Advanced pressure relief construction method for ultra-deep vertical shaft of metal mine

Abstract

The invention relates to the technical field of metal mine ultra-deep vertical shaft construction, in particular to an advanced pressure relief construction method for a metal mine ultra-deep vertical shaft, aims to solve the problems that the construction safety of a deep shaft is difficult to guarantee and the construction difficulty is high, and is used for a large-diameter vertical shaft with the depth exceeding 1500 m. The lithology and physical mechanics parameters of shaft surrounding rock are obtained by adopting methods such as shaft rock core logging, surrounding rock joint fissure investigation and rock mechanics tests; then mechanical properties of the shaft surrounding rock are analyzed, and shaft surrounding rock excavation disturbance stress field distribution characteristics are obtained; the supporting opportunity and the supporting thickness of the well wall concrete lining are determined, high stress accumulated in a rock mass is released through advanced pressure relief blasting, so that the stress state of the shaft surrounding rock of the non-lining section is actively regulated and controlled, the interaction between the shaft surrounding rock and the subsequent well wall concrete lining is weakened, and the construction difficulty is effectively reduced; various means such as shaft stratum transparency analysis and ground pressure disaster prevention and control early warning are adopted, and safety and high efficiency of digging and supporting construction of the ultra-deep shaft are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of ultra-deep shaft construction in metal mines, and in particular to an advanced pressure relief construction method for ultra-deep shafts in metal mines. Background Art

[0002] With the development of my country's mining industry, many mines have entered deep mining, and the development of deep mineral resources has become an inevitable trend in the future development of the world's mining industry. The depth of the shaft has increased from 1200m~1500m at the beginning to 1500m~2000m now, and is approaching 2000m. As the throat of mine construction and production, the shaft project is the most difficult basic project in the process of mine infrastructure construction. Therefore, the construction of ultra-deep shafts (deeper than 1500m) will become the primary basic project for deep mine construction.

[0003] Traditional vertical shafts mostly adopt the construction technology of "one digging and one paving". Due to the spatial effect of the vertical shaft excavation working surface, the stress and displacement of the surrounding rock are not fully released, resulting in interaction between the surrounding rock of the shaft and the shaft wall. Most of the existing support methods act on shallow buried vertical shafts (the depth is generally between 20 meters and 30 meters). Shallow buried vertical shafts usually use engineering analogy method, or according to Rankine's earth pressure theory, the side pressure of the shaft is determined by plane retaining wall or cylindrical retaining wall, and then the thickness of the shaft lining support is determined according to Lamé's formula, and the surrounding rock is lined and supported adjacent to the shaft excavation surface. When the shallow shaft excavation and support technology is applied to deep shafts, it is found that due to the excessively high lateral pressure in deep shafts, the shallow shaft support method is very likely to lead to a large lining design support thickness and a low safety factor, which can easily cause a large amount of economic waste; and as the shaft construction depth continues to increase, it is also very likely to cause the original rock stress in the surrounding rock body to continue to increase; at the same time, after excavation and unloading, due to the redistribution of stress inside the shaft surrounding rock, the stress in the surrounding rock body is highly concentrated, which is also easy to cause brittle-ductile transformation of the rock mass, and even plastic expansion, rock burst and other phenomena, resulting in the occurrence of many shaft safety accidents.

[0004] Furthermore, the failure of the surrounding rock of the shaft is the result of the combined effects of the geological characteristics of the excavation disturbance stress, the rock mass conditions and the excavation method. The study found that the disaster-causing process of the ultra-deep shaft excavation disturbance is directly related to the rock mass failure response under high stress, especially the change in displacement after the shaft excavation and the high strain energy storage state of the rock mass. The study also found that compared with the shallow shaft, the geological conditions and stress state of the ultra-deep shaft are quite different. Especially under the strong excavation unloading, the stress state of the deep shaft is more complicated, which is specifically manifested as follows: the surrounding rock of the deep shaft is subjected to a variety of forces, such as high ground stress, high confined water and high rock temperature; under the high stress and strong excavation unloading, the surrounding rock of the deep shaft has highly concentrated stress and deviatoric stress, which can easily cause significant changes in the deformation characteristics of the surrounding rock, that is, the transformation of the surrounding rock deformation from brittle to ductile, and the prominent rheology and expansion of the surrounding rock. It can be seen that compared with the shallow shaft, the construction of the deep shaft is more difficult and the construction safety is lower.

[0005] Therefore, there is an urgent need for a method for advanced pressure relief construction of ultra-deep vertical shafts in metal mines to solve the above problems. Summary of the invention

[0006] One object of the present invention is to provide a method for advanced pressure relief construction of ultra-deep vertical shafts in metal mines, so as to solve the problems of difficulty in ensuring construction safety and great construction difficulty in deep shafts.

[0007] To achieve the above object, the present invention provides a method for advanced pressure relief construction of ultra-deep vertical shaft in a metal mine, comprising: Establish an ultra-deep wellbore engineering disaster model; Conduct rock mechanics tests to determine basic rock strength parameters; According to the investigation of the joints and fissures of the surrounding rock of the wellbore and the basic strength parameters of the rock, the quality grade of the surrounding rock of the wellbore is divided and the mechanical parameters of the rock mass are determined; Excavate the shaft, analyze the mechanical properties of the surrounding rock of the shaft according to the rock mass mechanical parameters and use the elastic-plastic theory analysis and numerical simulation methods, and then judge the rock burst tendency of the surrounding rock of shafts at different depths; Determine the timing and thickness of concrete lining support for ultra-deep shafts; Determine the support parameters, and carry out energy release support and advance pressure relief blasting on the surrounding rock of the wellbore based on the rockburst tendency evaluation results at different depths.

[0008] Furthermore, the step of establishing the ultra-deep wellbore engineering disaster model includes: using ultra-deep vertical shaft engineering survey drilling core to catalog the bottom layer information of the core, classifying the rock mass quality grade according to the core characteristics and the characteristics of the joint and fissure development degree, and establishing an engineering disaster model of the ultra-deep vertical shaft bedrock lithology and rock mass quality; following the progress of the ultra-deep vertical shaft construction, investigating the joints and fissures of the surrounding rocks at different depths of the wellbore, and comparing the wellbore joint and fissure investigation results with the stratigraphic information revealed by the engineering survey drilling core, so as to correct / update the ultra-deep wellbore engineering disaster model.

