A method and system for predicting three-direction rock breaking forces of a TBM cutter based on a rotary cutting mode

Abstract

The application discloses a TBM cutter three-direction rock breaking force prediction method and system based on a rotary cutting mode, and comprises the following steps: a hyperbolic function model of a cutter edge width and a penetration depth is established, and a cutter geometric structure is optimized to adapt to different rock layers; an effective contact radius and a contact angle are calculated through a coupling motion trajectory equation of a cutter revolution and rotation; a pressure distribution coefficient is fitted in combination with pre-test data, a Hertz-Weibull stress coupling analysis model is constructed, and a cutting direction and a radial stress distribution are accurately characterized; based on contact pressure integration and force decomposition, explicit calculation formulas of vertical, rolling and lateral rock breaking forces are derived, respectively, and a cutter head speed, a pushing pressure and a cutter spacing are dynamically adjusted according to rock breaking force prediction results. The application significantly improves the rock breaking force prediction accuracy in complex rock layers, optimizes the TBM construction efficiency and the cutter life, reduces the overbreak risk and energy consumption, and is suitable for intelligent tunneling control in tunnel engineering.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cutter rock breaking, and particularly relates to a TBM cutter three-direction rock breaking force prediction method and system based on a rotary cutting mode. BACKGROUND

[0002] As of the end of 2023, there are 18573 railway tunnels in operation in China, with a total length of 23508 kilometers; among them, there are 4561 high-speed railway tunnels, with a total length of 7735 kilometers. In terms of highway and urban construction, as of the end of 2022, there are 24850 highway tunnels in operation, with a total length of 2678430000 meters, 8543 kilometers of subway have been built, 5100 kilometers of underground comprehensive pipe galleries, and the annual mileage of urban rail transit tunnels has broken through 1000 kilometers. The annual growth rate of tunnel construction during 2021-2023 has remained at 8%-10%, the application rate of intelligent construction technology has increased from 35% to 60%, and in particular, the development of TBM technology for full-face tunneling equipment has significantly improved the quality and efficiency of tunnel construction projects.

[0003] In the world, TBM tunneling technology has become the mainstream choice for long tunnel excavation. Compared with traditional drilling and blasting construction technology, TBM technology effectively reduces overbreak and construction cost. According to the way of disc cutter cutting rock, it can be divided into linear cutting rock breaking and rotary cutting rock breaking. Early researchers mainly conducted in-depth research on the process of linear cutting rock breaking of the cutter through indoor tests and numerical simulation, and widely used the CSM prediction model to predict the rock breaking force of the cutter. However, there are certain differences between linear cutting and rotary cutting rock mode in actual TBM construction, and the rotary cutting rock breaking mode of the cutter can better reflect the actual situation of TBM construction. Therefore, it is of great significance to carry out rotary cutting rock breaking research for in-depth understanding of the rock breaking mechanism of the cutter and optimization of TBM tunneling construction technology.

[0004] In the past research in the related field, although the process of cutter rock breaking has been deeply discussed and many achievements have been made, the rock breaking force prediction model studied is mostly derived based on the linear cutting of the cutter, resulting in a large error between the calculation results of lateral rock breaking force and the test data. In addition, in the numerical simulation research on the process of cutter rock breaking, the modeling process of the cutter ring model and the form of the cutter head are not elaborated, and the CCS disc cutter ring is directly modeled, which makes the simulation calculation time too long. In view of this, it is necessary to propose a TBM cutter three-direction rock breaking force prediction method and system based on a rotary cutting mode to solve the current problems and promote the further application and development of TBM technology in tunnel construction. SUMMARY

[0005] To solve the above technical problems, the application provides a TBM cutter three-dimensional rock breaking force prediction method and system based on a rotary cutting mode to solve the problems of the prior art.

