Zero-clear-distance construction method and system for multi-arch tunnel

Abstract

The invention relates to the technical field of tunnel construction, and discloses a zero-clear-distance construction method and system for a multi-arch tunnel. The method comprises the steps that construction area parameters are evaluated according to geological drilling data, surrounding rock stability indexes are established through multi-parameter fitting, and construction control parameters are obtained; excavating the right hole section by section according to the parameters, and obtaining an initial section by adopting a step method; a supporting structure is constructed for the initial section, and a supporting system is formed in a steel arch frame-spray mixing mode; a reserved groove is designed by taking a support system as a reference, and a standard space is obtained by controlling blasting; and the left hole is excavated, and an integral structure is formed through layered construction. According to the multi-arch tunnel zero-clear-distance construction method, the middle pilot tunnel construction link is omitted, left and right tunnel excavation is directly carried out, the construction efficiency is remarkably improved, and the engineering cost is saved.

Description

Technical Field

[0001] The present application relates to the technical field of tunnel construction, and in particular to a method and system for constructing a multi-arch tunnel with zero clearance. Background Art

[0002] A multi-arch tunnel is a common tunnel structure in geotechnical engineering, usually consisting of two single tunnels connected by a middle partition wall. The traditional construction method of a multi-arch tunnel is to first construct the middle guide tunnel, then the middle partition wall after the middle guide tunnel is completed, and finally the left and right tunnel bodies are excavated. This construction method requires strict control of blasting vibration during the middle guide tunnel stage to ensure construction safety; during the middle partition wall construction stage, it is necessary to tie steel bars and pour concrete in the narrow guide tunnel space; during the tunnel body excavation stage, it is necessary to control blasting parameters to avoid damaging the completed middle partition wall structure.

[0003] However, this traditional construction method has significant defects: due to the limited cross-sectional size of the middle guide tunnel, it is difficult for construction personnel and mechanical equipment to work efficiently in a small space, resulting in low efficiency in the construction of the middle partition wall; at the same time, the construction of the middle guide tunnel requires additional support works, which increases the consumption of engineering materials; in addition, due to too many construction processes, the construction period is often greatly extended. For example, a 26-meter-long multi-arch tunnel section requires a lot of manpower and material resources for the support of the middle guide tunnel using traditional construction methods, and the construction of the middle partition wall in a small space is inefficient, which seriously affects the construction progress. Summary of the invention

[0004] The present application provides a method and system for constructing a multi-arch tunnel with zero clearance, which is used to address the problems of limited guide tunnel space and low construction efficiency of middle partition walls in existing multi-arch tunnel construction. The application provides a method for constructing a multi-arch tunnel with zero clearance by eliminating the middle guide tunnel construction link and directly excavating the left and right tunnels, thereby significantly improving construction efficiency and saving engineering costs.

[0005] In the first aspect, the present application provides a method for constructing a continuous arch tunnel with zero clearance, and the method comprises: evaluating geological parameters of the construction area of ​​the continuous arch tunnel according to geological drilling data, establishing a surrounding rock stability index system through a multi-parameter fitting model, and obtaining a tunnel construction control parameter set; excavating the right tunnel in sections according to the tunnel construction control parameter set, controlling the excavation contour through a step method, and forming an initial section of the right tunnel; constructing a support structure based on the initial section of the right tunnel, and constructing a stable support system for the right tunnel by adopting a steel arch frame-spray-mix combined support method; using the stable support system for the right tunnel as a benchmark, designing a reserved groove for the partition wall in the excavation surface of the left tunnel, and forming a standardized reserved space through a controlled blasting method; excavating the main body of the left tunnel according to the standardized reserved space, and obtaining the overall structural system of the continuous arch tunnel through a layered construction process.

[0006] In a second aspect, the present application provides a zero-clearance construction system for a multi-arch tunnel, the multi-arch tunnel zero-clearance construction system comprising:

[0007] Establish a module to evaluate geological parameters of the construction area of ​​the double-arch tunnel based on geological drilling data, establish a surrounding rock stability index system through a multi-parameter fitting model, and obtain a set of tunnel construction control parameters;

[0008] An excavation module, used to excavate the right tunnel in sections according to the tunnel construction control parameter set, control the excavation profile by a step method, and form an initial section of the right tunnel;

[0009] A construction module is used to construct a support structure based on the initial section of the right tunnel, and to construct a stable support system for the right tunnel by adopting a steel arch frame-spray-mix combined support method;

[0010] A control module is used to design a reserved groove for the partition wall in the excavation surface of the left tunnel by using the stable support system of the right tunnel as a reference, and to form a standardized reserved space by controlled blasting;

[0011] The construction module is used to carry out the main excavation of the left tunnel according to the standardized reserved space, and obtain the overall structural system of the multi-arch tunnel through layered construction process.

[0012] The third aspect of the present invention provides a computer device, comprising: a memory and at least one processor, wherein the memory stores instructions; the at least one processor calls the instructions in the memory so that the computer device executes the above-mentioned zero-clearance construction method for a multi-arch tunnel.

[0013] A fourth aspect of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores instructions, which, when executed on a computer, enable the computer to execute the above-mentioned method for constructing a multi-arch tunnel with zero clearance.

[0014] In the technical solution provided in the present application, the zero-clearance construction method of the multi-arch tunnel establishes a surrounding rock stability index system through a multi-parameter fitting model, which can accurately evaluate the geological conditions of the construction area, provide a reliable parameter basis for subsequent construction, and avoid the problem of improper selection of support parameters due to inaccurate geological evaluation in traditional construction; when the step method is used to excavate the right tunnel, the over-excavation amount is significantly reduced by accurately controlling the excavation contour, ensuring the self-stabilization ability of the surrounding rock, and providing a regular construction surface for the subsequent support structure construction; the application of the steel arch frame-spray-mix combined support method gives full play to the synergistic effect of various support structures, forms a stable composite support system, and effectively controls the deformation of the surrounding rock; when designing the reserved groove for the middle partition wall in the excavation surface of the left tunnel, a standardized reserved space is formed by controlling the blasting method, avoiding the dilemma of construction in a narrow guide tunnel in traditional construction, and greatly improving the construction efficiency; finally, through the layered construction process, the effective connection between the left and right tunnels and the middle partition wall structure is achieved, forming a stable overall structural system of the multi-arch tunnel. Especially in the assessment of surrounding rock stability, the multi-parameter fitting model established a scientific evaluation system by comprehensively analyzing multiple parameters such as rock density, water content, compression coefficient, compressive strength, elastic modulus, Poisson's ratio, etc., making the selection of support parameters more accurate and avoiding the subjectivity in the traditional empirical method; at the same time, this method cancels the construction link of the middle guide tunnel and directly uses standardized reserved space for the construction of the middle partition wall, which not only saves engineering materials but also significantly shortens the construction period. In practical applications, this method can shorten the construction period of a 26-meter-long arch tunnel section by about one month and save construction costs of about 280,000 yuan, reflecting the significant advantages of this method in engineering practice. The connection of each process in the entire construction process is more compact, there is less interference between processes, and the construction quality is more guaranteed, providing a new efficient and economical method for the construction of arch tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0016] Figure 1 A schematic diagram of an embodiment of a method for constructing a double-arch tunnel with zero clearance in an embodiment of the present application;