[0009] Furthermore, the rock mechanics test is carried out to determine the basic strength parameters of the rock, including: sampling the rock mass at different excavation depths of the ultra-deep shaft, processing the rock mass into standard rock samples, and conducting uniaxial compressive strength tests, Brazilian splitting tests and shear tests respectively to determine the basic strength parameters of the rock; wherein the basic strength parameters of the rock include: the average density of the rock sample , Uniaxial compressive strength of rock , rock tensile strength , elastic modulus E, cohesion c, Poisson's ratio μ and internal friction angle φ.

[0010] Furthermore, the step of classifying the quality grade of the surrounding rock of the wellbore and determining the rock mechanical parameters according to the investigation of the joints and fissures of the surrounding rock of the wellbore and the basic strength parameters of the rock includes: classifying the quality of the rock mass at different depths of the wellbore according to the joints and fissures of the surrounding rock of the ultra-deep vertical shaft and the basic strength parameters of the rock, using the Barton rock quality index Q classification, rock geomechanics (RMR) classification and geological strength index GSI classification method; calculating according to the basic rock strength parameters and the classification of the rock mass quality at different depths of the wellbore to obtain the rock mechanical parameters of different depths (parts); wherein the rock mechanical parameters include rock density , rock mass compressive strength , rock mass tensile strength , elastic modulus E, Poisson's ratio and rock mass shear strength coefficient .

[0011] Furthermore, the excavation of the shaft, according to the mechanical parameters of the rock mass and using the elastoplastic theory analysis and numerical simulation method to analyze the mechanical properties of the surrounding rock of the shaft, and then judging the rockburst tendency of the surrounding rock of the shaft at different depths, comprises the following steps: after the shaft is excavated, the surrounding rock stress is redistributed, and the stress conditions of the surrounding rock of the shaft cross section under the conditions of hydrostatic pressure and non-hydrostatic pressure are analyzed respectively by the elastoplastic theory analysis and numerical simulation method, and the surrounding rock of the shaft is divided into three parts according to the analysis results: a loose zone, a surrounding rock bearing zone, and an initial stress zone; a numerical simulation method is used to analyze the spatial effect of the shaft excavation working face, the shaft excavation process is simulated, the deformation characteristic curve of the longitudinal section of the shaft is obtained, and the elastoplastic theory analysis method is used to analyze the interaction between the shaft surrounding rock and the concrete lining of the shaft wall under the conditions of uniform stress and non-uniform stress; the potential damage type of the shaft surrounding rock is determined in combination with the rock formation type determination chart; according to the rock physical and mechanical parameters, a comprehensive analysis and comparison is performed through the brittleness coefficient method, the Patton method and the stress intensity method to obtain a rockburst tendency evaluation.

[0012] Furthermore, the steps of using elastic-plastic theory analysis and numerical simulation methods to analyze the stress conditions of the surrounding rock in the cross section of the wellbore under hydrostatic pressure and non-hydrostatic pressure conditions respectively include: first, according to the formula , judge whether the surrounding rock of the wellbore exceeds the elastic limit and is in a plastic state, and divide the surrounding rock state into elastic state and plastic state; when the tangential stress of the surrounding rock of the wellbore When the following formula is satisfied, it is considered that plastic failure occurs in the surrounding rock of the wellbore: ,in, is the maximum horizontal principal stress; then calculate the elastic analysis solution under the hydrostatic pressure state: the following elastic analysis solution of surrounding rock stress and displacement is obtained by using the polar coordinate system. The specific formula is as follows: , , , , ,in, is the original rock stress, is the radial stress, is the tangential stress, is the shear stress, is the radial displacement, is the tangential displacement, is the shear modulus, is the lateral pressure coefficient, , is the wellbore radius, is the polar coordinate radius, is the angle in polar coordinates, is the passive response coefficient; finally, the numerical simulation method is used to calculate the analytical solution of the plastic zone and stress distribution of the wellbore surrounding rock under non-static pressure state.

[0013] Furthermore, the step of determining the timing and thickness of the concrete lining support for the ultra-deep vertical shaft includes: determining the unsupported self-stabilizing span and self-stabilizing time of the surrounding rock of the ultra-deep vertical shaft by RMR stability diagram method according to the quality classification of the shaft rock mass and the excavation size of the ultra-deep vertical shaft; based on the advanced sequential pressure release theory, comprehensively drawing the deformation characteristic curve of the surrounding rock cross section and the support characteristic curve to determine the timing of the concrete lining support for the ultra-deep vertical shaft wall; and comprehensively determining the support thickness of the ultra-deep vertical shaft wall lining according to the thick-walled cylinder theory and the empirical method.

[0014] Furthermore, the step of comprehensively drawing the deformation characteristic curve of the surrounding rock cross section and the support characteristic curve includes: analyzing the deformation characteristic curve of the wellbore longitudinal section, and drawing the deformation characteristic curve of the surrounding rock cross section according to the modified Fenner formula, the formula is as follows: ,in, is the support resistance, φ is the internal friction angle, is the cohesive force; the concrete lining support characteristic curve is drawn according to the relationship between the support force and the structural stiffness. The formula is as follows: ,in, For the supporting force, is the structural stiffness, is the radial displacement of the support.

[0015] Furthermore, the step of determining support parameters and performing energy release support and advance pressure relief blasting on the surrounding rock of the wellbore in combination with the rock burst tendency evaluation results at different depths includes: designing support for the exposed surrounding rock section between the well wall and the working face by adopting a temporary support method in the form of anchor mesh spraying; determining support parameters by comprehensively adopting the RMR rock mass geomechanics classification method and engineering analogy method; wherein the support parameters include: anchor rod diameter, length and spacing, metal mesh material, size and grid shape, length, diameter and spacing of double reinforcement bars; according to the rock burst tendency evaluation results at different depths, adopting advance pressure relief blasting in areas where rock burst may occur to release local high stress in the surrounding rock of the wellbore, thereby reducing the probability of rock burst in the surrounding rock of the wellbore.

