CN107545124B - Prediction method of wear condition of constant section disc hob of rock tunnel boring machine - Google Patents

Abstract

The method for predicting the wear condition of the constant section disc hob of the rock tunnel boring machine of the present invention relates to the construction technology of the tunnel boring equipment, from the real-time determination of the six interrelationships between various relevant parameters in the tunnel construction, including the determination of the rock tunnel boring machine The cutterhead speed n, tunneling rate v, cutterhead torque T, cutterhead thrust F, advance δ, cutting coefficient C, slip rate s, sliding distance l _i , contact stress P, hob weight wear G and cutterhead The relationship between the weight and wear G _i of the No. i front single-blade constant-section disc hob is used to realize the real-time prediction of the wear of the front single-blade constant-section disc hob at different installation positions of the cutter head. It overcomes the defect in the prior art that there is no effective technical means for directly detecting the wear of the disc-shaped hob with a constant section.

Description

Prediction method of wear condition of constant section disc hob of rock tunnel boring machine

technical field

The technical scheme of the invention relates to the construction technology of tunnel boring equipment, in particular to a method for predicting the wear condition of a constant section disc hob of a rock tunnel boring machine.

Background technique

The disc-shaped hob with constant section has high rock-breaking efficiency and long service life, and has been widely used in rock tunnel boring machines. Due to the high strength and hardness of rock, the problem of tool wear of rock tunnel boring machine is very serious in the process of rock geological construction. Frequent tool replacement not only delays the construction period, increases construction costs, and becomes an important factor that plagues construction safety, but also reduces the rock-breaking ability and increases energy consumption after the tool wears out. Once the wear limit is exceeded, the tool damage is irreparable and even endanger Therefore, the real-time detection of the tool wear status of rock tunnel boring machines has become an urgent need to improve tunneling efficiency, avoid construction failures, and save construction costs.

CN201510617860.4 discloses a real-time calculation method for the wear amount of disc hobs of hard rock tunnel boring machines. The method takes into account the factor that the change of hob geometric radius and the change of TBM tunneling parameters are interrelated, and predicts the hob by analyzing the changes of tunneling parameters. The change of the geometric radius can achieve the purpose of predicting the wear degree of the hob. However, it has the defect of ignoring the analysis of the internal mechanism and law of the hob wear evolution process, and it is difficult to accurately predict the intermediate process of the tool wear evolution. CN201610771253.8 discloses a method for estimating the weight and wear of disc hobs with constant cross-section for hard rock tunnel boring machines. The normal thrust load of the disc-shaped hob and the mechanical parameters of the material are used to predict the tool wear process. However, the normal thrust load of the disc-shaped hob cannot truly reflect the force on the contact micro-element when the hob breaks rocks, which affects the prediction results. accuracy flaws. In short, due to the harsh working environment of the cutter and the complicated rock-breaking process, there is still a lack of effective technical means to directly detect the wear of the constant-section disc hob.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for predicting the wear condition of the constant section disc hob of the rock tunnel boring machine, and to realize the real-time determination of the six interrelationships between various relevant parameters in the tunnel construction to realize the different cutter heads. The real-time prediction of the wear condition of the front single-edged constant-section disc hob at the installation position overcomes the defect in the prior art that there is no effective technical means for directly detecting the wear of the constant-section disc hob.

The technical solution adopted by the present invention to solve the technical problem is: the method for predicting the wear condition of the constant section disc hob of the rock tunnel boring machine, and the specific steps are as follows:

The first step is to determine the relationship between the cutter head speed, tunneling rate and footage of the rock tunnel boring machine:

The relationship between the cutter head speed, tunneling rate and footage of rock tunnel boring machine is determined by the following formula (1),

In the formula (1): δ is the footage of the rock tunnel boring machine, that is, the excavation distance of the rock tunnel boring machine per revolution of the cutterhead, in mm/r, and v is the tunneling speed of the rock tunnel boring machine, in mm/r min, n is the cutter head speed of the rock tunnel boring machine, the unit is r/min, the cutter head speed n and the tunneling speed v of the rock tunnel boring machine are collected in real time by the data acquisition system installed inside the rock tunnel boring machine equipment Excavation parameters;

The second step is to determine the relationship between the cutter head thrust, cutter head torque and cutting coefficient of the rock tunnel boring machine:

There is a mutual relationship among the cutterhead thrust, cutterhead torque and cutting coefficient of rock tunnel boring machine, which is determined by the following formula (2),

In the formula (2): C is the cutting coefficient of the rock tunnel boring machine, N is the number of hobs installed on the rock tunnel boring machine cutter head, and r _i is the number i hob installed on the rock tunnel boring machine cutter head Installation radius, the unit is m, is the sum of the installation radii of N hobs installed on the rock tunnel boring machine cutter head, in m, and T is the cutter head torque of the rock tunnel boring machine, in KN m, which is installed on the rock tunnel boring machine equipment The internal data acquisition system collects in real time, F is the cutter head thrust of the rock tunnel boring machine, the unit is KN, and it is collected in real time by the data acquisition system installed inside the rock tunnel boring machine equipment;

