Drilling operation method adopting pipe shed drilling machine

Abstract

The invention provides a drilling operation method adopting a pipe shed drilling machine, and belongs to the technical field of drilling operation of drilling machines. Initial positioning deviation is controlled through three-dimensional positioning calibration of a guide pipe and a space stabilization structure, drilling track deviation correction is achieved through real-time monitoring of a hole inclination angle and an eccentric drilling tool; the method comprises the following steps: dynamically adjusting drilling parameters according to a geological radar detection lithology type, establishing a slurry seepage diffusion fluid-solid coupling model to calculate a slurry diffusion radius and a filling rate, establishing a double-layer game optimization model to solve a Nash equilibrium point of grouting pressure and a slurry water-cement ratio, and adopting double-slurry pre-plugging combined with superfine cement reinforcement for a fracture zone. A drill rod and stratum interaction finite element model is established to recognize the dangerous section position, and a stabilizer or a thickened drill rod is additionally arranged, so that the technical problem that grouting reinforcement parameters and drilling track control precision are difficult to optimize synchronously in the pipe shed drilling process is solved.

Description

Technical Field

[0001] This invention belongs to the field of drilling operation technology, and more specifically, relates to a drilling operation method using a pipe roof drilling rig. Background Technology

[0002] In tunnel or underground engineering construction, pipe roof support technology, which forms a load-bearing arch through pre-drilling and grouting reinforcement, is a key method for traversing weak and fractured strata. In traditional pipe roof drilling operations, drilling parameters are mainly adjusted based on experience, guide pipe positioning is achieved using simple measurement methods, and grouting parameters are determined through field tests. However, due to the complex and variable lithology of the strata, traditional methods struggle to achieve precise control of the borehole trajectory. Accumulated deviations in guide pipe installation lead to inaccurate positioning of subsequent boreholes, and the lack of theoretical basis for setting grouting parameters results in uncontrollable grout diffusion range. Furthermore, a quantitative optimization relationship cannot be established between the strength of the consolidated body and the amount of grout used. These problems cause the borehole trajectory to deviate from the design direction during pipe roof drilling, making the grouting effect unpredictable and the reinforcement quality unstable. In other words, existing technologies suffer from the technical challenge of simultaneously optimizing grouting reinforcement parameters and drilling trajectory control accuracy during pipe roof drilling. Summary of the Invention

[0003] In view of this, the present invention provides a drilling operation method using a pipe roof drilling rig, which can solve the technical problem in the prior art that it is difficult to simultaneously optimize grouting reinforcement parameters and drilling trajectory control accuracy during pipe roof drilling.

[0004] This invention is implemented as follows: Before pouring concrete for the arch foot foundation, a guide pipe is welded and fixed to an I-beam frame. Three-dimensional positioning calibration is performed using a theodolite to control the deviation of the guide pipe's centerline position within 9mm. Reinforcing ribs are welded to the outer wall of the guide pipe every 0.5m to form a spatially stable structure. During concrete pouring, layered thin-layer vibration is used to prevent deviation of the guide pipe's axis. After the pipe roof drilling rig is in place, the drill rod tip is inserted into the guide pipe to start drilling. During drilling, the borehole inclination angle and azimuth angle are measured every 3m. When the deviation of the borehole inclination angle or azimuth angle exceeds 0.3 degrees, an eccentric drilling tool is used. Adjust drilling pressure to correct trajectory deviation; adjust drilling parameters according to lithological differences in the drilled formation; establish a fluid-structure interaction model for grout seepage and diffusion, inputting measured values ​​of grout Bingham yield stress, grout time-varying viscosity coefficient, rock mass initial permeability, and rock mass stress sensitivity coefficient, and solve for the grout pressure field distribution, grout velocity field distribution, and grout concentration field distribution, outputting calculated values ​​of grout diffusion radius and filling rate; establish a two-layer game optimization model based on the calculated values ​​of grout diffusion radius and filling rate to solve for the Nash equilibrium point and obtain the optimized grouting pressure value and optimized grout water-cement ratio; perform grouting operations using the optimized grouting pressure value and optimized grout water-cement ratio.

[0005] Among them, controlling the centerline position deviation of the guide tube to within 9mm means using theodolite three-dimensional positioning calibration technology to monitor the centerline coordinates of the guide tube in real time during the installation process, ensuring that the three-dimensional spatial deviation between the actual position of the guide tube and the designed position of the guide tube does not exceed 9mm.

[0006] Among them, the spatially stable structure refers to the multi-point support system formed by the reinforcing ribs welded every 0.5m on the outer wall of the guide tube and the I-beam frame, which resists the lateral extrusion force and vibration impact during the concrete pouring process through rigid connection.

[0007] Among them, layered thin-layer vibration refers to pouring concrete in layers with each layer controlled to a thickness of 300mm to 400mm, and using a vibrator to compact each layer to avoid forming concentrated lateral pressure around the guide pipe.

[0008] Among them, the borehole inclination angle refers to the angle between the borehole axis and the horizontal plane, which is obtained by measuring the borehole inclination instrument. The azimuth angle refers to the angle between the projection of the borehole axis on the horizontal plane and the due north direction, which is obtained by measuring the borehole inclination instrument.

[0009] Among them, eccentric drilling tools refer to correction drilling tools that have an eccentricity between the drill bit centerline and the drill rod axis. By adjusting the azimuth angle and drilling pressure of the eccentric drilling tool, a directional correction force is applied to the borehole that deviates from the design trajectory during the drilling process.

[0010] The step of adjusting drilling parameters according to the differences in lithology of the drilling strata involves determining the lithology by obtaining the wave velocity value of the rock strata ahead through ground-penetrating radar detection, reducing the drilling speed to 0.6 to 0.8 times the reference speed and increasing the drilling pressure to 1.2 to 1.5 times the reference drilling pressure in hard quartz vein sections.

[0011] Among them, the grout seepage diffusion fluid-structure interaction model refers to a mathematical and physical model that comprehensively considers the flow characteristics of grout in fractured rock mass and the interaction between rock mass deformation, and couples the Bingham rheological properties of grout, time-varying viscosity of grout, grout hydration reaction kinetics with the stress sensitivity of rock mass permeability.

[0012] Among them, the Bingham yield stress of the slurry refers to the minimum shear stress that the slurry needs to overcome to begin flowing. It is obtained by measuring the shear stress at different shear rates using a rotational viscometer and fitting the Bingham rheological equation.

[0013] Among them, the measured value of the time-varying viscosity coefficient of the grout refers to the dynamic parameter of the grout viscosity changing with time. As the cement hydration reaction continues, the grout viscosity gradually increases with the extension of the grouting time. It is obtained by measuring the apparent viscosity of grout at different ages using a Brookfield viscometer and fitting a time function.

[0014] The two-layer game optimization model refers to a nested optimization structure comprising an upper-layer model and a lower-layer model. The upper-layer model aims to maximize the compressive strength of the consolidated body, while the lower-layer model aims to minimize the amount of grout used. The upper and lower models influence each other through the calculated grout diffusion radius as a coupling parameter, forming a game relationship. The Nash equilibrium point is the strategy combination point in the two-layer game optimization model where the upper and lower models each pursue their own optimal goals, and unilaterally changing their decisions will not yield a better result. It is obtained by iteratively solving the objective functions of the upper and lower models.

[0015] In the fault fracture zone and fracture development section, water glass cement double-liquid grout is used for pre-grouting and sealing. By adjusting the modulus of water glass and the concentration of cement grout, the setting time of the double-liquid grout is controlled to be between 5 and 30 seconds. After the double-liquid grout has initially set, ordinary cement grout is injected for reinforcement.

[0016] In the extremely crushed section, ultrafine cement with an average particle size of no more than 10 μm is used, and 3% to 5% of bentonite by mass is added to increase the viscosity of the slurry.

[0017] Among them, a three-dimensional finite element model of the interaction between the drill pipe and the formation was established. The drill pipe structure was simulated by beam element type and the formation structure was simulated by solid element type. The friction boundary between the drill pipe and the borehole wall was handled by contact algorithm, and the stress distribution and bending deformation of each section of the drill pipe were solved.

[0018] Among them, the location of the dangerous section where the actual stress of the drill pipe cross section exceeds 0.85 times the allowable stress of the drill pipe is identified, and a stabilizer is added or a thicker drill pipe is used at the dangerous section location.

[0019] This invention proposes a drilling operation method using a pipe roof drilling rig. It utilizes a three-dimensional positioning and calibration technology for the guide tube combined with real-time monitoring of the borehole inclination angle. A fluid-structure interaction model for grout seepage and diffusion is established to calculate the grout diffusion radius and filling rate. A two-layer game-theoretic optimization model is constructed to solve for the Nash equilibrium point of the grouting parameters. A finite element model of drill rod-formation interaction is established to identify the location of critical sections. This method quantifies the interaction between grout rheological properties and rock mass deformation through the fluid-structure interaction model, transforming the setting of grouting pressure and grout water-cement ratio from empirical judgment to numerical optimization. The two-layer game-theoretic optimization model minimizes grout usage while ensuring the strength of the consolidated body. The spatial stability structure of the guide tube and real-time borehole inclination monitoring technology control the borehole positioning deviation to the millimeter level. The finite element model of the drill rod predicts the risk of drill rod failure through stress distribution calculation. In summary, this invention solves the technical problem mentioned in the background art of simultaneously optimizing grouting reinforcement parameters and drilling trajectory control accuracy during pipe roof drilling. Attached Figure Description

[0020] Figure 1 This is a flowchart of the method of the present invention.

[0021] Figure 2 This is a diagram showing the distribution of deviations in the centerline position of the guide tube.

[0022] Figure 3 This is a monitoring diagram of the borehole trajectory correction process.