[0016] Based on the foregoing description, those skilled in the art will be able to understand that, in the aforementioned technical solution of the present invention, a method for advance pressure relief construction of ultra-deep vertical shafts in metal mines is provided, which is mainly used for the pressure relief construction of large-diameter ultra-deep vertical shafts with a depth of more than 1500m and for the prevention and control of ground pressure disasters. By taking methods such as vertical shaft core logging, surrounding rock joint and fissure investigation, and rock mechanics testing, the lithology and physical and mechanical parameters of the shaft surrounding rock are obtained to achieve the purpose of transparent well construction and advance warning; then the mechanical properties of the shaft surrounding rock are analyzed to obtain the distribution characteristics of the stress field disturbed by shaft excavation; based on the advanced sequential pressure release theory, the timing and thickness of the shaft wall concrete lining support are determined, and a certain distance is maintained between the shaft wall lining and the shaft excavation working face. The energy release support structure is used to bear the deformation pressure caused by the redistribution of the stress of the shaft excavation surrounding rock, and the high stress accumulated in the rock mass is released through advanced pressure relief blasting. In this way, the stress state of the unlined section of the shaft surrounding rock is actively regulated, the interaction between the shaft surrounding rock and the subsequent shaft wall concrete lining is weakened, and the pressure release construction of the ultra-deep shaft is realized, reducing the construction difficulty.

[0017] Furthermore, the method for pre-decompression construction of ultra-deep vertical shafts in metal mines provided by the present invention is applicable to complex strata with deep high stress, strong compression and strong excavation disturbance. Through transparent analysis of vertical shaft strata, early warning of ground pressure disaster prevention and control, and the use of multiple means to gradually solve the construction safety problems existing in the ultra-deep vertical shaft construction process, the disaster hazards brought by the conventional construction methods of traditional vertical shafts are changed, the safety and efficiency of ultra-deep vertical shaft excavation and support construction, as well as the long-term stability of shaft construction and service period are guaranteed, so as to achieve the purpose of comprehensively improving shaft ground pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present invention, some embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood by those skilled in the art that the same reference numerals in different drawings indicate the same or similar components or parts; the drawings of the present invention are not necessarily drawn to scale. In the drawings: Figure 1 is a flow chart of a method for advanced pressure relief construction of an ultra-deep vertical shaft of a metal mine in some embodiments of the present invention; Figure 2 It is the connection between rock blocks - surface quality trend diagram; Figure 3 It is the rock mass geomechanical RMR stability diagram; Figure 4 It is a comprehensive curve drawing; Figure 5 It is a schematic diagram of temporary support design plan; Figure 6 This is a top view of the temporary support design.

[0019] Description of reference numerals: 1. Anchor rod; 2. Metal mesh; 3. Double reinforcement. DETAILED DESCRIPTION

[0020] It should be understood by those skilled in the art that the embodiments described below are only some embodiments of the present invention, rather than all embodiments of the present invention, and these embodiments are intended to explain the technical principles of the present invention, rather than to limit the protection scope of the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should still fall within the protection scope of the present invention.

[0021] It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "top", "bottom", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0022] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] Refer to the following Figures 1 to 6 , to explain in detail the method for pre-decompression construction of ultra-deep vertical shafts in metal mines in some embodiments of the present invention. Figure 1 is a flow chart of a method for advanced pressure relief construction of an ultra-deep vertical shaft of a metal mine in some embodiments of the present invention; Figure 2 It is the connection between rock blocks - surface quality trend diagram; Figure 3 It is the rock mass geomechanical RMR stability diagram; Figure 4 It is a comprehensive curve drawing; Figure 5 It is a schematic diagram of temporary support design plan; Figure 6 This is a top view of the temporary support design.

[0024] It should be noted that, for the convenience of description and to enable those skilled in the art to quickly understand the technical solution of the present invention, the following text only describes the technical features that are strongly related (directly or indirectly related) to the technical problem and / or technical concept to be solved by the present invention, and will not describe the technical features that are weakly related to the technical problem and / or technical concept to be solved by the invention. Since the technical features with a weaker degree of correlation belong to the common knowledge in the field, even if the present invention does not describe the features with a weaker degree of correlation, it will not lead to insufficient disclosure of the present invention.

[0025] The present invention is a construction technology method used in the construction of a vertical shaft under construction in a gold mine of Shandong Gold Group. The construction depth of the vertical shaft is expected to reach 2000m, and the net diameter of the shaft is 10.5m. The shaft is a large-diameter ultra-deep shaft. The deep strata of the ultra-deep shaft are in a state of high stress and strong compression. The rock is hard and has a high energy level. Under the disturbance of shaft construction, it is easy to produce strong rock dynamic disasters, which brings challenges to excavation and support. The traditional "one digging and one masonry" shaft construction method is used, which is very likely to cause the shaft surrounding rock to interact with the shaft wall, resulting in a low safety factor of the concrete shaft wall, and under the influence of high stress, the shaft wall structure is very likely to be deformed and damaged.

[0026] Therefore, the present invention provides a method for advanced pressure relief construction of ultra-deep vertical shafts in metal mines, which adopts advanced sequential pressure relief construction technology for ultra-deep vertical shaft construction. The method is suitable for large-diameter ultra-deep vertical shaft pressure relief construction and ground pressure disaster prevention and control with a depth of more than 1500m. According to the results of vertical shaft core logging and the distribution of joints and fissures in the surrounding rock of the shaft, as well as the physical and mechanical parameters of the rock as basic information, the vertical shaft strata are made transparent, and by analyzing the mechanical properties of the surrounding rock of the shaft, the theory and method of advanced sequential pressure relief are adopted to realize the pressure relief construction of ultra-deep vertical shafts and ensure construction safety.

[0027] like Figure 1 As shown, in some embodiments of the present invention, the method for advanced pressure relief construction of ultra-deep vertical shaft of metal mine includes: Step S110, establishing an ultra-deep wellbore engineering disaster model. Step S110, including: Step S111, using the ultra-deep vertical shaft engineering survey drilled core, the core bottom information is cataloged, according to the core characteristics and the characteristics of the joint and fissure development degree, the rock mass quality grade is divided, and the engineering disaster model of the ultra-deep vertical shaft bedrock lithology and rock mass quality is established. Specifically, the ultra-deep vertical shaft engineering survey drilled core is used to catalog the core. The core catalog includes the cataloging of the vertical shaft rock information, rock structure surface and rock structure surface fillings. The vertical shaft rock information includes rock color, weathering degree, rock structure, structure surface spacing, hardness, bedrock lithology and occurrence depth. The rock structure surface information includes the structure surface type, opening, whether there is filling, roughness and occurrence. The rock structure surface filling includes water content, color, thickness, coherence, hardness, filling type and source information. Among them, the structure surface type generally includes cracks, structural joints and general joints.

