Cutter head arrangement method for improving tunneling efficiency of TBM (Tunnel Boring Machine) hob in extremely hard rock tunneling

Abstract

The invention discloses a cutterhead arrangement method for improving TBM (tunnel boring machine) hob tunneling efficiency in extremely hard rock tunneling, which is characterized in that two rows of first multi-blade hobs, two rows of second single-blade hobs and two rows of side hobs are arranged on a cutterhead at intervals, the end faces of the blades of the first multi-blade hobs are higher than the end faces of the blades of the second single-blade hobs, and the first multi-blade hobs and the second single-blade hobs are arranged at intervals; the rear single-blade hobs are annularly arranged between the two rows of the front multi-blade hobs in the radial direction, the side hobs are arranged on the cutterhead excavation boundary arc lines on the outermost sides of the two rows of the front multi-blade hobs and adopt single blades, and by means of the arrangement method, specific energy consumption needed by rock breaking in unit volume is remarkably reduced, the economical efficiency and construction efficiency of TBM tunneling are improved, and the construction cost is reduced. The method is suitable for hard rock breaking scenes such as tunneling, mining and deep rock mass engineering.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of shield tunneling machines, and particularly relates to a cutter head arrangement method for improving the tunneling efficiency of a TBM cutter in extremely hard rock tunneling. BACKGROUND

[0002] A shield tunneling machine (TBM) is widely used for continuous tunneling in hard rock strata. A disc cutter is a core component of a TBM cutter head for breaking rock. During operation, the disc cutter cuts rock under the action of vertical thrust of a hydraulic jack and torque of the cutter head rotation, cutting a series of concentric circular cracks on the rock surface. With the advancement of the cutter head, the rock between adjacent cracks is gradually broken and collapsed, completing the rock breaking process. However, due to the high uniaxial compressive strength of hard rock, the complexity of disc cutter arrangement spacing and stress conditions, the rock breaking efficiency of the TBM in hard rock is usually low, and is accompanied by serious disc cutter eccentric wear, which is a key bottleneck affecting the tunneling efficiency and equipment life. Especially in the outer edge area of the cutter head, the edge disc cutter has an angle with the tunneling axis and has the longest travel, and is prone to rock "arch effect" phenomenon, that is, the rock cannot expand and release to the free surface after being compressed, but forms an arch-shaped stress transmission path along the edge of the cutter head, significantly increasing the local rock resistance and abnormally increasing the cutter load, thereby further reducing the rock breaking efficiency.

[0003] To improve the hard rock tunneling efficiency of the TBM, various auxiliary rock breaking methods have been proposed. For example, high-pressure water jets are introduced in front of the disc cutter to cut rock, or microwaves or lasers are used to irradiate the rock to produce thermal expansion and micro-cracks inside the rock, thereby reducing the rock strength and assisting in rock breaking. These auxiliary technologies can improve the rock breaking efficiency, but often require complex equipment, are expensive, and must solve the problem of coordinated operation of the auxiliary device and the disc cutter. In the existing TBM cutter head design, there is still a lack of a scheme for significantly improving the rock breaking efficiency through the structure arrangement itself.

[0004] The invention disclosed by the publication number CN106401595B discloses a method for arranging a cutter in a shield machine for directly cutting steel bars in concrete, and the technical solution points include that a plurality of double-blade cutters and a plurality of single-blade cutters capable of freely rotating are fixedly installed in a cutter head of the shield machine, the cutting edges of some of the double-blade cutters are in a first plane, the cutting edges of some of the double-blade cutters are in a second plane and / or a third plane, the distance from the second plane to the surface of the cutter head is greater than the distance from the first plane to the surface of the cutter head, the distance from the third plane to the surface of the cutter head is greater than the distance from the second plane to the surface of the cutter head, the cutting edges of some of the single-blade cutters are in the first plane, the cutting edges of some of the single-blade cutters are in the second plane and / or the third plane, the cutting edges of all the double-blade cutters and the single-blade cutters are sequentially numbered and arranged in a straight line, and the cutting edges of all the cutters are arranged in a zigzag shape, which mainly arranges the cutters in a zigzag shape, and the same root steel bar is first locally fractured under the rolling of the "zigzag" cutters, the length of the cut steel bar is reduced, and the cutter head and the screw conveyor are prevented from being stuck, but the structure is complex and the cost is high.

[0005] Therefore, a low-cost and simple-structure method is needed to improve the hard rock breaking efficiency by optimizing the arrangement of the cutters on the cutter head, and to avoid the dependence on high-cost auxiliary means. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a cutter head arrangement method for improving the TBM cutter tunneling efficiency in extremely hard rock tunneling, improving the hard rock tunneling efficiency, and reducing the wear of the cutters.