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

[0007] The physical property parameters of the rock to be broken and the cutter parameters are obtained, and a hyperbolic function model of the cutter tip edge width and the penetration depth is constructed; the cutter edge geometry is optimized through 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 the hyperbolic function model, a Hertz-Weibull stress coupling analysis model is constructed by fitting a pressure distribution coefficient expression through pre-experiment data;

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

[0011] Based on the differences in the cutting paths inside and outside the rotary cutting, the rock damage form and shape caused by the lateral force are assumed, and a lateral rock breaking force calculation formula in the process of single cutter penetrating into the rock is derived;

[0012] According to the vertical rock breaking force calculation formula, the rolling rock breaking force calculation formula and the lateral rock breaking force calculation formula, a three-dimensional rock breaking force prediction result is obtained, and the TBM tunneling parameters are adjusted based on the prediction result.

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

[0014]

[0015] wherein D p is the tip edge width, mm; D0 is the initial tip edge width, mm; is the 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 is the rock uniaxial compressive strength, Mpa; R is the cutter radius, i.e. the geometric radius from the cutter center point to the outermost edge of the edge, mm.

[0016] Optionally, based on the coupling motion of the cutter around the cutter disc axis and the coupling motion around its own central axis, the coupling motion trajectory equation of the cutter revolution and rotation is constructed based on the optimized cutting edge width, the cutter rotation cutting vertical penetration rock assumption is established and verified, and the contact angle between the cutter and the rock is calculated based on the coupling motion trajectory equation.

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

[0018] Through the experiment of fixing the cutter spacing, the average vertical rock breaking force and the average rolling rock breaking force data of the cutter under different penetration depths are obtained, and the experimental data set is generated; assuming that the pressure distribution function is exponential, and based on this, the integral equation is established, and the pressure distribution coefficient under different penetration depths is back calculated through the experimental data set; the relationship between the back calculated pressure distribution coefficient and the penetration depth is fitted, and the pressure distribution coefficient expressions corresponding to the average vertical rock breaking force and the average cutter rock breaking force are obtained respectively and optimized through the numerical calculation tool, and the pressure distribution coefficient expression is updated.

[0019] Optionally, based on the condition 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] Determine the stress condition of the cutter microelement, obtain the contact pressure calculation formula of the microelement at any point of the contact part of the cutter and the rock based on the Hertz-Weibull stress coupling analysis model; analyze the stress of the contact part of the cutter and the rock as a whole, obtain the contact pressure calculation formula of the microelement at any point on the contact section, and integrate along the contact surface angle direction to derive, and the resultant force calculation formula of the entire contact section of the cutter and the rock is obtained; finally, the resultant force is decomposed along the vertical and rolling directions, and the rolling friction effect is considered, and the vertical rock breaking force calculation formula and the rolling rock breaking force calculation formula are obtained.

[0022] Optionally, the contact pressure calculation formula of the microelement at any point of the contact part of the cutter and the rock is:

[0023]

[0024] Wherein, P(x, y) is the contact pressure acting on the micro-element, the action point is at the center of gravity of the micro-element, and the action line is along the radial direction of the hob; x is the integral variable, indicating 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, indicating 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, mm; R represents the radius of the hob; D p represents the width of the cutting edge of the tool tip; L represents the spacing of the hob; θ represents the contact angle of the hob and the rock; represents the contact pressure distribution coefficient; σ c represents the uniaxial compressive strength of the rock; σ t represents the uniaxial tensile strength of the rock.

[0025] Optionally, the vertical rock breaking force calculation formula is:

[0026]

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

[0028]

[0029] Wherein, μ is the friction coefficient between the hob and the rock.

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

[0031] Based on the difference between the inner and outer cutting paths of the hob during rotary cutting, it is assumed that the destruction form of the rock on both sides of the hob is shear failure when the hob invades the rock, and it is assumed that the destruction shape is triangular; the areas of the inner and outer rock breaking surfaces of the hob are calculated by introducing inner and outer correction amounts respectively; a dynamic attenuation relationship of the lateral force is established, and the lateral rock breaking force calculation formula is obtained in combination with the areas of the inner and outer rock breaking surfaces of the hob.

[0032] The application also provides a TBM hob three-way rock breaking force prediction system based on a rotary cutting mode, comprising:

[0033] A parameter acquisition module, a tool 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;

[0034] The parameter acquisition module is used to acquire the physical property parameters of the destroyed rock and the hob parameters.