The third step is to determine the relationship between the footage and cutting coefficient of the rock tunnel boring machine and the slip rate of the constant section disc hob when breaking rock:

There is a relationship between the footage δ of the rock tunnel boring machine, the cutting coefficient C of the rock tunnel boring machine, and the slip rate s of the disc-shaped hob with constant cross-section when breaking rock. This relationship is determined by the following formula (3):

s≈γ·δ ^0.5 ·C ^1.2 (3)

In the formula (3): s is the slip rate when the disc-shaped hob with constant section breaks the rock, it is a dimensionless parameter, and γ is a constant;

The fourth step is to determine the sliding distance of the i-th constant-section disc hob on the rock tunnel boring machine cutterhead in actual motion:

The sliding distance of the i-th constant-section disc hob on the rock tunnel boring machine cutter head in actual motion is determined by the following formula (4),

l _i ＝sL _i ＝γ·δ ^0.5 ·C ^1.2 ·nπr _i t (4)

In the formula (4): l _i is the sliding distance of the i-th constant-section disc hob on the rock tunnel boring machine cutterhead in actual motion, and the unit is m; Li is the _i -th constant section hob on the rock tunnel boring machine cutterhead. The actual movement distance of the cross-section disc hob, in m, and t is the time, in min;

The fifth step is to determine the contact stress acting on the contact arc length when the constant section disc hob of the rock tunnel boring machine breaks rock:

The contact stress P acting on the contact arc length when the constant section disc hob of the rock tunnel boring machine breaks the rock, the unit is Mpa, is determined by the following formula (5),

In formula (5): S is the distance between adjacent cutters on the rock tunnel boring machine cutter head, in mm, _σc is the uniaxial compressive strength of rock in excavation geology, in Mpa, and _σt is the excavation geology Rock tensile strength, unit is Mpa, d is the blade width of constant section disc hob, unit is mm, α is the angle between rock joint surface and tunnel axis, referred to as rock mass joint angle, unit is radian rad;

The sixth step is to determine the weight wear amount of any front single-edged constant-section disc-shaped hob on the rock tunnel boring machine cutter head and the characteristic coefficient of rock abrasion and the contact arc length of the constant-section disc-shaped hob when it breaks rock. Correlation between contact stress and its sliding distance in real motion:

Weight wear G of any front single-edge constant-section disc hob on the rock tunnel boring machine cutter head, rock abrasion characteristic coefficient W and contact stress P acting on the contact arc length of the constant-section disc hob when breaking rock The interrelationship between and the sliding distance l in the actual motion is determined by the following formula (6),

G＝ ^k ·Wa· ^Pb ·l (6)

In the formula (6): l is the sliding distance of the constant section disc hob in actual motion, the unit is m, k, a and b are constants, which are obtained through the standard ring block wear simulation test method;

The seventh step is to determine the specific value of the weight and wear of the i-th frontal single-blade constant-section disc hob on the cutterhead when the rock tunnel boring machine is normally excavated:

When the rock tunnel boring machine is normally tunneling, the specific value of the weight and wear of the i-th frontal single-edged disc-shaped hob with constant cross-section on the cutter head is determined by the following formula (7),

G _i = k · W ^a · P ^b · sL _i (7)

In the formula (7): G _i is the weight wear amount of the i-th single-edged disc hob with constant section on the front of the rock tunnel boring machine cutter head, the unit is Kg, and s is the slippage of the disc hob with constant section when breaking rock. The mobility is a dimensionless parameter, and L _i is the actual movement distance of the i-th constant-section disc hob on the rock tunnel boring machine cutter head;

The footage δ of the rock tunnel boring machine in the formula (1), the cutting coefficient C of the rock tunnel boring machine in the formula (2), the slip rate s of the constant section disc hob in the formula (3) when breaking rock, In the formula (4) is the sliding distance l _i of the i-th constant-section disc hob on the cutter head of the rock tunnel boring machine during the actual motion. In formula (5), the constant-section disc hob of the rock tunnel boring machine breaks rock The contact stress P acting on the contact arc length, the weight and wear amount G of any front single-edged constant-section disc hob on the rock tunnel boring machine cutter head in formula (6), and the rock tunnel weight wear amount G in formula (7) The weight and wear G _i of the i-th frontal single-edge constant-section disc hob on the boring machine cutterhead is the tunneling parameters collected in real time by the rock tunnel boring machine data acquisition system. The cutterhead speed n, the tunneling speed v, and the cutterhead torque T and cutter head thrust F, rock mass parameters rock joint angle α obtained from engineering geological survey, uniaxial compressive strength σ _c of excavation geological rock and tensile strength σ _t of excavation geological rock, rock abrasion characteristic coefficient W obtained from rock wear test and The constant values k, a and b obtained from the wear simulation test are quickly calculated by the computer, so as to complete the prediction of the wear of the constant section disc hob of the rock tunnel boring machine.

