Shallow-buried large-span roadway digging and anchoring integrated parallel operation method

Abstract

The invention discloses a shallow-buried large-span roadway digging and anchoring integrated parallel operation method which comprises the following steps: S1, analyzing a control principle of a shallow-buried large-section roadway through theoretical analysis and numerical calculation; s2, analyzing surrounding rock stability influence factors under different support major cycle step pitches; s3, the parallel operation distance of a large cycle is simulated and determined according to the analysis results of the step 1 and the step 2, the forward tunneling distance of the tunneling and anchoring all-in-one machine after primary supporting is determined, and secondary supporting of the anchor rod reversed loader is started; s4, carrying out first support according to the distance determined in the step 3: constructing part of anchor rods of the roof by using a digging and anchoring all-in-one machine; and S5, follow-up secondary supporting is conducted, specifically, all the anchor rods and the anchor cables are completed through construction of the hydraulic anchor rod trolley, and therefore one cycle operation is completed. According to the method, advancing and retreating of the heading machine and moving of the roof bolter are omitted, the unsupported roof time is greatly shortened, and temporary supporting and permanent supporting can be conducted on the roadway in time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal mining, in particular to a method for shallow-buried large-span roadway excavation and anchoring integrated parallel operation. BACKGROUND

[0002] At present, the fully-mechanized excavation working face of the coal mine in China generally adopts a cantilever type fully-mechanized excavator to excavate several cycles, temporarily supports every 3-5 m, and then supports by using a single anchor rod drilling machine, and then supplements the roof anchor cable and the rib-to-floor anchor rod every several dozens of meters. After the installation of the anchor rod is completed, the temporary support and the power pipeline of the single anchor rod drilling machine are removed. Then the cantilever type fully-mechanized excavator starts the next cycle operation. It is a semi-automated roadway excavation system, mainly consumes too much time for supporting, the cantilever type fully-mechanized excavator frequently advances and retreats, mainly relies on manpower for supporting, has low efficiency, and has the risk of illegal empty top operation. SUMMARY

[0003] In view of the above technical deficiencies, the purpose of the present application is to provide a method for shallow-buried large-span roadway excavation and anchoring integrated parallel operation.

[0004] To solve the above technical problems, the present application adopts the following technical solutions: The present application provides a method for shallow-buried large-span roadway excavation and anchoring integrated parallel operation, comprising the following steps: S1, analyzing the control principle of the shallow-buried large-span roadway through theoretical analysis and numerical calculation; S2, analyzing the influence factors of the surrounding rock stability under different supporting large cycle step distances; S3, simulating and determining a parallel operation distance of a large cycle according to the analysis results of step 1 and step 2, and determining how many meters the excavation and anchoring integrated machine advances after the initial support to start the secondary support by the anchor rod transloading machine; S4, performing the first support according to the determined distance of step 3: using the excavation and anchoring integrated machine to construct part of the anchor rods of the roof; S5, subsequent second support: using the hydraulic anchor rod jumbo to construct all the anchor rods and anchor cables, thereby completing one cycle operation.

[0005] Further, the step S1 comprises: S1.1, constructing a supporting large cycle step distance fast excavation numerical calculation model; The simulation scheme of the numerical calculation model is established according to the drilling columnar graph near the working face and the physical and mechanical parameters of the rock stratum.

[0006] Further, the step S2 comprises: S2.1, simulating the excavation and support process, and simulating and analyzing the vertical stress distribution characteristics of the roadway roof under different supporting large cycle step distance schemes in the excavation process; S2.2, simulate and analyze the vertical displacement distribution characteristics of the roof horizontal section after tunneling under different cycle step distances; S2.3, simulate and analyze the plastic zone distribution characteristics of the roadway after tunneling under different large cycle step distances.

[0007] The beneficial effects of the present application are: ①Avoiding the similar advancing and retreating of the cantilever type tunneling machine, reducing the time of the empty roof operation, saving the temporary support, and timely performing the permanent support of the roadway.

[0008] ②The on-board anchor rod drill of the tunneling and anchoring integrated device can provide a more reliable anchor rod installation power, timely apply the pre-tightening force, and ensure the safety of the construction personnel.

