation and release behavior. To accurately determine stress hazards under these conditions, experimental criteria under normal temperature and pressure cannot be directly applied. A new uniaxial compression test of the rock must be conducted under pre-set high-temperature, high-pressure conditions simulating a deep environment. Based on the experimental data obtained under this specific environment, the same procedure described above (i.e., calculating the failure index) should be followed. This is used to identify stress-controlled disasters. The environmental effects of thermal-water coupling are internalized into the most fundamental mechanical and energy response characteristics of rock samples.

[0267] Through the above three types of coupling corrections, this embodiment transforms the complex mechanism of multi-field interaction into a scientific adjustment and supplement to the existing quantitative criteria, thereby realizing a systematic and quantitative analysis of composite control type disasters from mechanism to discrimination, and significantly improving the scientificity and reliability of comprehensive disaster discrimination in deep and complex environments.

[0268] In this embodiment, the method also includes automatically matching corresponding disaster control measures such as engineering support, reinforcement, cooling, and drainage from a pre-established database of associated disaster control measures based on the specific disaster type determined at the end.

[0269] In summary, the geological energy-based hazard identification method for deep underground engineering provided in this embodiment constructs a unified evaluation system with energy density as the core indicator. It quantifies the effects of the geostress field, temperature field, and seepage field into stratum deformation energy, intra-earth thermal energy, and groundwater potential energy, and performs superposition calculations to achieve scientific zoning of engineering areas. This overcomes the shortcomings of traditional methods that rely on a single physical field and have inconsistent criteria. On this basis, differentiated hazard identification paths are established for different zones: for shallow engineering areas, the risk of collapse is determined based on the surrounding rock mechanics model; for deep engineering areas, the risk and level of rockburst or large deformation are determined by calculating the damage index, the risk of thermal damage is determined by comparing the heat entering and the heat dissipating, and the risk of sudden water inrush is determined by applying the energy law. Furthermore, multi-field coupling correction is performed for composite control type hazards, thereby significantly improving the early identification accuracy and reliability of multi-hazard coupling disasters in deep and complex geological environments.

[0270] Based on the above technical solutions, this embodiment also proposes a geological energy-based deep underground engineering hazard identification system to implement the geological energy-based deep underground engineering hazard identification method as described in the embodiment. Please refer to [link to relevant documentation]. Figure 9 The system includes:

[0271] The multi-source data acquisition module is used to acquire multi-source data of underground engineering, including engineering geometric parameters, rock mass physical and mechanical parameters, thermophysical parameters, hydrogeological parameters, construction support parameters, and test monitoring data.

[0272] The geological energy calculation module is used to calculate energy field components based on the multi-source data. The energy field components include stratum deformation energy, intra-earth thermal energy, and groundwater potential energy. The stratum deformation energy, intra-earth thermal energy, and groundwater potential energy are algebraically superimposed to obtain the total stratum energy, and the energy density of the engineering area is calculated based on the total stratum energy.

[0273] The engineering area division module is used to divide the engineering area into shallow engineering area or deep engineering area based on the comparison result of the energy density and the preset threshold, and then enter the corresponding disaster judgment process respectively.

[0274] The shallow engineering area disaster assessment module is used to calculate the surrounding rock deformation based on the surrounding rock mechanics model for shallow engineering areas and compare it with the deformation threshold to determine the collapse risk.

[0275] The deep engineering area hazard assessment module is used to identify potential stress-controlled, thermally controlled, seepage-controlled, and combined-controllable hazard types in deep engineering areas. For stress-controlled hazards, it calculates an index characterizing the failure tendency based on rock mechanics test data through energy analysis to assess the risk of rockburst or large deformation. For thermally controlled hazards, it calculates the heat budget of the chamber and assesses the risk of thermal damage by comparing the magnitude of incoming and outgoing heat. For seepage-controlled hazards, it applies a preset energy rule based on formation energy and groundwater dynamic parameters to assess the risk of sudden water inrush. For combined-controllable hazards, it analyzes the coupling effect between different energy fields, performs coupling correction on individual hazard criteria, and performs comprehensive hazard assessment based on the corrected coupling criteria.