The method for predicting the wear condition of the constant-section disc hob of the above-mentioned rock tunnel boring machine, the involved data acquisition system installed inside the rock tunnel boring machine equipment and its real-time acquisition method, rock wear test and standard ring block wear simulation test method It is well known in the technical field that the uniaxial compressive strength σ _c of the excavated geological rock, the tensile strength σ _t of the excavated geological rock and the characteristic coefficient of rock abrasion W are measured by experiments.

The beneficial effects of the present invention are as follows:

Compared with the prior art, the present invention has the following prominent substantive features:

(1) Compared with the technology disclosed in CN201510617860.4, the present invention has the following prominent substantive features:

1) Compare the methods used to predict wear:

During the excavation process of the rock tunnel boring machine, the hob under the joint action of the thrust and torque of the cutterhead contacts and crushes and cuts and peels off the rock. The cutter and the rock constitute a mechanical system that contacts and interacts with each other. Hob wear is the result of continuous contact between the surface material of the hob cutter ring and the surface material of the rock mass, and it changes with the change of the contact material, contact form, contact load and contact working conditions. The inherent law of hob wear evolution is the basis and key to predict the hob wear evolution process.

CN201510617860.4 Through the comparative analysis of the changes in tunneling parameters caused by the change of hob geometric radius before and after wear, a method for predicting the wear degree of TBM hobs was proposed, but no in-depth and systematic research was carried out on the essential process of hob wear evolution. It is difficult to predict the intermediate course of hob wear evolution. CN201510617860.4 considers the factor that the change of hob geometric radius and TBM (tunnel boring machine) tunneling parameter changes are interrelated, and predicts the change of hob geometric radius by analyzing the change of tunneling parameters, and then achieves the purpose of predicting the degree of hob wear. The disadvantages are that the analysis of the internal mechanism and law of the hob wear evolution process is ignored, and it is difficult to accurately predict the intermediate process of the tool wear evolution.

In the process of establishing the prediction method, based on the mechanism and test analysis of the hob wear evolution process, the present invention fully considers the control effect of the inner law of the hob wear evolution on the tool wear evolution process, and innovatively proposes a method based on wear evolution. Mechanism and test analysis, considering the influence of rock mass material and structure parameters and cutter head structure parameters, the multi-variate prediction method of hob wear process has realized the real-time prediction of the intermediate process of rock tunnel boring machine constant cross-section disc hob wear.

2) Comparison of the parameters used by the contrast prediction methods:

Wear is the result of the continuous interaction of two solid surface materials in contact with each other. The characteristics of contact materials, contact load and contact conditions are the key factors affecting wear evolution. During the specific construction process, the material of the rock tunnel boring machine hob is basically consistent. The rock mass is constantly changing with different geological conditions, and the abrasive properties of the rock directly affect the wear of the hob. Moreover, the structural features of the rock mass and the installation features of the cutter head will affect the force on the hob, and then affect the wear process of the hob.

CN201510617860.4 predicts hob wear by analyzing the relationship between driving parameters before and after hob wear, ignoring the influence of rock mass material and structural parameters on hob wear. CN201510617860.4 Utilize the relationship between tunneling parameters to predict the degree of tool wear. The disadvantage is that the analysis of the force on the hob by the parameters of the rock mass and the structural parameters of the cutter head is ignored, which affects the accuracy of the prediction results. Therefore, from the analysis Considering the interaction between the hob and the rock mass, this patent lacks an analysis of the impact of the rock mass material and structural parameters and the structural parameters of the cutter head on the wear of the hob.

In the process of analyzing the contact wear between the hob and the rock mass, the present invention fully considers the impact of the rock abrasion characteristics on the hob wear process, and combines the special damage process of the rock and the structural characteristics of the rock mass and the installation characteristics of the cutter head on the contact load. Influence, innovatively put forward the constant cross-section disc hob which is determined in real time from the six correlations among various relevant parameters in tunnel construction, with rock wear characteristics, contact stress, slip rate and driving distance as key parameters The wear prediction method, wherein the contact stress includes the impact of rock mechanics parameters, rock mass joints and cutter head structure parameters (knife spacing), and the slip rate includes the influence of tunneling parameters. The method of the present invention comprehensively uses the tunneling parameters, cutter head structure The relationship between the parameters and the rock mass parameters realizes the real-time prediction of the hob wear evolution process.

(2) Compared with the technology disclosed in CN201610771253.8, the present invention has the following prominent substantive features:

1) Analyze and compare from the perspective of load parameters used to predict wear:

Wear is the result of the contact between two solid surfaces, and the contact stress is a key mechanical parameter affecting the wear process. During the rock-breaking process of the hob, the contact between the hob and the rock mass is a surface contact, and the contact stress can directly reflect the stress of the material on each micro-element in the contact area.

