A method and control system for optimizing rock breaking efficiency of a TBM cutter based on coupling of penetration and cutter spacing

Abstract

The application discloses a TBM cutter rock breaking efficiency optimization method and control system based on penetration and cutter spacing coupling, comprising: constructing a double-cutter rock breaking linear cutting numerical model, wherein the double-cutter rock breaking linear cutting numerical model is a discrete element model; simulating the double-cutter rock breaking linear cutting numerical model, and calculating the rock breaking specific energy consumption under the cutting action of different penetrations and cutter spacings according to the simulation result, wherein the rock breaking specific energy consumption is calculated according to mechanical parameters and lithology parameters; fitting the rock breaking specific energy consumption under different penetrations, and obtaining an optimal cutter spacing according to the fitting result, calculating the cutter spacing and penetration ratio according to the optimal cutter spacing; obtaining an optimal penetration and cutter spacing combination according to the trend of the cutter spacing and penetration ratio; and adjusting the penetration and cutter spacing of the TBM cutter according to the optimal penetration and cutter spacing combination, so as to improve the rock breaking efficiency and construction speed of the TBM.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tunnel excavation construction, and particularly relates to a TBM disc cutter rock breaking efficiency optimization method and control system based on penetration and disc cutter spacing coupling. BACKGROUND

[0002] Full-face tunnel boring machine (TBM) has become the core equipment of underground engineering construction due to its advantages of high efficiency, safety and continuous construction. The rock breaking efficiency directly affects the project progress and economic benefits, and the performance of the disc cutter, as the core rock breaking component, is significantly restricted by the interaction of penetration and disc cutter spacing. The key challenge faced by the current TBM intelligent upgrading is that previous researchers have focused on the influence of a single parameter of penetration or disc cutter spacing on rock breaking efficiency, ignoring the coupling effect of the two, resulting in problems such as accelerated tool wear, rising energy consumption and unstable excavation efficiency, which further affects the overall performance and construction progress of the TBM, making it difficult to adapt to the precise control requirements under complex geological conditions.

[0003] The current control system of TBM relies on artificial experience or fixed parameter settings, lacking the ability to perceive real-time geological changes and dynamically adjust. In complex geological conditions, this static control method is difficult to adapt to the rapidly changing construction environment, causing the disc cutter to deviate from the optimal state, affecting the rock breaking efficiency and equipment life. SUMMARY

[0004] To solve the above technical problems, the application proposes a TBM disc cutter rock breaking efficiency optimization method and control system based on penetration and disc cutter spacing coupling. A new optimization method is proposed by considering the coupling relationship between penetration and disc cutter spacing, and a corresponding intelligent control system is designed to realize real-time monitoring and intelligent adjustment of disc cutter parameters, which can significantly improve the adaptability of TBM in complex strata, improve the rock breaking efficiency and construction speed of TBM, to solve the problems existing in the prior art.

[0005] To achieve the above purpose, the application provides a TBM disc cutter rock breaking efficiency optimization method based on penetration and disc cutter spacing coupling, comprising:

[0006] A double disc cutter rock breaking linear cutting numerical model is constructed, wherein the double disc cutter rock breaking linear cutting numerical model is a discrete element model;

[0007] The double disc cutter rock breaking linear cutting numerical model is simulated, and the rock breaking specific energy consumption under the cutting action of different disc cutters is calculated according to the simulation results, wherein the rock breaking specific energy consumption is calculated according to the mechanical parameters and lithology parameters;

[0008] Fitting the rock breaking specific energy consumption under different penetration depths, and obtaining an optimal tool spacing according to the fitting result, and calculating a tool spacing and penetration depth ratio according to the optimal tool spacing;

[0009] According to the trend of the tool spacing and penetration depth ratio, an optimal penetration depth and tool spacing combination is obtained;

[0010] According to the optimal tool spacing and penetration depth combination, the penetration depth and tool spacing of the TBM cutter are adjusted.

[0011] Optionally, the construction process of the double-cutter rock breaking linear cutting numerical model comprises:

[0012] Obtaining mechanical performance parameters of the cutter and mechanical performance parameters of the rock material, setting a three-dimensional calculation domain, and constructing a double-cutter ring geometry model in the three-dimensional calculation domain according to the mechanical performance parameters of the cutter, performing pure rolling constraint on the double-cutter geometry model, wherein the rolling speed is a linear translational speed, and the penetration depth is obtained according to the penetration depth, constructing a rock model, generating a multi-scale rock particle cluster of the rock model through a Voronoi tetrahedron subdivision algorithm, giving non-uniform compressive strength and tensile strength to the particle rock model through a Weibull distribution function according to the mechanical performance parameters of the rock material, constructing a contact bonding model of the multi-scale rock particle cluster, performing boundary and bottom surface constraint on the rock model, and constraining all degrees of freedom, establishing a face-face dynamic erosion contact algorithm through a normal vector separable contact model, generating a cutter-rock mass interface through the face-face dynamic erosion contact algorithm, and setting friction properties of the interface between the cutter and the rock mass to obtain the double-cutter rock breaking linear cutting numerical model.