[0276] It is understood that the geological energy-based deep underground engineering disaster identification system described in this embodiment is a system for implementing the geological energy-based deep underground engineering disaster identification method described in the embodiment. As the system disclosed in the embodiment corresponds to the method disclosed in the embodiment, the description is relatively simple. For relevant parts, please refer to the description of the method. It will not be repeated here.

Claims

1. A method for identifying hazards in deep underground engineering based on geological energy, characterized in that, The method includes: Acquire multi-source data for underground engineering, including engineering geometric parameters, rock mass physical and mechanical parameters, thermophysical parameters, hydrogeological parameters, construction support parameters, and test and monitoring data; The energy field components are calculated based on the multi-source data. The energy field components include stratum deformation energy, intra-earth thermal energy, and groundwater potential energy. The stratum deformation energy, intra-earth thermal energy, and groundwater potential energy are algebraically superimposed to obtain the total stratum energy. The energy density of the engineering area is then calculated based on the total stratum energy. The formula for calculating the total energy of the formation is as follows: ； The formula for calculating the energy density is as follows: ； in, Represents the total energy of the formation. Indicates the deformation energy of the strata. Indicates geothermal energy. Represents the potential energy of groundwater. Indicates energy density, Indicates the total volume of the rock mass within the engineering area; Based on the comparison results between the energy density and the preset threshold, the engineering area is divided into a shallow engineering area or a deep engineering area, and then enters the corresponding disaster identification process respectively. For shallow engineering areas, the deformation of the surrounding rock is calculated based on the surrounding rock mechanics model and compared with the deformation threshold to determine the risk of collapse. For deep engineering areas, potential stress-controlled, thermally controlled, seepage-controlled, and combined-controllable hazard types are identified. For stress-controlled hazards, based on rock mechanics test data, energy analysis is used to calculate indices characterizing the tendency to fail, thereby determining the risk of rockburst or large deformation. For thermally controlled hazards, the heat budget of the chamber is calculated, and the relationship between the amount of heat entering and the amount of heat dissipating is compared to determine the risk of heat damage. For seepage-controlled hazards, based on formation energy and groundwater dynamic parameters, a pre-defined energy rule is applied to determine the risk of sudden water inrush. For combined-controllable hazards, the coupling effect between different energy fields is analyzed, and the single hazard criteria are coupled and corrected. Based on the corrected coupled criteria, a comprehensive hazard assessment is performed.

2. The method for identifying deep underground engineering hazards based on geological energy according to claim 1, characterized in that, The calculation of energy field components based on the multi-source data specifically includes: Calculate formation deformation energy : ； in, Represents the stress tensor. Represents the strain tensor. This represents the inner product operation of tensors. This indicates the volume of the disturbed area from the underground engineering project; Calculate the geothermal energy : ； in, This indicates the specific heat capacity of the surrounding rock. Indicates the density of the surrounding rock. This indicates the permissible air temperature for underground engineering construction. This indicates the temperature of the undisturbed original rock. This indicates the radial distance from the center of the chamber is... The temperature of the surrounding rock at that location This indicates the volume of the area affected by the temperature of the surrounding rock during construction. Calculate groundwater potential energy : ； in, This indicates the density of water. Represents gravitational acceleration. This indicates the height of the groundwater level relative to the foundation slab of the project. Indicates the pressure of the pressurized water. Indicates the groundwater flow velocity. Indicates the first The total volume of groundwater storage space in hydrogeological structures. These correspond to the fissure type, fault type, karst cave type, and conduit and underground river type, respectively.

3. The method for identifying deep underground engineering hazards based on geological energy according to claim 2, characterized in that, The volume of the area affected by the surrounding rock temperature during the construction process. The methods for determining this include: The radius of temperature influence is determined using a heat conduction model. According to the temperature influence radius With the length of the chamber Calculate the volume of the area affected by the temperature of the surrounding rock during construction. For circular chambers, ; The governing equations of the heat conduction model are: ； in, Indicates radial distance. Indicates time, Indicates the thermal conductivity coefficient of the surrounding rock; The far-field boundary conditions of the heat conduction model are: ； in, It represents the radial distance originating from the center of the circular chamber; The near-field boundary conditions of the heat conduction model are as follows: ； in, Indicates the heat transfer coefficient. Indicates the temperature of the cave wall rock. Indicates the radius of the chamber; The radius of temperature influence The approximate solution is: ； in, This represents the thermal diffusivity.