[0017] Figure 2 This is a schematic diagram of an embodiment of a zero clearance construction system for a multi-arch tunnel in an embodiment of the present application;

[0018] Figure 3 It is a schematic block diagram of the structure of a computer device in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The embodiment of the present application provides a method and system for zero clearance construction of a multi-arch tunnel. The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described here can be implemented in an order other than that illustrated or described here. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0020] For ease of understanding, the specific process of the embodiment of the present application is described below. Figure 1 , an embodiment of the zero clearance construction method of the multi-arch tunnel in the embodiment of the present application includes:

[0021] Step S101, evaluating geological parameters of the construction area of ​​the double-arch tunnel according to geological drilling data, establishing a surrounding rock stability index system through a multi-parameter fitting model, and obtaining a tunnel construction control parameter set;

[0022] Step S102, excavating the right tunnel in sections according to the tunnel construction control parameter set, controlling the excavation profile by the step method, and forming the initial section of the right tunnel;

[0023] Step S103: construct a support structure based on the initial section of the right tunnel, and adopt a steel arch frame-spray-mix combined support method to build a stable support system for the right tunnel;

[0024] Step S104: using the stable support system of the right tunnel as a reference, designing a reserved groove for the partition wall in the excavation surface of the left tunnel, and forming a standardized reserved space by controlled blasting;

[0025] Step S105: excavate the main body of the left tunnel according to the standardized reserved space, and obtain the overall structural system of the multi-arch tunnel through layered construction technology.

[0026] It is understandable that the execution subject of the present application may be a zero clearance construction system for a multi-arch tunnel, or a terminal or a server, which is not specifically limited here. The present application embodiment is described by taking a server as the execution subject as an example.

[0027] Specifically, basic geological data are obtained through drilling sampling, including six key indicators: rock density, water content, compression coefficient, compressive strength, elastic modulus, and Poisson's ratio. In actual construction, the drilling points are arranged in a grid format, with a drilling point set every 100 meters in the longitudinal distance and a lateral spacing of 50 meters to form a regular exploration network. These raw data are discretized to generate a geological parameter distribution map, which reflects the spatial distribution law of geological parameters. The surrounding rock grade classification is based on the geological parameter distribution map, mainly considering three aspects: rock mass integrity, joint development degree, and groundwater conditions. The surrounding rock partition data is determined by a scoring system. For example, the rock mass integrity is scored from 0 to 100 points, with 90 points or more for complete rock mass, 60-90 points for relatively complete rock mass, 30-60 points for broken rock mass, and 30 points or less for extremely broken rock mass. These partition data are input into the surrounding rock stability evaluation matrix. Each element in the matrix represents the weight coefficient of different parameters, and the surrounding rock stability index is obtained through multi-parameter fitting calculation.

[0028] The right tunnel excavation stage strictly follows the guidance of the tunnel construction control parameter set. The step method excavation divides the section into two steps, the upper step height accounts for 60% of the total height, and the lower step accounts for 40%. The drilling and blasting parameters are determined according to the right tunnel section zoning diagram. The arrangement spacing of the smooth blasting holes is 50 cm, and the charge is controlled at 0.5 kg / m to ensure that a flat rock wall is formed after blasting. The support structure construction adopts a steel arch frame-spraying and mixing combined support method. The specification of the I-beam arch frame is 25a and the spacing is 60 cm. The sprayed concrete strength grade is C25, the total thickness is 25 cm, and it is sprayed in three layers: the first layer is 8 cm, the second layer is 8 cm, and the third layer is 9 cm. The anchor rod adopts a hollow anchor rod with a diameter of 25 mm, a length of 4 meters, a spacing of 1.2 meters × 1.2 meters, and an anchoring force of not less than 120 kN.

[0029] The construction of the reserved groove for the middle partition wall is the innovation of this method. The position of the reserved groove is calibrated by the coordinates of the benchmark control points determined by the preliminary measurement. The groove width is 50 cm and the depth is consistent with the design thickness of the middle partition wall. The controlled blasting adopts the micro-difference blasting technology. The charge is reduced by 30% compared with the ordinary blasting, and the hole spacing is reduced to 30 cm to ensure the excavation accuracy. The left hole excavation adopts the same step method as the right hole, but special attention should be paid to the control on the side close to the middle partition wall. The initial support parameters are the same as the right hole, but φ32 steel mesh is added at the connection of the middle partition wall for reinforcement. When constructing the middle partition wall, the steel mesh is arranged first. The main reinforcement adopts a double-layer arrangement with a diameter of 32 mm and a spacing of 20 cm. The stirrup diameter is 12 mm and the spacing is 30 cm. The concrete strength grade is C35, and it is cast in sections, with a height of 3 meters per section.

[0030] For example, during the entire construction process, the average rock compressive strength obtained from geological exploration for a 26-meter-long multi-arch tunnel section is 45 MPa, and the degree of joint development is moderate. Based on these parameters, the surrounding rock is determined to be Class III, and the corresponding support parameters include: steel arch spacing of 60 cm, and total thickness of shotcrete of 25 cm. In actual construction, the excavation section of the right tunnel is 12 meters wide and 11 meters high, with an upper step of 6.6 meters high and a lower step of 4.4 meters high. The reserved groove of the middle partition wall is 50 cm wide and 60 cm deep. Precision blasting technology is used, and the blasting vibration speed is controlled below 2 cm / s. After the left tunnel is excavated, the middle partition wall is constructed, using a double-layer steel mesh, a main reinforcement diameter of 32 mm, a stirrup diameter of 12 mm, and a concrete strength grade of C35 to ensure the integrity of the structure. This construction method directly constructs the left and right tunnels by eliminating the traditional middle guide tunnel construction link, and reserves space for the middle partition wall construction when the left tunnel is excavated. While ensuring the construction quality, it reduces the construction process and saves construction time. Each link of data processing is based on measured data, forming a construction control system.

