TBM hob three-way rock breaking force prediction method and system based on rotary cutting mode

Abstract

The invention discloses a TBM hob three-way rock breaking force prediction method and system based on a rotary cutting mode, and the method comprises the steps: building a hyperbolic function model of the cutting edge width and penetration depth of a hob, and optimizing the geometric structure of the hob to adapt to different rock stratums; an effective contact radius and a contact angle are calculated through a coupling motion trail equation of revolution and rotation of the hob; fitting a pressure distribution coefficient in combination with pre-test data, constructing a Hertz-Weibull stress coupling analysis model, and accurately representing stress distribution in the cutting direction and the radial direction; on the basis of contact pressure integration and stress decomposition, respectively deriving explicit calculation formulas of vertical, rolling and lateral rock breaking forces, and dynamically adjusting the rotating speed of the cutterhead, the propelling pressure and the hob spacing according to a rock breaking force prediction result. According to the method, the rock breaking force prediction precision in the complex rock stratum is remarkably improved, the TBM construction efficiency and the cutter service life are optimized, the over-excavation risk and energy consumption are reduced, and the method is suitable for intelligent tunneling control of tunnel engineering.

Description

Technical Field

[0001] The present invention belongs to the technical field of rock breaking by roller cutters, and in particular relates to a method and system for predicting the three-dimensional rock breaking force of a TBM roller cutter based on a rotary cutting mode. Background Art

[0002] By the end of 2023, my country will have 18,573 railway tunnels in operation, totaling 23,508 kilometers; of these, 4,561 will be high-speed railway tunnels, totaling 7,735 kilometers. In terms of highway and urban construction, by the end of 2022, 24,850 highway tunnels totaling 26.7843 million meters will be in operation, 8,543 kilometers of subways will be built, 5,100 kilometers of underground utility corridors will be constructed, and the annual mileage of urban rail transit tunnels will exceed 1,000 kilometers. Between 2021 and 2023, the average annual growth rate of tunnel construction will remain at 8%-10%, and the application rate of intelligent construction technology will increase from 35% to 60%. In particular, the development of full-face tunnel boring equipment (TBM) technology has significantly improved the quality and efficiency of tunnel construction.

[0003] Worldwide, TBM (Transport Bombardment) excavation technology has become the mainstream choice for long tunnel excavation. Compared to traditional drill-and-blast construction techniques, TBM technology effectively reduces overexcavation and construction costs. The way disc cutters cut rock can be divided into linear and rotary rock breaking. Early researchers conducted in-depth research on the linear rock breaking process of disc cutters, primarily through laboratory experiments and numerical simulations, and widely used the CSM prediction model to predict the rock-breaking force of disc cutters. However, there are certain differences between the linear cutting and rotary rock-breaking patterns used in actual TBM construction. The rotary rock-breaking pattern of disc cutters better reflects the actual conditions of TBM construction. Therefore, conducting research on rotary rock-breaking is of great significance for deepening the understanding of the disc cutter rock-breaking mechanism and optimizing TBM construction techniques.

[0004] While previous research in related fields has explored the rock-breaking process with disc cutters in depth and yielded numerous results, the rock-breaking force prediction models studied were mostly derived from linear rock-cutting by the disc cutter, resulting in significant discrepancies between the calculated lateral rock-breaking force and experimental data. Furthermore, numerical simulations of the disc cutter breaking process lack detailed explanations of the cutter ring modeling process and the cutter head form, directly using the CCS disc cutter ring model, resulting in excessively long simulation times. Therefore, it is necessary to propose a three-dimensional rock-breaking force prediction method and system for TBM disc cutters based on a rotary cutting mode to address current challenges and promote the further application and development of TBM technology in tunnel construction. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention proposes a three-dimensional rock-breaking force prediction method and system for TBM cutter based on a rotary cutting mode to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above objectives, the present invention provides a three-dimensional rock-breaking force prediction method for a TBM cutter based on a rotary cutting mode, comprising:

[0007] Obtain the physical properties of the rock mass to be broken and the cutter parameters, and construct a hyperbolic function model of the cutter tip width and penetration depth; optimize the cutter edge geometry using the hyperbolic function model;

[0008] The contact angle between the cutter and the rock is obtained based on the optimized cutter edge geometry.

[0009] Based on the contact angle and hyperbolic function model, the pressure distribution coefficient expression is fitted by pre-experimental data to construct a Hertz-Weibull stress coupling analysis model;

[0010] Based on the Hertz-Weibull stress coupling analysis model, the calculation formulas for vertical rock-breaking force and rolling rock-breaking force are obtained;

[0011] Based on the difference in cutting paths between the inner and outer sides of rotary cutting, and assuming the rock failure form and shape caused by lateral force, the calculation formula of the lateral rock breaking force during the process of single cutter invading rock is derived.