CN201610771253.8 It is difficult to truly reflect the force on the contact micro-element when the hob breaks rocks by using the normal thrust load of the disc hob to predict the tool wear. It can be seen from the content of the invention and the examples disclosed in CN201610771253.8 that this patent technology considers the influence factor of load, and tries to predict the tool wear process through the normal thrust load and material mechanical parameters of the disc hob, but its disadvantages are : The normal thrust load of the disc hob is difficult to reflect the material load on each micro-element in the contact area, which affects the accuracy of the prediction results.

In the process of establishing the prediction method, the present invention fully considers the influence of contact stress on the tool wear process, and innovatively proposes to use contact stress as a key mechanical parameter for predicting tool wear, so that the calculation model is closer to the actual rock-breaking process of the hob , which improves the accuracy of the prediction results.

2) Comparison of the mechanical analysis adopted by the contrast prediction method:

Rock materials are special brittle materials, and the failure process is complex, including not only elastic deformation, plastic deformation, but also damage failure process. At the same time, the structural characteristics of the rock mass and the installation characteristics of the cutter head and cutter will affect the force of the hob when breaking the rock.

It can be seen from the invention content and examples disclosed in CN201610771253.8 that this patented technology only uses the elastic modulus and Poisson's ratio of the material to calculate the load, trying to reflect the actual load characteristics through the elastic mechanics model. But its disadvantage is that a single elastic mechanical analysis cannot reflect the rock damage and failure process. Therefore, from the perspective of analyzing the rock-breaking mechanical process of the hob, there are large calculation errors in the load calculation process of this patented technology.

In the rock-breaking mechanical analysis process of the hob, the present invention fully considers the special rock-mass damage process and the influence of rock mass structural features and cutterhead tool installation features, and starts from the analysis of the rock-mass bearing capacity, and innovatively proposes to consider the The contact stress calculation formula influenced by the joint angle and the knife spacing reduces the prediction error and enhances the pertinence, applicability and universality of the prediction method.

Compared with prior art, the present invention has following remarkable progress:

(1) The present invention is based on the mechanical and mechanism analysis of the contact surface interaction, in conjunction with the wear test, proposes the prediction method of the wear condition of the constant section disc hob of the rock tunnel boring machine, from six parameters between various relevant parameters in the tunnel construction The real-time determination of the relationship is to realize the real-time prediction of the wear of the front single-edged constant-section disc hob on different installation positions of the cutter head, which overcomes the lack of effective methods for directly detecting the wear of the constant-section disc hob in the prior art. Defects in technical means.

(2) The method of the present invention realizes the refinement of the wear information of the front single-edge constant section disc hob from the response changes of the tunneling parameters and geological parameters, and is applied to the real-time estimation of the hob wear condition in the actual construction process, which is useful for improving rock tunnels The driving efficiency of the roadheader, optimizing the driving parameters and prolonging the tool life play an important role.

(3) The present invention is based on theoretical analysis, and test simulation is a means to explore the inner law of hob wear evolution under actual working conditions, comprehensively considering the wear performance of rock, rock mass joint angle, cutter head structural parameters (knife spacing ), excavation load, and load cycle effects, etc., use the excavation parameters collected in real time by the rock tunnel boring machine to estimate the motion state of the hob, and on this basis, use the real-time excavation load and geological parameter changes collected by the rock tunnel boring machine The estimation of hob wear condition provides a feasible way for real-time estimation of hob wear process in actual engineering.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is a schematic diagram of the installation of disc-shaped hobs on the cutter head of a rock tunnel boring machine used in a tunnel project.