[0031] In the embodiment of the present application, the zero-clearance construction method of the multi-arch tunnel establishes a surrounding rock stability index system through a multi-parameter fitting model, which can accurately evaluate the geological conditions of the construction area, provide a reliable parameter basis for subsequent construction, and avoid the problem of improper support parameter selection caused by inaccurate geological assessment in traditional construction; when the step method is used to excavate the right tunnel, the over-excavation amount is significantly reduced by accurately controlling the excavation contour, ensuring the self-stabilization ability of the surrounding rock, and providing a regular construction surface for the subsequent support structure construction; the application of the steel arch frame-spray-mix combined support method gives full play to the synergistic effect of various support structures, forms a stable composite support system, and effectively controls the deformation of the surrounding rock; when designing the reserved groove for the middle partition wall in the excavation surface of the left tunnel, a standardized reserved space is formed by controlling the blasting method, avoiding the dilemma of construction in a narrow guide tunnel in traditional construction, and greatly improving the construction efficiency; finally, through the layered construction process, the effective connection between the left and right tunnels and the middle partition wall structure is achieved, forming a stable overall structural system of the multi-arch tunnel. Especially in the assessment of surrounding rock stability, the multi-parameter fitting model established a scientific evaluation system by comprehensively analyzing multiple parameters such as rock density, water content, compression coefficient, compressive strength, elastic modulus, Poisson's ratio, etc., making the selection of support parameters more accurate and avoiding the subjectivity in the traditional empirical method; at the same time, this method cancels the construction link of the middle guide tunnel and directly uses standardized reserved space for the construction of the middle partition wall, which not only saves engineering materials but also significantly shortens the construction period. In practical applications, this method can shorten the construction period of a 26-meter-long arch tunnel section by about one month and save construction costs of about 280,000 yuan, reflecting the significant advantages of this method in engineering practice. The connection of each process in the entire construction process is more compact, there is less interference between processes, and the construction quality is more guaranteed, providing a new efficient and economical method for the construction of arch tunnels.

[0032] In a specific embodiment, the process of executing step S101 may specifically include the following steps:

[0033] (1) Obtain basic geological data on rock and soil density, water content, compression coefficient, compressive strength, elastic modulus, and Poisson's ratio through drilling sampling, and establish a geological parameter database;

[0034] (2) Discretize the data in the geological parameter database to generate a geological parameter distribution map;

[0035] (3) Based on the geological parameter distribution map, the surrounding rock grade is classified to obtain the surrounding rock zoning data;

[0036] (4) Establish a surrounding rock stability evaluation matrix using surrounding rock zoning data;

[0037] (5) Input the surrounding rock stability evaluation matrix into the multi-parameter fitting model to generate the surrounding rock stability index;

[0038] (6) According to the surrounding rock stability index, the key technical parameters of support parameters, excavation step distance, middle partition wall thickness, lining thickness, anchor length, and anchor spacing are determined to form a set of tunnel construction control parameters.

[0039] Specifically, the drilling sampling points are arranged in a grid format, with a drilling point set every 100 meters in the longitudinal direction and a horizontal spacing of 50 meters. The drilling depth needs to reach 20 meters below the tunnel excavation surface to ensure the integrity of the collected data. When obtaining the rock and soil density index through drilling, a cylindrical core sample with a diameter of 10 cm is taken, weighed and divided by the volume to obtain the density value. The moisture content is determined by the drying method. The sample is dried at 105°C for 24 hours, and the ratio of water loss weight to dry weight is calculated. The compression coefficient is obtained through a consolidation test, and the compression deformation of the sample is measured at different pressure levels. The compressive strength is determined by a rock pressure testing machine, and the core sample is processed into a cylinder with a height-to-diameter ratio of 2:1 for a uniaxial compression test. The elastic modulus and Poisson's ratio are obtained by measuring the axial deformation and lateral deformation of the rock sample during the force process through strain gauges. When the collected geological data is discretized, the continuous geological parameter values ​​are first discretized into several intervals. Taking rock and soil density as an example, 2.0-3.0g / cm 3 The range of is divided into 10 equally spaced intervals. For the compression coefficient, the range of 0.1-1.0MPa-1 is also divided into 10 intervals. The compressive strength is divided into intervals of 20MPa. This discretized data is convenient for establishing a geological parameter distribution map, which uses contour lines to show the spatial distribution law of each parameter.

[0040] The surrounding rock grade classification is based on the distribution map of geological parameters, mainly considering three aspects: hardness coefficient, integrity index, and weathering degree. The hardness coefficient is determined according to the compressive strength. Hard rock is greater than 50MPa, medium-hard rock is 15-50MPa, and soft rock is less than 15MPa. The integrity index is determined by the development degree of joints and fissures. The number of cracks per meter of core is less than 3 for complete, 3-10 for relatively complete, 10-20 for relatively broken, and more than 20 for broken. The degree of weathering is determined according to the color of the rock surface and the degree of change in mineral composition. Combining these indicators, the surrounding rock is divided into grades I-VI to form surrounding rock zoning data. The surrounding rock stability evaluation matrix structure is a 6×6 matrix, the rows of the matrix represent different evaluation indicators, and the columns represent the weight coefficients of each indicator. The evaluation indicators include: rock strength, joint development, groundwater development, rock structure, weathering degree, and initial ground stress state. The weight coefficient of each indicator is determined by the hierarchical analysis method, considering the influence of each indicator on the stability of the surrounding rock.

[0041] After the evaluation matrix is ​​input into the multi-parameter fitting model, the principal component analysis method is used to extract the main influencing factors. A correlation threshold is set in the model. When the correlation coefficient between two parameters is greater than 0.8, the parameter with a more significant influence is selected. After eigenvalue decomposition and eigenvector calculation, the surrounding rock stability index is obtained, and the index value range is between 0-100. When determining the construction parameters according to the surrounding rock stability index, the hierarchical correspondence principle is adopted. When the stability index is greater than 80, the support parameters are selected: I-beam support spacing of 1.0 meters and shotcrete thickness of 15 centimeters. When the stability index is between 60-80: the support spacing is reduced to 0.8 meters, and the shotcrete thickness is increased to 20 centimeters. When the stability index is less than 60: the support spacing is further reduced to 0.6 meters, and the shotcrete thickness is increased to 25 centimeters. The excavation step decreases with the decrease of the stability index, gradually decreasing from 2.0 meters to 1.0 meters. The thickness of the middle partition wall is determined according to the stability index and the tunnel span, generally 60-80 centimeters. The thickness of the lining also varies with the stability index, ranging from 30 to 50 cm. The length and spacing of the anchors are also adjusted accordingly, ranging from 3 to 6 meters in length and 0.8 to 1.5 meters in spacing.

[0042] For example, the original data obtained through drilling show that the compressive strength of the surrounding rock of this section of the tunnel is 35MPa, the number of joints per meter of the core is 8, and the groundwater is moderately developed. After discretization, the integrity index of this section of the surrounding rock is 65 points, corresponding to a relatively complete rock mass. Entering these data into the evaluation matrix, the surrounding rock stability index is calculated to be 75, which belongs to medium stability surrounding rock. Based on this, the construction parameters are determined: I-beam support spacing is 0.8 meters, shotcrete thickness is 20 centimeters, excavation step distance is 1.5 meters, middle partition wall thickness is 70 centimeters, lining thickness is 40 centimeters, anchor length is 4 meters, and spacing is 1.2 meters.