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

[0036] The motion analysis module is configured to establish a rotary cutting motion analysis model of the cutter, establish a rotary cutting motion trajectory equation of the cutter based on coupled motion of the cutter revolving around an axis of the cutter head and rotating around a middle axis of the cutter, and calculate a contact angle between the cutter and the rock based on the coupled motion trajectory equation.

[0037] The pre-experiment fitting module is configured to fit a pressure distribution coefficient expression based on pre-experiment data.

[0038] The first prediction module is configured 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 configured to, based on a difference between inner and outer cutting paths of the cutter in the rotary cutting process, assume that a failure mode of the rock on both sides of the cutter when the cutter invades the rock is shear failure, and assume that the failure shape is triangular, calculate areas of rock breaking surfaces on the inner and outer sides of the cutter by introducing inner and outer side correction amounts respectively, establish a dynamic attenuation relationship of the side force, and obtain a side rock breaking force calculation formula in combination with the areas of the rock breaking surfaces on the inner and outer sides of the cutter.

[0040] The control unit module is configured to obtain a three-way rock breaking force prediction result based on the vertical rock breaking force calculation formula, the rolling rock breaking force calculation formula, and the side rock breaking force calculation formula, and adjust TBM tunneling parameters based on the prediction result.

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

[0042] (1) The TBM cutter three-way rock breaking force prediction model established based on the rotary cutting mode in the present application fully considers the coupled motion characteristics of the cutter revolution and rotation, solves the problem of large prediction error of the side force of the traditional linear cutting model by reasonably optimizing the CCS-shaped cutter head, establishing a hyperbolic function model of the cutter tip edge width, and establishing a rotary cutting motion trajectory equation of the cutter, significantly improves the calculation accuracy of the vertical rock breaking force, the rolling rock breaking force, and the side rock breaking force, and provides a reasonable modeling basis for numerical simulation and shortens the simulation calculation time.

[0043] (2) The TBM cutter three-way rock breaking force prediction model provided in the present application can better reflect the actual situation of TBM construction, truly restores the dynamic interaction process between the cutter and the rock by analyzing the rotary cutting motion trajectory and the rock breaking mechanism, overcomes the defect that the traditional linear cutting model does not match the actual situation, provides a reliable theoretical basis for construction parameter optimization, and effectively guides the cutter wear evaluation, energy consumption optimization, and dynamic adjustment of tunneling parameters in TBM construction. BRIEF DESCRIPTION OF DRAWINGS

[0044] 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 this application, and their

[0045] Figure 1 Flow chart of the three-directional rock breaking force prediction method of the TBM cutter based on the rotary cutting mode of the embodiment of the application;

[0046] Figure 2 Flow chart of the fitting of the expression about the pressure distribution coefficient of the embodiment of the application;

[0047] Figure 3 Flow chart of the derivation of the calculation formula of the vertical rock breaking force and the rolling rock breaking force of the embodiment of the application;

[0048] Figure 4 Flow chart of the derivation of the calculation formula of the lateral rock breaking force of the embodiment of the application;

[0049] Figure 5 Schematic diagram of the inner and outer rock breaking surfaces of the cutter of the embodiment of the application;

[0050] Figure 6 Fitting diagram of the pressure distribution coefficient in the calculation formula of the vertical and rolling rock breaking force of the embodiment of the application, (1) is the fitting diagram of the pressure distribution coefficient of the vertical rock breaking force, and (2) is the fitting diagram of the pressure distribution coefficient of the rolling rock breaking force;

[0051] Figure 7 Comparison diagram of the change trend of the three-directional rock breaking force prediction method of the TBM cutter and the Gertsch full-size linear cutting test results of the embodiment of the application, (1) is the comparison diagram of the change trend of the vertical rock breaking force, and (2) is the comparison diagram of the change trend of the rolling rock breaking force;

[0052] Wherein, 1, the area of the outer rock breaking surface of the cutter; 2, the area of the inner rock breaking surface of the cutter; 3, the radius of the position of the cutter on the cutter head; 4, the angle through which the cutter rotates around the central axis of the cutter head; 5, the penetration depth; and 6, the width of the cutter tip edge. DETAILED DESCRIPTION

[0053] 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.