[0007] To solve the above technical problems, the technical solution adopted by the present application is: A cutter head arrangement method for improving the TBM cutter tunneling efficiency in extremely hard rock tunneling, including a plurality of multi-blade cutters, a plurality of single-blade cutters and a plurality of edge cutters arranged at intervals on the cutter head, the cutting edge end face of the multi-blade cutters is higher than that of the single-blade cutters, and both of them are arranged in a positive cutter manner, while the edge cutters are arranged at an angle and the angle between the edge cutters and the cutter head axis is defined as θ. The multi-blade cutters are arranged in two rows, the single-blade cutters are arranged in a ring shape along the radial direction between the two rows of multi-blade cutters, each row of multi-blade cutters provides a free surface for the adjacent single-blade cutters, and the size of the free surface is determined by the penetration depth of the multi-blade cutters, and the penetration depth is not less than 12mm. The edge cutters are arranged on the outermost cutter head excavation boundary arc of the two rows of multi-blade cutters and are single-blade cutters.

[0008] The blade-to-blade spacing between the adjacent multi-blade cutters is 80mm, and the penetration depth is 12mm.

[0009] The leading multi-blade roller is arranged in a cross shape.

[0010] The leading multi-blade roller is arranged in a cross shape.

[0011] The angle θ between the edge hob and the cutter head axis is 8°.

[0012] The distance between the leading double-blade hob and the trailing single-blade hob is not more than 120 mm.

[0013] The distance between the leading double-blade hob and the trailing single-blade hob is set to 100 mm.

[0014] The penetration of the trailing single-blade hob is set to 10 mm.

[0015] A cutter head arrangement method for improving TBM hob tunneling efficiency in extremely hard rock tunneling, comprising the following steps: Step (1), test and numerical simulation parameter determination The rock is sampled to make standard uniaxial size samples, the composition is analyzed and measured, and the samples are dried and subjected to indoor strength determination, and the samples are subjected to uniaxial compression test to test the rock strength; Based on the rock composition in PFC, a multi-phase model of the same size is established, the physical and mechanical parameters of the calibrated rock sample model are consistent with the physical and mechanical parameters obtained by experiment, and the calibrated rock sample model is obtained; Step (2), hob rock breaking model establishment (PFC) On the basis of the rock sample model of step (1), the model size is expanded, and the same simulation method is used to establish a hob rock breaking model; Step (3), analysis of the variation law of the normal force and rock breaking specific energy of multi-blade hob The normal force and rock breaking specific energy per unit volume of each hob in the rock breaking process in the simulation are recorded, and the rock breaking efficiency law of multi-blade hob under different hob spacing and penetration depth conditions is analyzed; Step (4), judgment of the weakening of the normal force and rock breaking specific energy of multi-blade hob Different hob spacing and penetration depth are set in the sample model, the multi-blade hob rock breaking result is compared with that of single-blade hob, and whether there is a synergistic weakening effect or the overall rock breaking specific energy is reduced is judged; Step (5), determination of the optimal hob spacing and penetration depth of the leading multi-blade hob The rock breaking specific energy and hob normal force under multiple simulation conditions are compared to preliminarily determine the hob spacing and penetration depth with obvious weakening effect; Step (6), analysis of the influence of the free surface formed after the penetration of the leading multi-blade hob on the normal force and rock breaking specific energy of the trailing single-blade hob On the basis of step (5), the optimal tool spacing and penetration are selected, and the distance and penetration depth of the rear single-blade cutter relative to the front multi-blade cutter are adjusted, and the influence range and intensity of the cooperative rock breaking are further observed; Step (7), judging the influence of the normal force and rock breaking specific energy of the rear single-blade cutter By comparing the responses of the rear single-blade cutter under different spacings and penetrations, it is determined whether the rear single-blade cutter obtains rock breaking weakening due to the free surface generated by the front cutter, that is, whether there is a cooperative rock breaking advantage; Step (8), determining the optimal spacing of the front multi-blade cutter and the rear single-blade cutter Through comparison of multiple groups of results, the optimal spacing and penetration combination between the front and rear cutters that can maximize the weakening of the normal force and rock breaking specific energy of the rear cutter are determined; Step (9), optimizing the spacing and penetration of the front double-blade cutter, and the distance between the front cutter and the rear single-blade cutter (positive spacing Based on all the simulation data, the cutter arrangement scheme is comprehensively optimized to obtain the optimal combination scheme of the spacing, penetration depth, and distance between the front double-blade cutter and the rear cutter; Step (10), analyzing the normal force variation law of the edge cutter with different included angles after forming a free surface On the basis of step (5), the optimal tool spacing and penetration are selected; First, the multi-blade cutter is penetrated at the junction of the circular arc and the horizontal line to form a free surface, and then edge cutters with different included angles are arranged at the circular arc, and through simulation comparison, the included angle with the smallest normal force of the edge cutter under the condition of the existing free surface is selected as the optimal arrangement angle of the edge cutter.