[0012] The three-dimensional rock-breaking force prediction results are obtained according to the vertical rock-breaking force calculation formula, the rolling rock-breaking force calculation formula, and the lateral rock-breaking force calculation formula, and the TBM excavation parameters are adjusted based on the prediction results.

[0013] Optionally, the hyperbolic function model of the hob cutter tip edge width and penetration depth is:

[0014]

[0015] Among them, D p is the cutting edge width of the tool tip, mm; D0 is the initial cutting edge width of the tool tip, mm; is the cutting edge deformation coefficient, E r is the rock elastic modulus, MPa; p is the current penetration depth, mm; p c is the critical penetration depth, mm, σ c The uniaxial compressive strength of rock is in MPa. R is the cutter radius, i.e. the geometric radius from the center point of the cutter to the outermost edge of the cutting edge, in mm.

[0016] Optionally, based on the coupled motion of the cutter's revolution around the cutterhead axis and its rotation around its own central axis and the optimized cutting edge width, a coupled motion trajectory equation of the cutter's revolution and rotation is constructed, the hypothesis that the cutter's rotary cutting vertically presses into the rock is established and verified, and the contact angle between the cutter and the rock is calculated based on the coupled motion trajectory equation.

[0017] Optionally, based on the contact angle and hyperbolic function model, the process of fitting the pressure distribution coefficient expression through pre-experimental data includes:

[0018] Through experiments with fixed cutter spacing, the average vertical rock-breaking force and average rolling rock-breaking force data of the cutters at different penetration depths were obtained to generate an experimental data set. The pressure distribution function was assumed to be in exponential form, and an integral equation was established based on this. The pressure distribution coefficient at different penetration depths was inferred from the experimental data set. The relationship between the inferred pressure distribution coefficient and the penetration depth was fitted, and the pressure distribution coefficient expressions corresponding to the average vertical rock-breaking force and the average cutter rock-breaking force were obtained, respectively. These expressions were optimized using numerical calculation tools and updated.

[0019] Optionally, based on the conditions that the cutting direction stress conforms to the Weibull distribution and the radial stress conforms to the Hertz distribution, a Hertz-Weibull stress coupling analysis model is constructed.

[0020] Optionally, the process of obtaining the vertical rock-breaking force calculation formula and the rolling rock-breaking force calculation formula based on the Hertz-Weibull stress coupling analysis model includes:

[0021] The force condition of the cutter microelement is determined, and the contact pressure calculation formula of the microelement at any point in the contact section between the cutter and the rock is obtained by combining the Hertz-Weibull stress coupling analysis model. The contact section between the cutter and the rock is subjected to a force analysis as a whole to obtain the contact pressure calculation formula of the microelement at any point on the contact section, and the integral derivation is performed along the angle direction of the contact surface to obtain the resultant force calculation formula of the entire contact section between the cutter and the rock. Finally, the resultant force is decomposed along the vertical and rolling cutting directions, and the rolling friction effect is taken into account to obtain the vertical rock breaking force calculation formula and the rolling rock breaking force calculation formula.

[0022] Optionally, the contact pressure of the microelement at any point in the contact between the cutter and the rock is calculated as follows:

[0023]

[0024] Where P(x,y) is the contact pressure acting on the microelement, with the point of action at the center of gravity of the microelement and the line of action along the radial direction of the hob; x is the integral variable, representing the distribution of the contact pressure in the width direction of the cutter head, which is constrained by the Hertz distribution; y is the integral variable, representing the distribution of the contact pressure in the rolling direction, which is constrained by the Weibull distribution; C is a dimensionless constant; k is the shape parameter of the Weibull distribution; λ is the scale parameter of the Weibull distribution, in mm; R is the radius of the hob; D p Indicates the width of the cutting edge; L indicates the distance between the cutters; θ indicates the contact angle between the cutter and the rock; represents the contact pressure distribution coefficient; σ c represents the uniaxial compressive strength of rock; σ t It represents the uniaxial tensile strength of rock.

[0025] Optionally, the vertical rock breaking force is calculated as:

[0026]

[0027] The calculation formula of rolling rock breaking force is:

[0028]

[0029] Where μ is the friction coefficient between the cutter and the rock.

[0030] Optionally, the process of obtaining the lateral rock-breaking force calculation formula includes:

[0031] Based on the difference in the inner and outer cutting paths of the disc cutter during the rotary cutting process, it is assumed that when the disc cutter penetrates the rock, the failure mode of the rocks on both sides is shear failure, and the failure shape is assumed to be triangular. The areas of the inner and outer rock breaking surfaces of the disc cutter are calculated respectively by introducing inner and outer correction values. The dynamic attenuation relationship of the lateral force is established, and the calculation formula of the lateral rock breaking force is obtained by combining the areas of the inner and outer rock breaking surfaces of the disc cutter.