[0028] In this embodiment, the lithology of the surrounding rock of the ultra-deep vertical shaft is mainly granite, accounting for 90%, and the average values ​​of RQD (rock quality, used to evaluate the integrity of the rock mass) at different levels are mostly above 70%. The angles of joints and fissures are mostly above 60°, and the opening is about 1mm, which belongs to micro-cracks with high inclination angles. According to the core characteristics and the characteristics of the development degree of joints and fissures, the rock mass is divided into four quality levels: relatively complete, relatively developed fissures, developed fissures, and broken zones. Based on the above core cataloging information and the characteristics of the development degree of joints and fissures, an engineering disaster model reflecting the bedrock lithology and rock mass quality of the ultra-deep vertical shaft is established.

[0029] Step S112, follow the progress of the ultra-deep vertical shaft construction, investigate the joints and fissures of the surrounding rocks at different depths of the wellbore, and compare the results of the wellbore joint and fissure investigation with the stratigraphic information revealed by the engineering survey drilling core to revise / update the ultra-deep wellbore engineering disaster model. Specifically, follow the progress of the ultra-deep vertical shaft construction, continue to carry out investigations on the joints and fissures of the surrounding rocks at different depths of the wellbore, and focus on investigating the surrounding rock joints and structural structures revealed after the wellbore excavation, including descriptions of the strike, inclination, inclination, crack density, opening, crack filling, etc. of the joints and structural structures. Then compare the results of the wellbore joint and fissure investigation with the stratigraphic information revealed by the engineering survey drilling core to revise / update the ultra-deep wellbore engineering disaster model constructed by drilling core in step S111.

[0030] Step S120, conducting rock mechanics tests to determine basic rock strength parameters. Step S120, includes: Step S121, sampling the rock mass at different excavation depths of the ultra-deep shaft, processing the rock mass into standard rock samples, and conducting uniaxial compressive strength tests, Brazilian splitting tests, and shear tests to determine the basic strength parameters of the rock. Rock strength is an important indicator reflecting the stability of rock engineering and is an essential parameter for calculating the strength of engineering rock. Sampling the rock mass at different excavation depths of the ultra-deep shaft, processing it into standard rock samples in accordance with the requirements of the ISRM "Standard for Rock Mechanics Test Methods", conducting uniaxial compressive strength tests, Brazilian splitting tests, and shear tests to obtain the basic strength parameters of the rock.

[0031] The basic strength parameters of rock include: the average density of the rock sample , Uniaxial compressive strength of rock , rock tensile strength , elastic modulus E, cohesion c, Poisson's ratio μ and internal friction angle .

[0032] First, according to the test content requirements and rock mechanics test standards, determine the rock sample specifications of the ultra-deep shaft granite, process the rock sample, and then grind the processed rock sample, and measure the physical parameters such as diameter, height and mass of the polished rock sample. In this embodiment, the granite rock sample specifications are: uniaxial compression rock sample diameter is 50mm, rock sample height is 100mm; shear test rock sample diameter is 50mm, rock sample height is 50mm; Brazilian splitting rock sample diameter is 50mm, rock sample height is 25mm. The average density of the rock sample is calculated based on the measurement results. In this embodiment, the average density of the rock sample is 2.52g / cm 3 .

[0033] Start the experiment: perform basic parameter tests, uniaxial compression tests, Brazilian splitting tests, and shear tests on rock samples to obtain rock mechanical parameter values ​​at different depths. Specifically, in this embodiment, rock density 2.66g / cm 3 , uniaxial compressive strength of rock The rock tensile strength is 150.36MPa. is 13.08MPa, elastic modulus E is 47.61MPa, cohesion c is 18.95MPa, internal friction angle It is 35.71°.

[0034] Step S130, based on the investigation of the joints and fissures of the surrounding rock of the wellbore and the basic strength parameters of the rock, the quality grade of the surrounding rock of the wellbore is classified and the mechanical parameters of the rock mass are determined. Step S130 includes: Step S131, based on the ultra-deep vertical shaft surrounding rock joints and fissures and basic rock strength parameters, the Patton rock mass quality index Q classification, rock mass geomechanics (RMR) classification and geological strength index GSI classification methods are used to classify the rock mass quality at different depths of the shaft. Specifically, based on the ultra-deep vertical shaft surrounding rock joints and fissures and rock mechanics test results (i.e., the basic rock strength parameters obtained in the experiment in step S120), the Patton rock mass quality index Q classification, rock mass geomechanics (RMR) classification and geological strength index GSI classification methods are used to classify the rock mass quality at different depths of the shaft to evaluate the stability of the shaft surrounding rock mass.

[0035] The Q classification method is based on the rock mass quality index RQD, joint roughness coefficient , joint alteration coefficient , Number of joint groups , Joint water reduction coefficient The Q value is calculated using the stress reduction factor SRF, and the rock mass is divided into 9 grades according to the size of the Q value.

[0036] The value of the rock mass quality index Q system classification index Q is determined by the following formula: .

[0037] In this embodiment, the Barton rock mass quality (Q) classification method is used, and the calculated Q value range is 0.001~1000, which represents that the surrounding rock is divided into 5 quality grades from extremely poor broken rock to extremely good hard and intact rock.

[0038] The surrounding rock is classified according to the Barton rock mass quality (Q) classification method in Table 1: Table 1. Classification of surrounding rock mass quality (Q) of Barton rock mass

[0039] The rock mass geomechanical classification index value RMR (Rock Mass Rating) consists of six index parameters: rock block strength R1, RQD value R2, joint spacing R3, joint condition R4, groundwater R5, and correction parameter R6 of the influence of joint direction on engineering. When classifying, the values ​​of various indicators are scored according to the standards in Table 2, and the total score RMR value is summed up. Finally, the category of the studied rock mass and the corresponding self-stabilization time and rock mass strength index of the unsupported underground engineering are obtained by comparing the corrected total score with Table 3.

[0040] The calculation formula of the total RMR value is as follows: .

[0041] The following are the classification parameters and scoring values ​​of the rock mass geomechanical classification index value RMR in Table 2: Table 2 RMR classification parameters and their scoring values

[0042] The following is a table of rock mass quality evaluation and engineering properties based on the total RMR score in Table 3: Table 3 Rock mass quality evaluation and engineering properties based on RMR total score

[0043] The GSI value is selected based on the rock mass joint distribution characteristics and joint surface characteristics. The rock mass joint distribution characteristics include the number of joint groups, block shape and degree of geological disturbance, and the joint surface characteristics are determined by the roughness of the joint surface, the degree of joint weathering and the filling condition. In this embodiment, the classification of the geological strength index GSI is as follows: Figure 2 Obtained in.