[0016] The beneficial effects of the present application are: (1) The present application discloses a cutter arrangement method for improving the TBM cutter tunneling efficiency in extremely hard rock tunneling, wherein the front multi-blade cutter, the rear single-blade cutter, and the edge cutter are arranged on the cutter head at intervals, the edge of the front multi-blade cutter is higher than the edge of the rear single-blade cutter, the front multi-blade cutter is arranged in two rows, the rear single-blade cutter is arranged in a ring shape along the radial direction between the two rows of front multi-blade cutters, and the edge cutter is arranged on the outermost cutting boundary arc of the two rows of front multi-blade cutters and adopts a single blade. This arrangement method significantly reduces the specific energy consumption required for breaking rock per unit volume, improves the economy and construction efficiency of TBM tunneling, and is suitable for hard rock breaking scenarios such as tunneling, mining, and deep rock engineering.

[0017] (2) The pre-arranged leading cutter structure is arranged at intervals: the leading cutter with a higher height is protrusively arranged on the cutter head, so that the leading cutter breaks rocks and forms a free surface in the rotary cutting, and the normal force of the trailing single-blade cutter is reduced. The leading cutter is designed as a multi-blade (double-blade or triple-blade) cutter, so that the total number of cutting blades is increased, the cutting load is shared, the stress of the single blade is reduced, and the tool wear rate is significantly reduced. The rock breaking structure is optimized by changing the geometric arrangement of the cutter, without additional high-cost auxiliary equipment, and the advantages of simple structure and low cost are achieved.

[0018] (3) The rock breaking efficiency is greatly improved through the free surface design of the pre-arranged multi-blade cutter; the free surface significantly weakens the rock constraint, and the normal force of the trailing single-blade cutter is significantly reduced, so that the cutting is easier to perform; after the load is shared by the pre-arranged multi-blade cutter, the normal force of each blade is reduced by 25.24% compared with the maximum normal force of the conventional single-blade cutter, the tool wear rate is effectively reduced, the tool life is prolonged, the comprehensive effect is to reduce the unit rock breaking energy consumption, improve the tunneling efficiency and reduce the construction cost, and the tool wear rate and the normal force are effectively reduced, and the construction performance is obviously improved.

[0019] (4) The pre-arranged double-blade cutter is arranged with a cutter spacing of 80mm and a penetration degree of 12mm, which can effectively form cooperative rock breaking and significantly reduce the cutter wear; and the spacing between the pre-arranged cutter and the trailing single-blade cutter is 100mm, which can minimize the normal force of the trailing single-blade cutter at each penetration degree. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural schematic diagram of the present application; Figure 2 is a front view of the present application; Figure 3 is a schematic diagram of the arrangement of the side cutter; Figure 4 is a stress-strain curve diagram of the rock sample; Figure 5 is a schematic diagram of rock breaking by the front cutter and the trailing cutter; Figure 6 is a schematic diagram of rock breaking by the side cutter and the trailing cutter; Figure 7 is a rock breaking model: (a) a front cutter rock breaking model; (b) a side cutter rock breaking model; Figure 8 is a comparison diagram of the average normal force of the pre-arranged double-blade cutter and the single-blade cutter; Figure 9 is a pre-arranged double-blade cutter breaking diagram: (a) cutter spacing 70mm; (b) cutter spacing 80mm; (c) cutter spacing 90mm; (d) cutter spacing 100mm; Figure 10is a normal force and rock breaking specific energy variation law diagram of the first cutter with a 80mm cutter spacing and 12mm penetration: (a) normal force variation; (b) rock breaking specific energy variation; Figure 11 is a cutter breaking diagram of the second cutter: (a) 80mm spacing; (b) 90mm spacing; (c) 100mm spacing; (d) 110mm spacing; (e) 120mm spacing; (f) 130mm spacing; Figure 12 is a sequential rock breaking diagram of the second cutter; Figure 13 is a normal force and rock breaking specific energy variation law diagram of the first cutter with a 80mm cutter spacing and 12mm penetration, the first double-blade cutter and the second single-blade cutter with a 100mm cutter spacing: (a) normal force variation; (b) rock breaking specific energy variation; Figure 14 is a cutter spacing influence diagram of the first cutter on the side cutter: (a) without the first cutter; (b) with the first cutter; Figure 15 is a side cutter breaking diagram; Figure 16 is a flowchart of the present application; Table 1 is a relative normal force reduction of different first double-blade cutter spacings compared to a single-blade cutter; Table 2 is a first second single-blade cutter normal force reduction compared to a single-blade cutter; Table 3 is a first second single-blade cutter rock breaking specific energy reduction compared to a single-blade cutter; Table 4 is a first cutter normal force reduction compared to a single-blade cutter with a first double-blade cutter; Table 5 is a positive cutter optimal parameter; Table 6 is a side cutter optimal parameter. DETAILED DESCRIPTION