[0023] Figure 4 This is a graph showing the relationship between the slurry diffusion radius and the filling rate.

[0024] Figure 5 This is a diagram showing the stress distribution across different sections of the drill pipe.

[0025] Figure 6 This is a drilling layout diagram from Example 3. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below.

[0027] like Figure 1 The diagram shows a flowchart of a drilling method using a pipe roof drilling rig provided by the present invention. This method includes the following steps:

[0028] S10. Before pouring concrete for the arch foot foundation, a guide pipe with a diameter of 140mm, a wall thickness of 6mm, and a length of 2.0m is welded and fixed on the I-beam frame. Three-dimensional positioning calibration is performed using a theodolite to control the deviation of the center line of the guide pipe within 9mm. Reinforcing ribs are welded to the outer wall of the guide pipe every 0.5m to form a spatially stable structure. When pouring concrete, layered thin-layer vibration is used to avoid the deviation of the guide pipe axis.

[0029] S20. After the pipe roof drilling rig is in place, the front end of the drill rod is guided into the guide pipe and the drilling operation is started. Seamless steel pipe with a diameter of 108mm and a wall thickness of 6mm is used as the pipe roof steel pipe. The external insertion angle is set to 2 degrees. During the drilling process, the hole inclination angle and azimuth angle are measured every 3m. When the hole inclination angle deviation or azimuth angle deviation exceeds 0.3 degrees, the eccentric drill tool is used to adjust the drilling pressure to correct the trajectory.

[0030] S30. Adjust drilling parameters according to the differences in lithology of the drilling strata. Use ground-penetrating radar to obtain the wave velocity value of the rock strata ahead to determine the lithology type. In hard quartz vein sections, reduce the drilling speed to 0.6 to 0.8 times the reference speed and increase the drilling pressure to 1.2 to 1.5 times the reference drilling pressure. In silty soft rock sections, increase the drilling speed to 1.2 to 1.4 times the reference speed and decrease the drilling pressure to 0.7 to 0.9 times the reference drilling pressure to maintain the balance of drill bit force.

[0031] S40. Establish a fluid-structure interaction model for grout seepage and diffusion. Divide the rock mass fracture network into a finite difference grid. Input the measured values ​​of the Bingham yield stress of the grout, the time-varying viscosity coefficient of the grout, the initial permeability of the rock mass, and the stress sensitivity coefficient of the rock mass. Solve for the distribution of the grout pressure field, the grout velocity field, and the grout concentration field. Output the calculated values ​​of the grout diffusion radius and the filling rate under different grout pressure settings and grout water-cement ratio settings.

[0032] S50. Based on the calculated values ​​of grout diffusion radius and filling rate, a two-layer game optimization model is established. The upper-layer model aims to maximize the compressive strength of the consolidated body. The calculated values ​​of grout diffusion radius, filling rate, and hydration age are used as input parameters of the upper-layer model's objective function to calculate the predicted value of the compressive strength of the consolidated body. The lower-layer model aims to minimize the amount of grout used. The set value of grouting pressure, grout consumption per unit volume, and grouting time are used as input parameters of the lower-layer model's objective function to calculate the predicted value of the total amount of grout used. The calculated value of grout diffusion radius is used as a coupling parameter to connect the objective functions of the upper-layer model and the lower-layer model. The Nash equilibrium point is solved to obtain the optimized grouting pressure value and the optimized grout water-cement ratio value.

[0033] S60. In fault fracture zones and fracture-developed sections, pre-grouting and sealing are first carried out using water glass cement double-liquid grout. The setting time of the double-liquid grout is controlled between 5 and 30 seconds by adjusting the modulus of water glass and the concentration of cement grout. After the double-liquid grout has initially set, ordinary cement grout is injected for reinforcement. In the extremely fractured section, ultrafine cement with an average particle size of no more than 10 μm is used and 3% to 5% of bentonite by mass is added to increase the viscosity of the grout. The grouting operation is carried out using optimized grouting pressure and optimized grout water-cement ratio.

[0034] S70. Establish a three-dimensional finite element model of the interaction between the drill pipe and the formation. Use beam elements to simulate the drill pipe structure and solid elements to simulate the formation structure. Use a contact algorithm to handle the friction boundary between the drill pipe and the borehole wall. Input the self-weight load of the drill pipe, the drilling pressure load, the torque load, and the formation lateral pressure load. Solve for the stress distribution and bending deformation of each section of the drill pipe. Identify the dangerous section locations where the actual stress of the drill pipe section exceeds 0.85 times the allowable stress of the drill pipe. Add stabilizers or use thicker drill pipes at the dangerous section locations.

[0035] The control of the centerline position deviation of the guide tube within 9mm means that the coordinates of the centerline of the guide tube are monitored in real time during the installation of the guide tube using theodolite three-dimensional positioning calibration technology. This ensures that the three-dimensional spatial deviation between the actual position of the guide tube and the designed position does not exceed 9mm, thus guaranteeing the positioning accuracy of subsequent drilling operations.

[0036] The spatial stabilizing structure refers to a multi-point support system formed by reinforcing ribs welded every 0.5m on the outer wall of the guide tube and the I-beam frame. The spatial stabilizing structure resists the lateral extrusion force and vibration impact during the concrete pouring process through rigid connection, preventing the guide tube from displaced and deformed.

[0037] The layered thin-layer vibration refers to pouring concrete in layers with each layer controlled to a thickness of 300mm to 400mm, and using a vibrator to compact each layer, avoiding concentrated lateral pressure around the guide pipe and reducing the risk of guide pipe axis deviation.

[0038] The borehole inclination angle refers to the angle between the borehole axis and the horizontal plane, which is obtained by measuring the borehole inclination angle. The borehole inclination angle deviation refers to the difference between the measured value of the borehole inclination angle and the designed value of the borehole inclination angle.

[0039] The azimuth angle refers to the angle between the projection of the borehole axis onto the horizontal plane and the due north direction, which is obtained by measuring with an inclinometer. The azimuth angle deviation refers to the difference between the measured azimuth angle value and the designed azimuth angle value.

[0040] The eccentric drill bit refers to a correction drill bit in which there is an eccentricity between the center line of the drill bit and the axis of the drill rod. By adjusting the azimuth angle and drilling pressure of the eccentric drill bit, a directional correction force is applied to the borehole that deviates from the design trajectory during the drilling process, so that the borehole trajectory gradually returns to the design direction.

[0041] The aforementioned ground-penetrating radar detection refers to a geophysical method that uses the reflection characteristics of electromagnetic waves at different lithological interfaces to detect the stratigraphic structure ahead. It involves emitting high-frequency electromagnetic waves and receiving reflected signals, and calculating the rock layer wave velocity value based on the travel time and amplitude of the reflected waves. The rock layer wave velocity value is used to determine the lithology type.

[0042] The reference rotational speed refers to the reference value of the drilling rig rotational speed determined based on the drill bit diameter and rock hardness when drilling in homogeneous rock formations. It is determined through rock drillability tests and drilling rig performance parameters, and serves as a reference benchmark for adjusting drilling parameters in different formations.

[0043] The reference drill pressure refers to the axial thrust reference value applied during drilling in homogeneous rock formations to ensure drilling efficiency and drill bit life. It is determined through rock drillability tests and drill bit strength calculations and serves as a reference benchmark for adjusting parameters for differentiated drilling in different formations.

[0044] The fluid-structure interaction model for grout seepage diffusion refers to a mathematical and physical model that comprehensively considers the flow characteristics of grout in fractured rock mass and the interaction between rock mass deformation. The fluid-structure interaction model for grout seepage diffusion couplings the Bingham rheological properties of grout, time-varying viscosity of grout, grout hydration reaction kinetics and stress sensitivity of rock mass permeability. It uses the finite difference method or lattice Boltzmann method to perform numerical calculations by solving the coupled system of Navier-Stokes equations and Darcy's law.

[0045] The measured Bingham yield stress of the grout refers to the minimum shear stress that the grout needs to overcome to begin flowing. It is obtained by measuring the shear stress at different shear rates using a rotational viscometer and fitting the Bingham rheological equation. The measured Bingham yield stress of the grout reflects the initial flow resistance of the grout. It varies with the cement content and the type of admixture, affecting the grout's ability to penetrate micro-cracks.

[0046] The measured value of the time-varying viscosity coefficient of the grout refers to the dynamic parameter of the grout viscosity changing with time. As the cement hydration reaction continues, the grout viscosity gradually increases with the extension of the grouting time. The measured value of the time-varying viscosity coefficient of the grout is obtained by measuring the apparent viscosity of the grout at different ages using a Brookfield viscometer and fitting a time function.

[0047] The initial permeability measurement value of the rock mass refers to the inherent permeability performance of the rock mass before grouting. It is obtained by measuring the injection flow rate and stable head through borehole water pressure test and calculating according to Darcy's law. The initial permeability measurement value of the rock mass is determined by the degree of development of rock mass fractures, rock mass porosity and fracture connectivity, and serves as the basic parameter for calculating grout seepage velocity and grout diffusion range.

[0048] The measured value of the rock mass stress sensitivity coefficient refers to the sensitivity of rock mass permeability to changes in effective stress. Increased grouting pressure leads to changes in the degree of closure of rock mass fissures, resulting in a corresponding decrease in permeability. The measured value of the rock mass stress sensitivity coefficient is obtained by measuring the slope of the stress-permeability relationship curve through triaxial flow tests.

[0049] The grout pressure field distribution refers to the spatial distribution of grout pressure in the rock fracture network during the grouting process. It is obtained by solving the grout seepage diffusion fluid-structure interaction model. The grout pressure field distribution evolves with grouting time and is affected by the grouting pressure set value and the initial permeability measurement value of the rock mass.