[0043] In a specific embodiment, the process of executing step S102 may specifically include the following steps:

[0044] (1) Generate the right tunnel section partition map based on the tunnel construction control parameter set and mark the upper and lower step boundary lines;

[0045] (2) Arrange the drilling and blasting hole network based on the right hole section zoning diagram and form a drilling and blasting parameter table;

[0046] (3) Input the drilling and blasting parameter table into the smooth blasting device to generate blasting control data;

[0047] (4) Excavate the upper step according to the blasting control data to obtain the upper excavation contour;

[0048] (5) Excavate the lower bench according to the blasting control data to form the lower excavation contour;

[0049] (6) The upper excavation contour and the lower excavation contour are trimmed to form the initial section of the right tunnel.

[0050] Specifically, in the right tunnel excavation stage, the section partition map is first generated according to the tunnel construction control parameter set. The generation process of the partition map is to divide the tunnel cross section into upper and lower steps according to the excavation order, with the upper step height accounting for 60% of the total height and the lower step accounting for 40%. When calibrating the dividing line, the center point of the tunnel is used as the reference, and the horizontal dividing line is drawn at the position of 60% of the total height upwards. The line divides the section into upper and lower areas. The layout of the drilling and blasting hole network is based on the right tunnel section partition map, and the drilling holes are arranged on the partition map according to the characteristics of different areas. The peripheral holes adopt the smooth blasting technology, the hole spacing is controlled at 50 cm, and the hole depth is 4 meters. The slot holes are arranged in the center of the excavation surface, using wedge-shaped slots, and the slot holes are arranged in a V shape with a hole spacing of 80 cm. The auxiliary holes are arranged between the slot holes and the peripheral holes, with a hole spacing of 70 cm. According to the arrangement of the drilling holes, a drilling and blasting parameter table is compiled, which records the specific location coordinates, hole depth, charge amount, and number of detonator sections of each blasting hole.

[0051] After the drilling and blasting parameter table is input into the smooth blasting device, the device calculates the precise charge of each blasting hole according to the input parameters. The charge of the peripheral smooth blasting hole is 0.4-0.6 kg / m, and the charge structure adopts interval charging. The charge of the slot hole is 1.0-1.2 kg / m, and continuous charging is adopted. The charge of the auxiliary hole is 0.8-1.0 kg / m, and continuous charging is also adopted. The blasting control data includes specific parameters such as charge, detonation sequence, and micro-difference interval time. When excavating the upper step, blasting is carried out according to the detonation sequence of the blasting control data. The slot hole is detonated first, with a micro-difference time of 25 milliseconds, followed by the auxiliary hole, with an interval of 50 milliseconds, and finally the peripheral hole, with an interval of 75 milliseconds. This detonation sequence ensures the flatness of the excavation profile. The over-excavation amount is strictly controlled during the excavation process, and the over-excavation of the upper excavation profile is controlled within 10 cm.

[0052] The lower step excavation uses the same blasting control parameters as the upper step, but the charge is appropriately reduced due to fewer constraints on the lower step. The control of the lower excavation contour is more critical because it will affect the construction quality of the subsequent invert. Measurements are taken immediately after blasting to ensure the accuracy of the lower excavation contour. The upper excavation contour is connected and trimmed with the lower excavation contour. Loose rocks are cleaned mechanically and local over-excavation or under-excavation areas are trimmed. After the contour trimming is completed, cross-section measurements are taken to ensure that the deviation between the excavation contour and the design contour is controlled within the allowable range, thereby forming a regular initial section of the right hole.

[0053] Take the excavation of the right tunnel of a multi-arch tunnel as an example: the tunnel excavation section is 11 meters high and 12 meters wide. According to the 60% ratio, the upper step height is 6.6 meters and the lower step height is 4.4 meters. 80 smooth blasting holes are arranged in the periphery, 15 slot holes are arranged in the slot area, and 45 auxiliary holes are arranged in the auxiliary area. When charging, the peripheral holes are charged at intervals, the diameter of the drug roll is 32 mm, the charge per meter hole is 0.5 kg, and the charge length is 3.5 meters. The slot holes are charged continuously, with a charge of 1.1 kg per meter hole and a charge length of 3.8 meters. The charge of the auxiliary hole is 0.9 kg / m, and the charge length is 3.6 meters. After blasting, the total station measurement found that the maximum deviation between the excavation contour line and the design contour line was 8 cm, which was within the allowable deviation range. After mechanical trimming, a standard initial section of the right tunnel was formed.

[0054] In a specific embodiment, the process of executing step S103 may specifically include the following steps:

[0055] (1) Generate an I-beam arch processing drawing based on the outline dimensions of the initial section of the right tunnel and make an I-beam support skeleton;

[0056] (2) Install the I-beam support frame at the initial section of the right tunnel according to the preset spacing to form a primary support frame;

[0057] (3) spraying concrete on the primary support frame through a layered spraying process to generate a foundation support layer;

[0058] (4) Systematic anchoring is performed on the foundation support layer according to the anchor rod arrangement diagram to form a composite support structure;

[0059] (5) Conduct strength testing and analysis on the composite support structure to generate support quality data;

[0060] (6) Based on the support quality data, reinforced concrete secondary lining is carried out to construct a stable support system for the right tunnel.

[0061] Specifically, the first step in the construction of the support structure is to generate an I-beam arch frame processing drawing based on the outline dimensions of the initial section of the right tunnel. The selection of the I-beam arch frame is based on the tunnel span and surrounding rock conditions. For a section with a span of 12 meters, a 25a I-beam is selected. The drawing of the processing drawing needs to take into account the overall shape of the arch frame, including the arch, side wall and reserved deformation. The reserved deformation of the arch frame is 1% of the design height of the arch, and the pre-arch of the top arch is 1 / 100 of the span. The I-beam support skeleton consists of the main arch frame, transverse connectors, and longitudinal connectors. The main arch frame is 60 cm apart. The transverse connectors use No. 16 channel steel and the longitudinal connectors use No. 14 I angle steel. When installing the I-beam support skeleton, the section is firstly laid out, and the arch frame installation position is marked every 60 cm on the excavation contour line. Before the arch frame is in place, the positioning steel bars are set at the predetermined position. Each positioning steel bar is 80 cm long and exposed 30 cm. The I-beam support frame is installed in sections, first installing the arch section, then installing the side wall sections on both sides, and each section is connected with M20 high-strength bolts. During the installation process, theodolite is used for measurement and correction to ensure that the plane position and elevation of the arch frame meet the design requirements. After the arch frame is in place, the transverse connectors and longitudinal connectors are immediately welded to form an overall primary support frame.