[0054] It should be noted that the steps shown in the flow chart 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 flow chart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0055] Embodiment one

[0056] As Figure 1 shown in the embodiment, a three-dimensional rock breaking force prediction method of TBM cutter based on rotary cutting mode is provided, comprising:

[0057] Obtaining the physical property parameters of the rock to be broken and the cutter parameters, and constructing a hyperbolic function model of the cutter tip edge width and the penetration depth; optimizing the cutter edge geometry through the hyperbolic function model;

[0058] Obtaining the contact angle between the cutter and the rock based on the optimized cutter edge geometry;

[0059] Based on the contact angle and the hyperbolic function model, fitting the pressure distribution coefficient expression through the pre-experiment data, and constructing a Hertz-Weibull stress coupling analysis model;

[0060] 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;

[0061] Based on the difference between the inner and outer cutting paths of rotary cutting, assuming the rock failure mode and failure shape caused by lateral force, and deriving the lateral rock breaking force calculation formula in the process of single cutter penetrating into rock;

[0062] Obtaining the three-dimensional rock breaking force prediction result 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 adjusting the TBM tunneling parameters based on the prediction result.

[0063] As Figure 2 shown: the expression for fitting the pressure distribution coefficient includes the following steps:

[0064] Through the experiment of fixed cutter spacing, the average vertical rock breaking force and the average rolling rock breaking force data of the cutter under different penetration depths are obtained, and the experimental data set is generated;

[0065] Assuming that the pressure distribution function is exponential, and based on this, an integral equation is established, and the pressure distribution coefficient under different penetration depths is back calculated through the experimental data set;

[0066] The relationship between the back calculated pressure distribution coefficient and the penetration depth is fitted, the pressure distribution coefficient expressions corresponding to the average vertical rock breaking force and the average cutter rock breaking force are obtained respectively, and a new pressure distribution coefficient expression is obtained through numerical calculation tool optimization.

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

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

[0069] The stress condition of the microelement of the cutter is determined, and the contact pressure calculation formula of the microelement at any point of the contact part of the cutter and rock is obtained by combining the Hertz-Weibull stress coupling analysis model;

[0070] The contact part of the cutter and rock is analyzed as a whole, the contact pressure calculation formula of the microelement at any point on the contact section is obtained, and the resultant force calculation formula of the entire contact section of the cutter and rock is obtained by integrating in the angle direction of the contact surface.

[0071] The resultant force is decomposed in the vertical and rolling directions, and the rolling friction effect is considered to obtain the vertical rock breaking force calculation formula and the rolling rock breaking force calculation formula.

[0072] As shown in Figure 4 , the lateral rock breaking force calculation formula is derived by the following steps:

[0073] Based on the difference between the cutting paths of the inner and outer sides of the cutter during the rotary cutting process, it is assumed that the destruction form of the rock on both sides is shear failure when the cutter invades the rock, and the destruction shape is assumed to be triangular.

[0074] The areas of the rock breaking surfaces on the inner and outer sides of the cutter are calculated by introducing inner and outer side correction amounts, respectively.

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

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

[0077] Table 1

[0078] Component Density (kg / m 3 )]]> Elastic modulus (Pa) Poisson's ratio Blade ring 7850 2.1E11 0.28

[0079] Table 2

[0080]

[0081] The cutter model is optimized, and a hyperbolic function model of the penetration degree of the cutter tip edge width is established:

[0082]

[0083] wherein D p is the cutter tip edge width, mm; D0 is the initial cutter tip edge width, mm. is the coefficient of edge shape change, E r is the elastic modulus of rock, Mpa; p is the current penetration depth, mm; p c is the critical penetration depth, mm, σ c is the uniaxial compressive strength of rock, Mpa; R c is the radius from the center of the cutter head to the outside of the edge, mm.