[0044] Based on the above three different rock mass quality classification methods, the rock mass quality grades at different depths (parts) of the wellbore are obtained, as shown in Table 4: Table 4 Rock mass quality classification results

[0045] Step S132, calculate according to the basic strength parameters of the rock and the grade classification of the rock mass quality at different depths of the wellbore to obtain the mechanical parameters of the rock mass at different depths (parts). Specifically, according to the Hoek-Brown strength criterion, the rock mass strength and deformation parameters are evaluated, and the engineering rock mass mechanical parameters are determined according to the "Engineering Rock Mass Classification Standard". Among them, the rock mass mechanical parameters include rock density ρ, rock mass compressive strength , rock mass tensile strength , elastic modulus E, Poisson's ratio and rock mass shear strength coefficient Step S132 includes: Uniaxial compressive strength of rock mass Calculation process: Using the Hoek-Brown strength criterion, according to the geological strength index GSI, the geological strength index GSI is found from the rock mass quality classification results in Table 4 in step S131, and then the rock mass characteristic constants s and a are taken according to the following formula: , , where D is the disturbance coefficient, ranging from 0 to 1; According to the rock mass characteristic constants s, a and the uniaxial compressive strength of rock The uniaxial compressive strength of rock mass is calculated according to the following formula: : .

[0046] Uniaxial tensile strength of rock mass Calculation process: First, according to the complete rock material constant , geological strength index GSI and disturbance coefficient D, and the empirical parameters of rock mass characteristics are calculated according to the following formula : , According to the uniaxial compressive strength of rock , Empirical parameters of rock mass characteristics And the rock mass characteristic constant s, the uniaxial tensile strength of the rock mass is calculated according to the following formula : .

[0047] Calculation process of rock elastic modulus Em: According to rock elastic modulus E, geological strength index GSI and disturbance coefficient D, the rock elastic modulus Em is calculated according to the following formula: .

[0048] Poisson's ratio of rock mass Calculation process: According to the rock elastic modulus E, rock mass elastic modulus Em and Poisson's ratio μ, determine the rock mass Poisson's ratio : .

[0049] Rock mass shear strength Value and Value calculation process: First, according to the empirical parameters of rock mass characteristics And the rock mass characteristic constants s, a, the rock mass shear strength is calculated according to the following formula value: , Among them, σ 3n = / , The upper limit of the stress limit between the Hoek-Brown criterion and the Mohr-Coulomb criterion; According to the uniaxial compressive strength of rock , rock mass characteristic constants s and a, empirical parameters of rock mass characteristics And the upper limit of stress limited by the relationship between the Hoek-Brown criterion and the Mohr-Coulomb criterion , calculated according to the following formula value: .

[0050] Finally, the rock mass compressive strength calculated according to the above steps is , rock mass tensile strength , elastic modulus E, Poisson's ratio and rock mass shear strength coefficient , combined with the rock mass location and rock density Draw a table of rock mass mechanical parameters, as shown in Table 5: Table 5 Rock mass mechanical parameters

[0051] Step S140, excavating a wellbore, analyzing the mechanical properties of the surrounding rock of the wellbore based on the rock mass mechanical parameters and using elastic-plastic theory analysis and numerical simulation methods, and then evaluating the rockburst tendency of the surrounding rock of the wellbore at different depths. Step S140 includes: Step S141, after the wellbore is excavated, the surrounding rock stress is redistributed, and the surrounding rock state is divided into elastic state and plastic state according to whether the magnitude of the surrounding rock redistributed stress exceeds the elastic limit of the rock mass; the stress state of the surrounding rock of the wellbore cross section under hydrostatic pressure and non-hydrostatic pressure conditions is analyzed by elastic-plastic theory analysis and numerical simulation methods, and the surrounding rock of the wellbore is divided into three parts according to the analysis results: loose area, surrounding rock bearing area, and initial stress area. Step S141, including: Step S1411, first according to the formula , to judge whether the surrounding rock of the wellbore exceeds the elastic limit and is in a plastic state, so as to divide the surrounding rock state into elastic state and plastic state. When the following formula is satisfied, it is considered that plastic failure occurs in the surrounding rock of the wellbore: , in, is the maximum horizontal principal stress.

[0052] Step S1412: Under the hydrostatic pressure state, the following elastic analysis solution of surrounding rock stress and displacement is calculated using the polar coordinate system. The specific formula is as follows: , , , , , in, is the original rock stress, is the radial stress, is the tangential stress, is the shear stress, is the radial displacement, is the tangential displacement, is the shear modulus, is the lateral pressure coefficient, , is the wellbore radius, is the polar coordinate radius, is the angle in polar coordinates, is the passive reaction coefficient.

[0053] Step S1413, under non-hydrostatic pressure state, a numerical simulation method is used to obtain an analytical solution of the plastic zone and stress distribution of the wellbore surrounding rock.

[0054] Step S1413, by analyzing the elasticity and plasticity of the wellbore surrounding rock in the hydrostatic state and the non-hydrostatic state, the wellbore surrounding rock is divided into three parts: a loose area, a surrounding rock bearing area, and an initial stress area.

[0055] Step S142, using numerical simulation methods to analyze the spatial effect of the shaft excavation working face, simulating the shaft excavation process, obtaining the shaft longitudinal section deformation characteristic curve, and using elastic-plastic theory analytical methods to analyze the interaction between the shaft surrounding rock and the shaft wall concrete lining under uniform stress and non-uniform stress conditions.

[0056] Affected by the excavation face, the stress redistribution state of the surrounding rock near the excavation face is significantly different from the stress state of the surrounding rock far away from the excavation face. The stress and displacement of the surrounding rock near the shaft excavation face cannot be completely released. The farther away from the excavation face, the more complete the release of the surrounding rock stress. Therefore, considering the spatial effect of the shaft excavation working face, assuming that the outer diameter of the lining is equal to the shaft excavation radius, the interaction between the shaft surrounding rock and the shaft wall concrete lining under uniform and non-uniform stress conditions is analyzed by the elastic-plastic theory analytical method. It is found that the parameters affecting the maximum principal stress in the lining include the horizontal maximum principal stress, the lateral pressure coefficient, the lining thickness and the lining shear modulus. Continuously increasing the strength and thickness of the lining concrete cannot effectively reduce the displacement and stress difference of the shaft surrounding rock. Therefore, it is concluded that the traditional shaft excavation support technology is not suitable for ultra-deep shaft construction.

[0057] Step S143, judging the potential damage type of the surrounding rock of the wellbore in combination with the rock formation type judgment chart.