Detailed ways

The embodiment shown in Fig. 1 shows the installation condition of the disc-shaped hob on the cutter head of a rock tunnel boring machine used in a tunnel project: the axis of the cutter head is located at the center of the cutter head, the radius of the cutter head is 2885 mm, and there are 42 cutter position numbers. Install 17in constant cross-section disc hobs, the tool position numbers are 1, 2, 3, ..., 40, 41, 42 respectively. The larger the tool position number, the farther the tool is from the center of the cutter head. The number between adjacent tool positions is the difference between the installation radii of adjacent tool positions, referred to as tool spacing, and the unit is mm. Four central double-edged hobs are installed on No. 1 to No. 8 tool positions. The installation radius of No. 1 tool position on the cutter head is 90 mm. The distance between No. 2 tool position and No. 1 tool position is 86 mm. No. 3 tool position The tool distance between No. 2 tool position and No. 2 tool position is 82mm; the tool distance between No. 4 tool position and No. 3 tool position is 86mm; the tool distance between No. 5 tool position and No. 4 tool position is 84mm; The tool spacing is 86mm, the tool spacing between No. 7 tool position and No. 6 tool position is 82mm, the tool distance between No. 8 tool position and No. 7 tool position is 86mm; 20 tools are installed between No. 8 tool position and No. 29 tool position The front single-edged hobs are numbered sequentially from No. 9 to No. 28, and 8 front single-edged hobs are installed between No. 8 and No. 16 knives. The number of knives is arranged from No. 9 to No. 16 , the tool spacing between No. 8 tool position and No. 16 tool position is 85mm, and the installation radius difference between No. 16 tool position and No. 8 tool position is 8×85=680mm; No. 16 tool position and 12 front single-edged hobs are installed between No. 29 tool positions, and the tool position numbers are arranged from No. 17 to No. 28. The distance between the adjacent tool positions between No. 16 and No. 29 tool positions is 84mm. The installation radius difference between No. 29 tool position and No. 16 tool position is 12×84=1092mm; 14 edge single-edged hobs are installed on No. 29 to No. 42 tool positions, and the tool distance between No. 30 tool position and No. 29 tool position The distance between No. 31 and No. 30 tool positions is 63mm, the distance between No. 32 and No. 31 tool positions is 60mm, the distance between No. 33 and No. 32 tool positions is 57mm, and the distance between No. 34 The distance between tool position and No. 33 tool position is 54mm, the tool distance between No. 35 tool position and No. 34 tool position is 43mm, and the tool distance between No. 36 and No. 35 tool position is 37mm. On the same installation radius of the cutter head, the tool distance between No. 38 tool position and No. 37 tool position is 30mm, No. 38 and No. 39 tools are installed on the same installation radius of the cutter head, and the tool distance between No. 40 tool position and No. 30 tool position 23mm, No. 40, No. 41 and No. 42 tools are installed on the same installation radius of the cutter head, and are located on the outermost edge of the cutter head.

Example 1

The method of the present invention will be further described below through specific examples. It should be noted that the scope of protection of the claims of the present invention is not limited by these examples.

The method for predicting the wear condition of constant section disc hobs of rock tunnel boring machines, the specific steps are as follows:

The first step is to determine the relationship between the cutter head speed, tunneling rate and footage of the rock tunnel boring machine:

The relationship between the cutter head speed, tunneling rate and footage of rock tunnel boring machine is determined by the following formula (1),

In the formula (1): δ is the footage of the rock tunnel boring machine, that is, the excavation distance of the rock tunnel boring machine per revolution of the cutterhead, in mm/r, and v is the tunneling speed of the rock tunnel boring machine, in mm/r min, n is the cutter head speed of the rock tunnel boring machine, the unit is r/min, the cutter head speed and the tunneling speed are the tunneling parameters collected in real time by the data acquisition system installed inside the rock tunnel boring machine equipment;

In this embodiment, the cutter head speed n=6.65r/min, when the tunneling rate v=78mm/min in one tunneling cycle, then the footage δ of the rock tunnel boring machine in this tunneling cycle is:

Use the same method to calculate the footage δ of the rock tunnel boring machine with the tunneling rate v of other different tunneling cycles;

The second step is to determine the relationship between the cutter head thrust, cutter head torque and cutting coefficient of the rock tunnel boring machine:

There is a mutual relationship among the cutterhead thrust, cutterhead torque and cutting coefficient of rock tunnel boring machine, which is determined by the following formula (2),

In the formula (2): C is the cutting coefficient of the rock tunnel boring machine, N is the number of hobs installed on the rock tunnel boring machine cutter head, and r _i is the number i hob installed on the rock tunnel boring machine cutter head Installation radius, the unit is m, is the sum of the installation radii of N hobs installed on the rock tunnel boring machine cutter head, in m, and T is the cutter head torque of the rock tunnel boring machine, in KN m, which is installed on the rock tunnel boring machine equipment The internal data acquisition system collects in real time, F is the cutter head thrust of the rock tunnel boring machine, the unit is KN, and it is collected in real time by the data acquisition system installed inside the rock tunnel boring machine equipment;

In this embodiment, the number of hobs installed on the cutter head of the rock tunnel boring machine is N=42, and the sum of the installation radii of the 42 hobs installed on the cutter head The cutterhead torque T=12234.760KN·m and the cutterhead thrust F=15456.636KN collected in real time in the above excavation cycle; then the cutting coefficient of the rock tunnel boring machine in this excavation cycle is:

The third step is to determine the relationship between the footage and cutting coefficient of the rock tunnel boring machine and the slip rate of the constant section disc hob when breaking rock:

There is a correlation between the footage δ, the cutting coefficient C of the rock tunnel boring machine, and the slip rate s of the disc-shaped hob with constant cross-section when breaking rock. This relationship is determined by the following formula (3):

s≈γ·δ ^0.5 ·C ^1.2 (3)

In the formula (3): s is the slip rate of the constant cross-section disc hob when breaking rock, which is a dimensionless parameter, and γ is a constant. For the commonly used 17in constant cross-section disc hob, within the normal wear range of 20mm, γ≈ 0.0054, for the commonly used 19in constant cross-section disc hob, within the normal wear range of 20mm, γ≈0.0051;