[0009] ③The tunneling and anchoring integrated device can realize the parallel operation of tunneling and anchor rod installation with the anchor rod trolley, the on-board anchor rod drill of the tunneling and anchoring integrated device can drill fast, some can realize the integrated installation of drilling and anchoring, and timely and effectively ensure the stability of the surrounding rock. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description, and obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0011] Figure 1 The tunneling and anchoring integrated roadway support section view provided for the embodiment of the present application; Figure 2 The numerical model diagram constructed in the embodiment of the present application; Figure 3 The support scheme simulation diagram in the embodiment of the present application, wherein a is the first part of the tunneling and anchoring integrated machine construction support scheme, and b is the anchor rod trolley final support scheme after the roadway is completed; Figure 4 The support scheme simulation diagram in the embodiment of the present application under different large cycle step distances; Figure 5 The support scheme simulation diagram in the embodiment of the present application under different large cycle step distances; Figure 6 The roadway surrounding rock vertical stress distribution cloud diagram under different large cycle step distances in the embodiment of the present application; Figure 7 The roadway surrounding rock vertical stress distribution cloud diagram under different large cycle step distances in the embodiment of the present application; Figure 8 The roadway surrounding rock vertical stress distribution cloud diagram under different large cycle step distances in the embodiment of the present application; Figure 9The vertical stress diagram of the shoulder angle of the 23303 gel transportation trough under different support step distances in the embodiment of the present application; Figure 10 The vertical displacement cloud chart of the surrounding rock of the 23303 gel transportation trough when simulating different cycle step distances in the embodiment of the present application; Figure 11 The vertical displacement cloud chart of the surrounding rock of the 23303 gel transportation trough when simulating different cycle step distances in the embodiment of the present application; Figure 12 The vertical displacement cloud chart of the surrounding rock of the 23303 gel transportation trough when simulating different cycle step distances in the embodiment of the present application; Figure 13 The vertical displacement of the roof of the 223303 gel transportation trough in the embodiment of the present application; Figure 14 The plastic zone distribution cloud chart of the surrounding rock of the 23303 gel transportation trough under different large cycle step distances in the embodiment of the present application; Figure 15 The plastic zone distribution cloud chart of the surrounding rock of the 23303 gel transportation trough under different large cycle step distances in the embodiment of the present application; Figure 16 The plastic zone distribution cloud chart of the surrounding rock of the 23303 gel transportation trough under different large cycle step distances in the embodiment of the present application.

[0012] Explanation of reference signs: No. 1 anchor rod 1, No. 2 anchor rod 2, No. 3 anchor rod, No. 4 anchor rod 4, No. 5 anchor rod 5, No. 6 anchor rod 6, No. 7 anchor rod 7, No. 8 anchor rod 8, No. 9 anchor rod 9, No. 10 anchor rod 10, No. 11 anchor rod 11, No. 12 anchor rod 12, No. 13 anchor rod 13, No. 14 anchor cable 14. DETAILED DESCRIPTION

[0013] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. EMBODIMENT

[0014] Taking the 23303 working face of Chuanlongwan Coal Mine as an example, the roadway is excavated with a width of 6.0 m, a net width of 5.8 m, an excavation height of 3.25 m, a net height of 3.0 m, and an excavation section area of 19.5 m 2 , and a net section area of 17.4 m 2 , which is a rectangular large-span section roadway.

[0015] The method for shallow-buried large-span roadway excavation and anchoring integrated parallel operation comprises the following steps: S1. Analysis of the control principle of large-span roadway deformation S1.1 Construction of numerical calculation model for fast excavation with large cycle step distance for support; The numerical model was developed based on drill hole histograms and the physical and mechanical parameters of the rock formations near the 23303 working face of the Zhuanlongwan Coal Mine. Specific physical and mechanical parameters of the coal and rock mass are shown in Table 3-1. Seven rock formations were selected: from top to bottom, medium-grained sandstone, mudstone, fine-grained sandstone, sandy mudstone, II-3 coal, sandy mudstone, and fine-grained sandstone. The thicknesses of the selected rock formations were 8.62m, 11.3m, 2.95m, 2.13m, 2.74m, 4.41m, and 6.85m, respectively. Furthermore, because the internal friction angles of the samples were measured using rock blocks, which differ from the large-span rock mass environment within the 23303 rubber conveyor drift, the rock physical and mechanical parameters differ.