[0013] Optionally, the process of simulating the double-cutter rock breaking linear cutting numerical model comprises:

[0014] The double-cutter rock breaking linear cutting numerical model is controlled in stages, and the first cutter cutting stage and the second cutter cutting stage are repeatedly alternated to complete the cutting of the cutter on the rock;

[0015] During the cutting process, based on the rock failure criterion of dynamic failure of particle bonding, a built-in bonding contact model is used to define the fracture condition, and the failed contacts are automatically deleted and the failed particles are screened out;

[0016] The average rolling rock breaking force and the average vertical rock breaking force of the double cutter during the cutting process are recorded, and the volume of the rock breaking area is calculated according to the effective failed particles.

[0017] Optionally, the process of obtaining the rock breaking specific energy consumption comprises:

[0018]

[0019] Wherein, SE represents the rock breaking specific energy consumption, F MRF is the average rolling rock breaking force of the disc cutter; F MV L is the average vertical rock breaking force of the disc cutter; L S P is the effective rolling cutting path of the disc cutter; P R V is the volume of the rock breaking area; V

[0020] Optionally, the formula for calculating the rock cuttability coefficient η is:

[0021]

[0022] σt is the tensile strength of the rock; σt t σc is the uniaxial compressive strength of the rock; σc c G is the shear modulus of the rock; G p Vp is the longitudinal wave velocity of the rock when breaking rock, Vp ρ is the density of the rock; ρ

[0023] Optionally, the optimal disc spacing is the lowest point of the second-order regression curve obtained by polynomial fitting of the rock breaking specific energy of different penetration depths, that is, the disc spacing corresponding to the minimum rock breaking specific energy.

[0024] Optionally, the process of obtaining the optimal penetration depth and disc spacing combination includes:

[0025] Obtain the trend linear fitting graph of the disc spacing and penetration depth ratio, and when the trend of the disc spacing and penetration depth ratio tends to be relatively stable, the disc spacing and penetration depth corresponding to the minimum rock breaking specific energy are the optimal penetration depth and disc spacing combination.

[0026] In another aspect, the present application provides a TBM disc cutter rock breaking control system based on the coupling of penetration depth and disc spacing, comprising:

[0027] a processing and optimization module, an execution module and a feedback module;

[0028] The basic data of the double-disc cutter rock breaking linear cutting numerical model is obtained by the processing and optimization module, and according to the basic data, the optimal disc spacing and penetration depth combination is obtained by using the above method;

[0029] The disc cutter penetration depth and disc spacing are controlled by the execution module according to the optimal disc spacing and penetration depth combination;

[0030] The real-time rock breaking specific energy is obtained by the feedback module, the real-time rock breaking specific energy is judged, and the optimal disc spacing and penetration depth combination is adjusted again by the processing and optimization module according to the judgment result.

[0031] Optionally, in the execution module, a manual control execution mode and a rolling control execution mode are included, in the manual control execution mode, the cutter penetration and the tool spacing are directly controlled according to the optimal cutter penetration and tool spacing combination, and in the rolling control execution mode, the rock breaking specific energy consumption is detected, the adjusted optimal cutter penetration and tool spacing combination is obtained in real time, and the cutter penetration and the tool spacing are controlled according to the adjusted optimal cutter penetration and tool spacing combination.

[0032] Optionally, the process of judging the real-time rock breaking specific energy consumption includes:

[0033] When the deviation of the real-time rock breaking specific energy consumption rises and exceeds a threshold value, the optimal cutter penetration and tool spacing combination is re-adjusted through the processing and optimization module, otherwise, no adjustment is performed.

[0034] Compared with the prior art, the present application has the following advantages and technical effects:

[0035] (1) The present application proposes a rock breaking efficiency optimization method based on the coupling of cutter penetration and tool spacing, a second-order regression curve is used to determine the optimal S / P value through polynomial fitting, which breaks through the limitation of traditional single parameter optimization. When calculating the rock breaking specific energy consumption SE, the method introduces the parameter of the rolling cutter and the time-varying friction energy consumption degradation coefficient of the rock mass, fully considers the energy efficiency improvement caused by friction overheating after the rolling cutter breaks rocks for a long time in actual engineering. The method accurately calculates the rock breaking specific energy consumption under different parameter combinations through numerical simulation, reduces the energy consumption and tool wear rate of the rolling cutter in complex strata, significantly improves the tunneling efficiency of the TBM in complex strata, reduces the construction cost and shortens the construction period. At the same time, through the fine simulation of the rock breaking process, the risks such as stuck cutter and cutter disc vibration are effectively predicted, and the construction safety and quality are guaranteed.