[0032] The present invention also provides a three-dimensional rock-breaking force prediction system for a TBM cutter based on a rotary cutting mode, comprising:

[0033] Parameter acquisition module, tool tip optimization module, motion analysis module, pre-test fitting module, first prediction module, second prediction module, control unit module;

[0034] The parameter acquisition module is used to obtain the physical property parameters of the destroyed rock and the parameters of the roller cutter;

[0035] The tool tip optimization module is used to construct a hyperbolic function model of the hob cutter tip edge width and penetration depth and optimize the hob cutter edge geometry;

[0036] The motion analysis module is used to establish a rotary cutting motion analysis model for the disc cutter, establish a rotary cutting motion trajectory equation for the disc cutter based on the coupled motion of the disc cutter's revolution around the cutterhead axis and its rotation around its own central axis, and calculate the contact angle between the disc cutter and the rock based on the coupled motion trajectory equation;

[0037] The pre-experiment fitting module is used to fit the pressure distribution coefficient expression through pre-experiment data;

[0038] The first prediction module is used to obtain a vertical rock-breaking force calculation formula and a rolling rock-breaking force calculation formula based on a Hertz-Weibull stress coupling analysis model;

[0039] The second prediction module is used to calculate the areas of the inner and outer rock breaking surfaces of the disc cutter respectively based on the difference in the inner and outer cutting paths of the disc cutter during the rotary cutting process, assuming that when the disc cutter penetrates the rock, the failure mode of the rocks on both sides is shear failure, and assuming that the failure shape is triangular; establish a dynamic attenuation relationship of the lateral force, and combine the areas of the inner and outer rock breaking surfaces of the disc cutter to obtain a calculation formula for the lateral rock breaking force;

[0040] The control unit module is used to obtain three-dimensional rock breaking force prediction results based on the vertical rock breaking force calculation formula, the rolling rock breaking force calculation formula and the lateral rock breaking force calculation formula, and adjust the TBM excavation parameters based on the prediction results.

[0041] Compared with the prior art, the present invention has the following advantages and technical effects:

[0042] (1) The three-dimensional rock-breaking force prediction model of the TBM cutter established in the present invention is based on the rotary cutting mode. It fully considers the coupled motion characteristics of the cutter's revolution and rotation. By rationally optimizing the CCS-shaped cutter head, establishing a hyperbolic function model of the blade edge width and the equation of the cutter's rotary cutting motion trajectory, it solves the problem of large lateral force prediction errors in the traditional linear cutting model, significantly improves the calculation accuracy of vertical rock-breaking force, rolling rock-breaking force and lateral rock-breaking force, and provides a reasonable modeling basis for numerical simulation, shortening the simulation calculation time.

[0043] (2) The three-dimensional rock-breaking force prediction model of the TBM cutter provided by the present invention can better reflect the actual situation of TBM actual construction. By analyzing the rotary cutting motion trajectory and rock-breaking mechanism, the dynamic interaction process between the cutter and the rock is truly restored, overcoming the defect that the traditional linear cutting model does not match the actual situation, providing a reliable theoretical basis for the optimization of construction parameters, and thus effectively guiding the tool wear assessment, energy consumption optimization and dynamic adjustment of tunneling parameters in TBM construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0045] Figure 1 Flowchart of a method for predicting the three-dimensional rock-breaking force of a TBM cutter based on a rotary cutting mode according to an embodiment of the present invention;

[0046] Figure 2 A flow chart of obtaining an expression for a pressure distribution coefficient by fitting an embodiment of the present invention;

[0047] Figure 3 This is a flow chart of the derivation of the calculation formulas for vertical rock-breaking force and rolling rock-breaking force according to an embodiment of the present invention;

[0048] Figure 4 This is a flow chart of the lateral rock-breaking force calculation formula derived according to an embodiment of the present invention;

[0049] Figure 5 Schematic diagram of the inner and outer rock breaking surfaces of the roller cutter according to an embodiment of the present invention;

[0050] Figure 6 The pressure distribution coefficient fitting diagrams in the vertical and rolling rock-breaking force calculation formulas for different penetration degrees of the embodiment of the present invention are shown in FIG1 , (1) is the vertical rock-breaking force pressure distribution coefficient fitting diagram, and (2) is the rolling rock-breaking force pressure distribution coefficient fitting diagram;

[0051] Figure 7 The following are comparison diagrams of the change trends of the three-dimensional rock-breaking force prediction method of the TBM cutter according to the embodiment of the present invention and the Gertsch full-scale linear cutting test results: (1) vertical rock-breaking force change trend comparison diagram, (2) rolling rock-breaking force change trend comparison diagram;

[0052] Among them, 1. The area of ​​the rock-breaking surface on the outside of the hob; 2. The area of ​​the rock-breaking surface on the inside of the hob; 3. The radius of the hob's position on the cutterhead; 4. The angle of the hob's rotation around the center axis of the cutterhead; 5. The penetration rate; 6. The width of the cutting edge of the cutting tip. DETAILED DESCRIPTION

[0053] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0054] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0055] Example 1

[0056] like Figure 1 As shown, this embodiment provides a three-dimensional rock breaking force prediction method for a TBM cutter based on a rotary cutting mode, including:

[0057] Obtain the physical properties of the rock mass to be broken and the cutter parameters, and construct a hyperbolic function model of the cutter tip width and penetration depth; optimize the cutter edge geometry using the hyperbolic function model;

[0058] The contact angle between the cutter and the rock is obtained based on the optimized cutter edge geometry.