The disc-shaped hob used in this embodiment is a 17in constant-section disc-shaped hob, taking γ≈0.0054, then the slip rate s of the constant-section disc-shaped hob when breaking rocks is:

s≈γ·δ ^0.5 ·C ^1.2 ＝0.0054×11.7 ^0.5 ×0.4555 ^1.2 ＝0.007189

The fourth step is to determine the sliding distance of the i-th constant-section disc hob on the rock tunnel boring machine cutterhead in actual motion:

The sliding distance of the i-th constant-section disc hob on the rock tunnel boring machine cutter head in actual motion is determined by the following formula (4),

l _i ＝sL _i ＝γ·δ ^0.5 ·C ^1.2 ·nπr _i t (4)

In formula (4): l _i is the sliding distance of the i-th constant-section disc hob on the cutter head of the rock tunnel boring machine in actual motion, in m, and s is the slippage of the constant-section disc hob when it breaks rock Rate is a dimensionless parameter, L _i is the actual movement distance of the i-th constant section disc hob on the cutter head of the rock tunnel boring machine, the unit is m, t is the time, the unit is min;

In this embodiment, s = 0.007189 is obtained from the third step above, and the No. 9 to No. 28 cutter positions of the rock tunnel boring machine cutter head are front single-edged disc-shaped hobs, wherein L ₁₂ is the rock tunnel boring machine cutter The actual movement distance of the No. 12 constant-section disc hob on the disk, L ₂₂ is the actual movement distance of the No. 22 constant-section disc hob on the rock tunnel boring machine cutter head, which is installed on the No. 12 rock tunnel boring machine cutter head The installation radius r ₁₂ of the hob = 1.022m, the installation radius of the No. 22 hob installed on the rock tunnel boring machine cutter head r ₂₂ = 1.866m, the actual excavation time t = 10.3min in the above excavation cycle, then In this excavation cycle, the sliding distance l ₁₂ of the No. 12 hob installed on the cutterhead of the rock tunnel boring machine and the sliding distance l ₂₂ of the actual movement of the No. 22 hob installed on the cutterhead of the rock tunnel boring machine They are:

l ₁₂ ＝sL ₁₂ ＝0.007189×2×6.65×π×1.022×10.3＝3.162m

l ₂₂ ＝sL ₂₂ ＝0.007189×2×6.65×π×1.866×10.3＝5.773m

The fifth step is to determine the contact stress acting on the contact arc length when the constant section disc hob of the rock tunnel boring machine breaks rock:

The contact stress P acting on the contact arc length when the constant section disc hob of the rock tunnel boring machine breaks the rock, the unit is Mpa, is determined by the following formula (5),

In formula (5): S is the distance between adjacent cutters on the rock tunnel boring machine cutter head, in mm, _σc is the uniaxial compressive strength of rock in excavation geology, in Mpa, and _σt is the excavation geology Rock tensile strength, unit is Mpa, d is the blade width of constant section disc hob, unit is mm, α is the angle between rock joint surface and tunnel axis, referred to as rock mass joint angle, unit is radian rad;

In the present embodiment, according to the schematic diagram of installation of disc-shaped hobs on the rock tunnel boring machine cutterhead used in a tunnel engineering shown in Figure 1, the distance between the No. 12 hob and the adjacent cutter on the rock tunnel boring machine cutterhead is Knife spacing = 85mm, the tool spacing between the No. 22 hob and adjacent cutters = 84mm; the uniaxial compressive strength σ _c = 62.0Mpa of the excavation geological rock, the tensile strength σ _t = 5.0Mpa of the excavation geological rock; the blade width d=12mm; rock mass joint angle α=π/3.

Then when the cutter spacing S=85mm, the contact stress P acting on the contact arc length when the rock tunnel boring machine constant section disc hob breaks rock is:

Then when the cutter spacing S=84mm, the contact stress P acting on the contact arc length when the rock tunnel boring machine constant section disc hob breaks rock is:

The sixth step is to determine the weight wear amount of any front single-edged constant-section disc-shaped hob on the rock tunnel boring machine cutter head and the characteristic coefficient of rock abrasion and the contact arc length of the constant-section disc-shaped hob when it breaks rock. Correlation between contact stress and its sliding distance in real motion:

Weight wear G of any front single-edge constant-section disc hob on the rock tunnel boring machine cutter head, rock abrasion characteristic coefficient W and contact stress P acting on the contact arc length of the constant-section disc hob when breaking rock The interrelationship between and the sliding distance l in the actual motion is determined by the following formula (6),

G＝ ^k ·Wa· ^Pb ·l (6)

In the formula (6): l is the sliding distance of the constant section disc hob in actual motion, the unit is m, k, a and b are constants, which are obtained through the standard ring block wear simulation test method;