[0050] The slurry velocity field distribution refers to the vector field of slurry flow velocity in rock fractures, which is obtained by solving the momentum conservation equation in the slurry seepage diffusion fluid-structure interaction model. The slurry velocity field distribution determines the diffusion rate and filling efficiency of the slurry.

[0051] The slurry concentration field distribution refers to the spatial distribution of cement particle concentration in the slurry within the rock fracture network. It is obtained by solving the mass conservation equation in the slurry seepage diffusion fluid-structure interaction model. The slurry concentration field distribution reflects the diffusion range and dilution degree of the slurry.

[0052] The calculated value of the grout diffusion radius refers to the radial distance from the center of the grouting hole to the grout penetration front, which is obtained by calculation through the grout seepage diffusion fluid-structure interaction model. The calculated value of the grout diffusion radius determines the influence range of single-hole grouting and is directly related to the grouting pressure setting value, the measured value of the grout Bingham yield stress, and the measured value of the initial permeability of the rock mass.

[0053] The calculated filling rate refers to the percentage of the volume of rock mass fissures and pores filled by grout, which is obtained by calculation using a grout seepage diffusion fluid-solid coupling model. The calculated filling rate reflects the grouting reinforcement effect. The higher the calculated filling rate, the better the integrity of the consolidated body and the stronger its bearing capacity and impermeability.

[0054] The aforementioned two-layer game optimization model refers to a nested optimization structure containing an upper-layer model and a lower-layer model. The upper-layer model aims to maximize the compressive strength of the consolidated body, while the lower-layer model aims to minimize the amount of grout used. The upper-layer model and the lower-layer model influence each other and form a game relationship by using the calculated value of the grout diffusion radius as a coupling parameter.

[0055] The objective function of the upper-level model is used to calculate the predicted value of the compressive strength of the consolidated body. The input parameters of the objective function of the upper-level model include the calculated value of the slurry diffusion radius, the calculated value of the filling rate, and the hydration age. The predicted value of the compressive strength of the consolidated body is the power function relationship of the calculated filling rate multiplied by the logarithmic function of the hydration age, divided by the square root of the calculated slurry diffusion radius, and multiplied by the reference compressive strength value, ensuring that the dimensions of the left and right sides of the equal sign are unified in the unit of pressure.

[0056] The objective function of the lower-level model is used to calculate the predicted value of the total grout usage. The input parameters of the objective function of the lower-level model include the grouting pressure setting value, the grout consumption per unit volume, and the grouting time. The predicted value of the total grout usage is an exponential function of the product of the grout consumption per unit volume and the grouting time, multiplied by the ratio of the grouting pressure setting value to the benchmark grouting pressure, ensuring that the dimensions on both sides of the equal sign are unified to the volume unit.

[0057] The coupling parameter refers to a shared variable that appears simultaneously in the objective functions of the upper-level model and the lower-level model. The calculated value of the grout diffusion radius, as a coupling parameter, affects the predicted value of the compressive strength of the consolidated body in the objective function of the upper-level model, and indirectly affects the predicted value of the total grout usage in the objective function of the lower-level model through the grouting pressure setting value. The upper-level model and the lower-level model form a mutually restrictive game relationship through the coupling parameter.

[0058] The Nash equilibrium point refers to the strategy combination point in a two-level game optimization model where the upper-level model and the lower-level model each pursue their own optimal goal, and neither side can obtain a better result by unilaterally changing the decision. The optimized grouting pressure value and the optimized grout water-cement ratio value corresponding to the Nash equilibrium point are obtained by iteratively solving the objective functions of the upper-level model and the lower-level model.

[0059] The optimized grouting pressure value refers to the optimal setting value of grouting pressure obtained by solving the Nash equilibrium point through a two-layer game optimization model. The optimized grouting pressure value minimizes the predicted total amount of grout used while ensuring that the predicted compressive strength of the consolidated body meets the support requirements. Compared with the empirical value method, it saves 15% to 20% of the grout usage.

[0060] The optimized water-cement ratio of the slurry refers to the optimal water-cement ratio setting obtained by solving the Nash equilibrium point through a two-layer game optimization model. The optimized water-cement ratio affects the measured value of the Bingham yield stress and the measured value of the time-varying viscosity coefficient of the slurry, and thus affects the calculated value of the slurry diffusion radius and the calculated value of the filling rate.

[0061] The water glass cement dual-liquid grout refers to a quick-setting grout in which water glass solution and cement grout are pumped into the grouting hole through two separate pipelines. After the water glass solution and cement grout come into contact in the crack, they quickly undergo a chemical reaction to form a gel. The setting time of the dual-liquid grout is controlled within the range of 5 to 30 seconds by adjusting the modulus of water glass and the concentration of cement grout.

[0062] The modulus of water glass refers to the concentration of water glass in the solution. and The molar ratio is calculated by chemical analysis of the water glass composition, and the modulus of the water glass affects the setting time and gel strength of the water glass cement two-component slurry.

[0063] The ultrafine cement refers to extra-fine cement particles with an average particle size of no more than 10 μm. Compared with ordinary cement, the particle size is reduced by 5 to 10 times, which has stronger permeability and larger specific surface area. It is suitable for grouting reinforcement to seal micro-cracks and extremely broken rock masses.

[0064] The three-dimensional finite element model of drill pipe-formation interaction refers to the mechanical model of the interaction between drill pipe and formation established using the finite element analysis method. The three-dimensional finite element model of drill pipe-formation interaction discretizes the drill pipe structure into beam element type and the formation structure into solid element type. By defining contact pairs and friction coefficients, it simulates the contact friction behavior between drill pipe and borehole wall. By inputting load boundary conditions such as drill pipe self-weight load, drill pressure load, torque load and formation lateral pressure load, it solves for the axial stress, bending stress, shear stress and deflection deformation of each section of drill pipe.

[0065] The beam element type refers to a one-dimensional element type used in finite element analysis to simulate slender rods. The beam element type has axial tensile and compressive deformation capacity, bending deformation capacity, and torsional deformation capacity. It describes the displacement and rotation angle of the drill pipe through nodal degrees of freedom and is suitable for the analysis of drill pipe structures with a length-to-diameter ratio greater than 10.

[0066] The solid element type refers to the element type used in finite element analysis to simulate a three-dimensional continuum. The solid element type describes the three-dimensional stress-strain state of the formation through nodal displacement interpolation functions, which can accurately reflect the heterogeneity and anisotropy of the formation.

[0067] The contact algorithm refers to a numerical method in finite element analysis for handling the contact problem between the surfaces of two objects. The contact algorithm determines the direction and magnitude of the contact force by detecting the contact state, and calculates the tangential friction force according to Coulomb's law of friction, thereby realizing the normal non-embedded constraint and tangential friction transmission between the drill rod and the hole wall.

[0068] The self-weight load of the drill rod refers to the axial tensile force generated by the weight of the drill rod itself, which is calculated by the density of the drill rod material, the cross-sectional area of ​​the drill rod, and the length of the drill rod. The self-weight load of the drill rod increases with the increase of the drilling depth.

[0069] The drill pressure load refers to the axial thrust applied to the drill rod by the drilling rig, which is calculated by the pressure of the drilling rig's hydraulic system and the piston area. The drill pressure load is used to overcome the rock-breaking resistance of the drill bit and promote drilling operations.

[0070] The torque load refers to the torsional moment applied to the drill rod by the drilling rig, which is calculated by the output power of the drilling rig power system and the drill rod speed. The torque load drives the drill bit to rotate and break the rock.

[0071] The formation lateral pressure load refers to the lateral load that is transmitted to the drill pipe through contact action by the radial pressure exerted by the formation on the borehole wall. It is obtained by in-situ stress measurement and elasticity theory calculation. The formation lateral pressure load varies with burial depth and geological structure.

[0072] The stress distribution of each section of the drill pipe refers to the stress state on each cross section of the drill pipe along the axial direction, including axial stress distribution, bending stress distribution and shear stress distribution, which is obtained by solving a three-dimensional finite element model of drill pipe-formation interaction.

[0073] The bending deformation of the drill pipe refers to the radial displacement and rotation changes of the drill pipe under the action of its own weight load, drilling pressure load and formation lateral pressure load. It is obtained by solving a three-dimensional finite element model of the interaction between the drill pipe and the formation. The bending deformation of the drill pipe affects the accuracy of the drilling trajectory and the fatigue life of the drill pipe.

[0074] The allowable stress of the drill pipe refers to the maximum stress value that the drill pipe material is allowed to withstand during use. It is obtained by dividing the yield strength of the drill pipe material by a safety factor, which is determined based on the complexity of the drilling conditions and the service life of the drill pipe.

[0075] The critical section location refers to the section location in the stress distribution of each section of the drill pipe where the actual stress of the drill pipe section exceeds 0.85 times the allowable stress of the drill pipe. It is identified by a three-dimensional finite element model of the interaction between the drill pipe and the formation. The critical section location has the risk of drill pipe buckling failure and reinforcement measures need to be taken.

[0076] The stabilizer is a support device installed on the outside of the drill pipe to constrain the radial displacement of the drill pipe. The stabilizer provides lateral support force by contacting the borehole wall, reducing the free cantilever length of the drill pipe, reducing the bending deformation and lateral vibration of the drill pipe, and improving the stability of the drilling trajectory.

[0077] The thickened drill pipe refers to a reinforced drill pipe with a wall thickness greater than that of a conventional drill pipe. The thickened drill pipe has higher bending stiffness and a larger section modulus. At critical section locations, the thickened drill pipe is used to replace the conventional drill pipe to reduce the bending stress level and prevent drill pipe buckling failure.

[0078] The specific implementation methods of the above steps are described in detail below.