[0062] The primary support frame is sprayed with concrete using the layered shotcrete process. The concrete strength grade is C25, the water-cement ratio is controlled at 0.4-0.45, and 5% of the quick-setting agent is added. The spraying is carried out in three layers: the first layer is 8 cm thick and mainly fills the gap behind the arch frame; the second layer is 8 cm thick and is used to lay the steel mesh. The steel mesh is made of Double layer, overlap length not less than 30 cm; the third layer thickness is 9 cm, forming the foundation support layer. The interval between each layer of spraying is not less than 4 hours to ensure that the previous layer has a certain strength. During the system anchoring construction, the anchor position is marked on the foundation support layer according to the anchor arrangement diagram. Hollow grouting anchor rods are 4 meters long, 1.2 meters x 1.2 meters apart, and arranged in a plum blossom shape. The borehole diameter is 40 mm, and the inclination is 15° upward. Grouting is carried out after the anchor rod is installed. The grouting pressure is 0.3-0.5MPa. The grouting material is cement mortar with a water-cement ratio of 0.45. The grouting volume of each anchor rod is about 8-10 liters. After the grouting material is solidified, the anchor rod tension test is carried out. The anchoring force requirement is not less than 120kN.

[0063] The strength test of the composite support structure includes concrete strength test and overall stability test. The concrete strength is tested by the rebound method, with 3 sections measured every 10 meters and 10 points measured on each section. Convergence measuring points and stress monitoring points are installed at the same time, with one section of convergence measuring points every 10 meters and 5 measuring points on each section. By analyzing the test data, a support quality data report is generated, which includes concrete strength value, surrounding rock deformation value, and support structure stress value. Before the secondary lining construction, the support quality data is analyzed to determine the lining parameters. The lining adopts reinforced concrete structure, concrete strength grade C30, and lining thickness 50 cm. The main reinforcement adopts Double-layer layout, structural reinforcement A hydraulic lining trolley is used for construction, with each pouring length of 12 meters. The concrete strength must reach 75% of the design strength before the trolley moves. After the lining is completed, the waterproof layer is constructed to form a stable right tunnel support system.

[0064] For example: the right tunnel section of a multi-arch tunnel is 12 meters wide and 11 meters high, and the surrounding rock is Grade III. The I-beam support frame adopts 25a type with a spacing of 60 cm. The total thickness of the initial support concrete spraying is 25 cm. After the rebound method test, the 28-day strength reaches 31.5MPa. The anchor rod adopts Hollow anchor rods, 4 meters long, 1.2 meters x 1.2 meters apart, the average anchoring force test result is 135kN. The maximum deformation value of the convergence observation is 32 mm, which tends to be stable after 28 days. Based on these monitoring data, the secondary lining thickness is determined to be 50 cm, the concrete strength grade is C30, and a stable support system for the right tunnel is formed.

[0065] In a specific embodiment, the process of executing step S104 may specifically include the following steps:

[0066] (1) Extract the coordinates of the benchmark control points from the right tunnel stability support system and generate the positioning parameters of the left tunnel;

[0067] (2) The axis position of the middle partition wall is calibrated by the left hole positioning parameters to form a reserved groove boundary map;

[0068] (3) Arrange the controlled blasting holes according to the reserved slot boundary map and generate an accurate blasting grid;

[0069] (4) Design a delayed detonation sequence according to the precise blasting grid to form a blasting control plan;

[0070] (5) Perform smooth blasting based on the blasting control plan to obtain the initial contour of the reserved groove;

[0071] (6) Mechanically trim the initial contour of the reserved groove to form a standardized reserved space.

[0072] Specifically, the construction of the reserved groove for the middle partition wall first extracts the coordinates of the benchmark control points from the stable support system of the right tunnel. A total station is used to set a control point every 5 meters on the arch of the right tunnel and a control point every 3 meters on the side wall. The three-dimensional coordinates of each control point are measured and recorded to form a coordinate data set. These coordinate points are connected to form the contour line of the right tunnel, and the positioning parameters of the left tunnel are generated in combination with the design axis of the tunnel. The positioning parameters of the left tunnel include the coordinates of the axis of the left tunnel, the design section size, and the reserved deformation. The axis of the middle partition wall is calibrated according to the positioning parameters of the left tunnel, and the axis of the middle partition wall is located at the center between the left and right tunnels. The drawing of the reserved groove boundary map needs to take into account the design thickness and construction error of the middle partition wall. The groove width is designed to be the thickness of the middle partition wall plus a 20 cm construction allowance. The reserved groove boundary map includes key dimensions such as the groove bottom elevation, side wall inclination, and groove depth. The groove bottom elevation is consistent with the tunnel design floor elevation, the side wall is set vertically, and the groove depth is determined according to the height of the middle partition wall.

[0073] After the reserved groove boundary map is completed, the arrangement of the controlled blasting holes is carried out. A smooth blasting hole is arranged every 30 cm on the outline of the reserved groove, with a hole depth of 4 meters and an inclination parallel to the side wall of the reserved groove. Auxiliary holes are arranged inside with a hole spacing of 60 cm to form a precise blasting grid. The blasting grid divides the entire reserved groove area into several small units, and the drilling position, depth, and charge are marked in each unit. The design of the delayed detonation sequence is based on the precise blasting grid and adopts a row-by-row detonation method. The blasting area is divided into multiple detonation zones, and the blasting holes in each zone are detonated in order from the center to the sides. The detonation time interval between adjacent blasting holes is 25 milliseconds, and the detonation interval between adjacent areas is 50 milliseconds. The blasting control plan records in detail the number of detonation sections, charge structure, and detonation time of each blasting hole.

[0074] During smooth blasting construction, directional charging technology is used in the peripheral smooth blasting holes, the charging amount is controlled at 0.3-0.4 kg / m, and the charging structure is interval charging. Special spacers are used for charging intervals, and the interval length is 20 cm. The charging amount of the internal auxiliary holes is 0.6-0.8 kg / m, and continuous charging is used. The initial contour of the reserved groove formed after blasting basically meets the design requirements, and the over-excavation is controlled within 10 cm. The contour of the reserved groove is trimmed mechanically, using a breaker and a pneumatic pick to clean up loose rocks and trim local over-excavation or under-excavation areas. During the trimming process, special attention is paid to protecting the completed right hole support structure to avoid vibration damage. After the trimming is completed, cross-section measurement is carried out to ensure that the width, depth, flatness and other indicators of the reserved groove meet the design requirements to form a standardized reserved space.