[0084] A rotary cutting motion analysis model of the cutter is established, based on the coupled motion of the cutter revolving around the cutter head axis and rotating around its own central axis, a trajectory equation of the rotary cutting motion of the cutter is established, the assumption of vertical penetration of rock by the rotary cutting of the cutter is verified, and a calculation formula of the contact angle θ between the cutter and the rock is derived;

[0085] A rock breaking force prediction model is established, and a pre-test is performed to refer to an exponential function for fitting to obtain an expression of the pressure distribution coefficient ;

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

[0087] Further, the step of establishing a rock breaking force prediction model, performing a pre-test, and referring to an exponential function for fitting to obtain an expression of the pressure distribution coefficient includes:

[0088] A pre-test is performed to obtain the average vertical rock breaking force and the average rolling rock breaking force at the same cutter spacing under the condition of fixed cutter spacing, and a data set is generated, in this embodiment, the data of the average vertical rock breaking force and the average rolling rock breaking force are obtained by Gertsch full-size linear cutting rock test data, and the data is shown in Table 3;

[0089] Table 3

[0090]

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

[0092] Table 4

[0093]

[0094]

[0095] The pre-test data is fitted by referring to the exponential function, and the expressions of the average vertical rock breaking force and the average cutter rock breaking force about the pressure distribution coefficient are obtained respectively, and the fitting results are shown in Table 5;Figure 6 is shown;

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

[0097] R 2 = 0.97691;

[0098] R 2 = 0.99889;

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

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

[0101] Further, the distribution form of the contact pressure of the interaction part of the hob and the rock is determined, and the steps for deriving the vertical rock breaking force and the rolling rock breaking force calculation formula include:

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

[0103] The stress of the hob microelement is determined, and the calculation formula of the contact pressure P(x,y) of the microelement at any point of the contact part of the hob and the rock is derived:

[0104]

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

[0106] The contact section of the cutter and the rock is taken out for overall force analysis, the contact pressure calculation formula of the microelement at any point on the contact section is obtained, and the resultant force F of the contact section of the cutter and the rock is obtained by integral derivation along the angle direction of the contact surface. P

[0107]

[0108] The resultant force of the contact section of the cutter and the rock is decomposed along the vertical direction and the rolling direction, and the rolling friction effect is considered, and the calculation formula of the vertical rock breaking force F V and the rolling rock breaking force F R is derived:

[0109]

[0110] Wherein, μ is the friction coefficient of the cutter and the rock.

[0111] Further, the calculation formula of the vertical rock breaking force F V and the rolling rock breaking force F R is used to more accurately estimate the vertical rock breaking force and the rolling rock breaking force, and the comparison result with the Gertsch full-size linear cutting test result is shown in Table 5:

[0112] Table 5

[0113]

[0114]

[0115] As shown in Table 5, the maximum error of the vertical rock breaking force is not more than 21% and the maximum error of the rolling rock breaking force is not more than 15% when the cutter spacing is 76mm and the different penetration degrees are used in the TBM cutter three-direction rock breaking force prediction method based on the rotary cutting mode and the Gertsch full-size linear cutting test method. Figure 7 The comparison chart of the change trend of the TBM cutter three-direction rock breaking force prediction method and the Gertsch full-size linear cutting test result is shown in Table 5, and the change trend of the model calculation result and the test result of the vertical rock breaking force and the cutter rock breaking force is the same. Therefore, the error and the change trend of the data of the two methods can determine that the calculation formula of the vertical rock breaking force and the rolling rock breaking force in the TBM cutter three-direction rock breaking force prediction method based on the rotary cutting mode is reasonable.

[0116] Example Two

[0117] ​The three-direction rock breaking force prediction method of the TBM cutter based on the rotary cutting mode is compared with the tunneling rock breaking test method of the Zhang Zhaohuang team of Huabei Electric Power University, and the lateral rock breaking force calculation formula of the application is verified. The cutter structure parameters and rock mechanical property parameters used in the comparison and verification of the above two methods are completely consistent.