[0079] The specific implementation of step S10 is as follows: First, the preparation of the guide pipe is completed before the construction of the arch foot foundation. A seamless steel pipe with a diameter of 140mm and a wall thickness of 6mm is selected and cut to a length of 2.0m according to the design requirements as the guide pipe. Then, the guide pipe is welded and fixed to the I-beam frame at the designed interval to form a guide pipe assembly. During the welding process, a reinforcing rib is welded to the outer wall of the guide pipe every 0.5m to connect with the I-beam frame to form a spatially stable structure. The spatially stable structure is based on the principle of triangle stability and the principle of multi-point constraint. It resists the lateral disturbance force during concrete pouring by increasing the connection stiffness between the guide pipe and the I-beam frame. After the guide pipe assembly is welded, a theodolite is used for three-dimensional positioning. Calibration involves calculating the spatial position of the guide tube's centerline by measuring the three-dimensional coordinates of both ends of the guide tube. When the deviation of the guide tube's centerline position exceeds 9mm, the posture of the I-beam frame is adjusted until the deviation is controlled within 9mm. During concrete pouring, a layered thin-layer vibration method is adopted, pouring concrete in layers with each layer's thickness controlled within the range of 300mm to 400mm. A vibrator is used to compact each layer to avoid forming concentrated lateral pressure around the guide tube. The layered thin-layer vibration method is based on the stress dispersion principle. By reducing the thickness of each vibration layer, the lateral pressure of the concrete is evenly distributed on the surface of the guide tube, reducing the risk of guide tube axis deviation and ensuring the positioning accuracy of the guide tube, providing a reliable positioning benchmark for subsequent drilling operations.

[0080] The specific implementation of step S20 is as follows: First, the pipe roof drilling rig is moved to the construction position and leveled. The horizontality of the drilling rig is adjusted by hydraulic outriggers so that both the longitudinal and lateral inclination angles are less than 0.5 degrees. Then, the front end of the drill rod is inserted into the guide tube to achieve coaxial positioning between the drill rod and the guide tube. Drilling operation is started. Seamless steel pipes with a diameter of 108mm and a wall thickness of 6mm are used as the pipe roof steel pipes. The external insertion angle is set at 2 degrees, which meets the design requirements. During the drilling process, drilling is stopped every 3m, and the borehole inclinometer is lowered to the bottom of the borehole to measure the borehole inclination angle and azimuth angle. The borehole inclinometer is based on the principle of gravity acceleration sensor and magnetic field sensor. The borehole inclinometer measures the inclination angle in three-dimensional space. The attitude angle calculation determines the borehole inclination angle and azimuth angle of the borehole axis. The measured value of the borehole inclination angle is compared with the designed value to obtain the borehole inclination angle deviation, and the measured value of the azimuth angle is compared with the designed value to obtain the azimuth angle deviation. When the borehole inclination angle deviation or azimuth angle deviation exceeds 0.3 degrees, it is determined that the borehole trajectory has deviated and needs to be corrected. An eccentric drill bit is used to replace the conventional drill bit, and the azimuth angle of the eccentric drill bit is adjusted according to the direction of deviation. The drill bit force state is changed by increasing or decreasing the drilling pressure to generate a directional correction force. The eccentric drill bit correction method is based on the principles of mechanical balance and trajectory control. By actively applying asymmetrical cutting force, the borehole trajectory is gradually returned to the design direction, thereby achieving precise control of the borehole trajectory.

[0081] The specific implementation of step S30 is as follows: First, a ground-penetrating radar (GPR) is used to detect the stratigraphic structure ahead. The GPR emits high-frequency electromagnetic waves with a frequency of 100MHz to 500MHz and receives the reflected signals from the rock strata interface. The wave velocity value of the rock strata is calculated based on the travel time and amplitude of the reflected waves. When the wave velocity value is greater than 4000m / s, it is determined that the area ahead is a hard quartz vein segment; when the wave velocity value is less than 2500m / s, it is determined that the area ahead is a silty soft rock segment. The GPR detection method is based on the principle of electromagnetic wave propagation and the principle of wave impedance difference. The differences in dielectric constant and conductivity of different lithologies cause electromagnetic waves to be reflected at the rock strata interface. By analyzing the characteristics of the reflected waves, the lithology type is identified, and pre-drilling geological prediction is achieved. The report states that in hard quartz vein sections, the drilling rig speed is reduced to 0.6 to 0.8 times the reference speed, and the drilling pressure is increased to 1.2 to 1.5 times the reference drilling pressure. This parameter adjustment strategy is based on the principle of rock breaking energy matching. Hard rocks require greater unit cutting energy. By reducing the speed, idling losses are reduced, and by increasing the drilling pressure, the rock breaking efficiency of the drill bit is improved. In silty soft rock sections, the drilling rig speed is increased to 1.2 to 1.4 times the reference speed, and the drilling pressure is reduced to 0.7 to 0.9 times the reference drilling pressure to avoid excessive drilling pressure causing the drill bit to get stuck in the soft rock and produce a mud-packing effect. Through the above-mentioned differentiated drilling parameter adjustment, the force balance of the drill bit in different rock types is maintained, drilling efficiency is improved, and the service life of the drill bit is extended.

[0082] The specific implementation of step S40 is as follows: A fluid-structure interaction model for grout seepage diffusion is established to solve the diffusion behavior of grout in fractured rock mass. First, the rock mass fracture network is divided into a finite difference grid. The grid size is determined based on the fracture width and computational accuracy requirements. Input parameters include: the Bingham yield stress of the grout measured by a rotational viscometer; the time-varying viscosity coefficient of the grout obtained by measuring the viscosity of grout at different ages using a Brookfield viscometer and fitting a time function; the initial permeability of the rock mass obtained by borehole water pressure tests; and the stress sensitivity coefficient of the rock mass obtained by determining the stress-permeability relationship curve through triaxial flow tests. This fluid-structure interaction model for grout seepage diffusion is based on the principles of continuum mechanics and multiphase flow theory. This study couples the Navier-Stokes equations describing grout flow with Darcy's law describing rock seepage. The finite difference method is used to discretize and solve the governing equations, calculating the grout pressure, velocity, and concentration field distributions at different times. The location of the grout diffusion front is determined by tracing the grout concentration threshold contour lines. The distance from the grout diffusion front to the center of the grouting hole is used as the calculated grout diffusion radius. The ratio of the grout-filled area volume to the total volume of rock fractures is used to obtain the calculated filling rate. Parametric calculations are performed for different grouting pressure and water-cement ratio settings, outputting parameter sensitivity curves for the calculated grout diffusion radius and filling rate, providing a theoretical basis for optimizing grouting parameters.

[0083] The specific implementation of steps S50 and S60 is as follows: A two-layer game optimization model is established based on the calculated values ​​of grout diffusion radius and filling rate obtained in step S40. This two-layer game optimization model is based on game theory and multi-objective optimization theory. The upper-layer model aims to maximize the compressive strength of the consolidated body, using the calculated values ​​of grout diffusion radius, filling rate, and hydration age as input parameters of the upper-layer model's objective function. The lower-layer model aims to minimize grout consumption, using the setpoint of grouting pressure, grout consumption per unit volume, and grouting time as input parameters of the lower-layer model's objective function. The calculated value of grout diffusion radius serves as a coupling parameter, simultaneously affecting both the upper and lower-layer models. A successive approximation method is used to solve for the Nash equilibrium point. First, assuming the initial setpoints of grouting pressure and grout water-cement ratio, the lower-layer model calculates the predicted total grout consumption. The calculated value of grout diffusion radius output by the lower-layer model is then passed to the upper-layer model, which calculates the predicted value of the consolidated body's compressive strength. The predicted value of the consolidated body's compressive strength is then determined to be... If the support requirements are not met, the grouting pressure setting value is increased or the water-cement ratio setting value of the grout is adjusted and recalculated. If the requirements are met, it is determined whether the predicted total grout usage value has reached the minimum. The optimized grouting pressure value and optimized grout water-cement ratio value corresponding to the Nash equilibrium point are obtained through iterative optimization. In the fault fracture zone and fracture development section, the optimized grouting pressure value and optimized grout water-cement ratio value are used to perform grouting operations. First, water glass cement two-component grout is used for pre-grouting and sealing. The water glass modulus is adjusted to 2.5 to 3. Within a certain range and with a cement slurry concentration, the setting time of the two-component grout is controlled to be between 5 and 30 seconds. After the initial setting of the two-component grout, ordinary cement slurry is injected for reinforcement. In the extremely broken section, ultrafine cement with an average particle size of no more than 10 μm is used and 3% to 5% of bentonite by mass is added to increase the viscosity of the grout and reduce the seepage loss. The segmented grouting and plugging technology is based on the principle of matching the rheological properties of the grout and the principle of time-sequence grouting. First, a fast-setting grout is used to seal large cracks to form a low-permeability barrier, and then conventional grout is used to fill the residual pores to improve the strength of the solidified body.