[0016] Table 3-1 Physical and mechanical parameters of coal and rock mass in numerical simulation

[0017] The simulated stress-deformation characteristics of the coal seam and various rock formations met the Mohr-Coulomb yield criterion. The final model dimensions were: length × width × height = 60m × 40m × 50m. Horizontal displacements were fixed at the left, right, and lateral boundaries of the model, and horizontal and vertical displacements were fixed at the bottom boundary. A vertical stress of 5 MPa was applied to the top boundary of the model. The final numerical model is shown in Figure 2.

[0018] The simulation scheme is as follows: 1) Tunnel excavation cross-sectional dimensions: width × height = 6000 × 3250 mm.

[0019] 2) After the tunnel is excavated, the excavator and anchor machine constructs four anchor rods on the top plate: the specifications of the four anchor rods on the top plate are Φ20×2200mm left-handed unreinforced threaded steel anchor bolts are spaced 1100mm apart. The top anchor bolts on both sides are Φ18×1800mm threaded steel anchor bolts with a spacing of 1100mm. The anchor bolts on the coal pillar side are Φ18×1800mm fiberglass anchor bolts with a spacing of 1100mm.

[0020] 3) Anchor rod trolley hysteresis construction remaining roof anchor rod, anchor cable, anchor rod.23303 rubber transport trough support scheme: the final support scheme: the roof is left-handed without longitudinal reinforcement thread steel anchor rod (six, specification Φ20x2200mm), row distance 1100mm, anchor cable is Φ17.8x6000mm steel strand, two rows per row, row distance 3300mm; The coal pillar anchor rod adopts three Φ18x2000mm thread steel anchor rods, with a row distance of 1100mm; The recovery anchor rod adopts three Φ18x2000mm glass steel anchor rods, with a row distance of 1100mm.

[0021] 4) Fix a cutting cycle step of 5m (0-5m in front of the clearance roof area, no support), respectively simulate the support cycle step distance difference, that is, determine how many meters the combined excavation and anchoring machine is excavated forward after the initial support to start the secondary support of the anchor rod transloading machine: 15m (5-15m range roof support four anchor rods), 20m (5-20m range roof support four anchor rods), 25m (5-25m range roof support four anchor rods), 30m (5-30m range roof support four anchor rods), 40m (5-40m range roof support four anchor rods), 50m (5-50m range roof support four anchor rods) Different support cycle step schemes, the stress, plastic zone and roof displacement distribution characteristics of surrounding rock under different support cycle step schemes are shown in Figs. 3, 4 - Figure 5 .

[0022] S2, analyze the influence factors of surrounding rock stability under different support cycle steps; S2.1 Vertical stress distribution characteristics of roadway The simulation analysis of the 23303 rubber transport trough excavation and support process is carried out. The vertical stress distribution characteristics of the roof under the 15m, 20m, 25m, 30m, 40m and 50m support cycle step (i.e. determine how many meters the combined excavation and anchoring machine is excavated forward after the initial support to start the secondary support of the anchor rod transloading machine) scheme during the excavation process are simulated. The vertical section along the central axis of the roadway and the horizontal section at the middle of the roadway are made. When the large cycle step is 15m, 20m, 25m, 30m, 40m and 50m, the vertical stress distribution cloud chart of the roadway surrounding rock is shown in Figures 6-8 . The vertical stress at the shoulder angle is shown in Figure 9 .

[0023] From Figures 6-9As can be seen from the figure, an elliptical stress ring zone exists within the surrounding rock mass after tunnel excavation. From the tunnel surface to the depth, the vertical stress distribution characteristics of the tunnel surrounding rock during tunnel excavation are less affected by the large cyclic support step. The stress peak is approximately 4 m in front of the coal wall, with minimal stress concentration. Furthermore, the stress concentration levels in the front of the tunnel and in the tunnel side remain essentially unchanged with increasing cyclic step. Therefore, this cyclic support step can meet the requirements for both tunnel roof safety and surrounding rock stability.