[0058] Based on field observations and laboratory tests, according to the failure mechanism of surrounding rock, surrounding rock failure types can be roughly divided into four categories: single rock or local instability failure, overall surrounding rock failure, rock burst failure and deliquescence expansion failure, as shown in Table 6. Through field investigation, the potential failure forms of the surrounding rock of the ultra-deep shaft in this embodiment are mainly structural surface controlled failure, deep stress induced failure, rock burst, low confining pressure shear failure, spalling and a combination of multiple failure types.

[0059] Table 6 Potential damage types of wellbore surrounding rock

[0060] Step S144, according to the rock physical and mechanical parameters, a comprehensive analysis and comparison is performed by the brittleness coefficient method, the Patton method and the stress intensity method to obtain a rock burst tendency evaluation. Specifically, based on the rock physical and mechanical test results of the ultra-deep vertical shaft and the core logging data of the exploration hole, the brittleness coefficient method, the Patton method and the stress intensity method are used to evaluate the rock burst tendency evaluation results at different depths in the deep as shown in Table 7 below: Table 7 Rockburst tendency assessment results

[0061] Step S150, determining the timing and thickness of the ultra-deep shaft concrete lining support according to the quality grade of the shaft surrounding rock. Step S150, including: Step S151, according to the rock mass quality classification of the shaft and the excavation size of the ultra-deep shaft, the unsupported self-stabilization span and self-stabilization time of the surrounding rock of the ultra-deep shaft are determined by the RMR stability chart method. Specifically, based on the RMR rock mass quality classification results, it can be determined that the maximum unsupported self-stabilization time interval of the surrounding rock of the shaft is 1 week to 1 month, and the unsupported self-stabilization span interval is 10m to 20m.

[0062] Step S152, based on the advanced sequential pressure release theory, comprehensively draw the surrounding rock cross-section deformation characteristic curve and support characteristic curve, and combine the shaft longitudinal section deformation characteristic curve obtained by numerical simulation analysis of the shaft excavation process in step S142 to determine the timing of concrete lining support for the ultra-deep shaft wall. The advanced sequential pressure release theory technology and method is established based on the convergence constraint method theory. By analyzing the longitudinal section deformation curves of the shaft surrounding rock at different depths obtained in step S142, it is found that as the shaft depth increases, the deformation of the shaft surrounding rock gradually increases, and the surrounding rock deformation tends to be stable at a position 10m away from the shaft excavation working face. According to the modified Fenner formula, the surrounding rock cross-section deformation characteristic curve is drawn. Specifically, step S152 includes: Step S1521, draw the deformation characteristic curve of the surrounding rock cross section according to the modified Fenner formula, the formula is as follows: , in, To support resistance.

[0063] Step S1522, draw a concrete lining support characteristic curve according to the relationship between the support force and the structural stiffness, the formula is as follows: ; in, For the supporting force, is the structural stiffness, is the radial displacement of the support.

[0064] By comprehensively drawing the longitudinal section deformation characteristic curve, the surrounding rock cross-section deformation characteristic curve and the support characteristic curve, such as Figure 4 As shown, the timing of concrete lining of the ultra-deep shaft is determined. In this embodiment, the timing of concrete lining is when the radial displacement of the shaft surrounding rock reaches 17.8mm, and the concrete lining can be poured. The distance between the lining support and the working surface should be at least 5m, and should be less than the self-stabilizing height of the unsupported surrounding rock. Finally, it is determined that the distance between the lining support and the shaft excavation surface is 12m, with an interval of three operation cycles.

[0065] Step S153, comprehensively determine the thickness of the lining support of the ultra-deep shaft wall according to the thick-walled cylinder theory and the empirical method. Specifically, a graph of unsupported self-stabilization time / h-unsupported self-stabilization span / m is drawn according to the thick-walled cylinder theory and the empirical method, such as Figure 3 As shown, according to Figure 3 Determine the lining support thickness of the ultra-deep shaft wall by empirical method. In this embodiment, the shaft wall thickness is 0.8m~1.0m, which is obviously too large. By referring to the shaft wall support design at home and abroad and comprehensively judging according to the empirical method, the lining thickness of the ultra-deep shaft wall is corrected to 0.5m.

[0066] Step S160, determine the support parameters, and carry out energy release support and advance pressure relief blasting on the surrounding rock of the wellbore in combination with the rockburst tendency evaluation results at different depths. Energy release support and advance pressure relief blasting are adopted for the surrounding rock of the wellbore to actively control the stress state and stress distribution characteristics of the surrounding rock. Step S160 includes: Step S161, design support for the exposed surrounding rock section between the well wall and the working face by using a temporary support method in the form of anchor mesh spraying.

[0067] Step S162, by comprehensively adopting the RMR rock mass geomechanics classification method and the engineering analogy method, the support parameters are determined. The support parameters are designed in combination with the actual site engineering, and the anchor support parameters are checked using the surrounding rock shear slip theory.

[0068] Among them, the support parameters include: anchor rod diameter, length and spacing, anchor cable density, metal mesh material, size and grid shape, double reinforcement length, diameter and spacing, and tray specifications.

[0069] The support parameter design is shown in Table 8 and Table 9: Table 8 Support parameter design based on RMR classification

[0070] Table 9 Support parameter design based on engineering analogy method

[0071] Among them, the length of the anchor rod is determined according to Barton's empirical formula, which is as follows: , Wherein, B is the distance between the lining support and the shaft excavation surface, unit / meter; ESR is the excavation support ratio.

[0072] Based on the above analysis, a temporary support design diagram was drawn. Combined with the thickness of the loosened area of ​​the surrounding rock of the wellbore on site, the specifications of the anchor rod, tray, metal mesh and double reinforcement were finally determined.

[0073] like Figure 5 and Figure 6 As shown, in this embodiment, the length L of the anchor rod 1 is 2.25m, the spacing S×A is 1.0m×1.0m, and J energy-release anchor rod support is adopted. The tray specification is 120mm×120mm×8mm. The metal mesh 2 adopts 8# wire diamond galvanized metal mesh, and the double ribs 3 are welded by two parallel Φ8mm steel bars. The spacing S of the double ribs is 80mm, and the length L of the double ribs is 3m. The safety factor of the anchor rod support is checked using the surrounding rock shear slip theory, and the safety factor of the anchor rod support is 2.5, which meets the safety requirements. The specific support installation steps can be determined according to the actual operation of the staff, and the present invention does not limit them. The plan schematic diagram after the support installation is completed is as shown. Figure 5 and Figure 6 As shown, it will not be described again here.