[0036] (2) The present application breaks through the traditional static control mode by constructing a closed-loop control system including data acquisition, numerical model, optimization algorithm and feedback mechanism, realizes real-time monitoring and dynamic adjustment of the rolling cutter parameters, and makes the TBM adapt to the lithology change of complex strata in real time, enhances the equipment adaptability. Combined with numerical simulation and real-time data feedback, the intelligent regulation and control of the rolling cutter parameters are realized, which provides technical support for the intelligent upgrading of the TBM, and promotes the tunnel construction to the direction of high efficiency, digitization and precision. BRIEF DESCRIPTION OF DRAWINGS

[0037] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the present application illustrated in the drawings and their descriptions are used to explain the present application and do not limit the present application. In the drawings:

[0038] Figure 1 The flowchart of the TBM rolling cutter rock breaking efficiency optimization method based on the coupling of cutter penetration and tool spacing of the embodiments of the present application;

[0039] Figure 2 For the linear cutting mode of the cutter of the embodiment of the application, a flowchart of a numerical model of double cutter rock breaking linear cutting is established by using PFC3D discrete element software;

[0040] Figure 3 For the flowchart of numerical simulation of the numerical model of double cutter rock breaking linear cutting loaded in PFC3D of the embodiment of the application;

[0041] Figure 4 For the flowchart of a TBM cutter rock breaking efficiency optimization control system based on the coupling of penetration and cutter spacing of the embodiment of the application;

[0042] Figure 5 For the linear fitting graph of rock breaking specific energy consumption under 1.9mm penetration of the embodiment of the application;

[0043] Figure 6 For the linear fitting graph of rock breaking specific energy consumption under 3.2mm penetration of the embodiment of the application;

[0044] Figure 7 For the linear fitting graph of rock breaking specific energy consumption under 3.8mm penetration of the embodiment of the application;

[0045] Figure 8 For the linear fitting graph of rock breaking specific energy consumption under 5.1mm penetration of the embodiment of the application;

[0046] Figure 9 For the linear fitting graph of rock breaking specific energy consumption under 6.4mm penetration of the embodiment of the application;

[0047] Figure 10 For the linear fitting graph of rock breaking specific energy consumption under 7.6mm penetration of the embodiment of the application. DETAILED DESCRIPTION

[0048] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a group of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0050] To solve the above technical problems, the present application provides a TBM cutter rock breaking efficiency optimization method and control system based on the coupling of penetration and cutter spacing.

[0051] The technical scheme provided by the present application is as follows:

[0052] A TBM cutter rock breaking efficiency optimization method based on the coupling of penetration and cutter spacing, comprising the following steps:

[0053] Based on the linear cutting mode of the cutter, a double-cutter rock breaking linear cutting numerical model is established by using PFC3D discrete element software;

[0054] Load the double-cutter rock breaking linear cutting numerical model in PFC3D for numerical simulation;

[0055] Use numerical simulation to calculate the rock breaking specific energy consumption under the action of different cutter penetrations and linear cutting of cutter spacing;

[0056] Polynomial fitting is performed on the rock breaking specific energy consumption under different penetrations, and the optimal cutter spacing is determined through a second-order regression curve, and the corresponding cutter spacing to penetration ratio S / P value is calculated;

[0057] The combination of the minimum rock breaking specific energy consumption when the S / P value tends to be stable is the optimal penetration and cutter spacing combination of the simulated rock;

[0058] Adjust the penetration and cutter spacing of the TBM cutter according to the optimal penetration and cutter spacing combination of the broken rock obtained by numerical simulation.

[0059] Further, as shown in Figure 2 The step of establishing a double-cutter rock breaking linear cutting numerical model based on the linear cutting mode of the cutter and using PFC3D discrete element software comprises:

[0060] Obtain the mechanical properties of the TBM cutter and the mechanical properties of the rock material;

[0061] Define a three-dimensional calculation domain through the domain extent command stream, which should be greater than 1.2 times the size of the preset cutter and rock, and set the x / y / z axis direction as the geological coordinate system;

[0062] According to the TBM parameters, extract the cutter parameters and action range, and establish a double-cutter ring geometric model through the command stream clump template createname. The double-cutter ring model is arranged in parallel with a preset spacing, and the axis spacing error is ≤1mm;

[0063] According to the penetration conversion linear translational velocity, set the rotation angular velocity of the cutter model through the wall attribute spin to realize pure rolling constraint, and set the same motion parameters for the two cutter models;

[0064] According to the geological exploration data, inverse the HJC constitutive model parameters of the rock, and give non-uniform compressive strength and tensile strength through the Weibull distribution function;

[0065] The generation of the non-uniform granular rock model is performed through a command stream ball generate, a Voronoi tetrahedron partitioning algorithm is used to generate a multi-scale rock particle cluster, and an initial porosity φ = 15% ± 5% is set;

[0066] A contact bonding model (BPM) of the particles inside the rock model is established through a command stream contact property, the bonding normal strength is defined as 110% of the uniaxial compressive strength of the rock, the tangent strength ratio is 0.35, the rock mass is subjected to a z-axis negative direction gravity through model gravity, and a self-weight stress field of the rock mass is simulated;