[0084] The specific implementation of step S70 is as follows: A three-dimensional finite element model of the drill pipe-formation interaction is established to analyze the mechanical response of the drill pipe under complex loads. A beam element type is used to simulate the drill pipe structure, based on Euler-Bernoulli beam theory or Timoshenko beam theory. The axial, bending, and torsional deformations of the drill pipe are described through nodal displacement and rotation degrees of freedom. A solid element type is used to simulate the formation structure, based on continuum mechanics theory. The three-dimensional stress-strain state of the formation is described through nodal displacement interpolation functions. A contact algorithm is used to handle the frictional boundary conditions between the drill pipe and the borehole wall. This contact algorithm is based on the Lagrange multiplier method or penalty function method. The contact state is determined by detecting the relative displacement between nodes. The tangential friction force is calculated according to Coulomb's law of friction to simulate the interaction between the drill pipe and the borehole wall. The input drill pipe self-weight load is obtained by calculating the drill pipe material density, cross-sectional area, and length. The input drill pressure load is obtained by... The hydraulic system pressure and piston area of ​​the drilling rig are calculated. The input torque load is calculated using the output power of the drilling rig's power system and the drill rod speed. The input lateral pressure load of the formation is calculated using ground stress measurement and elasticity theory. The stress distribution of each section of the drill rod, including axial stress distribution, bending stress distribution, and shear stress distribution, is solved. The radial displacement and rotation angle of each section of the drill rod are obtained by solving for the bending deformation of the drill rod. The location of the critical section where the actual stress of the drill rod section exceeds 0.85 times the allowable stress of the drill rod is identified. The stress threshold of 0.85 times is based on fatigue strength theory and the principle of safety reserve. Stabilizers are added at the critical section location to provide lateral support or thicker drill rods are used to improve bending stiffness. The reinforcement measures are based on the principle of structural mechanics optimization. By reducing the free cantilever length of the drill rod or increasing the section modulus, the bending stress level of the critical section is reduced, preventing the drill rod from buckling failure during long-distance drilling and ensuring the safety and continuity of drilling operations.

[0085] It should be noted that the key technical concept of this invention includes the spatial stabilization structure fixing technology for the guide tube. By welding reinforcing ribs every 0.5m on the outer wall of the guide tube to form a multi-point constraint system with the I-beam frame, based on the principle of triangular stability and rigid connection, it resists the lateral disturbance and vibration impact during the concrete pouring process. Compared with the traditional simple support fixing method that relies only on end constraints and is prone to overall displacement under the action of concrete lateral pressure, the spatial stabilization structure disperses the constraint points to the entire length of the guide tube to achieve continuous support. Combined with layered thin-layer vibration to avoid lateral pressure concentration, the control accuracy of the guide tube centerline position deviation is improved from ±20mm in the traditional method to within ±9mm. This provides a high-precision positioning benchmark for subsequent drilling operations and solves the technical problem of difficulty in ensuring the positioning accuracy of the guide tube in pipe shed construction. The fluid-structure interaction modeling and bi-layer game optimization technique for grout seepage diffusion is developed by establishing a multi-physics coupled model that comprehensively considers the Bingham rheological properties of grout, time-varying viscosity, hydration reaction kinetics, and rock mass permeability stress sensitivity. The coupled system of the Navier-Stokes equations and Darcy's law is solved using the finite difference method to simulate the spatiotemporal evolution of the grout pressure, velocity, and concentration fields. Compared to traditional empirical formula methods that only consider steady-state seepage and ignore the effects of grout rheological property changes and rock mass deformation, this fluid-structure interaction model can accurately predict the dynamic diffusion behavior of grout in complex fracture networks. Combined with a bi-layer game optimization model, the grout usage is minimized while ensuring the compressive strength of the consolidated body meets support requirements. The Nash equilibrium point is solved by the game relationship between the upper model's pursuit of maximizing strength and the lower model's pursuit of minimizing usage, thus achieving multi-objective optimization design of grouting parameters. The three-dimensional finite element analysis and critical section identification technology for drill pipe-formation interaction establishes a coupled mechanical model of the drill pipe using beam elements and the formation using solid elements. It employs a contact algorithm to handle the frictional boundary conditions between the drill pipe and the borehole wall, comprehensively considering various load conditions such as drill pipe self-weight, drilling torque, and formation lateral pressure. This model solves for the three-dimensional stress state and bending deformation of each section of the drill pipe. Compared to traditional simplified calculation methods that treat the drill pipe as a simply supported beam or cantilever beam and ignore formation constraints and contact friction effects, this three-dimensional finite element model can realistically reflect the stress characteristics of the drill pipe in complex formations. By setting a stress threshold of 0.85 times the allowable stress, it identifies the location of critical sections, providing a quantitative basis for stabilizer placement and the selection of thicker drill pipes, thus preventing buckling failure of the drill pipe during long-distance drilling.The synergistic effect of the above three key technologies lies in the fact that precise positioning of the guide pipe lays the foundation for borehole trajectory control, slurry diffusion simulation and game optimization provide theoretical support for grouting parameter design, and drill rod mechanical analysis provides safety assurance for drill tool combination optimization. The three technologies respectively construct a complete pipe roof drilling technology system from three dimensions: pre-drilling positioning, in-drill grouting, and drill rod protection. Compared with traditional methods where each link is independent and relies on experience judgment, the synergistic technology system achieves refined control and intelligent decision-making throughout the pipe roof construction process through multi-physics coupling modeling, numerical simulation analysis, and multi-objective optimization design, significantly improving the overall stability and support effect of the pipe roof system.

[0086] It should be noted that this invention also solves the following technical problem: during drilling in complex formations, frequent changes in lithology cause drilling parameter settings to lag behind changes in formation conditions, resulting in drill bit stress imbalance and leading to borehole deviation or drill bit damage. This invention uses ground-penetrating radar to obtain real-time wave velocity values ​​of the preceding rock strata to determine the lithology type. In hard quartz vein sections, the drilling rig speed is reduced and the drilling pressure is increased; in silty soft rock sections, the drilling rig speed is increased and the drilling pressure is reduced, achieving predictive adjustment of drilling parameters, maintaining drill bit stress balance, and avoiding drilling accidents caused by parameter lag. Furthermore, in fault fracture zones and fracture-developed areas, traditional single-slurry grouting methods struggle to simultaneously meet the dual requirements of rapid sealing and long-term strength, leading to grout loss or insufficient reinforcement. This invention uses a water glass-cement dual-liquid grout for pre-grouting and sealing. By adjusting the modulus of the water glass and the concentration of the cement grout, the setting time is controlled within 5 to 30 seconds to achieve rapid grouting cessation. After the dual-liquid grout has initially set, ordinary cement grout or ultrafine cement grout is injected for secondary reinforcement, thus solving the contradiction between the sealing speed and the strength of the solidified body in the grouting reinforcement of fractured strata.

[0087] Specifically, the principle of this invention is as follows: The core principle lies in transforming borehole trajectory control and grouting parameter optimization from an experience-driven to a model-driven systematic method. The three-dimensional positioning and calibration technology of the guide pipe establishes a high-precision initial positioning benchmark through a multi-point support system of I-beams, eliminating the source of cumulative deviations in subsequent drilling. Real-time monitoring of borehole inclination angle and correction of eccentric drill bits form a closed-loop trajectory control system. The fluid-structure interaction model of grout seepage diffusion solves the interaction equations between the grout pressure field, velocity field, and rock deformation, incorporating the time-varying viscosity of the grout Bingham yield stress and the stress-sensitive permeability of the rock mass into a unified calculation framework, transforming the grout diffusion radius and filling rate from qualitative descriptions into calculable and predictable quantitative indicators. The two-layer game optimization model uses the grout diffusion radius as a coupling parameter to connect the solidified body strength objective and the grout usage objective, solving for the Nash equilibrium point to achieve multi-objective collaborative optimization. The finite element model of drill pipe-formation interaction simulates the friction boundary between the drill pipe and the borehole wall through a contact algorithm, calculates the drill pipe stress distribution, identifies the location of dangerous sections, and provides a mechanical basis for drill bit configuration.

[0088] The following provides a specific embodiment 1 of the present invention. The specific implementation methods of steps S10, S020, S30 and S60 in this embodiment 1 are the same as those described above, and will not be repeated in detail here. The specific implementation methods of other steps are described in detail below.

[0089] The specific implementation of step S40 involves establishing a fluid-structure interaction model for grout seepage and diffusion. The rock mass fracture network is divided into a finite difference grid. The measured values ​​of the grout Bingham yield stress, the grout time-varying viscosity coefficient, the initial permeability of the rock mass, and the rock mass stress sensitivity coefficient are input. The grout pressure field distribution, grout velocity field distribution, and grout concentration field distribution are solved. The calculated values ​​of the grout diffusion radius and filling rate under different grout pressure and water-cement ratio settings are output. The flow of grout in fractured rock mass follows the Bingham rheological equation, specifically expressed as follows:

[0090] ;

[0091] In the formula, This represents the shear stress of the slurry, expressed in Pa. The measured Bingham yield stress of the slurry is expressed in Pa. The plastic viscosity of the slurry is expressed in units of... ; The slurry shear rate is expressed in units of... The parameter acquisition method is as follows: The shear stress was obtained by measuring the shear stress at different shear rates using a rotational viscometer and fitting the Bingham rheological equation. Obtained by a rotational viscometer, it represents the internal frictional resistance during slurry flow; The viscosity coefficient of the slurry is obtained from the slurry flow velocity gradient. The formula for calculating the time-varying viscosity coefficient of the slurry is as follows:

[0092] ;

[0093] In the formula, The viscosity of the slurry is time-varying, and the unit is 1000 liters. ; The initial viscosity of the slurry, in units of... ; This is a dimensionless measurement of the time-varying viscosity coefficient of the slurry. Grouting time, in seconds; For reference time, the unit is seconds (s), and the empirical value is 3600 seconds. Among them, The flow resistance of freshly mixed slurry is obtained by measuring the slurry using a Brookfield viscometer, reflecting the initial state of the slurry. The apparent viscosity of slurry at different ages was determined using a Brookfield viscometer and fitted with a time function. The stress-sensitivity relationship of rock mass permeability is expressed by the following formula:

[0094] ;

[0095] In the formula, The current permeability of the rock mass, in units of ; This is the initial permeability measurement value of the rock mass, in units of... ; The measured value of the rock mass stress sensitivity coefficient is dimensionless. This represents the effective stress in the rock mass, expressed in MPa. This is a reference stress, measured in MPa, with an empirical value of 1 MPa. The injection flow rate and steady head were measured by borehole pressure tests and calculated according to Darcy's law. The slope of the stress-permeability relationship curve was determined by triaxial flow testing. Obtained from in-situ stress measurements. The formula for calculating the slurry diffusion radius is as follows:

[0096] ;

[0097] In the formula, This is the calculated value of the slurry diffusion radius, in meters (m). The reference diffusion radius is in meters (m), with an empirical value of 1 m. For reference penetration rate, the unit is... experience value ; This is the grouting pressure setting value, in MPa. Reference viscosity, unit: The empirical value is 0.03. The formula for calculating the filling rate is as follows:

[0098] ;

[0099] In the formula, This is a dimensionless value representing the calculated filling rate. The total volume of grout injected, in units of ; The total volume of crack pores within the reference diffusion radius, in units of ,pass Calculated, in the formula The thickness affected by grouting is measured in meters (m), with an empirical value of 5 to 10 meters. The porosity of rock mass fractures is dimensionless. The values ​​are obtained through core physical property testing, with empirical values ​​ranging from 0.05 to 0.15. The slurry pressure field distribution is solved based on the mass conservation equation and the momentum conservation equation; the pressure field calculation formula is expressed as follows:

[0100] ;

[0101] ;

[0102] In the formula, The density of the slurry is expressed in units of... The experience value is 1400 to 1600. ; This is the slurry velocity vector, with units of m / s; This refers to the slurry pressure, expressed in Pa. The gradient operator, when applied to a scalar field, yields a vector field, and when applied to a vector field, it yields either a scalar or tensor field. The slurry velocity field distribution is obtained by solving the momentum conservation equation. This distribution reflects the flow direction and velocity of the slurry within the fracture network. The slurry concentration field distribution is solved based on the mass transport equation, and the formula for calculating the concentration field is as follows:

[0103] ;

[0104] In the formula, The concentration of cement particles in the grout, in units of ; This is the slurry diffusion coefficient, in units of... experience value to .

[0105] The specific implementation of step S50 involves establishing a two-layer game optimization model based on the calculated values ​​of the grout diffusion radius and the filling rate. The upper-layer model aims to maximize the compressive strength of the consolidated body, while the lower-layer model aims to minimize the grout usage. The calculated grout diffusion radius is used as a coupling parameter to connect the objective functions of the upper and lower models. The optimal grouting pressure and water-cement ratio are obtained by solving for the Nash equilibrium point. The objective function of the upper-layer model is expressed as follows:

[0106] ;

[0107] In the formula, This is the predicted compressive strength of the consolidated body, in MPa. This is the baseline compressive strength value, in MPa, with an empirical value of 20 to 30 MPa. The filling rate influence coefficient is dimensionless, with an empirical value of 0.6 to 0.8. The hydration age is expressed in days (d). For reference age, the unit is days (d), and the empirical value is 1 day. Among them, The objective function of the lower-level model is determined based on the grouting construction plan.

[0108] ;

[0109] In the formula, This is the predicted total amount of slurry used, in units of... ; This refers to the consumption of slurry per unit volume, in units of... ; This refers to the grouting time, expressed in hours (h). This is the baseline grouting pressure, expressed in MPa, with an empirical value of 2 to 3 MPa. Obtained through grouting pump flow monitoring; The relationship between the water-cement ratio of the grout and the Bingham yield stress of the grout is determined according to the grouting construction plan. The formula is expressed as follows:

[0110] ;

[0111] In the formula, The reference yield stress is expressed in Pa, with an empirical value of 10 to 50 Pa. The water-cement ratio of the slurry is dimensionless. For reference, the water-cement ratio is dimensionless and has an empirical value of 0.8; The water-cement ratio influence index is dimensionless, with an empirical value of 2.0 to 3.0. The formula expressing the influence of the slurry water-cement ratio on the initial viscosity of the slurry is as follows:

[0112] ;

[0113] In the formula, For reference initial viscosity, the unit is... The empirical value is 0.02 to 0.05. ; The water-cement ratio is the exponent of its influence on viscosity; it is dimensionless and has an empirical value of 1.5 to 2.5. The Nash equilibrium point is determined using an iterative algorithm, with the water-cement ratio of the slurry being the decision variable in the upper-level model. The decision variable in the lower-level model is the grouting pressure. The iterative formula is expressed as follows:

[0114] ;

[0115] ;

[0116] In the formula, The grouting pressure for the kth iteration is expressed in MPa. Let be the water-cement ratio of the slurry in the k-th iteration, which is dimensionless; and The iteration step size parameter is dimensionless and has an empirical value of 0.01 to 0.05. Let be the partial derivative of the lower-level objective function with respect to the grouting pressure, in units of . ; For reference partial derivative values, the unit is . The experience value is 1. ; This is the partial derivative of the upper-level objective function with respect to the water-cement ratio, in MPa; The reference partial derivative value is in MPa, with an empirical value of 10 MPa. The iteration termination condition is... and ,in This is the pressure convergence threshold, in MPa, with an empirical value of 0.01 MPa. The water-cement ratio convergence threshold is dimensionless and has an empirical value of 0.01.

[0117] The specific implementation of step S70 involves establishing a three-dimensional finite element model of the interaction between the drill pipe and the formation. Beam elements are used to simulate the drill pipe structure, and solid elements are used to simulate the formation structure. A contact algorithm is used to handle the frictional boundary between the drill pipe and the borehole wall. The self-weight load, drill pressure load, torque load, and formation lateral pressure load are input. The stress distribution and bending deformation of each section of the drill pipe are solved, and the location of the critical section where the actual stress of the drill pipe section exceeds 0.85 times the allowable stress of the drill pipe is identified. The formula for calculating the stress of the drill pipe section is as follows:

[0118] ;

[0119] In the formula, The stress is the combined stress of the drill pipe section, in MPa. This represents axial stress, measured in MPa. The stress is bending stress, and the unit is MPa. Shear stress, in MPa; , , All values ​​are reference stresses, in MPa, and empirical values ​​are all 100 MPa. This is a comprehensive stress reference value, in MPa, with an empirical value of 100 MPa. Among them, Caused by the self-weight of the drill pipe and the drilling pressure load, the calculation formula is as follows: In the formula This represents the weight of the drill pipe, expressed in N. This refers to the drilling load, expressed in N (N). This represents the cross-sectional area of ​​the drill pipe, in units of... .in, The calculation formula is In the formula Density of drill pipe material, unit: The experience value is 7850. ; This is the acceleration due to gravity, in units of 1. The value is 9.8 ; This refers to the drill pipe length, in meters (m). Pressure from the drilling rig's hydraulic system and piston area The calculation formula is as follows: In the formula The unit is Pa. Units are ; The calculation formula is In the formula The outer diameter of the drill pipe is in meters (m). This is the inner diameter of the drill pipe, in meters (m). Caused by bending moment, the calculation formula is: In the formula The bending moment is expressed in units of 1000 ppm. ; This is the distance to the neutral axis, in meters. The moment of inertia of the cross section is expressed in units of 1000 m / s. .in, Obtained by solving the finite element model; Values ; The calculation formula is . Caused by torque, the calculation formula is: In the formula Torque load, unit: ; The outer radius of the drill pipe is in meters (m). The polar moment of inertia, in units of . .in, The calculation formula is In the formula This refers to the output power of the drilling rig's power system, measured in kW. The drill pipe rotation speed is expressed in r / min; the constant 9550 is the conversion factor between power, rotation speed, and torque to ensure the consistency of the formula dimensions. Values ; The calculation formula is The formula for calculating the allowable stress of drill pipe is as follows:

[0120] ;

[0121] In the formula, This represents the allowable stress of the drill pipe, in MPa. The yield strength of the drill pipe material is expressed in MPa, with an empirical value of 400 to 600 MPa. The safety factor is dimensionless and has an empirical value of 1.5 to 2.0. The criteria for determining the critical section are as follows: For cross-sectional locations that meet this condition, a stabilizer needs to be added or a thicker drill rod needs to be used.

[0122] To better understand and implement this invention, the following is a specific application scenario of this invention, Example 2:

[0123] A technical team applied the pipe roof drilling method of this invention in a pumped storage power station tunnel project. The construction area was a silty slate slope with complex geological conditions, including multiple fault fracture zones and interbedded hard quartz veins. An advanced large-scale pipe roof support system was required at the tunnel entrance to ensure construction safety. Based on the engineering geological survey report, the technical team determined that the total length of the pipe roof was 40m, using seamless steel pipes with a diameter of 108mm and a wall thickness of 6mm, with a circumferential spacing of 0.4m and an outward insertion angle of 2 degrees. A total of 85 pipe roof steel pipes were required.

[0124] The technical team first carried out the installation and positioning of the guide pipes. Before pouring concrete for the arch foot foundation, they prepared the guide pipe assembly, selecting seamless steel pipes with a diameter of 140mm, a wall thickness of 6mm, and a length of 2.0m as the guide pipes. Eighty-five guide pipes were welded and fixed to four 18-beam steel frames at a circumferential spacing of 0.4m. Every 0.5m, a reinforcing rib with a thickness of 8mm and a width of 50mm was welded to the outer wall of each guide pipe, connecting it to the I-beam steel frame to form a spatially stable structure. Figure 2 As shown, after the guide tube assembly was welded, a theodolite was used for three-dimensional positioning calibration. The three-dimensional coordinates of the two ends of each guide tube were measured, and the spatial position of the guide tube centerline was calculated. Initial measurements revealed that the centerline position deviation of guide tube No. 23 was 12mm, exceeding the control requirement of 9mm. After adjusting the posture of the I-beam frame, the technical team remeasured, and the centerline position deviation of guide tube No. 23 was reduced to 7mm, meeting the accuracy requirements. The centerline position deviation of all 85 guide tubes was controlled within 9mm. Concrete pouring adopted a layered thin-layer vibration method, with each layer controlled at 350mm thickness. A 50mm diameter vibrator was used to compact each layer. During the pouring process, the theodolite was used to remeasure the centerline position of the guide tubes every hour to ensure that the guide tubes did not shift before the concrete solidified.