[0059] Based on the contact angle and hyperbolic function model, the pressure distribution coefficient expression is fitted by pre-experimental data to construct a Hertz-Weibull stress coupling analysis model;

[0060] Based on the Hertz-Weibull stress coupling analysis model, the calculation formulas for vertical rock-breaking force and rolling rock-breaking force are obtained;

[0061] Based on the difference in cutting paths between the inner and outer sides of rotary cutting and the assumption of rock failure morphology and shape caused by lateral force, the calculation formula for the lateral rock breaking force during the process of single cutter intrusion into rock was derived.

[0062] The three-dimensional rock-breaking force prediction results are obtained according to the vertical rock-breaking force calculation formula, the rolling rock-breaking force calculation formula, and the lateral rock-breaking force calculation formula, and the TBM excavation parameters are adjusted based on the prediction results.

[0063] like Figure 2 As shown: Fitting to obtain the expression for the pressure distribution coefficient includes the following steps:

[0064] Through experiments with fixed cutter spacing, the average vertical rock-breaking force and average rolling rock-breaking force data of the cutters at different penetration rates were obtained to generate an experimental data set.

[0065] Assuming that the pressure distribution function is in exponential form, an integral equation is established based on this, and the pressure distribution coefficient under different penetration rates is inferred from the experimental data set.

[0066] The relationship between the back-calculated pressure distribution coefficient and the penetration rate was fitted, and the pressure distribution coefficient expressions corresponding to the average vertical rock-breaking force and the average roller cutter rock-breaking force were obtained respectively. A new pressure distribution coefficient expression was obtained by optimizing it through numerical calculation tools.

[0067] like Figure 3 As shown: The derivation of the calculation formula for vertical rock breaking force and rolling rock breaking force includes the following steps:

[0068] Based on the conditions that the cutting direction stress conforms to the Weibull distribution and the radial stress conforms to the Hertz distribution, a Hertz-Weibull stress coupling analysis model is constructed;

[0069] Determine the stress condition of the cutter microelement, and obtain the contact pressure calculation formula of the microelement at any point of the contact between the cutter and the rock by combining the Hertz-Weibull stress coupling analysis model;

[0070] The contact area between the cutter and the rock is analyzed as a whole to obtain the contact pressure calculation formula of the microelement at any point on the contact section. The integral is then derived along the angle direction of the contact surface to obtain the formula for calculating the resultant force of the entire contact section between the cutter and the rock.

[0071] The resultant force is decomposed along the vertical and rolling directions, and the rolling friction effect is considered to obtain the calculation formulas for the vertical rock-breaking force and the rolling rock-breaking force.

[0072] like Figure 4 As shown: The derivation of the lateral rock breaking force calculation formula includes the following steps:

[0073] Based on the difference in the cutting paths of the inner and outer sides of the disc cutter during the rotary cutting process, it is assumed that when the disc cutter penetrates the rock, the failure mode of the rocks on both sides is shear failure, and the failure shape is assumed to be triangular;

[0074] By introducing the inner and outer correction values, the areas of the inner and outer rock breaking surfaces of the cutter are calculated respectively;

[0075] The dynamic attenuation relationship of the lateral force is established, and the calculation formula of the lateral rock-breaking force is obtained by combining the areas of the inner and outer rock-breaking surfaces of the cutter.

[0076] Obtain the physical properties of the destroyed rock and the parameters of the CCS disc cutter used. The mechanical parameters of the cutter used in the test are shown in Table 1, and the mechanical properties of the rock in the test are shown in Table 2.

[0077] Table 1

[0078] part <![CDATA[Density (kg / m 3 )]]> Elastic modulus (Pa) Poisson's ratio Knife ring 7850 2.1E11 0.28

[0079] Table 2

[0080]

[0081] The hob model is optimized to establish a hyperbolic function model of the cutting edge width of the penetration degree:

[0082]

[0083] Among them, D p is the cutting edge width of the tool tip, mm; D0 is the initial cutting edge width of the tool tip, mm; is the cutting edge deformation coefficient, E r is the rock elastic modulus, MPa; p is the current penetration depth, mm; p c is the critical penetration depth (mm), σ c Uniaxial compressive strength of rock, MPa; R c The radius from the center of the cutter head to the outside of the cutting edge, mm.