[0067] A no-reflection boundary is applied to four sides of the rock model through a command stream combination WALL-BOUNDARY-DAMPING, four fixed walls are generated using wall create plane to surround the rock domain, and local damping is set by wall attribute damp to absorb stress wave reflection;

[0068] The bottom surface of the rock model is fully constrained through a command stream combination WALL-FIX-BASE, the bottom wall is established through a command wall create plane, and all degrees of freedom are constrained by wall fix velocity spin;

[0069] A face-face dynamic erosion contact algorithm is established using a normal separable contact model linear-cohesive through a command stream contact model assignlinear-cohesive, a cutter-rock interface is generated, and the friction properties of the cutter-rock interface are defined.

[0070] Further, the defined friction properties of the cutter-rock interface are as follows: the static friction coefficient is set to 0.6, the dynamic friction coefficient is set to 0.4, the dynamic friction attenuation coefficient is set to 0.85, and the normal bonding strength of the rock below the cutter is set to 110% of the uniaxial compressive strength of the rock.

[0071] Further, the tangent strength ratio is the ratio of the tangent limit shear strength of the bonding to the normal limit tensile strength of the bonding.

[0072] Further, as shown in Figure 3 The step of loading the double-cutter rock breaking linear cutting numerical model in PFC3D for numerical simulation includes:

[0073] A stepwise cutting control is performed through a command stream combination Stepwise Cutting Control, the first cutter cutting stage and the second cutter cutting stage are repeatedly alternated to complete the cutting of the rock by the cutters.

[0074] Based on the rock failure criterion of particle bond dynamic failure, the fracture condition is defined using the built-in bond contact model (linear parallel bond), the failed contact is automatically deleted by the contact delete command, and the effective failed particles are screened by ball attribute dis;

[0075] Through the command stream history addwall force id<wall_id>component<x|y|z>

[0076] Record the average rolling rock breaking force F of the double cutter MR And the average vertical rock breaking force F MV ;

[0077] Record the rigid cutter displacement by the command stream history add wall displacement id<wall_id>component<x|y|z>, and calculate the effective path L of the cutter rolling cutting based on the displacement integral S ;

[0078] Screen the effective failed particles by the command stream ball list attribute disp, and calculate the volume V of the rock breaking area in the model loading process by measure volume region R .

[0079] Further, the step of the first cutter cutting stage of the staged cutting control is: in the first cutter cutting stage, the cutter two is fully constrained by wall.activate id=2off, the displacement control of the cutter one is activated by wall.vel id=1(v_x, v_y, 0), and the x-direction translational displacement and the rolling displacement around the y-axis of the cutter one are released;

[0080] Further, the step of the second cutter cutting stage of the staged cutting control is: in the second cutter cutting stage, the cutter one is fully constrained by wall.vel id=1off, the displacement control of the cutter two is activated by wall.vel id=2(v_x, v_y, 0), and the x-direction translational displacement and the rolling displacement around the y-axis of the cutter two are released;

[0081] Further, the defined rock failure criterion is that: for the rock particle units in contact with the cutter, when the maximum compressive stress is greater than the dynamic compressive strength of the rock, the rock failure can delete the unit; for the rock particle units between the cutters in contact with the cutter, when the tensile stress is greater than the tensile strength of the rock, the rock failure can delete the unit; for the rock particle units near the cutter (not in contact with the cutter but in contact with the rock particle units), when the inter-particle cohesive normal force exceeds the tensile strength, the cohesive fracture is triggered, and the rock failure can delete the unit.

[0082] Further, in the calculation content of the rock breaking specific energy, the present application does not use a simple mechanical index as an influencing variable, and as an improvement, the present application considers the influence of time-varying cutter wear and temperature rise friction on the rock breaking specific energy in the above rock breaking specific energy calculation process, quantifies the influence through related parameters, introduces the influence of friction on the final rock breaking specific energy calculation, considers the damage effect of rock breaking forces in different directions on the rock, quantifies the damage effect through related parameters to represent the influence of rock inherent properties on the final rock breaking specific energy, and finally quantifies the influence of different levels of principal stress on the difficulty and energy consumption in the rock breaking process to represent the influence of the stress environment of the rock on the rock breaking difficulty and energy consumption. Through the above different considerations, the present application provides a quantitative energy consumption calculation method that considers the coupling influence of multiple factors on the rock breaking process, comprehensively calculates the rock breaking specific energy from multiple influencing aspects, and provides a rock breaking specific energy calculation method under the coupling action of multiple factors.

[0083] The calculation formula of the rock breaking specific energy SE introduces the time-varying friction energy consumption degradation coefficient λ of the cutter and the rock mass to quantify the friction energy efficiency loss with cutter wear and temperature rise. The rock breaking specific energy SE comprehensively considers the damage effect of the rolling rock breaking force and the vertical rock breaking force on the rock, introduces the rock cuttability coefficient η to represent the influence of rock inherent properties on the rock breaking energy consumption, and introduces the maximum and minimum principal stresses of the rock to reflect the influence of the stress environment of the rock on the rock breaking difficulty and energy consumption.