In the project of this embodiment, the rock abrasion characteristic coefficient W of the geological rock formation where the above-mentioned excavation cycle is located is measured by a rock wear test, using a steel needle with a 90° needle tip angle hardness of 54HRC to slide 10mm on the rock surface for 1 second under a load of 70N The distance is to measure the width of the needle tip after wear, and use 10 times of this width to characterize the characteristic coefficient of rock abrasion. The test shows that W=2.34; k, a and b are constants, which can be obtained through the wear simulation test method. Use the hob material in this example to make tool samples, and use the rock materials of the typical geology of the project to make rock samples. According to the principle of similar geometric configuration, consistent material properties, similar contact stress and relative motion between the simulation system and the actual system, 180 sets of standard ring block wear simulation tests were carried out on the M-2000 wear testing machine. According to the test results, the constant k=2.37×10 ^-9 , a=1.93, b=2.38 were obtained;

The seventh step is to determine the specific value of the weight and wear of the i-th frontal single-blade constant-section disc hob on the cutterhead when the rock tunnel boring machine is normally excavated:

When the rock tunnel boring machine is normally tunneling, the specific value of the weight and wear of the i-th frontal single-edged disc-shaped hob with constant cross-section on the cutter head is determined by the following formula (7),

G _i = k · W ^a · P ^b · sL _i (7)

In the formula (7): G _i is the weight wear amount of the i-th single-edged disc hob with constant section on the front of the rock tunnel boring machine cutter head, the unit is Kg, and s is the slippage of the disc hob with constant section when breaking rock. The mobility is a dimensionless parameter, and L _i is the actual movement distance of the i-th constant-section disc hob on the rock tunnel boring machine cutter head;

In the present embodiment, obtained by the above-mentioned fifth step: when the knife spacing S=85mm, P=108.849Mpa; 2.37×10 ^-9 , a=1.93 and b=2.38, and l ₁₂ ＝s L ₁₂ ＝3.162 and l ₂₂ ＝s L ₂₂ ＝5.773 obtained in the fourth step above. , the weight wear amount G ₁₂ of the No. 12 front single-blade constant-section disc hob installed on the rock tunnel boring machine cutter head and the No. 22 front single-blade constant-section disc hob installed on the rock tunnel boring machine cutter head The weight wear amounts of G ₂₂ are:

G ₁₂ = k·W ^a ·P ^b ·l ₁₂ =2.37×10 ^-9 ×2.34 ^1.93 ×(108.849) ^2.38 ×3.162kg＝0.0027kg

G ₂₂ = k·W ^a ·P ^b ·l ₁₂ =2.37×10 ^-9 ×2.34 ^1.93 ×(108.420) ^2.38 ×5.773kg＝0.0049kg

In this embodiment, the results of the above-mentioned formulas (1) to (7) are all calculated quickly by a computer, so as to complete the prediction of the wear of the constant-section disc hob of the rock tunnel boring machine.

The weight wear of the No. 12 front single-blade constant-section disc hob and the No. 22 front single-blade constant-section disc hob on the cutter head of the rock tunnel boring machine during the 16-ring excavation of the typical rock formation in this embodiment project See attached table 1 for the calculated value

Table 1. On the cutter head of the rock tunnel boring machine during the excavation of 16 rings in the typical rock mass formation

Calculated value of wear by weight of No. 12 and No. 22 front single-edged constant-section disc hobs

In the above-mentioned embodiments, the data acquisition system and its real-time acquisition method installed inside the rock tunnel boring machine equipment involved, the rock wear test and the standard ring block wear simulation test method are well known in the art. The compressive strength σ _c , the tensile strength σ _t of excavation geological rock and the characteristic coefficient of rock abrasion W are measured by experiments.

Claims (1)