[0021] The following describes the embodiments of the present application by specific examples, and other advantages and effects of the present application can be easily understood by those skilled in the art from the disclosure.

[0022] The present application provides a cutter disc arrangement method for improving TBM cutter tunneling efficiency in extremely hard rock tunneling, as shown in Figures 1 to 16 .

[0023] The present application provides a cutter disc arrangement method for improving TBM cutter tunneling efficiency in extremely hard rock tunneling, as shown in Figure 1 . Figure 3The edge hob 4 is arranged on the outermost cutting edge boundary arc line of the two rows of the preceding multi-blade hobs and is provided as a single-blade hob.

[0024] The preceding multi-blade hobs 2 are arranged in two rows, and the following single-blade hobs 3 are arranged in a ring shape between the two rows of the preceding multi-blade hobs 2 in the radial direction, each row of the preceding multi-blade hobs 2 provides a free surface for the adjacent following single-blade hobs, and the size of the free surface is determined by the penetration depth of the preceding multi-blade hobs 2, and the penetration depth is not less than 12 mm. The edge hob 4 is arranged on the outermost cutting edge boundary arc line of the two rows of the preceding multi-blade hobs and is provided as a single-blade hob.

[0025] The preceding multi-blade hobs are arranged in a cross shape in the embodiment, the blade spacing between the adjacent hobs of the preceding multi-blade hobs 2 is 80 mm, the penetration depth is 12 mm, and the spacing between the preceding double-blade hobs and the following single-blade hobs is not more than 120 mm; in the embodiment, the spacing between the preceding double-blade hobs and the following single-blade hobs is 100 mm, and the penetration depth of the following single-blade hobs is 10 mm.

[0026] To verify the protruding height, the blade spacing of the preceding multi-blade hobs, and the position relationship between the preceding multi-blade hobs and the following single-blade hobs, simulation analysis can be performed by using a particle flow software.

[0027] 1. Determine the preliminary arrangement scheme of the preceding multi-blade hobs and the following single-blade hobs on the cutter head: In the embodiment, the edge hob 4 is arranged on the outermost cutting edge boundary arc line of the two rows of the preceding multi-blade hobs and is provided as a single-blade hob.

[0028] In order to reduce the wear of the edge hob, the multi-blade preceding hobs are arranged at the transition between the circular arc and the straight line of the cutter head, and then the reasonable blade spacing angle of the edge hob is determined through calculation.

[0029] 2. Test and numerical simulation parameter determination: Rock samples are taken, standard uniaxial size samples are prepared, and their indoor strength is measured; then, a corresponding model is established in PFC, and uniaxial compression simulation is performed on the test, and the microscopic parameters of the test are calibrated, so that the physical and mechanical parameters of the calibrated rock sample model are consistent with the physical and mechanical parameters of the rock sample to be simulated, to ensure the accuracy of the numerical model.

[0030] 3. Simulation of hob rock breaking: (1) Rollers with different protrusion heights are arranged on the cutter head at intervals, including a "leading roller" with a higher protrusion in the pre-cutting area and a relatively lower following single-edged roller. The leading multi-edged roller contacts the rock first and breaks the rock during the rotation of the cutter head, so that the working surface of the following single-edged roller forms a free surface, which effectively reduces the normal force of the single-edged roller and achieves the effect of assisting in rock breaking.

[0031] (2) The leading hob adopts a multi-flute hob structure to control wear. The multi-flute hob has multiple cutting edges on the cutter ring, which can distribute the total load and reduce the normal force on each cutting edge, thereby slowing down the wear rate of the leading hob; by appropriately adjusting the inter-edge spacing of the double-flute / triple-flute hob, the cutting difficulty of a single edge can be further reduced.