[0084] Further, the calculation formula of the rock breaking specific energy SE is:

[0085]

[0086] wherein, F MR is the average rolling rock breaking force of the cutter, KN; F MV is the average vertical rock breaking force of the cutter, KN; L S is the effective rolling cutting path of the cutter, m; P is the penetration, mm; V R is the volume of the rock breaking area, 10 -5 m 3; λ is the time-varying friction energy consumption deterioration coefficient of the cutter and the rock mass; η is the rock cuttability coefficient; σ1 is the maximum principal stress of the rock; and σ3 is the minimum principal stress of the rock.

[0087] Further, the calculation formula of the rock cuttability coefficient η is as follows:

[0088]

[0089] wherein σ t is the tensile strength of the rock; σ c is the uniaxial compressive strength of the rock; G is the shear modulus of the rock; E is the elastic modulus of the rock; v p is the longitudinal wave velocity of the rock during rock breaking, ρ is the density of the rock; and υ is the Poisson's ratio of the rock.

[0090] Further, the optimal cutter spacing is the lowest point of the second-order regression curve obtained through polynomial fitting.

[0091] As shown in the accompanying drawings, Figure 4 the application further provides a TBM cutter rock breaking efficiency optimization control system based on the coupling of penetration and cutter spacing, the control system being used for realizing any one of the methods, and the system comprising: a rock-cutter interaction data acquisition module, a numerical model data processing and analysis module, a rock optimal S / P value optimization algorithm module, an artificial control execution module, a cutter rock breaking and feedback self-adaption module, a rock breaking stage S / P value optimization algorithm module, and a cutter control execution module.

[0092] The rock-cutter interaction data acquisition module comprises: real-time acquisition of geological data, inversion of the material mechanics performance parameters of the current broken rock, and transmission of the material mechanics performance parameters of the rock to the numerical model data processing and analysis module.

[0093] The numerical model data processing and analysis module comprises: modification of the numerical model parameters according to the material mechanics performance parameters of the rock, loading and running of the numerical model, and acquisition of the rock breaking data.

[0094] The rock optimal S / P value optimization algorithm module comprises: calculation of the rock breaking specific energy consumption according to the average rolling force, the rolling cutting distance, the rock breaking volume and other rock breaking data in the non-running state of the cutter, linear fitting of the different penetrations to determine the optimal cutter spacing, and determination of the optimal penetration and cutter spacing combination of the simulated broken rock.

[0095] The artificial control execution module comprises: adjusting the disc cutter spacing S in the non-running state of the TBM disc cutter according to the optimal penetration and spacing combination of the simulated broken rock, and dynamically adjusting the propulsion hydraulic system pressure and the disc cutter rotating speed to adjust the penetration P of the disc cutter after the TBM disc cutter resumes running, so that the penetration and spacing combination in the initial running stage of the TBM disc cutter is the optimal penetration and spacing combination of the simulated broken rock.

[0096] The disc cutter rock breaking and feedback adaptive module comprises: the disc cutter continuously breaks rock and monitors the rock breaking tunneling efficiency, if the rock breaking specific energy consumption deviation rises by 10%, the rock-disc interaction data acquisition module is triggered, the S / P value optimization algorithm module and the disc cutter control execution module in the running state of the disc cutter are used to feedback and adjust the penetration parameter.

[0097] The rock breaking stage S / P value optimization algorithm module comprises: in the running state of the disc cutter, the rock breaking specific energy consumption is calculated according to the average rolling force, the rolling cutting distance, the rock breaking volume and other rock breaking data, the optimal penetration is determined by linear fitting with the current disc cutter spacing, and the optimal penetration and spacing combination in the current rock breaking stage is determined.

[0098] The disc cutter control execution module comprises: dynamically adjusting the propulsion hydraulic system pressure and the disc cutter rotating speed to control the penetration P of the disc cutter according to the optimal penetration and spacing combination in the current rock breaking stage, calculating the rock breaking specific energy consumption SE of the current optimal penetration and spacing combination in real time, and transmitting to the disc cutter rock breaking and feedback adaptive module.

[0099] In view of the above scheme, the present application is described in detail in combination with related cases.

[0100] In this embodiment, as shown in Figure 1 A TBM disc cutter rock breaking efficiency optimization method based on penetration and spacing coupling, comprising the following steps:

[0101] Based on the linear cutting mode of the disc cutter, a double-disc cutter rock breaking linear cutting numerical model is established by using PFC3D discrete element software.

[0102] The double-disc cutter rock breaking linear cutting numerical model is loaded in PFC3D for numerical simulation.

[0103] The rock breaking specific energy consumption of rock under the action of different disc cutter penetrations and spacing linear cutting is calculated by numerical simulation.