[0084] A kinematic analysis model for rotary cutting was established. Based on the coupled motion of the cutter's revolution around the cutterhead's axis and its rotation around its own centerline, the equation for the cutter's kinematic trajectory was established. This validated the assumption that the cutter's rotational cutting motion penetrates the rock vertically, and the formula for calculating the contact angle θ between the cutter and the rock was derived.

[0085] Establish a rock breaking force prediction model, conduct preliminary tests and obtain the pressure distribution coefficient by fitting with the exponential function. Expressions of

[0086] The distribution of contact pressure at the interaction site between the cutter and the rock is determined, and the calculation formulas for the vertical rock-breaking force and the rolling rock-breaking force are derived.

[0087] Furthermore, a rock breaking force prediction model was established and a preliminary test was carried out to obtain the pressure distribution coefficient by fitting the exponential function. The steps of the expression include:

[0088] A preliminary test was conducted to obtain the average vertical rock-breaking force and average rolling rock-breaking force at different penetration rates under the same cutter spacing conditions to generate a data set. In this embodiment, the data for the average vertical rock-breaking force and average rolling rock-breaking force were obtained from the Gertsch full-scale linear cutting rock test data, as shown in Table 3.

[0089] Table 3

[0090]

[0091] Assuming that the pressure distribution function is in exponential form, the integral equation is used to inversely calculate the pressure distribution coefficient at different penetration depths. The calculation results are shown in Table 4.

[0092] Table 4

[0093]

[0094]

[0095] The pre-test data were fitted with the exponential function to obtain the average vertical rock breaking force and the average cutter rock breaking force with respect to the pressure distribution coefficient. The fitting result is as follows: Figure 6 As shown;

[0096] Furthermore, the average vertical rock breaking force calculation formula pressure distribution coefficient index Expression, average cutter rock breaking force calculation formula pressure distribution coefficient index The expression is:

[0097] R 2 =0.97691;

[0098] R 2 =0.99889;

[0099] GNU Octave is used to optimize the above two fitting formulas to obtain a new pressure distribution coefficient expression:

[0100] in represents the pressure distribution coefficient, and p represents the penetration rate.

[0101] Furthermore, the steps of determining the distribution of contact pressure at the interaction site between the cutter and the rock and deriving the calculation formulas for the vertical rock breaking force and the rolling rock breaking force include:

[0102] Assuming that the contact pressure distribution on the rock breaking surface conforms to Weibull distribution in the cutting direction and Hertz distribution in the radial direction, a Hertz-Weibull stress coupling analysis model is proposed.

[0103] Determine the force on the cutter microelement and derive the calculation formula for the contact pressure P(x,y) of the microelement at any point in the contact between the cutter and the rock:

[0104]

[0105] Wherein, P(x,y) represents the contact pressure acting on the microelement, with the point of action at the center of gravity of the microelement and the line of action along the radial direction of the hob; x is the integral variable, representing the distribution of the contact pressure in the width direction of the cutter head (radial direction), which is constrained by the Hertz distribution; y is the integral variable, representing the distribution of the contact pressure in the rolling direction (longitudinal direction), which is constrained by the Weibull distribution; C is a dimensionless constant, which is taken as 4.15; k is the shape parameter of the Weibull distribution; λ is the scale parameter of the Weibull distribution, in mm; R represents the radius of the hob; D p represents the width of the cutting edge; L represents the distance between the cutters; θ represents the contact angle between the cutter and the rock; represents the contact pressure distribution coefficient; σ c represents the uniaxial compressive strength of rock; σ t It represents the uniaxial tensile strength of rock.

[0106] The contact part between the cutter and the rock is taken out for overall force analysis to obtain the contact pressure calculation formula of the microelement at any point on the contact section. The integral derivation along the angle direction of the contact surface is used to solve the resultant force F of the entire contact section between the cutter and the rock. P The calculation formula of

[0107]

[0108] The resultant force of the entire contact section between the cutter and the rock is decomposed along the vertical and rolling cutting directions, and the rolling friction effect is considered to derive the vertical rock breaking force F V and rolling rock breaking force F R The calculation formula is:

[0109]

[0110] Where μ is the friction coefficient between the cutter and the rock.

[0111] Furthermore, through the vertical rock breaking force F V and rolling rock breaking force F R The calculation formula of the proposed method can accurately estimate the vertical rock breaking force and the rolling rock breaking force, and is compared with the results of the Gertsch full-scale linear cutting test. The comparison results are shown in Table 5:

[0112] Table 5

[0113]

[0114]

[0115] As shown in Table 5, the three-dimensional rock-breaking force prediction method for TBM cutters based on the rotary cutting mode described in the present invention and the Gertsch full-scale linear cutting test method have a maximum error of no more than 21% in vertical rock-breaking force and no more than 15% in rolling rock-breaking force at different penetration depths when the cutter spacing is 76 mm. Figure 7 This chart compares the changing trends of the three-dimensional rock-breaking force prediction method for TBM cutters presented in this embodiment with the results of a Gertsch full-scale linear cutting test. The model-calculated results for vertical and rolling rock-breaking forces show the same changing trends as the test results. Therefore, based on the data errors and changing trends between the two methods, it can be determined that the calculation formulas for vertical and rolling rock-breaking forces in the three-dimensional rock-breaking force prediction method for TBM cutters based on the rotary cutting mode provided in this embodiment are reasonable.