[0032] (3) Optimization measures for the edge hobbing area: To address the severe "arching effect" problem caused by the side cutter head, a set of advance cutters is installed on the excavation boundary arc of the cutterhead. This allows them to first break the boundary rock mass, forming pre-cut gaps, thereby reducing the formation of the arching effect.

[0033] 4. Determine the optimal parameters: Based on the simulation results, the effects of different leading multi-bladed cutter spacing, penetration depth, and the spacing between the following single-bladed cutter and the leading multi-bladed cutter were compared and analyzed to determine the optimal parameter combination, so as to improve rock breaking efficiency, reduce cutter load and reduce tool wear, while significantly reducing rock breaking specific energy and improving TBM tunneling efficiency.

[0034] The following description, in conjunction with specific embodiments, provides further details.

[0035] Step 1: Determination of Experimental and Numerical Simulation Parameters Rock samples were taken and made into standard uniaxial specimens. The main components of the granite were determined by X-ray diffraction analysis. After drying, the specimens were subjected to indoor strength tests. The uniaxial compression test was conducted on the specimens using a universal testing machine to test the rock strength.

[0036] Based on rock test results, the simulation results are made consistent with the test results to ensure accuracy, such as... Figure 4 The stress-strain curve of the rock sample is shown. Based on the rock mineral composition, a multiphase model of the same size is established in PFC. The physical and mechanical parameters of the rock sample model after microscopic parameter calibration are made consistent with the experimentally obtained physical and mechanical parameters, thus obtaining the calibrated rock sample model. Figure 4 It can be seen that the experimental strength of 132.4 MPa and the numerical simulation strength of 133.1 MPa are highly consistent, with the error being within 2%, indicating that the model parameter settings and combination method are reasonable.

[0037] Step 2: Establishing the Roller Cutter Rock Breaking Model (PFC) After the calibration of the small size model, the size of the model is expanded and the same simulation method is used to establish the model of rock breaking by disc cutters to study the rock breaking process under actual working conditions.

[0038] Step three, analysis of the variation law of normal force and rock breaking specific energy of multi-blade disc cutter (positive disc cutter) The normal force and rock breaking specific energy per unit volume of each disc cutter in the rock breaking process are recorded in the simulation, and the rock breaking efficiency law of multi-blade disc cutter under different disc cutter spacing and penetration depth conditions is analyzed.

[0039] Step four, judgment of the weakening of normal force and rock breaking specific energy of multi-blade disc cutter (positive disc cutter) Different disc cutter spacing and penetration depth are set in the sample model, the rock breaking results of multi-blade disc cutter are compared with those of single-blade disc cutter, and it is judged whether there is a synergistic weakening effect under certain arrangement, i.e. whether the normal force on each cutter can be reduced or the overall rock breaking specific energy is reduced.

[0040] Step five, determination of the optimal spacing and penetration of the leading multi-blade disc cutter (positive disc cutter) By comparing the rock breaking specific energy and disc cutter normal force under multiple simulation conditions, the disc cutter spacing and penetration depth with obvious weakening effect are preliminarily determined, laying a parameter foundation for subsequent synergistic rock breaking analysis.

[0041] Step six, analysis of the influence of the free surface formed after the penetration of the leading multi-blade disc cutter (positive disc cutter) on the normal force and rock breaking specific energy of the trailing single-blade disc cutter (positive disc cutter) On the basis of step five, the optimal disc cutter spacing and penetration are selected, and then the distance of the trailing single-blade disc cutter relative to the leading multi-blade disc cutter and its penetration depth are adjusted, as shown in Figure 5 The influence range and intensity of synergistic rock breaking are further observed, and the most favorable distance and depth combination are explored.

[0042] Step seven, judgment of the influence of the normal force and rock breaking specific energy of the trailing single-blade disc cutter (positive disc cutter) The responses of the trailing single-blade disc cutter under different spacing and penetration are compared to determine whether the trailing disc cutter obtains rock breaking weakening due to the free surface generated by the leading disc cutter, i.e. whether there is a synergistic rock breaking advantage.

[0043] Step eight, determination of the optimal spacing of the leading multi-blade disc cutter and the trailing single-blade disc cutter Through comparison of multiple results, the optimal spacing and penetration combination between the leading and trailing disc cutters that can maximize the weakening of the normal force and rock breaking specific energy of the trailing disc cutter is determined.

[0044] Step nine, optimization of the spacing and penetration of the leading double-blade disc cutter (positive disc cutter) and the spacing between the leading disc cutter (positive disc cutter) and the trailing single-blade disc cutter (positive disc cutter) On the basis of all the simulation data, the optimal combination scheme of the interval, penetration depth and distance between the first double-edge cutter and the subsequent cutter is obtained to guide the cutter layout design and achieve the goal of efficient and low-energy rock breaking.