[0104] The rock breaking specific energy consumption under different penetrations is polynomially fitted, the optimal spacing is determined by a second-order regression curve, and the corresponding spacing and penetration ratio S / P value is calculated.

[0105] The combination of the optimal penetration and the cutter spacing of the broken rock with the minimum energy consumption of the rock breaking is the optimal penetration and cutter spacing combination of the simulated rock when the S / P value tends to be stable;

[0106] The optimal penetration and cutter spacing combination of the broken rock obtained by the numerical simulation is used to adjust the penetration and cutter spacing of the TBM cutters.

[0107] Further, the step of establishing the linear cutting numerical model of the double cutters for breaking rock based on the linear cutting mode of the cutters and by using the PFC3D discrete element software comprises:

[0108] The mechanical performance parameters of the cutters of the used TBN and the mechanical performance parameters of the rock material are obtained, as shown in Tables 1 and 2:

[0109] Table 1

[0110] Density (kg / m3 3 )]]> Elastic modulus (Pa) Poisson's ratio 7850 2.1 x 10 11 ]]> 0.28

[0111] Table 2

[0112]

[0113] A three-dimensional calculation domain is defined by a domain extent command stream, the range of which should be greater than 1.2 times the size of the preset cutters and rock, and the x / y / z axis directions are set as the geological coordinate system;

[0114] The cutter parameters and the action range are extracted according to the TBM parameters, and a double-cutter ring geometric model is established by a command stream clump template createname, the double-cutter ring model is arranged in parallel according to a preset spacing, and the error of the axis spacing is less than or equal to 1 mm;

[0115] According to the conversion of the penetration into the linear translational velocity, the rotation angular velocity of the cutter model is set by a wall attribute spin to realize the pure rolling constraint, and the same motion parameters are set for the two cutter models;

[0116] The HJC constitutive model parameters of the rock are inverted according to the geological exploration data, the non-uniform compressive strength and tensile strength are given by a Weibull distribution function, and the HJC constitutive model parameters are shown in Table 3:

[0117] Table 3

[0118]

[0119]

[0120] The non-uniform granular rock model is generated by a command stream ball generate, a multi-scale rock particle cluster is generated by using a Voronoi tetrahedron subdivision algorithm, and the initial porosity φ is set to 15%±5%;

[0121] The contact property is used to establish the contact bonding model (BPM) of the particles inside the rock model by the command stream, the bonding normal strength is defined as 110% of the uniaxial compressive strength of the rock, the shear strength ratio is taken as 0.35, the model gravity is used to apply the gravity in the negative z-axis direction to the rock mass to simulate the self-weight stress field of the rock mass;

[0122] The command stream combination WALL-BOUNDARY-DAMPING is set to apply the non-reflecting boundary to the four sides of the rock model, the four fixed walls are generated by using the wall create plane to surround the rock domain, and the local damping is set by using the wall attribute damp to absorb the stress wave reflection;

[0123] The command stream combination WALL-FIX-BASE is set to fully constrain the bottom surface of the rock model, the bottom wall is established by using the wall create plane, and all degrees of freedom are constrained by using the wall fix velocity spin;

[0124] The linear-cohesive normal separable contact model is established by using the command stream contact model assignlinear-cohesive to establish the dynamic erosion contact algorithm of the surface-to-surface, the cutter-rock interface is generated, and the friction properties of the cutter-rock interface are defined.

[0125] Further, the defined friction properties of the cutter-rock interface are as follows: the static friction coefficient is set to 0.6, the dynamic friction coefficient is set to 0.4, the dynamic friction attenuation coefficient is set to 0.85, and the normal bonding strength of the rock below the cutter is set to 110% of the uniaxial compressive strength of the rock.

[0126] Further, the step of loading the linear cutting numerical model of the double-cutter rock breaking in PFC3D for numerical simulation comprises:

[0127] The command stream Stepwise Cutting Control is set to perform the stage-by-stage cutting control, the first cutter cutting stage and the second cutter cutting stage are repeatedly alternated to complete the cutting of the rock by the cutter;

[0128] Based on the rock failure criterion of the dynamic failure of the particle bonding, the built-in bonding contact model (linear parallel bond) is used to define the fracture condition, the failed contact is automatically deleted by using the contact delete command, and the effective failed particles are screened by using the ball attribute dis;

[0129] Record the average rolling rock breaking force F of double-roller cutter by the command stream history addwall force id<wall_id>component<x|y|z>

[0130] Record the average rolling rock breaking force F of double-roller cutter by the command stream history addwall force id<wall_id>component<x|y|z> MR and the average vertical rock breaking force F MV ;

[0131] Record the displacement of rigid roller cutter by the command stream history add wall displacement id<wall_id>component<x|y|z>, and calculate the effective rolling cutting path L of roller cutter based on displacement integral S ;

[0132] Screen the effective failure particles by the command stream ball list attribute disp, and count the volume V of rock breaking area in the model loading process by measure volume region R .