[0074] Step S163, according to the rockburst tendency evaluation results at different depths, energy release support and advanced pressure relief blasting are used in the area where rockburst may occur to release the local high stress of the wellbore surrounding rock, thereby reducing the probability of rockburst in the wellbore surrounding rock. Specifically, according to the analysis of the rockburst tendency evaluation results at different depths in Table 6 in step S144, energy release support and advanced pressure relief blasting are used in the area where rockburst may occur, and horizontal and inclined blasting boreholes are arranged in the wellbore surrounding rock, and cutting grooves and cutting cracks are formed by blasting, thereby releasing the local high stress of the wellbore surrounding rock, thereby reducing the probability of rockburst in the wellbore surrounding rock.

[0075] It can be understood by those skilled in the art that the present invention provides a method for pre-pressure relief construction of ultra-deep vertical shafts in metal mines, which is mainly used for pressure relief construction of large-diameter ultra-deep vertical shafts with a depth of more than 1500m and prevention and control of ground pressure disasters. By adopting methods such as vertical shaft core recording, surrounding rock joint and fissure investigation, rock mechanics test, etc., the rock properties and physical and mechanical parameters of the surrounding rock of the shaft are obtained to achieve the purpose of transparent well construction and pre-warning; then the mechanical properties of the surrounding rock of the shaft are analyzed to obtain the distribution characteristics of the stress field of the surrounding rock excavation disturbance of the shaft; based on the theory of pre-sequential pressure relief, the timing and thickness of the concrete lining support of the shaft wall are determined, and a certain distance is maintained between the shaft wall lining and the shaft excavation working face, and the energy release support structure is used to bear the deformation pressure generated by the redistribution of the stress of the surrounding rock during shaft excavation, and the high stress accumulated in the rock mass is released by pre-pressure relief blasting, so as to actively regulate the stress state of the surrounding rock of the unlined section of the shaft, weaken the interaction between the surrounding rock of the shaft and the subsequent concrete lining of the shaft wall, and realize the pressure relief construction of ultra-deep vertical shafts.

[0076] Furthermore, the method for pre-decompression construction of ultra-deep vertical shafts in metal mines provided by the present invention is applicable to complex strata with deep high stress, strong compression and strong excavation disturbance. Through transparent analysis of vertical shaft strata, early warning of ground pressure disaster prevention and control, and the use of multiple means to gradually solve the construction safety problems existing in the ultra-deep vertical shaft construction process, the disaster hazards brought by the conventional construction methods of traditional vertical shafts are changed, the safety and efficiency of ultra-deep vertical shaft excavation and support construction, as well as the long-term stability of shaft construction and service period are guaranteed, so as to achieve the purpose of comprehensively improving shaft ground pressure.

[0077] So far, the technical solution of the present invention has been described in combination with the above multiple embodiments, but it is easy for those skilled in the art to understand that the protection scope of the present invention is not limited to these specific embodiments. Without departing from the technical principles of the present invention, those skilled in the art can split and combine the technical solutions in the above embodiments, and can also make equivalent changes or replacements to the relevant technical features. Any changes, equivalent replacements, improvements, etc. made within the technical concept and / or technical principles of the present invention will fall within the protection scope of the present invention.

Claims

1. A method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines, characterized in that: include: Establish an ultra-deep wellbore engineering disaster model; Conduct rock mechanics tests to determine basic rock strength parameters; According to the investigation of the joints and fissures of the surrounding rock of the wellbore and the basic strength parameters of the rock, the quality grade of the surrounding rock of the wellbore is divided and the mechanical parameters of the rock mass are determined; Excavate the shaft, analyze the mechanical properties of the surrounding rock of the shaft according to the rock mass mechanical parameters and use the elastic-plastic theory analysis and numerical simulation methods, and then judge the rock burst tendency of the surrounding rock of shafts at different depths; Determine the timing and thickness of concrete lining support for ultra-deep shafts; Determine the support parameters, and carry out energy release support and advance pressure relief blasting on the surrounding rock of the wellbore based on the rockburst tendency evaluation results at different depths.

2. The method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines according to claim 1 is characterized in that: The steps of establishing the ultra-deep wellbore engineering disaster model include: Using the drill cores from ultra-deep shaft engineering surveys, the bottom layer information of the cores is catalogued, and the rock mass quality is graded according to the core characteristics and the degree of development of joints and fissures, and an engineering disaster model of the ultra-deep shaft bedrock lithology and rock mass quality is established; Following the progress of ultra-deep shaft construction, investigate the joints and fissures of the surrounding rocks at different depths of the shaft, and compare the shaft joint and fissure investigation results with the stratigraphic information revealed by the engineering survey drilling core to revise / update the ultra-deep shaft engineering disaster model.

3. The method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines according to claim 1 is characterized in that: The steps of conducting rock mechanics tests and determining basic rock strength parameters include: Sampling the rock mass at different excavation depths of the ultra-deep shaft, processing the rock mass into standard rock samples, and conducting uniaxial compressive strength tests, Brazilian splitting tests and shear tests to determine the basic strength parameters of the rock; Among them, the basic strength parameters of rock include: the average density of rock samples , Uniaxial compressive strength of rock , rock tensile strength , elastic modulus E, cohesion c, Poisson's ratio μ and internal friction angle φ.

4. The method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines according to claim 3 is characterized in that: The steps of classifying the quality grade of the surrounding rock of the wellbore and determining the mechanical parameters of the rock mass according to the investigation of the joints and fissures of the surrounding rock of the wellbore and the basic strength parameters of the rock include: According to the joints and fissures of the surrounding rock of the ultra-deep vertical shaft and the basic strength parameters of the rock, the rock quality at different depths of the shaft is graded using the Barton rock quality index Q classification, rock geomechanics RMR classification and geological strength index GSI classification methods; Calculate according to the basic strength parameters of the rock and the grade classification of the rock mass quality at different depths of the wellbore to obtain the mechanical parameters of the rock mass at different depths; Among them, rock mass mechanical parameters include rock density , rock mass compressive strength , rock mass tensile strength , elastic modulus E, Poisson's ratio and rock mass shear strength coefficient .