4. The method for identifying deep underground engineering hazards based on geological energy according to claim 1, characterized in that, For shallow engineering areas, methods for determining collapse risk include: An elastoplastic mechanical model of the surrounding rock is established based on the Mohr-Coulomb criterion, the characteristic curve of the surrounding rock is determined, and the displacement around the surrounding rock is calculated; when the displacement around the surrounding rock is greater than 40 mm, it is determined that there is a risk of collapse. Based on the aforementioned surrounding rock characteristic curve, the methods for determining the surrounding rock displacement at each stage include: For the elastic stage, the displacement of the surrounding rock The calculation formula is: ； in, Indicates the radius of the tunnel excavation. Indicates the initial ground stress. Indicates support strength. Represents Poisson's ratio. Indicates the elastic modulus of the rock mass; For the plastic stage, the displacement of the surrounding rock The calculation formula is: ； in, Indicates the shear strength of the rock mass. Indicates the friction angle within the rock mass. The radius of the plastic zone is represented by the following formula: ； in, This represents the extreme value of shear strength after the surrounding rock has been weakened. This represents the extreme value of the internal friction angle after the surrounding rock has been weakened; For the loosening stage, the displacement of the surrounding rock The calculation formula is: ； in, Indicates the internal friction angle of the rock mass in the loosened zone. The stress in the loosened zone is represented by the following formula: ； in, Indicates the cohesion of the rock mass in the loosened area. Indicates the weight of the rock mass.

5. The method for identifying deep underground engineering hazards based on geological energy according to claim 1, characterized in that, For stress-controlled disasters, methods for assessing the risk of rockbursts or large deformations include: Calculate the cross-sectional area of ​​the specimen based on uniaxial compression test data. Axial stress Axial strain Uniaxial compressive strength and elastic modulus The calculation formulas are as follows: ； ； ； ； ； in, Indicates the diameter of the sample. Indicates axial load. Indicates the amount of axial deformation. Indicates the initial height of the sample. Indicates the maximum load at which the specimen fails. and These represent the stress increment and the corresponding strain increment during the linear elastic stage, respectively. Stress-strain curves were plotted based on the uniaxial compression test data, and energy analysis was performed on the stress-strain curves to calculate the total energy absorbed by the specimen during loading. Releaseable elastic strain energy With dissipated energy The calculation formula is as follows: ； ； ； in, This indicates that the specimen has reached uniaxial compressive strength. The corresponding axial strain at that time, This represents the strain when the load is unloaded to zero. Represents the unloading stress function; Calculate the energy release rate Energy dissipation rate and destruction index : ； ； ； According to the damage index The value is used to determine: when At that time, it was determined that the tendency was mainly towards large deformation; when At that time, it was determined that both large deformation and rockburst were prominent; when At that time, it was determined that the tendency was mainly rockburst.

6. The method for identifying deep underground engineering hazards based on geological energy according to claim 5, characterized in that, For heat-controlled disasters, methods for assessing heat hazard risk include: Calculate the total heat entering the chamber per unit time. : ； ； ； ； in, Indicates the heat transfer rate of the surrounding rock. Indicates the heat transfer rate of hot water. Indicates the heat-carrying capacity of hot gas. Indicates a unit of time. Indicates the thermal conductivity of the surrounding rock. This indicates the area of ​​exposed surrounding rock during tunnel excavation. Indicates the original rock temperature. Indicates the temperature of the tunnel wall. Indicates the calculated thickness of the heat-affected zone of the surrounding rock. This indicates the density of water. This indicates the specific heat capacity of water. This indicates the total flow rate of hot water entering the chamber. Indicates the temperature of the gushing water. Indicates the density of harmful gases. Indicates the specific heat capacity of a gas. This indicates the volumetric flow rate of the high-temperature gas entering the chamber. Indicates gas temperature; Calculate the total heat dissipated by the chamber per unit time. : ； ； ； ； in, Indicates the ventilation and heat dissipation rate. Indicates the heat transfer efficiency of the insulation layer. Indicates the unsteady-state heat absorption rate of the surrounding rock. Indicates air density, This indicates the specific heat capacity of air at constant pressure. This indicates the volumetric flow rate of ventilation within the chamber. This indicates the temperature of the fresh air supplied to the chamber. This indicates the surface area of ​​the insulation layer. Indicates the temperature of the outside of the insulation layer. Indicates the thermal resistance of the insulation layer. Indicates the thickness of the insulation layer. This indicates the thermal conductivity of the insulation material. Indicates the density of the surrounding rock. Indicates the specific heat capacity of the surrounding rock. This indicates the volume of the heat-affected zone of the surrounding rock involved in heat exchange. This indicates that the surrounding rock in this area has a time... The average temperature rise inside; When satisfied At that time, it was determined that there was a risk of heat damage.