[0133] Further, the step of the first roller cutter cutting stage of the staged cutting control is: in the first roller cutter cutting stage, roller cutter two is fully constrained by wall.activate id=2off, roller cutter one is activated by wall.vel id=1(v_x, v_y, 0) to control the displacement, and the x-direction translational displacement and the rolling displacement around the y-axis of roller cutter one are released;

[0134] Further, the step of the second roller cutter cutting stage of the staged cutting control is: in the second roller cutter cutting stage, roller cutter one is fully constrained by wall.vel id=1off, roller cutter two is activated by wall.vel id=2(v_x, v_y, 0) to control the displacement, and the x-direction translational displacement and the rolling displacement around the y-axis of roller cutter two are released;

[0135] Further, the rock failure criterion is defined as follows: for the rock particle units in contact with the roller cutter directly below the roller cutter, when the maximum compressive stress is greater than the dynamic compressive strength of rock, the rock failure can delete the units; for the rock particle units in contact with the roller cutter between the roller cutters, when the tensile stress is greater than the tensile strength of rock, the rock failure can delete the units; for the rock particle units near the roller cutter (not in contact with the roller cutter but in contact with the rock particle units), when the inter-particle cohesive normal force exceeds the tensile strength, the cohesive fracture is triggered, and the rock failure can delete the units.

[0136] Further, the calculation formula of the rock breaking specific energy SE is:

[0137]

[0138] wherein, FMR F is the average rolling rock breaking force of the cutter, KN; KN MV F is the average vertical rock breaking force of the cutter, KN; KN S P is the penetration, mm; V is the effective path of rolling cutting of the cutter, m; KN R F is the volume of the rock breaking area, 10 -5 m 3 ; lambda is the time-varying friction energy consumption deterioration coefficient of the cutter and rock mass, the rock lambda = 0.28; eta is the rock cuttability coefficient; sigma1 is the maximum principal stress of the rock, sigma1 = 0.37; sigma3 is the minimum principal stress of the rock, sigma3 = 0.18.

[0139] Further, the calculation formula of the rock cuttability coefficient eta is:

[0140]

[0141] Wherein, sigma t is the tensile strength of the rock; sigma c is the uniaxial compressive strength of the rock; G is the shear modulus of the rock; E is the elastic modulus of the rock; v p is the longitudinal wave velocity of the rock when breaking rock, rho is the density of the rock; and v is the Poisson's ratio of the rock.

[0142] The process of simulating TBM rolling rock for 10 minutes is simulated, and the data obtained by numerical simulation and the rock breaking specific energy consumption are shown in Table 4:

[0143] Table 4

[0144]

[0145]

[0146] Further, as shown in Figures 5-10 , a linear fitting graph of rock breaking specific energy consumption under different penetrations is provided, and the optimal cutter spacing is the lowest point of the second-order regression curve obtained by fitting. Among them, the collected values in the above table 4 are actually collected values, but the collected values may be affected by outliers and interference, and the collected values are not accurate, and the measured values are only part of the data. Through the fitting of the above values, the influence of certain errors can be reduced, and the lowest point of the fitting curve is sought by fitting the above values to the fitting curve. The lowest point is more representative and universal than the minimum value in the data set which may be affected by outliers. Therefore, the application does not take the lowest value affected by the actual value as the optimal spacing, but takes the value of the lowest point of the fitted curve as the final optimal spacing.

[0147] In combination Figures 5-10The optimal tool spacing obtained by fitting curves under different penetration depths is shown in Table 5:

[0148] Table 5

[0149]

[0150] Further, the combination of the rock breaking specific energy minimum when the S / P value tends to be stable is the optimal penetration depth and tool spacing combination of this rock: penetration depth P = 6.4 mm, tool spacing S = 100.99 mm.

[0151] Further, the standard for the S / P value to tend to be stable is to arrange the penetration depths from small to large, and the range (the difference between the maximum value and the minimum value) of the S / P values of the adjacent four groups of data is less than or equal to 2.5, that is, the S / P values of this section of data are considered to tend to be stable.