5. The method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines according to claim 1 is characterized in that: The step of excavating a wellbore, analyzing the mechanical properties of the surrounding rock of the wellbore according to the rock mass mechanical parameters and using elastic-plastic theory analysis and numerical simulation methods, and then judging the rock burst tendency of the surrounding rock of the wellbore at different depths includes: After the wellbore is excavated, the surrounding rock stress is redistributed. The elastic-plastic theory analysis and numerical simulation methods are used to analyze the stress conditions of the wellbore cross-section surrounding rock under hydrostatic pressure and non-hydrostatic pressure conditions. According to the analysis results, the wellbore surrounding rock is divided into three parts: loose area, surrounding rock bearing area, and initial stress area. The numerical simulation method is used to analyze the spatial effect of the shaft excavation working face, simulate the shaft excavation process, obtain the shaft longitudinal section deformation characteristic curve, and use the elastic-plastic theory analytical method to analyze the interaction between the shaft surrounding rock and the shaft wall concrete lining under uniform stress and non-uniform stress conditions. Combined with the rock formation type determination chart, the potential damage type of the wellbore surrounding rock is determined; Based on the physical and mechanical parameters of rock, the rock burst tendency evaluation was obtained through comprehensive analysis and comparison of three methods: brittleness coefficient method, Barton method and stress intensity method.

6. The method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines according to claim 5 is characterized in that: The steps of using elastic-plastic theory analysis and numerical simulation methods to analyze the stress conditions of the surrounding rock in the cross section of the wellbore under hydrostatic pressure and non-hydrostatic pressure conditions respectively include: First, according to the formula , judge whether the surrounding rock of the wellbore exceeds the elastic limit and is in a plastic state, and divide the surrounding rock state into elastic state and plastic state; when the tangential stress of the surrounding rock of the wellbore When the following formula is satisfied, it is considered that plastic failure occurs in the surrounding rock of the wellbore: ， in, is the maximum horizontal principal stress; Then calculate the elastic analysis solution under the hydrostatic pressure state: the following elastic analysis solution of surrounding rock stress and displacement is obtained by polar coordinate system calculation. The specific formula is as follows: ， ， ， ， ， in, is the original rock stress, is the radial stress, is the tangential stress, is the shear stress, is the radial displacement, is the tangential displacement, is the shear modulus, is the lateral pressure coefficient, , is the wellbore radius, is the polar coordinate radius, is the angle in polar coordinates, is the passive reaction coefficient; Finally, numerical simulation method is used to calculate the analytical solution of plastic zone and stress distribution of wellbore surrounding rock under non-static pressure state.

7. The method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines according to claim 5 is characterized in that: The step of determining the timing and thickness of the ultra-deep shaft concrete lining support comprises: According to the rock mass quality classification of the shaft and the excavation size of the ultra-deep shaft, the unsupported self-stabilizing span and self-stabilizing time of the surrounding rock of the ultra-deep shaft are determined by the RMR stability diagram method; Based on the theory of advanced sequential pressure release, the deformation characteristic curve and support characteristic curve of the surrounding rock cross section are comprehensively drawn to determine the timing of concrete lining support for the ultra-deep shaft wall; The thickness of the lining support for ultra-deep shafts is determined comprehensively based on thick-walled cylinder theory and empirical method.

8. The method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines according to claim 7 is characterized in that: The step of comprehensively drawing the surrounding rock cross-section deformation characteristic curve and the support characteristic curve includes: The deformation characteristic curve of the surrounding rock cross section is drawn according to the modified Fenner formula, and the formula is as follows: ， in, is the support resistance, φ is the internal friction angle, for cohesion; The concrete lining support characteristic curve is drawn based on the relationship between the support force and the structural stiffness. The formula is as follows: ， in, For the supporting force, is the structural stiffness, is the radial displacement of the support.

9. The method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines according to claim 1, characterized in that: The step of determining support parameters and performing energy release support and advanced pressure relief blasting on the surrounding rock of the wellbore in combination with the rockburst tendency evaluation results at different depths includes: A temporary support method in the form of anchor mesh spraying is used to design support for the exposed surrounding rock section between the shaft wall and the working face; The support parameters are determined by comprehensively adopting the RMR rock mass geomechanics classification method and engineering analogy method; the support parameters include: anchor diameter, length and spacing, metal mesh material, size and mesh shape, double reinforcement length, diameter and spacing; According to the evaluation results of rockburst tendency at different depths, the advanced pressure relief blasting method is used in the area where rockburst may occur to release the local high stress of the wellbore surrounding rock and reduce the probability of rockburst in the wellbore surrounding rock.

10. The method for advanced pressure relief construction of ultra-deep vertical shaft in metal mines according to claim 4, characterized in that: The step of calculating according to the basic strength parameters of the rock and the grade classification of the rock mass quality at different depths of the wellbore to obtain the mechanical parameters of the rock mass at different depths includes: Uniaxial compressive strength of rock mass Calculation process: Using the Hoek-Brown strength criterion and according to the geological strength index GSI, firstly determine the rock mass characteristic constants s and a according to the following formula: ， , where D is the disturbance coefficient, ranging from 0 to 1; According to the rock mass characteristic constants s, a and the uniaxial compressive strength of rock , the uniaxial compressive strength of rock mass is calculated according to the following formula : ； Uniaxial tensile strength of rock mass Calculation process: First, according to the complete rock material constant , geological strength index GSI and disturbance coefficient D, and the empirical parameters of rock mass characteristics are calculated according to the following formula : , According to the uniaxial compressive strength of rock , Empirical parameters of rock mass characteristics And the rock mass characteristic constant s, the uniaxial tensile strength of the rock mass is calculated according to the following formula : ； Calculation process of rock elastic modulus Em: According to rock elastic modulus E, geological strength index GSI and disturbance coefficient D, the rock elastic modulus E is calculated according to the following formula: m : ； Poisson's ratio of rock mass Calculation process: According to the rock elastic modulus E, rock mass elastic modulus E m and Poisson's ratio μ, determine the rock mass Poisson's ratio : ； Rock mass shear strength Value and Value calculation process: First, according to the empirical parameters of rock mass characteristics And the rock mass characteristic constants s, a, the rock mass shear strength is calculated according to the following formula value: ， Among them, σ 3n = / , The upper limit of the stress limit between the Hoek-Brown criterion and the Mohr-Coulomb criterion; According to the uniaxial compressive strength of rock , rock mass characteristic constants s and a, empirical parameters of rock mass characteristics And the upper limit of stress limited by the relationship between the Hoek-Brown criterion and the Mohr-Coulomb criterion , calculated according to the following formula value: ； Finally, the rock mass compressive strength calculated according to the above steps is , rock mass tensile strength , elastic modulus E, Poisson's ratio and rock mass shear strength coefficient , combined with the rock mass location and rock density Draw a table of rock mass mechanics parameters.

Images