7. The method for identifying deep underground engineering hazards based on geological energy according to claim 6, characterized in that, For seepage-controlled disasters, methods for assessing the risk of sudden water inrush include: Establish the First Law of Energy: ； in, Indicates the deformation energy of the strata. Represents the potential energy of groundwater. This indicates the fracture energy of the water-resistant rock mass. This indicates the area of ​​the fracture surface of the water-impermeable rock mass; Establish the Second Law of Energy: ； in, This indicates the density of water. This indicates the volumetric flow rate of the water after it surges into the chamber. This indicates the cross-sectional area of ​​the chamber through which water flows. When the stratum deformation energy and groundwater potential energy simultaneously satisfy the first energy law and the second energy law, it is determined that a sudden water inrush disaster will occur.

8. The method for identifying deep underground engineering hazards based on geological energy according to claim 7, characterized in that, For complex control-type disasters, the individual disaster criteria are coupled and modified, including: For situations where thermo-mechanical coupling affects seepage-controlled disasters, the first energy law used to identify seepage-controlled disasters is modified as follows: ； in, Indicates geothermal energy; Using the modified first energy law to identify penetration-controlled disasters; For situations where water-mechanical coupling affects thermally controlled disasters, the total heat entering the chamber per unit time will be used to calculate the total heat entering the chamber. Revised to The calculation formula is as follows: ； ； in, This represents the heat energy generated by friction. This represents the average shear stress on the sliding surface. This represents the effective contact area where sliding occurs. Indicates the cumulative slip; Using the corrected total heat The total heat dissipated by the chamber per unit time Compare, if satisfied If so, it is determined that there is a risk of heat damage; To address the situation where stress-controlled disasters are influenced by thermal-water coupling, uniaxial compression tests of rocks are conducted under preset high-temperature and high-pressure conditions. The failure index is calculated based on the corresponding uniaxial compression test data to identify stress-controlled disasters.

9. A deep underground engineering hazard identification system based on geological energy, characterized in that, For implementing the deep underground engineering hazard identification method based on geological energy as described in any one of claims 1 to 8, the system comprises: The multi-source data acquisition module is used to acquire multi-source data of underground engineering, including engineering geometric parameters, rock mass physical and mechanical parameters, thermophysical parameters, hydrogeological parameters, construction support parameters, and test monitoring data. The geological energy calculation module is used to calculate energy field components based on the multi-source data. The energy field components include stratum deformation energy, intra-earth thermal energy, and groundwater potential energy. The stratum deformation energy, intra-earth thermal energy, and groundwater potential energy are algebraically superimposed to obtain the total stratum energy, and the energy density of the engineering area is calculated based on the total stratum energy. The engineering area division module is used to divide the engineering area into shallow engineering area or deep engineering area based on the comparison result of the energy density and the preset threshold, and then enter the corresponding disaster judgment process respectively. The shallow engineering area disaster assessment module is used to calculate the surrounding rock deformation based on the surrounding rock mechanics model for shallow engineering areas and compare it with the deformation threshold to determine the collapse risk. The deep engineering area hazard assessment module is used to identify potential stress-controlled, thermally controlled, seepage-controlled, and combined-controllable hazard types in deep engineering areas. For stress-controlled hazards, it calculates an index characterizing the failure tendency based on rock mechanics test data through energy analysis to assess the risk of rockburst or large deformation. For thermally controlled hazards, it calculates the heat budget of the chamber and assesses the risk of thermal damage by comparing the magnitude of incoming and outgoing heat. For seepage-controlled hazards, it applies a preset energy rule based on formation energy and groundwater dynamic parameters to assess the risk of sudden water inrush. For combined-controllable hazards, it analyzes the coupling effect between different energy fields, performs coupling correction on individual hazard criteria, and performs comprehensive hazard assessment based on the corrected coupling criteria.

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