1. The method for predicting the wear condition of the constant section disc hob of rock tunnel boring machine is characterized in that the specific steps are as follows: The first step is to determine the relationship between the cutter head speed, tunneling rate and footage of the rock tunnel boring machine: The relationship between the cutter head speed, tunneling rate and footage of rock tunnel boring machine is determined by the following formula (1), In the formula (1): δ is the footage of the rock tunnel boring machine, that is, the excavation distance of the rock tunnel boring machine per revolution of the cutterhead, in mm/r, and v is the tunneling speed of the rock tunnel boring machine, in mm/r min, n is the cutter head speed of the rock tunnel boring machine, the unit is r/min, the cutter head speed n and the tunneling speed v of the rock tunnel boring machine are collected in real time by the data acquisition system installed inside the rock tunnel boring machine equipment Excavation parameters; The second step is to determine the relationship between the cutter head thrust, cutter head torque and cutting coefficient of the rock tunnel boring machine: There is a mutual relationship among the cutterhead thrust, cutterhead torque and cutting coefficient of rock tunnel boring machine, which is determined by the following formula (2), In the formula (2): C is the cutting coefficient of the rock tunnel boring machine, N is the number of hobs installed on the rock tunnel boring machine cutter head, and r _i is the number i hob installed on the rock tunnel boring machine cutter head Installation radius, the unit is m, is the sum of the installation radii of N hobs installed on the rock tunnel boring machine cutter head, in m, and T is the cutter head torque of the rock tunnel boring machine, in KN m, which is installed on the rock tunnel boring machine equipment The internal data acquisition system collects in real time, F is the cutter head thrust of the rock tunnel boring machine, the unit is KN, and it is collected in real time by the data acquisition system installed inside the rock tunnel boring machine equipment; The third step is to determine the relationship between the footage and cutting coefficient of the rock tunnel boring machine and the slip rate of the constant section disc hob when breaking rock: There is a relationship between the footage δ of the rock tunnel boring machine, the cutting coefficient C of the rock tunnel boring machine, and the slip rate s of the disc-shaped hob with constant cross-section when breaking rock. This relationship is determined by the following formula (3): s≈γ·δ ^0.5 ·C ^1.2 (3) In the formula (3): s is the slip rate when the disc-shaped hob with constant section breaks the rock, it is a dimensionless parameter, and γ is a constant; The fourth step is to determine the sliding distance of the i-th constant-section disc hob on the rock tunnel boring machine cutterhead in actual motion: The sliding distance of the i-th constant-section disc hob on the rock tunnel boring machine cutter head in actual motion is determined by the following formula (4), l _i ＝sL _i ＝γ·δ ^0.5 ·C ^1.2 ·nπr _i t (4) In the formula (4): l _i is the sliding distance of the i-th constant-section disc hob on the rock tunnel boring machine cutterhead in actual motion, and the unit is m; Li is the _i -th constant section hob on the rock tunnel boring machine cutterhead. The actual movement distance of the cross-section disc hob, in m, and t is the time, in min; The fifth step is to determine the contact stress acting on the contact arc length when the constant section disc hob of the rock tunnel boring machine breaks rock: The contact stress P acting on the contact arc length when the constant section disc hob of the rock tunnel boring machine breaks the rock, the unit is Mpa, is determined by the following formula (5), In formula (5): S is the distance between adjacent cutters on the rock tunnel boring machine cutter head, in mm, _σc is the uniaxial compressive strength of rock in excavation geology, in Mpa, and _σt is the excavation geology Rock tensile strength, unit is Mpa, d is the blade width of constant section disc hob, unit is mm, α is the angle between rock joint surface and tunnel axis, referred to as rock mass joint angle, unit is radian rad; The sixth step is to determine the weight wear amount of any front single-edged constant-section disc hob on the rock tunnel boring machine cutter head and the characteristic coefficient of rock abrasion and the contact arc length of the constant-section disc hob when it breaks rock. Correlation between contact stress and its sliding distance in real motion: Weight wear G of any front single-edged constant-section disc hob on the rock tunnel boring machine cutter head, rock abrasion characteristic coefficient W, and contact stress P acting on the contact arc length of the constant-section disc hob when breaking rock The interrelationship between and the sliding distance l in the actual motion is determined by the following formula (6), G＝ ^k ·Wa· ^Pb ·l (6) In the formula (6): l is the sliding distance of the constant section disc hob in actual motion, the unit is m, k, a and b are constants, which are obtained through the standard ring block wear simulation test method; The seventh step is to determine the specific value of the weight and wear of the i-th frontal single-blade constant-section disc hob on the cutterhead when the rock tunnel boring machine is normally excavated: The specific value of the weight and wear amount of the i-th frontal single-edged constant-section disc hob on the cutter head during normal tunneling of the rock tunnel boring machine is determined by the following formula (7): G _i = k · W ^a · P ^b · sL _i (7) In the formula (7): G _i is the weight wear amount of the i-th single-edged disc hob with constant section on the front of the rock tunnel boring machine cutter head, the unit is Kg, and s is the slippage of the disc hob with constant section when breaking rock. The mobility is a dimensionless parameter, and L _i is the actual movement distance of the i-th constant-section disc hob on the rock tunnel boring machine cutter head; The footage δ of the rock tunnel boring machine in the formula (1), the cutting coefficient C of the rock tunnel boring machine in the formula (2), the slip rate s of the constant section disc hob in the formula (3) when breaking rock, In the formula (4) is the sliding distance l _i of the i-th constant-section disc hob on the cutter head of the rock tunnel boring machine during the actual motion. In formula (5), the constant-section disc hob of the rock tunnel boring machine breaks rock The contact stress P acting on the contact arc length, the weight and wear amount G of any front single-edged constant-section disc hob on the rock tunnel boring machine cutter head in formula (6), and the rock tunnel weight wear amount G in formula (7) The weight and wear G _i of the i-th frontal single-edge constant-section disc hob on the boring machine cutterhead is the tunneling parameters collected in real time by the rock tunnel boring machine data acquisition system. The cutterhead speed n, the tunneling speed v, and the cutterhead torque T and cutter head thrust F, rock mass parameters rock joint angle α obtained from engineering geological survey, uniaxial compressive strength σ _c of excavation geological rock and tensile strength σ _t of excavation geological rock, rock abrasion characteristic coefficient W obtained from rock wear test and The constant values k, a and b obtained from the wear simulation test are quickly calculated by the computer, so as to complete the prediction of the wear of the constant section disc hob of the rock tunnel boring machine.