[0024] S2.2 Distribution characteristics of vertical displacement of roof The vertical displacement distribution characteristics of the horizontal section of the roof after the 23303 rubber transport tunnel excavation are simulated with cycle step distances of 15m, 20m, 25m, 30m, 40m, and 50m, as shown in the following figure: Figure 10 At the same time, a measuring point is arranged every 5m in the middle of the top plate of the 23303 rubber transport chute, with a total of ten measuring points. The data are as follows Figures 11-12 shown.

[0025] S2.3 Distribution characteristics of plastic zone in roadway After excavation with different large cycle step distances of 15m, 20m, 25m, 30m, 40m and 50m, the distribution cloud of the plastic zone of 23303 rubber transport drift is as follows: Figure 13 shown.

[0026] Depend on Figures 14-16 It can be seen that the development range of the plastic zone represents the stress and bearing state of the surrounding rock mass. With the increase of the cycle step, the range of the plastic zone of the tunnel surrounding rock does not show an expanding trend, indicating that the support state during the rapid excavation operation can already meet the tunnel surrounding rock support requirements.

[0027] S3. Determine the construction plan based on the analysis results of steps 1 and 2; S4. First support: Use the anchoring machine to construct four anchors on the top (anchor 1, anchor 3, anchor 4, anchor 6) and two anchors on the side (anchor 7, anchor 10); Figure 1 shown.

[0028] S5. Subsequent second support: Use the hydraulic anchor trolley to construct two top anchors (anchor No. 2 and anchor No. 5), four side anchors (anchor No. 8, anchor No. 9, anchor No. 11, anchor No. 12) and two anchor cables (anchor No. 13 and anchor No. 14) on the top plate, thus completing a cycle of operations. Figure 1 shown.

[0029] The stress, displacement and plastic zone of the roof of the roadway surrounding rock under different support large cycle step are simulated in this embodiment, and it is shown that the plastic zone and the deformation of the roadway surrounding rock under different support large cycle step do not have obvious expansion trend. The roadway head-on surrounding rock under different support large cycle step is in the mutual superposition of "concave structure" and the support body of the combined machine and anchor rod trolley construction, forming "ring structure", which plays a good supporting role for the head-on roof, and the deformation of the roadway surrounding rock is small, and the plastic zone range is small, which can ensure the stability of the roadway surrounding rock under different support large cycle step (15-50 m range).

[0030] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method for integrated parallel operation of shallow buried large-span tunnel boring and anchoring, characterized in that: The following steps are involved: S1. Analyze the control principle of shallow buried large cross-section tunnels through theoretical analysis and numerical calculation; S2. Analyze the factors affecting the stability of surrounding rock under different support large cycle step distances; S3. Based on the analysis results of steps 1 and 2, a large cycle parallel operation distance is simulated and determined, and the number of meters of forward excavation after the initial support of the anchor drill is determined before the secondary support of the anchor transfer machine is implemented; S4. Perform the first support according to the distance determined in step 3: Use the anchoring machine to construct some anchor rods on the top plate; S5. Subsequent second support: Use the hydraulic anchor trolley to complete all anchor rods and anchor cables, thus completing a cycle of operations.

2. The shallow buried large span tunnel excavation and anchoring integrated rapid excavation and support method according to claim 1, characterized in that: The step S1 comprises: S1.

1. Construction of numerical calculation model for fast excavation with large support cycle step; The simulation scheme of the numerical calculation model is established based on the drill hole histogram near the working face and the physical and mechanical parameters of the rock formation.

3. The shallow buried large span tunnel excavation and anchoring integrated rapid excavation and support method according to claim 1 or 2, characterized in that: The step S2 comprises: S2.

1. Simulate the tunneling support process and analyze the vertical stress distribution characteristics of the tunnel roof under different support large cycle step distance schemes during tunneling; S2.

2. Simulate and analyze the vertical displacement distribution characteristics of the horizontal section of the roof after excavation under different cycle step lengths; S2.

3. Simulate and analyze the distribution characteristics of the plastic zone in the tunnel after excavation using different large cycle step sizes.

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