[0152] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for optimizing rock breaking efficiency of TBM disc cutters based on coupling of penetration and cutter spacing, characterized in that, include: A numerical model for linear rock breaking and cutting by double roller cutters is constructed, wherein the numerical model for linear rock breaking and cutting by double roller cutters is a discrete element model. The numerical model for linear rock breaking by double roller cutter was simulated, and the rock breaking energy consumption under different roller cutter penetration and cutter spacing was calculated based on the simulation results. The rock breaking energy consumption was calculated based on mechanical parameters and lithological parameters. The rock breaking energy consumption under different penetration depths of the roller cutters is fitted, and the optimal cutter spacing is obtained based on the fitting results. The cutter spacing and penetration ratio are then calculated based on the optimal cutter spacing. Based on the trend of the ratio of tool spacing to penetration, the optimal combination of penetration and tool spacing is obtained; Adjust the penetration and tool spacing of the TBM hob according to the optimal combination of tool spacing and penetration. The construction process of the numerical model for linear rock breaking by double roller cutters includes: The mechanical performance parameters of the roller cutter and the mechanical performance parameters of the rock material are obtained. A three-dimensional computational domain is set up, and a geometric model of the double roller cutter ring is constructed in the three-dimensional computational domain according to the mechanical performance parameters of the roller cutter. Pure rolling constraints are applied to the geometric model of the double roller cutter, wherein the rolling speed is a linear translational speed obtained according to the penetration. A rock model is constructed, and a multi-scale rock particle cluster of the rock model is generated by the Voronoi tetrahedral partitioning algorithm. According to the mechanical performance parameters of the rock material, the particle rock model is given non-uniform compressive strength and tensile strength by the Weibull distribution function. A contact bonding model of the multi-scale rock particle cluster is constructed. Boundary and bottom constraints are applied to the rock model, and all degrees of freedom are constrained. A surface dynamic erosion contact algorithm is established using a normal vector separable contact model. The roller cutter rock mass interface is generated by the surface dynamic erosion contact algorithm, and the friction properties of the contact between the roller cutter and the rock mass at the interface are set to obtain a linear cutting numerical model of double roller cutter rock breaking.

2. The method according to claim 1, characterized in that, The simulation process of the numerical model for linear rock breaking by the double roller cutter includes: A staged cutting control was implemented for the linear cutting numerical model of double-roll cutter rock breaking. The first and second roller cutter cutting stages were repeatedly alternated to complete the cutting of the rock by the roller cutter. During the cutting process, based on the rock failure criterion of dynamic failure of particle bonding, the fracture conditions are defined using the built-in bonding contact model, and the failure contacts are automatically deleted and the failure particles are screened. Record the average rolling rock-breaking force and average vertical rock-breaking force of the double roller cutter during the cutting process, and calculate the volume of the rock fracture zone based on the effective failed particles.

3. The method according to claim 1, characterized in that, The process of obtaining the rock-breaking energy consumption includes: ， in, Indicates the energy consumption for rock breaking. This represents the average rolling rock-breaking force of the roller cutter; This represents the average vertical rock-breaking force of the roller cutter. This is the effective path for the rolling cutter; Penetration degree; The volume of the rock fracture zone; The degradation coefficient of time-varying frictional energy consumption between the cutter and the rock mass; The rock machinability coefficient; This represents the maximum principal stress in the rock. This represents the minimum principal stress in the rock.

4. The method according to claim 3, characterized in that, The rock machinability coefficient The calculation formula is: ， in, Tensile strength of rock; It represents the uniaxial compressive strength of the rock. For rock shear modulus; The elastic modulus of the rock; The longitudinal wave velocity of the rock during rock breaking. ; Density of the rock; The Poisson's ratio for rocks.

5. The method according to claim 3, characterized in that, The optimal cutter spacing is the lowest point of the second-order regression curve obtained by polynomial fitting of rock breaking energy consumption for different penetration depths, that is, the cutter spacing corresponding to the minimum rock breaking energy consumption.

6. The method according to claim 1, characterized in that, The process of obtaining the optimal combination of penetration depth and tool spacing includes: Obtain a linear fitting graph of the trend of the ratio of cutter spacing to penetration. When the trend of the ratio of cutter spacing to penetration tends to be relatively stable, the cutter spacing and penetration corresponding to the minimum rock breaking energy consumption is the optimal combination of penetration and cutter spacing.

7. A TBM cutter rock-breaking control system based on the coupling of penetration depth and cutter spacing, characterized in that, include: The module includes a processing and optimization module, an execution module, and a feedback module. The basic data of the linear cutting numerical model of double roller cutter rock breaking is obtained by the processing and optimization module. Based on the basic data, the optimal combination of cutter spacing and penetration is obtained by adopting the method described in any one of claims 1-6 above. The execution module controls the hob penetration and optimal tool spacing based on the optimal tool spacing and penetration combination. The real-time rock breaking energy consumption is obtained through the feedback module, and the real-time rock breaking energy consumption is judged. Based on the judgment result, the optimal cutter spacing and penetration depth combination is readjusted through the processing and optimization module.

8. The system according to claim 7, characterized in that, The execution module includes a manual control execution mode and a rolling control execution mode. In the manual control execution mode, the cutter penetration and optimal cutter spacing are directly controlled according to the optimal cutter spacing and penetration combination. In the rolling control execution mode, the rock breaking energy consumption is detected, the adjusted optimal cutter spacing and penetration combination is obtained in real time, and the cutter penetration and optimal cutter spacing are controlled according to the adjusted optimal cutter spacing and penetration combination.

9. The system according to claim 7, characterized in that, The process of determining the real-time rock breaking energy consumption includes: When the deviation of the real-time rock breaking energy consumption exceeds the threshold, the optimal cutter spacing and penetration combination will be readjusted through the processing and optimization module; otherwise, no adjustment will be made.

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