[0075] For example, when constructing the reserved groove of the middle partition wall of a multi-arch tunnel, the design thickness of the middle partition wall is 60 cm, the width of the reserved groove is 80 cm, and the depth is 11 meters. 75 smooth blasting holes are arranged on the outline of the reserved groove, with a hole spacing of 30 cm, and 35 auxiliary holes are arranged inside. The charge of the smooth blasting hole is 0.35 kg / m, and a 20 cm long spacer is used for interval charging. The MS8 series millisecond detonator is used for blasting, and the interval between adjacent holes is 25 milliseconds, which is divided into 5 detonation areas. After blasting, it was measured that the maximum deviation between the outline of the reserved groove and the design line was 8 cm. After mechanical trimming, it met the requirements of standardized reserved space. This precisely controlled construction method ensures the standardization of the construction space of the middle partition wall and creates good conditions for subsequent construction.

[0076] In a specific embodiment, the process of executing step S105 may specifically include the following steps:

[0077] (1) Generate a left tunnel excavation flow chart based on the standardized reserved space to form a construction sequence plan;

[0078] (2) Carry out step-by-step excavation through the construction sequence plan to obtain the basic outline of the left tunnel;

[0079] (3) The support structure is constructed for the basic outline of the left tunnel according to the support parameters of the right tunnel to generate the support system of the left tunnel;

[0080] (4) Arrange the middle partition wall steel mesh in the standardized reserved space to form a skeleton structure;

[0081] (5) Connect the skeleton structure with the left tunnel support system to construct the middle partition wall structure;

[0082] (6) The middle partition wall structure is connected to the right tunnel stability support system through waterproof materials to obtain the overall structural system of the multi-arch tunnel.

[0083] Specifically, the left tunnel section is divided into upper and lower steps at a ratio of 60% and 40%. Considering the location of the standardized reserved space, the excavation sequence is advanced from the side away from the reserved space to the reserved space. The construction sequence plan includes specific contents such as excavation footage, support timing, and construction process connection. The footage of each cycle is determined according to the surrounding rock level and is generally controlled at about 2 meters. The stepped excavation is carried out strictly in accordance with the construction sequence plan. The upper step excavation adopts smooth blasting technology, the blasting hole spacing is 50 cm, and the charge is 0.4 kg / m. When excavating the lower step, due to the constraints of the upper step support structure, the blasting parameters are adjusted accordingly, and the charge of the surrounding holes is reduced to 0.3 kg / m. During the excavation process, pay close attention to the status of the constructed standardized reserved space and monitor the deformation of the reserved space in real time. The formation of the basic outline of the left tunnel requires precise control of the over-excavation, especially the contour line close to the reserved space.

[0084] The construction of the left tunnel support structure adopts the same support parameters as the right tunnel to ensure the symmetry of the structural force. The spacing of the I-beam support frame is 60 cm, and the 25a model is adopted. The shotcrete is constructed in three layers with a total thickness of 25 cm, 8 cm in the first layer, 8 cm in the second layer, and 9 cm in the third layer. The No. 14 I-angle steel is used to connect the steel brackets to form an overall force system. The middle partition wall connection steel bars are reserved on the support structure close to the reserved space to prepare for the subsequent structural connection. The layout of the middle partition wall steel mesh is the key link in the entire construction process. A double-layer steel mesh is laid in the standardized reserved space. The main reinforcement is 32 mm in diameter and 20 cm in spacing. The stirrups are 12 mm in diameter and 30 cm in spacing. The steel mesh size is strictly processed according to the requirements of the design drawings to ensure accurate geometric dimensions. Reinforcement bars are set at the connection between the middle partition wall and the arch wall to ensure the structural strength of the joint.

[0085] The connection between the skeleton structure and the left tunnel support system is welded. First, clean the connection surface to ensure the welding quality. The main reinforcement is overlapped and welded, and the overlap length is not less than 35 times the diameter of the steel bar. The connection points between the stirrups and the main reinforcement are all fully welded, and the weld length is not less than 10 times the diameter of the stirrups. During the connection process, attention should be paid to controlling welding deformation to ensure the integrity of the structure. The last process is the construction of the waterproof layer and the structural connection. Apply waterproof paint on both sides of the middle partition wall with a thickness of 2 mm. Then lay the waterproof membrane with an overlap width of not less than 10 cm. The waterproof layer extends to 50 cm on both sides of the cave wall to ensure the overall waterproof performance of the structure. The concrete pouring of the middle partition wall is constructed in sections, with a height of 3 meters for each section and a concrete strength grade of C35. An inserted vibrator is used for compaction during pouring.

[0086] For example, during the construction of a multi-arch tunnel, the left tunnel section is 12 meters wide and 11 meters high, the upper step is 6.6 meters high, and the lower step is 4.4 meters high. The excavation cycle advance is 2 meters, and 80 smooth blasting holes and 45 auxiliary holes are used in each cycle. The support structure uses 25a I-beams with a spacing of 60 cm, shotcrete C25, and a total thickness of 25 cm. The steel mesh of the middle partition wall adopts a double-layer arrangement, with a main reinforcement diameter of 32 mm and a spacing of 20 cm, and a stirrup diameter of 12 mm and a spacing of 30 cm. The concrete strength grade of the middle partition wall is C35, and it is poured in 6 sections. Through this refined construction process, a multi-arch tunnel structure system with stable structure and good integrity is formed.

[0087] In a specific embodiment, the process of executing step S106 may specifically include the following steps:

[0088] (1) Position and measure the skeleton structure and generate a connection point coordinate table;

[0089] (2) Determine the main reinforcement connection position based on the connection point coordinate table and form a connection layout diagram;

[0090] (3) Arrange shear reinforcement according to the connection layout diagram to obtain a load-bearing skeleton;

[0091] (4) Weld the connection points of the load-bearing skeleton and the left tunnel support system to form an overall frame;

[0092] (5) Tie horizontal distribution bars on the overall frame to form a reinforcement grid;

[0093] (6) The reinforcement grid is cast in sections to construct the middle partition wall structure.

[0094] Specifically, a total station is used to arrange measurement control points every 1 meter in the reserved space, and the coordinates of the control points are measured relative to the left and right tunnel axes. A cross mark is set at each control point to mark the longitudinal positioning line and the transverse connection line. The connection point coordinate table contains the three-dimensional coordinates and relative elevation of each control point, which serves as a reference for subsequent construction. The main reinforcement connection position is determined based on the connection point coordinate table. The main reinforcement uses steel bars with a diameter of 32 mm, and one is arranged every 20 cm in the longitudinal direction. According to the measured coordinate points, the connection position of the main reinforcement and the left and right tunnel support structures is calibrated to form a connection layout diagram. The specific position, connection method, and lap length of each connection point are marked on the layout diagram, and the bending angle and bending position of the steel bar are also marked.