[0045] Step ten, analysis of the normal force variation law of the different angle edge cutters after the formation of the free surface On the basis of step five, the optimal cutter interval and penetration depth are selected. First, the multi-edge cutter is penetrated at the junction of the circular arc and the horizontal line to form a free surface, and then the edge cutters with different angles are arranged at the circular arc, as shown in Figure 6 Through the comparison of the simulation results, the angle with the minimum normal force of the edge cutter under the condition of the existence of the free surface is selected as the optimal arrangement angle of the edge cutter.

[0046] The following sets TBM to tunnel in granite at 132.4 MPa, and the tunnel adopts a uniform confining pressure of 5 MPa. For the positive cutter, as shown in Figure 7 (a), the first multi-edge cutter penetrates the rock and completes rock breaking, and then the subsequent cutter, i.e. the subsequent single-edge cutter, penetrates and breaks the rock from the left side of the first cutter.

[0047] The interval of the first cutter is set to 70 mm, 80 mm, 90 mm and 100 mm, and the penetration depth is set to 16 mm to explore the influence on the normal force and specific energy of the subsequent cutter. The penetration depth of the subsequent cutter is set to 10 mm, and the interval between the subsequent cutter and the first cutter is set to 80 mm, 90 mm, 100 mm, 110 mm, 120 mm and 130 mm. For the edge cutter, as shown in Figure 7 (b), the first cutter is located at the junction of the plane and the circular arc, and the direction is parallel to the TBM axial direction. During the rock breaking process, the first cutter penetrates the rock and completes rock breaking, and then the subsequent cutter penetrates from the left side of the first cutter; the penetration depth of the cutter is set to 10 mm, the angle between the cutters is controlled by adjusting the inclination angle of the subsequent cutter, and the influence on the normal force of the subsequent cutter under the condition of different angles 8°, 10°, 12°, 14° and 16° is analyzed.

[0048] Combined with Figure 8 the comparison chart of the average normal force of the first double-edge cutter and the single-edge cutter only, Figure 9 the breaking chart of the first double-edge cutter, it is found that the first cutter can form collaborative rock breaking only when the penetration depth reaches 12 mm, and when the penetration depth continues to increase, the normal force begins to decrease, as shown in Table 1, which means that the cutter wear begins to increase. Therefore, when the interval of the first cutter is 80 mm and the penetration depth is 12 mm, effective rock breaking can be formed, and the wear of the first cutter and the subsequent cutter can be reduced.

[0049] Table 1 Relative normal force reduction amplitude of different first double-edge cutter intervals to single-edge cutter only In this example, by reasonably arranging the multi-blade cutter, the normal force and the rock breaking specific energy of the trailing single-blade cutter can be effectively reduced, and the maximum reduction of the normal force can reach 48.46%, and the maximum reduction of the rock breaking specific energy can reach 96.32%, as shown in FIG. 2 and FIG. 3. Figure 10 As shown in FIG. 2, FIG. 3 and Table 2, Table 3, it can also be found that when the distance between the leading double-blade cutter and the trailing single-blade cutter is 100 mm, the normal force is the smallest at different penetrations; and the distance between the leading double-blade cutter and the trailing single-blade cutter cannot exceed 120 mm, otherwise the normal force will increase, and the wear of the cutter will increase. From the perspective of the rock breaking effect, the distance between the leading double-blade cutter and the trailing single-blade cutter cannot exceed 110 mm, otherwise the rock breaking effect will be weakened. Figure 11 As can be seen from FIG. 2 and FIG. 3, with the increase of the distance between the leading cutter and the trailing cutter, the rock breaking effect is gradually weakened, and when the distance is greater than 110 mm, the cutters do not form effective rock breaking.

[0050] Table 2 Reduction of the normal force of the first trailing single-blade cutter relative to the single-blade cutter only Table 3 Reduction of the rock breaking specific energy of the first trailing single-blade cutter relative to the single-blade cutter only As can be seen from the above analysis, when the distance between the leading double-blade cutter is 80 mm and the penetration is 12 mm, the normal force of the cutter is significantly reduced. Therefore, this parameter is selected and the distance between the leading double-blade cutter and the trailing single-blade cutter is 100 mm according to the rock breaking effect. Figure 1 The positive cutter disc model is used, and the single-blade cutters are simultaneously penetrated on both sides to provide a free surface for the trailing single-blade cutters. Then the trailing single-blade cutters are penetrated in turn, the distance between the two trailing single-blade cutters is set to 60 mm, and the distance between the leading double-blade cutter and the trailing single-blade cutter is selected to be 100 mm, as shown in FIG. 4. Figure 12 FIG. 5 shows the rock breaking diagram after the second trailing single-blade cutter is penetrated. As shown in FIG. 6, Figure 13 the normal force and the rock breaking specific energy are significantly reduced when the second trailing single-blade cutter is penetrated relative to the single-blade cutter only. When the penetration is 4 mm, 6 mm, 8 mm and 10 mm, the normal force is reduced by 1.15%, 22.31%, 34.54% and 36.71% respectively, and the rock breaking specific energy is reduced by 82.92%, 64.61%, 73.93% and 72.11% respectively.