[0118] The specific steps of the three-direction rock breaking force prediction method of the TBM cutter based on the rotary cutting mode are as follows:

[0119] The physical property parameters of the broken rock and the parameters of the CCS disc-shaped cutter are obtained, and the rock mechanical property parameters in the test are shown in Table 6;

[0120] Table 6

[0121]

[0122] The physical property parameters of the rock to be broken and the cutter parameters are obtained, and a hyperbolic function model of the cutter tip edge width and the penetration depth is constructed; the cutter edge geometry is optimized through 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 the hyperbolic function model, a pressure distribution coefficient expression is fitted through pre-experiment data, and a Hertz-Weibull stress coupling analysis model is constructed;

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

[0126] Based on the differences between the inner and outer cutting paths of rotary cutting, the rock failure mode and shape caused by lateral force are assumed, and a lateral rock breaking force calculation formula during the single cutter intrusion into rock is derived;

[0127] According to the vertical rock breaking force calculation formula, the rolling rock breaking force calculation formula and the lateral rock breaking force calculation formula, the three-direction rock breaking force prediction results are obtained, and the TBM tunneling parameters are adjusted based on the prediction results.

[0128] Further, based on the differences between the inner and outer cutting paths of rotary cutting, the rock failure mode and shape caused by lateral force are assumed, and the steps of deriving the lateral rock breaking force calculation formula include:

[0129] Based on the differences between the inner and outer cutting paths of rotary cutting, it is assumed that the failure mode of the rock on both sides of the cutter during the intrusion into the rock is shear failure, and the failure shape is triangular;

[0130] The areas of the rock breaking surfaces on the inner side and the outer side of the cutter are calculated by introducing inner and outer side correction amounts respectively;

[0131] The dynamic attenuation relationship of the lateral force is established, and the lateral rock breaking force F is obtained by combining the rock breaking surface area of the inner side and the outer side of the roller cutter S The calculation formula.

[0132] Further, the rock breaking surface area A i of the inner side of the roller cutter and the rock breaking surface area A o of the outer side of the roller cutter are calculated as follows:

[0133]

[0134] Wherein, R represents the radius of the roller cutter, that is, the geometric radius from the center point of the roller cutter to the outermost edge of the cutting edge, mm; r represents the radius of the position of the roller cutter on the cutter head; γ represents the angle turned by the roller cutter around the central axis of the cutter head, δ(r) is the inner and outer side correction amount, k is a dimensionless correction coefficient, and the value range is 0.03-0.15.

[0135] Further, the calculation formula of the lateral rock breaking force F S is as follows:

[0136]

[0137] Wherein, η(p) is the stress distribution transmission efficiency coefficient of the lateral force, is the lateral force pressure distribution coefficient, δ is the efficiency attenuation coefficient, δ=2.35; τ r is the corrected rock shear strength, τ r =τ·(1-0.1·v c ); τ is the rock shear strength; v c is the linear speed of the roller cutter head, m / s; A o is the rock breaking surface area of the outer side of the roller cutter; A i is the rock breaking surface area of the inner side of the roller cutter. The area is calculated according to Figure 5 .

[0138] Further, the vertical lateral rock breaking force is more accurately estimated through the calculation formula of the lateral rock breaking force F S , and the comparison with the tunneling rock breaking test results of Zhang Zhaohuang team is shown in Table 7:

[0139] Table 7

[0140]

[0141] Further, the prediction model in the embodiment calculates the results that, in the case of similar penetration, the lateral force generated by the cutter gradually increases with the increasing installation radius of the cutter; in the case of similar cutter spacing, the lateral force generated by the cutter gradually increases with the increasing penetration. The change trend is consistent with the theoretical evolution law of the lateral force of the cutter in the process of rock breaking. Therefore, it can be determined that the lateral rock breaking force calculation formula in the embodiment is reasonable.

[0142] Embodiment three

[0143] Based on the same inventive concept, the present application also provides a TBM cutter three-direction rock breaking force prediction system based on rotary cutting mode, which is used to realize any one of the methods. The system comprises 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 acquire the physical property parameters of the broken rock and the cutter parameters.

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

[0146] The motion analysis module is used to establish a rotary cutting motion analysis model of the cutter, establish a cutter rotary cutting motion trajectory equation based on the coupled motion of the cutter revolving around the cutter disc axis and rotating around its own central axis, and calculate the contact angle between the cutter and the rock based on the coupled motion trajectory equation.