[0095] Arrange the shear reinforcement according to the connection layout diagram. The shear reinforcement uses 12 mm diameter steel bars with a spacing of 30 cm and is arranged in a plum blossom shape. Double-sided welding is used at the intersection of the shear reinforcement and the main reinforcement, and the weld length is not less than 6 times the diameter of the reinforcement. At the connection between the middle partition wall and the arch wall, a densification area is set, and the spacing of the shear reinforcement is reduced to 20 cm to form a load-bearing skeleton. When connecting the load-bearing skeleton to the left hole support system, use E50 type welding rods with a welding current of 280-320 amperes. The connection point welding adopts a symmetrical welding method, first spot welding is performed in the middle to fix it, and then full welding is performed in sections. The weld is required to be full, uniform, and free of cracks and pores. After welding is completed, the weld is polished to ensure a smooth surface.

[0096] The horizontal distribution reinforcement is tied on the overall frame. The horizontal distribution reinforcement is made of 16 mm diameter steel bars with a spacing of 25 cm. The intersection of the distribution reinforcement and the main reinforcement is double-tied with a special binding wire with a diameter of 2 mm. In order to ensure the overall rigidity of the skeleton, a layer of protective reinforcement is added on the outside of the horizontal distribution reinforcement to form a reinforcement grid. When the reinforcement grid is poured in sections, the height of each section is controlled at 3 meters, the concrete strength grade is C35, and the water-cement ratio is 0.45. During the pouring process, an inserted vibrator is used for compaction, and the vibration time is controlled at 30-40 seconds. To prevent concrete segregation, the material height does not exceed 2 meters. During the pouring process, measurement and monitoring are carried out simultaneously to observe the deformation of the structure in real time. After the pouring is completed, the concrete is moisturized and maintained for no less than 14 days to form a stable intermediate partition wall structure.

[0097] For example: During the construction of the middle partition wall of a multi-arch tunnel, 22 measurement control points were arranged in the reserved space to form a connection point coordinate table. According to the coordinate table, 110 main bars were arranged, with a single main bar length of 11.2 meters and a lap length of 1.12 meters at the connection. A total of 330 shear steel bars were arranged, and they were densely arranged within 20 cm of the arch wall connection. A total of 660 connection points were completed in the welding process, and the length of each weld was not less than 72 mm. 45 layers of horizontal distribution bars were laid, each layer was 12 meters long. Concrete pouring was completed in 4 sections, each section was 3 meters high, and the total volume was 156 cubic meters. By strictly controlling the construction quality of each process, a structurally reliable middle partition wall system was formed.

[0098] The above describes the zero clearance construction method of the double arch tunnel in the embodiment of the present application. The following describes the zero clearance construction system of the double arch tunnel in the embodiment of the present application. Figure 2 In the embodiment of the present application, an embodiment of the zero clearance construction system of the multi-arch tunnel includes:

[0099] Establish a module to evaluate geological parameters of the construction area of ​​the double-arch tunnel based on geological drilling data, establish a surrounding rock stability index system through a multi-parameter fitting model, and obtain a set of tunnel construction control parameters;

[0100] An excavation module, used to excavate the right tunnel in sections according to the tunnel construction control parameter set, control the excavation profile by a step method, and form an initial section of the right tunnel;

[0101] A construction module is used to construct a support structure based on the initial section of the right tunnel, and to construct a stable support system for the right tunnel by adopting a steel arch frame-spray-mix combined support method;

[0102] A control module is used to design a reserved groove for the partition wall in the excavation surface of the left tunnel by using the stable support system of the right tunnel as a reference, and to form a standardized reserved space by controlled blasting;

[0103] The construction module is used to carry out the main excavation of the left tunnel according to the standardized reserved space, and obtain the overall structural system of the multi-arch tunnel through layered construction process.

[0104] Through the coordinated cooperation of the above-mentioned components, the zero-clearance construction method of the multi-arch tunnel establishes a surrounding rock stability index system through a multi-parameter fitting model, which can accurately evaluate the geological conditions of the construction area, provide a reliable parameter basis for subsequent construction, and avoid the problem of improper support parameter selection caused by inaccurate geological assessment in traditional construction; when the step method is used for right tunnel excavation, the over-excavation volume is significantly reduced by accurately controlling the excavation contour, ensuring the self-stabilization ability of the surrounding rock, and providing a regular construction surface for the subsequent support structure construction; the application of the steel arch frame-spray-mix combined support method gives full play to the synergistic effect of various support structures, forming a stable composite support system and effectively controlling the deformation of the surrounding rock; when designing the reserved groove for the middle partition wall on the excavation surface of the left tunnel, a standardized reserved space is formed by controlling the blasting method, avoiding the dilemma of construction in a narrow guide tunnel in traditional construction, and greatly improving the construction efficiency; finally, through the layered construction process, the effective connection of the left and right tunnels and the middle partition wall structure is achieved, forming a stable overall structural system of the multi-arch tunnel. Especially in the assessment of surrounding rock stability, the multi-parameter fitting model established a scientific evaluation system by comprehensively analyzing multiple parameters such as rock density, water content, compression coefficient, compressive strength, elastic modulus, Poisson's ratio, etc., making the selection of support parameters more accurate and avoiding the subjectivity in the traditional empirical method; at the same time, this method cancels the construction link of the middle guide tunnel and directly uses standardized reserved space for the construction of the middle partition wall, which not only saves engineering materials but also significantly shortens the construction period. In practical applications, this method can shorten the construction period of a 26-meter-long arch tunnel section by about one month and save construction costs of about 280,000 yuan, reflecting the significant advantages of this method in engineering practice. The connection of each process in the entire construction process is more compact, there is less interference between processes, and the construction quality is more guaranteed, providing a new efficient and economical method for the construction of arch tunnels.

[0105] Reference Figure 3In an embodiment of the present invention, a computer device is also provided. The computer device may be a server, and its internal structure may be as follows: Figure 3 As shown. The computer device includes a processor, a memory, a display screen, an input device, a network interface and a database connected through a system bus. Among them, the processor designed by the computer is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store the corresponding data in this embodiment. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the above method is implemented.

[0106] Those skilled in the art will understand that Figure 3 The structure shown in the figure is merely a block diagram of a portion of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied.

[0107] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the above method is implemented. It can be understood that the computer-readable storage medium in this embodiment can be a volatile readable storage medium or a non-volatile readable storage medium.

[0108] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided by the present invention and used in the embodiments can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double-speed data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM.

[0109] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems, systems and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0110] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0111] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for constructing a double-arch tunnel with zero clearance, characterized in that: The zero-clearance construction method of the multi-arch tunnel comprises: The geological parameters of the double-arch tunnel construction area were evaluated based on geological drilling data, and a surrounding rock stability index system was established through a multi-parameter fitting model to obtain a set of tunnel construction control parameters. Excavating the right tunnel in sections according to the tunnel construction control parameter set, controlling the excavation profile by a step method, and forming an initial section of the right tunnel; Based on the initial section of the right tunnel, the support structure is constructed, and a steel arch frame-spray-mix combined support method is adopted to construct a stable support system for the right tunnel; Using the stable support system of the right tunnel as a reference, a reserved groove for the partition wall is designed in the excavation surface of the left tunnel, and a standardized reserved space is formed by controlled blasting; The main body of the left tunnel is excavated according to the standardized reserved space, and the overall structural system of the multi-arch tunnel is obtained through layered construction technology.