[0116] Example 2

[0117] The proposed three-dimensional rock-breaking force prediction method for TBM cutters based on the rotary cutting mode was compared with the tunneling rock-breaking test method developed by Zhang Zhaohuang's team at North China Electric Power University to verify the proposed formula for calculating lateral rock-breaking force. The cutter structural parameters and rock mechanical properties used in the two methods were identical.

[0118] A method for predicting the three-dimensional rock-breaking force of a TBM cutter based on a rotary cutting mode includes the following steps:

[0119] The physical properties of the destroyed rock and the parameters of the CCS disc cutter used were obtained. The mechanical properties of the rock in the test are shown in Table 6.

[0120] Table 6

[0121]

[0122] Obtain the physical properties of the rock mass to be broken and the cutter parameters, and construct a hyperbolic function model of the cutter tip width and penetration depth; optimize the cutter edge geometry using the hyperbolic function model;

[0123] The contact angle between the cutter and the rock is obtained based on the optimized cutter edge geometry.

[0124] Based on the contact angle and hyperbolic function model, the pressure distribution coefficient expression is fitted by pre-experimental data to construct a Hertz-Weibull stress coupling analysis model;

[0125] Based on the Hertz-Weibull stress coupling analysis model, the calculation formulas for vertical rock-breaking force and rolling rock-breaking force are obtained;

[0126] Based on the difference in cutting paths between the inner and outer sides of rotary cutting and the assumption of rock failure morphology and shape caused by lateral force, the calculation formula for the lateral rock breaking force during the process of single cutter intrusion into rock was derived.

[0127] The three-dimensional rock-breaking force prediction results are obtained according to the vertical rock-breaking force calculation formula, the rolling rock-breaking force calculation formula, and the lateral rock-breaking force calculation formula, and the TBM excavation parameters are adjusted based on the prediction results.

[0128] Furthermore, based on the difference in the inner and outer cutting paths of rotary cutting, and assuming the rock failure form and failure shape caused by the lateral force, the steps to derive the calculation formula for the lateral rock breaking force include:

[0129] Based on the difference in the cutting paths of the inner and outer sides of the disc cutter during the rotary cutting process, it is assumed that when the disc cutter penetrates the rock, the failure mode of the rocks on both sides is shear failure, and the failure shape is assumed to be triangular;

[0130] By introducing the inner and outer correction values, the areas of the inner and outer rock breaking surfaces of the cutter are calculated respectively;

[0131] Establish the dynamic attenuation relationship of the lateral force, and combine the areas of the inner and outer rock breaking surfaces of the cutter to obtain the lateral rock breaking force F S Calculation formula.

[0132] Furthermore, the rock breaking surface area A on the inner side of the cutter i and the outer rock-breaking surface area A o The calculation formula is:

[0133]

[0134] Where R is the cutter radius, i.e. the geometric radius from the center of the cutter to the outermost edge of the cutting edge, in mm; r is the radius of the cutter on the cutter head; γ is the angle that the cutter rotates around the center axis of the cutter head. δ(r) is the inner and outer correction amount, k is the dimensionless correction coefficient, ranging from 0.03 to 0.15.

[0135] Furthermore, the lateral rock breaking force F S The calculation formula is:

[0136]

[0137] Where η(p) is the efficiency coefficient of stress distribution on lateral force transmission, is the lateral force pressure distribution coefficient, δ is the efficiency attenuation coefficient, δ = 2.35; τ r To correct the rock shear strength, τ r =τ·(1-0.1·v c ); τ is the rock shear strength; v c A is the linear speed of the cutter disc, m / s; o A is the rock breaking surface area outside the cutter; i The rock breaking surface area inside the cutter. Figure 5 Calculated area shown.

[0138] Furthermore, through the lateral rock breaking force F S The calculation formula of the proposed method can more accurately estimate the vertical and lateral rock breaking forces, and is compared with the rock breaking test results of Zhang Zhaohuang's team. The comparison results are shown in Table 7:

[0139] Table 7

[0140]

[0141] Furthermore, the prediction model calculation results in this embodiment show that, for similar penetration rates, the lateral force generated by the cutter increases with increasing cutter installation radius. For similar cutter spacing, the lateral force generated increases with increasing penetration. This trend is consistent with the theoretical evolution of lateral force during rock breaking by the cutter. Therefore, it can be concluded that the lateral rock breaking force calculation formula in this embodiment is reasonable.