[0051] As for the side cutter, the optimal distance between the double-blade cutters is selected on the basis of the positive cutter, the distance between the cutters is 80 mm, and then the side cutters of different angles are penetrated. It can be found from FIG. 7 and Table 4 that the normal force is significantly reduced when the included angle between the cutters is 8°, 12° and 14°, and the maximum reduction can reach 29.56%; while the included angle between the cutters is 10° and 16°, the normal force will increase, that is, the wear of the cutter will increase. As can be seen from FIG. 7, Figure 14 only when the included angle between the cutters is 8°, the cutters can form rock breaking. Figure 15 only when the included angle between the cutters is 8°, the cutters can form rock breaking.

[0052] Table 4 Normal force reduction of pre-rolling double-blade hob compared with no pre-rolling In summary, compared with the traditional cutter arrangement, the arrangement method significantly reduces the specific energy consumption required for breaking rock per unit volume, improves the economy and construction efficiency of TBM tunneling, and is suitable for hard rock breaking scenes such as tunneling, mining and deep rock engineering. The specific optimal parameters are shown in Tables 5 and 6.

[0053] Table 5 Optimal parameters of positive hob Table 6 Optimal parameters of edge hob Parameter Value Optimal angle (°) 8° Corresponding normal force drop (%) 29.56% For the positive hob: the optimal arrangement of the pre-rolling double-blade hob is: hob spacing 80mm, penetration 12mm. Under this combination, synergistic rock breaking can be effectively formed and hob wear is significantly reduced.

[0054] The optimal spacing between the pre-rolling hob and the trailing single-blade hob is 100mm, at which the normal force on the trailing hob is the smallest at each penetration.

[0055] For the edge hob area, simulation analysis found that when the included angle between the two adjacent edge hobs is 8°, the normal force reduction is the largest, about 29.56%. At other angles, such as 10°, 12°, 14°, 16°, the normal force reduction is not obvious, and it is difficult to form effective rock breaking. Therefore, the optimal included angle is 8°, corresponding to a normal force reduction of about 29.56%.

[0056] In this patent, the words "first", "second", etc. are used to limit parts. Those skilled in the art should know that the use of "first", "second" is only for the convenience of describing the invention and simplifying the description, and the above words have no special meaning.

[0057] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed invention. The scope of protection of the present application is defined by the appended claims and equivalents thereof.

[0058] In the description of the application, it needs to be understood that the terms "front", "back", "left", "right", "center", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the protection scope of the application.

Claims

1. A method for improving the efficiency of TBM cutter wheel arrangement in extremely hard rock tunneling, characterized in that: The invention relates to a multi-blade hobbing cutter, which comprises a leading multi-blade hobbing cutter, a trailing single-blade hobbing cutter and a side hobbing cutter, the end face of the leading multi-blade hobbing cutter is higher than that of the trailing single-blade hobbing cutter, and the two are arranged in a positive hobbing mode, and the side hobbing cutter is arranged at an angle and the angle between the side hobbing cutter and the axis of the cutter head is defined as theta. The leading multi-blade hobbing cutter is arranged in two rows, the trailing single-blade hobbing cutter is arranged in a ring shape between the two rows of leading multi-blade hobbing cutters in the radial direction, each row of leading multi-blade hobbing cutters provides a free surface for the adjacent trailing single-blade hobbing cutter, and the size of the free surface is determined by the penetration depth of the leading multi-blade hobbing cutter, and the penetration depth is not less than 12mm. The side hobbing cutter is arranged on the outermost cutting edge boundary arc line of the two rows of leading multi-blade hobbing cutters and is a single-blade hobbing cutter.

2. The method of arranging the cutter head of TBM to improve the efficiency of tunneling in extremely hard rock according to claim 1, characterized in that: The blade spacing between adjacent leading multi-blade hobbing cutters is 80mm, and the penetration depth is 12mm.