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

[0148] The first prediction module is used to obtain the vertical rock breaking force calculation formula and the rolling rock breaking force calculation formula based on the 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 cutter by introducing inner and outer side correction amounts based on the difference between the inner and outer cutting paths of the cutter in the rotary cutting process, assuming that the destruction of the rock on both sides of the cutter is shear failure when the cutter invades the rock, and assuming that the destruction shape is triangular; establish a dynamic attenuation relationship of the lateral force, and obtain the lateral rock breaking force calculation formula in combination with the areas of the inner and outer rock breaking surfaces of the cutter.

[0150] The control unit module is used to obtain the three-direction rock breaking force prediction results 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 adjust the TBM tunneling parameters based on the prediction results.

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

[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, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in 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 predicting three-dimensional rock breaking forces of a TBM cutter based on a rotary cutting mode, characterized in that, The method comprises the following steps: obtaining physical property parameters of the rock to be broken and parameters of the disc cutter and constructing a hyperbolic function model of the disc cutter tip edge width and the penetration depth; optimizing the disc cutter edge geometry through the hyperbolic function model; obtaining the contact angle between the disc cutter and the rock based on the optimized disc cutter edge geometry; based on the contact angle and the hyperbolic function model, fitting a pressure distribution coefficient expression through pre-experiment data, and constructing a Hertz-Weibull stress coupling analysis model; obtaining a vertical rock breaking force calculation formula and a rolling rock breaking force calculation formula based on the Hertz-Weibull stress coupling analysis model; based on the differences between the inner and outer cutting paths of the rotary cutting, assuming the rock damage form and shape caused by the lateral force, and deducing a lateral rock breaking force calculation formula in the process of single disc cutter invading the rock; obtaining a three-way rock breaking force prediction result 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 adjusting the TBM tunneling parameters based on the prediction result; the hyperbolic function model of the disc cutter tip edge width and the penetration depth is: ； wherein, is the width of the cutting edge, mm; is the initial width of the cutting edge, mm; is the deformation coefficient of the cutting edge, ; is the elastic modulus of the rock, Mpa; is the current penetration depth, mm; is the critical penetration depth, mm, ; is the uniaxial compressive strength of the rock, Mpa; is the radius of the cutter, i.e. the geometric radius from the center point of the cutter to the outermost edge of the cutting edge, mm.

2. The three-way rock breaking force prediction method of the TBM disc cutter based on the rotary cutting mode according to claim 1, characterized in that, based on the coupling motion of the disc cutter revolving around the disc cutter axis and rotating around its own central axis and the optimized edge width, a disc cutter rotary cutting motion trajectory equation of the disc cutter revolution and rotation is constructed, and the contact angle between the disc cutter and the rock is calculated based on the disc cutter rotary cutting motion trajectory equation.

3. The three-way rock breaking force prediction method of the TBM disc cutter based on the rotary cutting mode according to claim 1, characterized in that, the process of fitting a pressure distribution coefficient expression based on the contact angle and the hyperbolic function model through pre-experiment data includes: through experiments with fixed disc cutter spacing, obtaining average vertical rock breaking force and average rolling rock breaking force data of the disc cutter under different penetration depths, generating an experimental data set; assuming that the pressure distribution function is in exponential form, and based on this, establishing an integral equation, and through the experimental data set, backstepping the pressure distribution coefficients under different penetration depths; fitting the relationship between the backstepped pressure distribution coefficients and the penetration depths, respectively obtaining the pressure distribution coefficient expressions corresponding to the average vertical rock breaking force and the average disc cutter rock breaking force, and optimizing the pressure distribution coefficient expressions through a numerical calculation tool.