[0142] Example 3

[0143] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present invention further provides a three-dimensional rock-breaking force prediction system for a TBM cutter based on a rotary cutting mode, the system being used to implement any of the methods described above, the system comprising: a parameter acquisition module, a cutter tip optimization module, a motion analysis module, a pre-test fitting module, a first prediction module, a second prediction module, and a control unit module;

[0144] The parameter acquisition module is used to obtain the physical property parameters of the destroyed rock and the parameters of the roller cutter;

[0145] The tool tip optimization module is used to construct a hyperbolic function model of the hob cutter tip edge width and penetration depth and optimize the hob cutter edge geometry;

[0146] The motion analysis module is used to establish a rotary cutting motion analysis model for the disc cutter, establish a rotary cutting motion trajectory equation for the disc cutter based on the coupled motion of the disc cutter's revolution around the cutterhead axis and its rotation around its own central axis, and calculate the contact angle between the disc cutter and the rock based on the coupled motion trajectory equation;

[0147] The pre-experiment fitting module is used to fit the pressure distribution coefficient expression through pre-experiment data;

[0148] The first prediction module is used to obtain a vertical rock-breaking force calculation formula and a rolling rock-breaking force calculation formula based on a Hertz-Weibull stress coupling analysis model;

[0149] The second prediction module is used to calculate the areas of the inner and outer rock breaking surfaces of the disc cutter respectively based on the difference in the inner and outer cutting paths of the disc cutter during the rotary cutting process, assuming that when the disc cutter penetrates the rock, the failure mode of the rocks on both sides is shear failure, and assuming that the failure shape is triangular; establish a dynamic attenuation relationship of the lateral force, and combine the areas of the inner and outer rock breaking surfaces of the disc cutter to obtain a calculation formula for the lateral rock breaking force;

[0150] The control unit module is used to obtain three-dimensional rock breaking force prediction results based on the vertical rock breaking force calculation formula, the rolling rock breaking force calculation formula and the lateral rock breaking force calculation formula, and adjust the TBM excavation parameters based on the prediction results.

[0151] The system of the above embodiment is used to implement a corresponding method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0152] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode, characterized in that: The following steps are involved: Obtain the physical properties of the rock mass to be broken and the cutter parameters, and construct a hyperbolic function model of the cutter tip width and penetration depth; optimize the cutter edge geometry using the hyperbolic function model; The contact angle between the cutter and the rock is obtained based on the optimized cutter edge geometry. Based on the contact angle and hyperbolic function model, the pressure distribution coefficient expression is fitted by pre-experimental data to construct a Hertz-Weibull stress coupling analysis model; Based on the Hertz-Weibull stress coupling analysis model, the calculation formulas for vertical rock-breaking force and rolling rock-breaking force are obtained; Based on the difference in cutting paths between the inner and outer sides of rotary cutting, and assuming the rock failure form and shape caused by lateral force, the calculation formula of the lateral rock breaking force during the process of single cutter invading rock is derived. The three-dimensional rock-breaking force prediction results are obtained according to the vertical rock-breaking force calculation formula, the rolling rock-breaking force calculation formula, and the lateral rock-breaking force calculation formula, and the TBM excavation parameters are adjusted based on the prediction results.

2. The method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode according to claim 1 is characterized in that: The hyperbolic function model of the hob cutter tip edge width and penetration depth is: Among them, D p is the cutting edge width of the tool tip, mm; D0 is the initial cutting edge width of the tool tip, mm; is the cutting edge deformation coefficient, E r is the rock elastic modulus, MPa; p is the current penetration depth, mm; p c is the critical penetration depth, mm, σ c The uniaxial compressive strength of rock is in MPa. R is the cutter radius, i.e. the geometric radius from the center point of the cutter to the outermost edge of the cutting edge, in mm.

3. The method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode according to claim 1 is characterized in that: Based on the coupled motion of the cutter's revolution around the cutterhead axis and its rotation around its own central axis and the optimized cutting edge width, the coupled motion trajectory equation of the cutter's revolution and rotation is constructed. The contact angle between the cutter and the rock is calculated based on the coupled motion trajectory equation.

4. The method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode according to claim 1 is characterized in that: Based on the contact angle and hyperbolic function model, the process of fitting the pressure distribution coefficient expression through pre-experimental data includes: Through experiments with fixed cutter spacing, the average vertical rock-breaking force and average rolling rock-breaking force data of the cutters at different penetration depths were obtained to generate an experimental data set. The pressure distribution function was assumed to be in exponential form, and an integral equation was established based on this. The pressure distribution coefficient at different penetration depths was inferred from the experimental data set. The relationship between the inferred pressure distribution coefficient and the penetration depth was fitted, and the pressure distribution coefficient expressions corresponding to the average vertical rock-breaking force and the average cutter rock-breaking force were obtained, respectively. These expressions were optimized using numerical calculation tools and updated.