3. The method of arranging the cutter head of TBM to improve the efficiency of tunneling in extremely hard rock according to claim 1, characterized in that: The leading multi-blade hobbing cutters are arranged in a cross shape.

4. The method of claim 3, wherein the method is characterized in that: The leading multi-blade hobbing cutters are arranged in a cross shape.

5. The method of claim 3, wherein the method is characterized in that: The angle theta between the side hobbing cutter and the axis of the cutter head is 8 degrees.

6. The method of arranging the cutter head of TBM for improving the efficiency of tunneling in extremely hard rock according to claim 1, characterized in that: The distance between the leading double-blade hobbing cutter and the trailing single-blade hobbing cutter is not more than 120mm.

7. The method of arranging cutters of a cutterhead for improving the efficiency of TBM cutter wheel tunneling in extremely hard rock tunneling according to claim 6, characterized in that: The distance between the leading double-blade hobbing cutter and the trailing single-blade hobbing cutter is 100mm.

8. The method of arranging the cutter head of TBM for improving the efficiency of tunneling in extremely hard rock according to claim 1, characterized in that: The penetration depth of the trailing single-blade hobbing cutter is 10mm.

9. The method of arranging the cutter head of TBM for improving the efficiency of tunneling in extremely hard rock according to claim 1, characterized in that: The method comprises the following steps: Step (1), test and numerical simulation parameter determination Rock samples are taken, standard uniaxial size samples are prepared, the composition is analyzed and measured, the samples are dried and indoor strength determination is carried out, uniaxial compression test is carried out on the samples, and rock strength is tested; Based on the composition of the rock, a multi-phase model of the same size is established in PFC, the physical and mechanical parameters of the calibrated rock sample model are consistent with the physical and mechanical parameters obtained by experiment, and the calibrated rock sample model is obtained; Step (2), establishment of hobbing cutter rock breaking model (PFC) On the basis of the rock sample model in step (1), the model size is expanded, and the same simulation method is used to establish a hobbing cutter rock breaking model; Step (3), analysis of the variation law of the normal force and rock breaking specific energy of multi-blade hobbing cutter The normal force and rock breaking specific energy unit volume energy consumption of each hobbing cutter in the rock breaking process are recorded, and the rock breaking efficiency law of multi-blade hobbing cutter under different blade spacing and penetration depth conditions is analyzed; Step (4), judgment of the weakening condition of the normal force and rock breaking specific energy of multi-blade hobbing cutter Different hobbing cutter spacing and penetration depth are set in the sample model, the rock breaking results of multi-blade hobbing cutter are compared with those of single-blade hobbing cutter, and it is judged whether there is a synergistic weakening effect or the overall rock breaking specific energy is reduced; Step (5), determination of the optimal spacing and penetration depth of the leading multi-blade hobbing cutter The rock breaking specific energy and hobbing cutter normal force under multiple simulation conditions are compared, and the hobbing cutter spacing and penetration depth with obvious weakening effect are preliminarily determined; Step (6), analysis of the influence of the free surface formed after the penetration of the leading multi-blade hobbing cutter on the normal force and rock breaking specific energy of the trailing single-blade hobbing cutter On the basis of step (5), the optimal hobbing cutter spacing and penetration depth are selected, and the distance of the trailing single-blade hobbing cutter relative to the leading multi-blade hobbing cutter and the penetration depth thereof are adjusted, and the influence range and intensity of the synergistic rock breaking are further observed; Step (7), judgment of the influence of the normal force and rock breaking specific energy of the trailing single-blade hobbing cutter To compare the responses of the single blade behind the multi-blade, to determine whether the single blade is weakened by the free surface caused by the multi-blade, and whether there is a synergistic advantage in rock breaking; Step (8), determine the optimal distance between the multi-blade and the single blade behind Through the comparison of multiple groups of results, determine the optimal distance and penetration depth combination between the multi-blade and the single blade behind that can maximize the weakening of the normal force and specific energy of the single blade behind; Step (9), optimize the distance and penetration depth of the multi-blade, and the distance between the multi-blade and the single blade behind (positive distance Based on all the simulation data, optimize the layout scheme of the multi-blade and the single blade behind to obtain the optimal combination scheme of the distance, penetration depth, and distance between the multi-blade and the single blade behind; Step (10), analyze the normal force variation of the edge blade with different angles after the formation of the free surface Based on step (5), select the optimal distance and penetration depth; First, penetrate the multi-blade at the junction of the circular arc and the horizontal line to form a free surface, then arrange edge blades with different angles at the circular arc, and through simulation comparison, select the angle with the smallest normal force of the edge blade as the optimal arrangement angle of the edge blade.

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