2. The method for constructing a multi-arch tunnel with zero clearance according to claim 1, characterized in that: The geological parameters of the construction area of ​​the double-arch tunnel are evaluated according to the geological drilling data, and a surrounding rock stability index system is established through a multi-parameter fitting model to obtain a tunnel construction control parameter set, including: Through drilling sampling, basic geological data on rock and soil density, water content, compression coefficient, compressive strength, elastic modulus, and Poisson's ratio are obtained to establish a geological parameter database; Discretizing the data in the geological parameter database to generate a geological parameter distribution map; Based on the geological parameter distribution map, surrounding rock grades are classified to obtain surrounding rock zoning data; Using the surrounding rock partition data, a surrounding rock stability evaluation matrix is ​​established; Inputting the surrounding rock stability evaluation matrix into a multi-parameter fitting model to generate a surrounding rock stability index; The key technical parameters of support parameters, excavation step distance, middle partition wall thickness, lining thickness, anchor rod length, and anchor rod spacing are determined according to the surrounding rock stability index to form the tunnel construction control parameter set.

3. The method for constructing a multi-arch tunnel with zero clearance according to claim 1, characterized in that: The step of excavating the right tunnel in sections according to the tunnel construction control parameter set, controlling the excavation profile by a step method, and forming an initial section of the right tunnel includes: Generate a right tunnel section partition diagram according to the tunnel construction control parameter set, and mark the upper and lower step boundary lines; Arrange a drilling and blasting hole network based on the right hole section zoning diagram to form a drilling and blasting parameter table; Inputting the drilling and blasting parameter table into a smooth blasting device to generate blasting control data; Performing upper step excavation according to the blasting control data to obtain an upper excavation profile; Excavate the lower step according to the blasting control data to form a lower excavation profile; The upper excavation contour and the lower excavation contour are contour-trimmed to form the initial section of the right hole.

4. The method for constructing a multi-arch tunnel with zero clearance according to claim 1, characterized in that: The support structure is constructed based on the initial section of the right tunnel, and a steel arch frame-spray-mix combined support method is adopted to construct a stable support system for the right tunnel, including: Generate an I-beam arch processing drawing based on the outline size of the initial section of the right tunnel, and make an I-beam support skeleton; Install the I-beam support frame at the initial section of the right hole according to a preset spacing to form a primary support frame; Spraying concrete on the primary support frame by a layered spraying process to generate a foundation support layer; Performing systematic anchoring on the foundation support layer according to the anchor rod arrangement diagram to form a composite support structure; Performing strength testing and analysis on the composite support structure to generate support quality data; According to the support quality data, reinforced concrete secondary lining is carried out to construct the stable support system of the right tunnel.

5. The method for constructing a multi-arch tunnel with zero clearance according to claim 1, characterized in that: The above-mentioned method uses the stable support system of the right tunnel as a reference, designs a reserved groove for the partition wall in the excavation surface of the left tunnel, and forms a standardized reserved space by controlled blasting, including: Extracting the coordinates of the reference control points from the right tunnel stable support system to generate the left tunnel positioning parameters; The axis position of the middle partition wall is calibrated by the left hole positioning parameters to form a reserved groove boundary map; Arranging controlled blasting holes according to the reserved slot boundary map to generate a precise blasting grid; Designing a delayed detonation sequence according to the precise blasting grid to form a blasting control plan; Perform smooth blasting based on the blasting control scheme to obtain an initial profile of the reserved groove; The initial contour of the reserved groove is mechanically trimmed to form the standardized reserved space.

6. The method for constructing a multi-arch tunnel with zero clearance according to claim 1, characterized in that: The main body of the left tunnel is excavated according to the standardized reserved space, and the overall structure system of the multi-arch tunnel is obtained through layered construction process, including: Generate a left tunnel excavation flow chart based on the standardized reserved space to form a construction sequence plan; Step-by-step excavation is performed through the construction sequence scheme to obtain the basic outline of the left tunnel; The support structure is constructed for the basic outline of the left tunnel according to the support parameters of the right tunnel to generate a support system for the left tunnel; Arranging the middle partition wall steel mesh in the standardized reserved space to form a skeleton structure; Connecting the skeleton structure with the left tunnel support system to construct a middle partition wall structure; The middle partition wall structure is connected to the right tunnel stability support system through waterproof materials to obtain the overall structural system of the multi-arch tunnel.

7. The method for constructing a multi-arch tunnel with zero clearance according to claim 6, characterized in that: The method of connecting the skeleton structure with the left tunnel support system to construct a middle partition wall structure includes: Performing positioning measurement on the skeleton structure to generate a connection point coordinate table; Determine the main reinforcement connection position based on the connection point coordinate table to form a connection layout diagram; Arrange shear reinforcement according to the connection arrangement diagram to obtain a load-bearing skeleton; Welding the load-bearing skeleton to the connection points of the left tunnel support system to form an overall frame; tying horizontal distribution reinforcements on the overall frame to form a reinforcement grid; The reinforcement grid is cast in sections to construct the middle partition wall structure.

8. A zero-clearance construction system for a multi-arch tunnel, used to implement the zero-clearance construction method for a multi-arch tunnel as claimed in any one of claims 1 to 7, characterized in that: The multi-arch tunnel zero clearance construction system comprises: Establish a module to evaluate geological parameters of the construction area of ​​the double-arch tunnel based on geological drilling data, establish a surrounding rock stability index system through a multi-parameter fitting model, and obtain a set of tunnel construction control parameters; An excavation module, used to excavate the right tunnel in sections according to the tunnel construction control parameter set, control the excavation profile by a step method, and form an initial section of the right tunnel; A construction module is used to construct a support structure based on the initial section of the right tunnel, and to construct a stable support system for the right tunnel by adopting a steel arch frame-spray-mix combined support method; A control module is used to design a reserved groove for the partition wall in the excavation surface of the left tunnel by using the stable support system of the right tunnel as a reference, and to form a standardized reserved space by controlled blasting; The construction module is used to carry out the main excavation of the left tunnel according to the standardized reserved space, and obtain the overall structural system of the multi-arch tunnel through layered construction process.

9. A computer device, characterized in that: It comprises a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and is characterized in that when the processor executes the computer program, the zero-clearance construction method for a multi-arch tunnel described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the processor is enabled to execute the zero-clearance construction method for a multi-arch tunnel as claimed in any one of claims 1 to 7.

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