[0125] After the pipe roof drilling rig was in place, drilling operations began. The technical team first conducted a test drill on the No. 1 pipe roof hole, guiding the front end of the drill rod into the guide tube to achieve coaxial positioning, and starting drilling with an external insertion angle of 2 degrees. Figure 3As shown, drilling was stopped every 3 meters during the drilling process, and an inclinometer was lowered to monitor the trajectory. At the 9-meter mark, the borehole inclination angle was measured at 2.4 degrees, which was 0.4 degrees lower than the design value of 2 degrees, exceeding the 0.3-degree correction threshold. The azimuth angle was measured at 185 degrees, which was 5 degrees lower than the design value of 180 degrees. The technical team determined that the borehole trajectory had deviated and needed correction. An eccentric drill bit was used instead of the conventional drill bit. Based on the direction of the deviation, the azimuth angle of the eccentric drill bit was adjusted to 175 degrees, and the drilling pressure was increased from the baseline 120 kN to 156 kN. After drilling for another 3 meters, the borehole inclination angle was measured again, and it returned to 2.1 degrees. The azimuth angle returned to 182 degrees, indicating good trajectory correction.

[0126] When drilling reached the 18m mark, the technical team used ground-penetrating radar (GPR) to detect the underlying geological structure. The GPR emits high-frequency electromagnetic waves at 200MHz, and after receiving the reflected signals, the calculated rock wave velocity was 4680m / s, indicating a hard quartz vein section ahead. As shown in Table 1, the technical team adjusted drilling parameters according to the lithology. In the hard quartz vein section, the drilling rig speed was reduced from the baseline 80r / min to 56r / min, and the drilling pressure was increased from the baseline 120kN to 168kN, maintaining stable drilling efficiency. When drilling reached the 27m mark, the GPR detected a rock wave velocity of 2180m / s, indicating the entry into a silty soft rock section. The technical team then increased the drilling rig speed to 104r / min and reduced the drilling pressure to 90kN to prevent the drill bit from getting stuck in the soft rock and causing a mud-packing effect.

[0127] Table 1 Drilling Parameter Adjustment Table for Different Lithology Sections

[0128]

[0129] When the drilling reached a depth of 33m, the technical team encountered a fault fracture zone. The drilling resistance suddenly decreased, and a large amount of rock cuttings and powder appeared in the returned cuttings, indicating that they had entered a fractured section. The team established a fluid-structure interaction model for grout seepage and diffusion to optimize grouting parameters. The Bingham yield stress of the grout was measured to be 18 Pa using a rotational viscometer, and the time-varying viscosity coefficient was determined to be 0.0032 using a Brinell viscometer. The initial permeability of the rock mass was measured to be 3.6 × 10⁻⁶ through borehole water pressure testing. The stress sensitivity coefficient of the rock mass was determined to be 0.15 through triaxial seepage tests. The measured values ​​are input into a fluid-structure interaction model for grout seepage and diffusion. The model divides the rock mass fracture network into a finite difference grid of 0.05m × 0.05m × 0.05m, and uses the finite difference method to solve the coupled system of the Navier-Stokes equations and Darcy's law. Figure 4As shown, the model outputs the calculated values ​​of grout diffusion radius and filling rate under different grouting pressure settings. When the grouting pressure setting is 1.5MPa, the calculated value of grout diffusion radius is 2.8m and the calculated value of filling rate is 68%. When the grouting pressure setting is 2.5MPa, the calculated value of grout diffusion radius is 4.2m and the calculated value of filling rate is 85%.

[0130] The technical team established a two-layer game-theoretic optimization model based on the calculated values ​​of grout diffusion radius and filling rate. The upper-layer model aims to maximize the compressive strength of the consolidated body, using the calculated grout diffusion radius, filling rate, and hydration age of 28 days as input parameters. The lower-layer model aims to minimize grout consumption, using the set grout pressure, grout consumption per unit volume, and grouting time as input parameters. The Nash equilibrium point was solved using a successive approximation method. The initial grouting pressure was set at 2.0 MPa and the grout water-cement ratio at 0.8. After 15 iterations, the optimized grouting pressure corresponding to the Nash equilibrium point was obtained as 2.2 MPa, and the optimized grout water-cement ratio as 0.75. At this point, the predicted compressive strength of the consolidated body was 8.6 MPa, meeting the 5.0 MPa strength standard required for support. The predicted total grout consumption was 186... The technical team optimized the grouting pressure and the water-cement ratio of the grout for the grouting operation. First, a water glass-cement dual-liquid grout was used for pre-grouting and sealing. The modulus of water glass was adjusted to 3.2, and the concentration of cement grout was adjusted to a water-cement ratio of 1.0, so that the setting time of the dual-liquid grout was controlled at 18 seconds. After the pre-grouting was completed, ordinary cement grout was injected for reinforcement after the dual-liquid grout had set for 2 hours. In the extremely broken section, ultrafine cement with an average particle size of 8μm was used and 4% bentonite by mass was added to increase the viscosity of the grout.

[0131] The technical team established a three-dimensional finite element model of the interaction between the drill pipe and the formation to analyze the mechanical response of the drill pipe in a 40m long borehole. Beam elements were used to simulate the drill pipe structure, with an outer diameter of 89mm and a wall thickness of 9mm. Solid elements were used to simulate the formation structure. A contact algorithm was used to handle the frictional boundary conditions between the drill pipe and the borehole wall, setting the friction coefficient to 0.3. Figure 5 As shown, the input drill pipe self-weight load is 1850N, the drill pressure load is 120000N, and the torque load is 4500N. The formation lateral pressure load was 0.8 MPa. The model solution obtained the stress distribution and bending deformation of each section of the drill pipe, identifying three critical section locations between the 28m and 32m borehole depths. The actual stress of the drill pipe section at these critical section locations was 286 MPa, exceeding the allowable stress of 320 MPa by 0.85 times, or 272 MPa. The technical team added stabilizers at these critical section locations. The stabilizers had an outer diameter of 107 mm and were placed every 6m, with three stabilizers added at the 28m, 30m, and 32m locations. After recalculation, the actual stress of the drill pipe section at the critical section locations decreased to 248 MPa, which is less than 0.85 times the allowable stress, meeting the safety requirements.

[0132] As shown in Table 2, the technical team completed the drilling and grouting operations for all 85 pipe roof holes. The drilling trajectory deviation and grouting effect of each pipe roof hole were statistically analyzed. The average hole inclination angle deviation was 0.18 degrees, the average azimuth angle deviation was 0.23 degrees, both of which met the control requirement of 0.3 degrees. The average grout diffusion radius was 3.9 m, the average filling rate was 82%, and the average compressive strength of the consolidated body was 8.2 MPa. The overall stability of the pipe roof support system was good.

[0133] Table 2 Statistical Table of Pipe Roof Construction Quality

[0134]

[0135] The advancements of this invention compared to traditional methods lie in the fact that the spatial stabilization structure fixing technology for the guide tube solves the problem of guide tube displacement during concrete pouring caused by traditional simple support fixing methods through multi-point constraints and rigid connection principles. Combined with layered thin-layer vibration to avoid lateral pressure concentration, this significantly improves the positioning accuracy of the guide tube, laying the foundation for subsequent borehole trajectory control. The fluid-structure interaction modeling and two-layer game optimization technology for grout seepage diffusion overcomes the limitations of traditional empirical formula methods that ignore changes in grout rheological properties and the influence of rock deformation. Through multi-physics field coupling simulation, it accurately predicts grout diffusion behavior, and combined with the two-layer game optimization model, it minimizes grout usage while ensuring support strength, avoiding the blind selection of grouting pressure and grout ratio in traditional methods. The three-dimensional finite element analysis technology for drill rod-formation interaction overcomes the shortcomings of traditional simplified calculation methods that treat the drill rod as a simply supported beam or cantilever beam and ignore the constraints of the formation. By comprehensively considering various load conditions and contact friction boundaries, it truly reflects the stress characteristics of the drill rod, providing a quantitative basis for stabilizer placement and the selection of thicker drill rods, preventing drill rod buckling failure during long-distance drilling. The synergistic effect of the three key technologies has constructed a refined control system for the entire process of pipe roof drilling construction. From ensuring the positioning accuracy before drilling to real-time correction of the drilling trajectory, and then to the optimization design of grouting parameters and the safety protection of the drill rod, a complete technical closed loop has been formed, which has significantly improved the construction quality and support effect of the pipe roof system under complex geological conditions.

[0136] The following is a simplified construction scenario example 3 of the present invention: A technical team applied the pipe roof drilling method of the present invention in a mountain tunnel project. The tunnel entrance is located at the junction of strongly weathered mudstone and moderately weathered sandstone, with a stratum dip angle of approximately 35 degrees and obvious soft and hard interlayering. According to the design requirements, 29 advanced pipe roof steel pipes need to be constructed at the tunnel entrance section, with a total pipe roof length of 30m. Seamless steel pipes with a diameter of 108mm and a wall thickness of 6mm are used, with a circumferential spacing of 0.5m and an outward insertion angle of 2 degrees.

[0137] like Figure 6 As shown, the technical team first carried out the installation of guide pipes. Before pouring the concrete for the arch foot foundation, 29 guide pipes, each 140mm in diameter, 6mm thick, and 2.0m long, were welded onto an I-beam frame at the designed spacing. Reinforcing ribs were welded to the outer wall of each guide pipe every 0.5m to form a spatially stable structure. A theodolite was used to perform three-dimensional positioning calibration of the guide pipe assembly. The measurement results showed that the deviation of the centerline position of all guide pipes was controlled within 8mm, meeting the accuracy requirements. During concrete pouring, a layered, thin-layer vibration method was used, with each layer controlled to a thickness of 350mm. The position of the guide pipes was continuously monitored during the pouring process to ensure no deviation occurred.