5. The method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode according to claim 1 is characterized in that: Based on the conditions that the cutting direction stress conforms to the Weibull distribution and the radial stress conforms to the Hertz distribution, a Hertz-Weibull stress coupling analysis model is constructed.

6. The method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode according to claim 1 is characterized in that: The process of obtaining the vertical rock-breaking force calculation formula and the rolling rock-breaking force calculation formula based on the Hertz-Weibull stress coupling analysis model includes: The force condition of the cutter microelement is determined, and the contact pressure calculation formula of the microelement at any point in the contact section between the cutter and the rock is obtained by combining the Hertz-Weibull stress coupling analysis model. The contact section between the cutter and the rock is subjected to a force analysis as a whole to obtain the contact pressure calculation formula of the microelement at any point on the contact section, and the integral derivation is performed along the angle direction of the contact surface to obtain the resultant force calculation formula of the entire contact section between the cutter and the rock. Finally, the resultant force is decomposed along the vertical and rolling cutting directions, and the rolling friction effect is taken into account to obtain the vertical rock breaking force calculation formula and the rolling rock breaking force calculation formula.

7. The method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode according to claim 6 is characterized in that: The formula for calculating the contact pressure of the microelement at any point in the contact between the cutter and the rock is: Where P(x,y) is the contact pressure acting on the microelement, with the point of action at the center of gravity of the microelement and the line of action along the radial direction of the hob; x is the integral variable, representing the distribution of the contact pressure in the width direction of the cutter head, which is constrained by the Hertz distribution; y is the integral variable, representing the distribution of the contact pressure in the rolling direction, which is constrained by the Weibull distribution; C is a dimensionless constant; k is the shape parameter of the Weibull distribution; λ is the scale parameter of the Weibull distribution, in mm; R is the radius of the hob; D p Indicates the width of the cutting edge; L indicates the distance between the cutters; θ indicates the contact angle between the cutter and the rock; represents the contact pressure distribution coefficient; σ c represents the uniaxial compressive strength of rock; σ t It represents the uniaxial tensile strength of rock.

8. The method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode according to claim 7 is characterized in that: The vertical rock breaking force calculation formula is: The calculation formula of rolling rock breaking force is: Where μ is the friction coefficient between the cutter and the rock.

9. The method for predicting the three-dimensional rock breaking force of a TBM cutter based on a rotary cutting mode according to claim 1, characterized in that: The process of obtaining the lateral rock-breaking force calculation formula includes: Based on the difference in the inner and outer cutting paths of the disc cutter during the rotary cutting process, it is assumed that when the disc cutter penetrates the rock, the failure mode of the rocks on both sides is shear failure, and the failure shape is assumed to be triangular. The areas of the inner and outer rock breaking surfaces of the disc cutter are calculated respectively by introducing inner and outer correction values. The dynamic attenuation relationship of the lateral force is established, and the calculation formula of the lateral rock breaking force is obtained by combining the areas of the inner and outer rock breaking surfaces of the disc cutter.

10. A three-dimensional rock breaking force prediction system for TBM cutter based on rotary cutting mode, characterized in that: Parameter acquisition module, tool tip optimization module, motion analysis module, pre-test fitting module, first prediction module, second prediction module, control unit module; The parameter acquisition module is used to obtain the physical property parameters of the destroyed rock and the parameters of the roller cutter; The tool tip optimization module is used to construct a hyperbolic function model of the hob cutter tip edge width and penetration depth and optimize the hob cutter edge geometry; The motion analysis module is used to establish a rotary cutting motion analysis model for the disc cutter, establish a rotary cutting motion trajectory equation for the disc cutter based on the coupled motion of the disc cutter's revolution around the cutterhead axis and its rotation around its own central axis, and calculate the contact angle between the disc cutter and the rock based on the coupled motion trajectory equation; The pre-experiment fitting module is used to fit the pressure distribution coefficient expression through pre-experiment data; The first prediction module is used to obtain a vertical rock-breaking force calculation formula and a rolling rock-breaking force calculation formula based on a Hertz-Weibull stress coupling analysis model; The second prediction module is used to calculate the areas of the inner and outer rock breaking surfaces of the disc cutter respectively based on the difference in the inner and outer cutting paths of the disc cutter during the rotary cutting process, assuming that when the disc cutter penetrates the rock, the failure mode of the rocks on both sides is shear failure, and assuming that the failure shape is triangular; establish a dynamic attenuation relationship of the lateral force, and combine the areas of the inner and outer rock breaking surfaces of the disc cutter to obtain a calculation formula for the lateral rock breaking force; The control unit module is used to obtain three-dimensional rock breaking force prediction results based on the vertical rock breaking force calculation formula, the rolling rock breaking force calculation formula and the lateral rock breaking force calculation formula, and adjust the TBM excavation parameters based on the prediction results.

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