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

5. The three-way rock breaking force prediction method of the TBM disc cutter based on the rotary cutting mode according to claim 1, characterized in that, the process of obtaining a vertical rock breaking force calculation formula and a rolling rock breaking force calculation formula based on the Hertz-Weibull stress coupling analysis model includes: Determine the force condition of the micro-element of the cutter, and obtain the contact pressure calculation formula of the micro-element at any point of the contact part of the cutter and the rock by combining the Hertz-Weibull stress coupling analysis model; the contact part of the cutter and the rock is analyzed as a whole, the contact pressure calculation formula of the micro-element at any point on the contact section is obtained, and the integral derivation is carried out along the angle direction of the contact surface to obtain the resultant force calculation formula of the whole contact section of the cutter and the rock; finally, the resultant force is decomposed along the vertical and rolling directions, and the rolling friction effect is considered to obtain the vertical rock breaking force calculation formula and the rolling rock breaking force calculation formula.

6. The TBM cutter three-direction rock breaking force prediction method based on the rotary cutting mode according to claim 5, wherein the contact pressure calculation formula of the micro-element at any point of the contact part of the cutter and the rock is:

7. The TBM cutter three-direction rock breaking force prediction method based on the rotary cutting mode according to claim 6, wherein the vertical rock breaking force calculation formula is: ； wherein, is the contact pressure acting on the microelement, the action point is at the center of gravity of the microelement, and the action line is along the radial direction of the roller cutter; 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; is the integral variable, representing the distribution of the contact pressure in the rolling direction, which is constrained by the Weibull distribution; is a dimensionless constant; is the shape parameter of the Weibull distribution; is the scale parameter of the Weibull distribution, mm; represents the radius of the roller cutter; represents the width of the cutting edge of the cutter; represents the spacing of the roller cutter; represents the contact angle between the roller cutter and the rock; represents the contact pressure distribution coefficient; represents the uniaxial compressive strength of the rock; represents the uniaxial tensile strength of the rock.

8. The TBM cutter three-direction rock breaking force prediction method based on the rotary cutting mode according to claim 1, wherein the process of obtaining the lateral rock breaking force calculation formula comprises: Based on the difference between the inner and outer cutting paths of the cutter in the rotary cutting process, it is assumed that the destruction form of the rock on both sides of the cutter when invading the rock is shear failure, and it is assumed that the destruction shape is triangular; the areas of the rock breaking surfaces on the inner and outer sides of the cutter are calculated respectively by introducing inner and outer correction amounts; a dynamic attenuation relationship of the lateral force is established, and the lateral rock breaking force calculation formula is obtained in combination with the areas of the rock breaking surfaces on the inner and outer sides of the cutter. ； Comprise: ； wherein, is the coefficient of friction between the cutter and the rock. 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; The parameter acquisition module is used to acquire the physical property parameters of the destroyed rock and the cutter parameters. The cutter tip optimization module is used to construct a hyperbolic function model of the cutter tip edge width and the penetration depth and optimize the cutter edge geometry.

9. A three-directional rock breaking force prediction system of TBM cutter based on rotary cutting mode, for implementing the method of any one of claims 1-8, characterized in that, The motion analysis module is used to establish a rotary cutting motion analysis model of the cutter, establish a cutter rotary cutting motion trajectory equation based on the coupled motion of the cutter revolving around the cutter disc axis and revolving around its own central axis, and calculate the contact angle between the cutter and the rock based on the cutter rotary cutting motion trajectory equation. The pre-test fitting module is used to fit the pressure distribution coefficient expression through pre-test data. The first prediction module is used to obtain the vertical rock breaking force calculation formula and the rolling rock breaking force calculation formula based on the Hertz-Weibull stress coupling analysis model. The second prediction module is used to calculate the areas of the rock breaking surfaces on the inner and outer sides of the cutter respectively by introducing inner and outer correction amounts based on the difference between the inner and outer cutting paths of the cutter in the rotary cutting process, assume that the destruction form of the rock on both sides of the cutter when invading the rock is shear failure, and assume that the destruction shape is triangular; a dynamic attenuation relationship of the lateral force is established, and the lateral rock breaking force calculation formula is obtained in combination with the areas of the rock breaking surfaces on the inner and outer sides of the cutter. ​ ​ ​ ​ The control unit module is used for obtaining three-direction rock breaking force prediction results according to a vertical rock breaking force calculation formula, a rolling rock breaking force calculation formula and a lateral rock breaking force calculation formula, and adjusting TBM tunneling parameters based on the prediction results.

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