[0138] After the pipe roof drilling rig was in place, drilling began on the first pipe roof borehole. The drill rod tip was guided into the guide pipe for coaxial positioning, and drilling was started with an external insertion angle of 2 degrees. During drilling, the borehole inclination angle and azimuth angle were measured every 3 meters. At the 6-meter mark, the borehole inclination angle was measured at 2.2 degrees, a deviation of 0.2 degrees from the design value of 2 degrees. The azimuth angle was measured at 178 degrees, a deviation of 2 degrees from the design value of 180 degrees. Both were within the 0.3-degree control range and no correction was required. When the technical team continued drilling to the 12-meter mark, they used ground-penetrating radar to detect the geological structure ahead. The radar transmission frequency was 250MHz, and the measured rock wave velocity was 4350m / s, indicating that the section ahead was a moderately weathered sandstone hard rock. Adjust the drilling parameters according to the rock type, reduce the drilling speed from the reference speed of 75 r / min to 52 r / min, increase the drilling pressure from the reference drilling pressure of 115 kN to 161 kN, and stabilize the drilling speed at 1.9 m / h.

[0139] At the 19m mark, the ground-penetrating radar detected a sudden drop in rock velocity to 2380m / s, indicating the entry into a section of strongly weathered mudstone soft rock. The technical team immediately adjusted the drilling parameters, increasing the drill speed to 98r / min and reducing the drilling pressure to 86kN to prevent the drill bit from getting stuck in the soft rock. Continuing to drill to the 21m mark, the borehole inclination gauge measured an inclination angle of 2.5 degrees, exceeding the 0.3-degree correction threshold by 0.5 degrees. The azimuth measurement was 175 degrees, with an azimuth deviation of 5 degrees. The technical team determined that the borehole trajectory had significantly deviated and used an eccentric drill string for trajectory correction. Based on the direction of the deviation, the azimuth angle of the eccentric drill string was adjusted to 170 degrees, and the drilling pressure was increased to 138kN. After drilling 3m further, the inclination angle was measured again, returning to 2.1 degrees, and the azimuth angle to 179 degrees, indicating successful trajectory correction.

[0140] At a drilling depth of 25m, a fractured section was encountered, resulting in a significant decrease in drilling resistance and the appearance of broken rock fragments in the cut-back. The technical team established a fluid-structure interaction model for grout seepage and diffusion to design grouting parameters. Field tests determined the Bingham yield stress of the grout to be 16 Pa and the time-varying viscosity coefficient to be 0.0028 Pa. The initial permeability of the rock mass is 4.2 × The rock mass stress sensitivity coefficient is 0.18. The measured values ​​were input into the model for calculation. The model divided the fracture network into a finite difference grid and then solved for the distribution of grout pressure, grout velocity, and grout concentration fields. Parameter optimization was performed using a two-layer game theory optimization model. The upper-layer model aimed to maximize the compressive strength of the consolidated body, while the lower-layer model aimed to minimize the grout usage. After iterative calculation, the optimized grouting pressure was obtained at 2.0 MPa, and the optimized water-cement ratio was 0.8. The technical team used the optimized parameters to perform the grouting operation. First, pre-grouting and sealing were performed using a water glass-cement dual-liquid grout. The water glass modulus was adjusted to 3.0, and the setting time of the dual-liquid grout was controlled within 15 seconds. After the dual-liquid grout had initially set, ordinary cement grout was injected for reinforcement. After grouting, the compressive strength of the consolidated body reached 7.8 MPa, meeting the support requirements.

[0141] The technical team established a three-dimensional finite element model of the interaction between the drill rod and the formation to analyze the stress state of the drill rod in a 30m long borehole. Inputting the drill rod's self-weight load, drilling pressure load, torque load, and formation lateral pressure load, the model identified two critical section locations between 22m and 26m in the borehole depth. The actual stress at the drill rod section was 278MPa, exceeding the allowable stress of 310MPa by 0.85 times, or 264MPa. The team added stabilizers at the critical section locations. The stabilizers had an outer diameter of 107mm, with one stabilizer at each of the 22m and 26m locations. After adding the stabilizers, the stress at the critical section decreased to 242MPa, meeting the safety requirements. Finally, the construction of all 29 pipe roof boreholes was completed, with an average borehole inclination angle deviation of 0.16 degrees and an average azimuth angle deviation of 0.21 degrees. The overall stability of the pipe roof support system was good, providing reliable support for the tunnel portal excavation.

[0142] It should be noted that the variables involved in this invention are explained in detail in Tables 3 and 4.

[0143] Table 3. Variable Explanation Table (Part 1)

[0144]

[0145] Table 4. Variable Explanation Table (Part Two)

[0146]

[0147] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A drilling method using a pipe roof drilling rig, characterized in that, Before pouring concrete for the arch foot foundation, the guide pipe is welded and fixed to the I-beam frame, and three-dimensional positioning calibration is performed using a theodolite to control the deviation of the guide pipe's centerline position within 9mm. Reinforcing ribs are welded to the outer wall of the guide pipe every 0.5m to form a spatially stable structure. During concrete pouring, layered thin-layer vibration is used to prevent deviation of the guide pipe's axis. After the pipe roof drilling rig is in place, the drill rod tip is inserted into the guide pipe to start drilling. During drilling, the borehole inclination angle and azimuth angle are measured every 3m. When the borehole inclination angle or azimuth angle deviation exceeds 0.3 degrees, an eccentric drill bit is used to adjust the drilling pressure and correct the trajectory. Based on the drilling progress... Drilling parameters were adjusted based on lithological differences in the formation. A fluid-structure interaction model for grout seepage and diffusion was established, inputting the measured values ​​of the grout Bingham yield stress, the time-varying viscosity coefficient, the initial permeability of the rock mass, and the stress sensitivity coefficient of the rock mass. The distribution of the grout pressure field, the grout velocity field, and the grout concentration field were solved, and the calculated values ​​of the grout diffusion radius and the filling rate were output. Based on the calculated values ​​of the grout diffusion radius and the filling rate, a two-layer game optimization model was established to solve for the Nash equilibrium point and obtain the optimized grouting pressure value and the optimized grout water-cement ratio. Grouting operations were performed using the optimized grouting pressure value and the optimized grout water-cement ratio.

2. The drilling method using a pipe roof drilling rig according to claim 1, characterized in that, Controlling the centerline position deviation of the guide tube to within 9mm means using theodolite three-dimensional positioning calibration technology to monitor the centerline coordinates of the guide tube in real time during the installation process, ensuring that the three-dimensional spatial deviation between the actual position of the guide tube and the designed position of the guide tube does not exceed 9mm.

3. The drilling method using a pipe roof drilling rig according to claim 2, characterized in that, A spatially stable structure refers to a multi-point support system formed by reinforcing ribs welded every 0.5m on the outer wall of the guide tube and an I-beam frame. This system resists lateral compressive forces and vibration impacts during the concrete pouring process through rigid connections.

4. The drilling method using a pipe roof drilling rig according to claim 3, characterized in that, Layered thin-layer vibration compaction refers to pouring concrete in layers with each layer controlled to a thickness of 300mm to 400mm, and using a vibrator to compact each layer one by one to avoid the formation of concentrated lateral pressure around the guide pipe.

5. The drilling method using a pipe roof drilling rig according to claim 4, characterized in that, The borehole inclination angle is the angle between the borehole axis and the horizontal plane, which is obtained by measuring the borehole inclination instrument. The azimuth angle is the angle between the projection of the borehole axis onto the horizontal plane and the due north direction, which is obtained by measuring the borehole inclination instrument.

6. The drilling method using a pipe roof drilling rig according to claim 5, characterized in that, An eccentric drill bit is a corrective drill bit that has an eccentricity between the centerline of the drill bit and the axis of the drill rod. By adjusting the azimuth angle and drilling pressure of the eccentric drill bit, a directional corrective force is applied to the borehole that deviates from the design trajectory during the drilling process.

7. The drilling method using a pipe roof drilling rig according to claim 6, characterized in that, The steps for adjusting drilling parameters based on the differences in lithology of the drilling strata are as follows: Specifically, the rock type is determined by obtaining the wave velocity value of the rock strata ahead through ground-penetrating radar detection; in hard quartz vein sections, the drilling speed is reduced to 0.6 to 0.8 times the reference speed and the drilling pressure is increased to 1.2 to 1.5 times the reference drilling pressure.

8. The drilling method using a pipe roof drilling rig according to claim 7, characterized in that, The fluid-structure interaction model for grout seepage diffusion is a mathematical and physical model that comprehensively considers the flow characteristics of grout in fractured rock mass and the interaction between rock mass deformation. It couples the Bingham rheological properties of grout, time-varying viscosity of grout, grout hydration reaction kinetics, and stress sensitivity of rock mass permeability.

9. The drilling method using a pipe roof drilling rig according to claim 8, characterized in that, The Bingham yield stress of slurry refers to the minimum shear stress that the slurry needs to overcome to begin flowing. It is obtained by measuring the shear stress at different shear rates using a rotational viscometer and fitting the Bingham rheological equation.

10. The drilling method using a pipe roof drilling rig according to claim 9, characterized in that, The time-varying viscosity coefficient of grout refers to the dynamic parameter of grout viscosity changing over time. As the cement hydration reaction continues, the grout viscosity gradually increases with the extension of grouting time. It is obtained by measuring the apparent viscosity of grout at different ages using a Brookfield viscometer and fitting a time function.

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