Construction method of shield tunneling with large longitudinal slope and empty push and translation transfer in mining tunnel section

Abstract

The invention discloses a method for shield pushing and translation transfer of large longitudinal slope in a mining tunnel section, which comprises two parts: shield pushing and translation transfer of large longitudinal slope in a mining tunnel section. The shield pushing and translation transfer of large longitudinal slope in a mining tunnel section comprises: construction of a pushing guide platform; receiving the shield machine; installing a reaction force device; shield pushing and backfilling the guide platform; the translation transfer comprises the following steps: construction of a steering platform; installation of a receiving bracket; translation and steering of the shield body; secondary pushing of the shield machine and steering of a matching trolley; the needs of pushing and translation construction on a large longitudinal slope can be met, and the translation transfer is efficient and fast, and can significantly speed up the construction progress.

Description

Technical Field

[0001] The invention relates to the technical field of engineering construction, and in particular to a large longitudinal slope empty pushing and translation transfer construction method of a shield tunnel section of a mining method. Background Art

[0002] According to the project construction plan, the shield machine needs to start from the left line with a small mileage, and after excavating to a large mileage, it needs to be pushed through the dark excavation section of the mining method tunnel, and then moved to the dark excavation entrance of the right line for assembly and debugging. After the debugging is completed, it needs to be pushed through the dark excavation section of the mining method tunnel and start from the right line with a large mileage, and excavate to the right line with a small mileage to receive. The entire mining method tunnel section has a large longitudinal slope, which brings great difficulty to the empty push, and the traditional empty push method cannot be applied; in addition, for the shield machine to turn around and start, the method of disassembling the shield machine and then hoisting it is generally adopted, which is not only time-consuming and labor-intensive, but also costly. Summary of the invention

[0003] In view of the above problems, the present invention aims to provide a shield empty pushing and translation transfer construction method for a mining method tunnel section, which can meet the needs of empty pushing construction on a large longitudinal slope, and the translation transfer is efficient and fast, which can significantly speed up the construction progress.

[0004] To this end, the technical solution adopted by the present invention is: a mining method tunnel section shield large longitudinal slope empty push and translation transfer construction method, including mining method tunnel section shield large longitudinal slope empty push and translation transfer two parts, wherein:

[0005] (A) The shield tunneling process of the mining method tunnel section with large longitudinal slope includes the following steps:

[0006] (A.1) Construction of empty derivation platform;

[0007] After the construction of the mining tunnel is completed, an empty guide platform is constructed at the bottom of the tunnel. Before the guide platform is cast, a row of PVC pipes is buried on the guide platform every 80±10cm along the extension direction of the mining tunnel, which is used for the later installation of through-hole rods to provide the shield machine with empty thrust reaction force. After the steel bars are tied, the buried position of the PVC pipe is measured and marked, and the front and rear wires are used to reinforce the PVC pipe. The bottom of the PVC pipe is tied with plastic bags to ensure that concrete does not invade the pipe to avoid the failure to install through-hole rods in the later stage. The PVC pipe and the steel bars are tied and reinforced, and multiple reinforcements are adopted from top to bottom. After the guide platform is cast, the shield machine sliding rails are installed on both sides of the guide platform, and they are fixed to the embedded steel plates on both sides of the guide platform with rail clamps;

[0008] (A.2) Shield receiving;

[0009] The cutterhead should be rotated before the shield machine steps onto the guide platform. It is strictly forbidden to rotate the cutterhead during the later stage of empty push construction. The four side rollers close to the sliding guide rail should be removed to prevent the cutterhead from gnawing the rail. Then the shield machine should be started, the pipe segments should be assembled, and the shield machine should be pushed onto the guide platform rail to complete the reception.

[0010] (A.3) Install the reaction device;

[0011] Multiple through-rods are welded and fixed to the steel frame as reaction frames. The guide platforms on the left and right sides are each equipped with a reaction frame. The through-rods are inserted into a row of pre-buried PVC pipes, and a reaction block is welded on each side of the left and right sides of the shield shell at the shield tail.

[0012] (A.4) Shield tunneling and guide platform backfilling;

[0013] The jack is placed between the reaction frame and the reaction block, and combined with the hydraulic jack at the bottom of the shield itself, they are pushed together to increase the empty pushing speed, and the interval between two adjacent rows of PVC pipes is regarded as a cycle footage for repeated pushing. After each cycle footage, the reaction frame is taken out from the previous row of PVC pipes and inserted into the next row of PVC pipes to push the next cycle footage until all the empty pushing of the mining method tunnel section is completed, and then the guide platform is backfilled;

[0014] (B) The translation transition includes the following steps:

[0015] (B.1) Steering platform construction;

[0016] The ground at the exit of the mining tunnel section is excavated, a steel mesh is laid on the bottom plate, and embedded steel parts are configured, which are then cast in one step using concrete. Then the platform steel plate is laid, and the joints of the steel plates are welded and polished flat. The platform steel plate is welded and fixed to the embedded concrete steel parts to prevent the platform steel plate from horizontal displacement during the horizontal pushing process of the shield machine.

[0017] (B.2) Receiving bracket installation;

[0018] Weld the receiving bracket on the platform steel plate. The receiving bracket rail surface height is 10-20mm lower than the guide rail of the guide platform to prevent the bracket from slipping when the shield machine steps on the receiving bracket.

[0019] (B.3) Shield translation and steering;

[0020] Preparation before turning: Separate the front and rear supporting trolleys of the receiving bracket on the shield machine, weld and fix the receiving bracket on the shield machine, cut off the welding between the receiving bracket and the platform steel plate, and apply oil on the platform steel plate;

[0021] The first step of turning: first, use the guide platform concrete to provide reaction force, install two jacks, and move the shield body and the receiving bracket longitudinally as a whole; then weld the jack force piers on the platform steel plate, and move the shield body and the receiving bracket longitudinally as a whole again;

[0022] The second step of turning: In order to ensure that the shield screw machine can follow the turning and prevent collision with the open hole during turning, the jack bearing pier is welded on the platform steel plate, and the shield body and the receiving bracket are horizontally translated as a whole to start the turning construction;

[0023] The third step of steering: after the shield body is translated into place, the steering construction begins. Use two jacks on the left and right sides that are staggered front and back to push the bracket to form a rotating force couple. During the rotation process, observe the position of the screw machine. After rotating to a certain angle, stop rotating and start to translate the bracket. After repeated rotation and translation, the screw machine is ready for overall rotation.

[0024] The fourth step of turning: rotate the shield as a whole until it completes a 180-degree turn, with the front of the shield facing the direction of the secondary excavation.

[0025] Step 5: Weld the jack reaction support on the platform steel plate on one side of the receiving bracket, and use the hydraulic jack to push the shield and the receiving bracket to the right line starting axis after multiple horizontal pushes;

[0026] The sixth step of steering: weld the jack reaction pier on the platform steel plate behind the receiving bracket, use the hydraulic jack to push the shield body and the receiving bracket to the entrance of the right line starting tunnel after multiple longitudinal pushes, complete the steering, cut off the welding between the shield machine and the receiving bracket, and prepare for the right line empty push tunnel;

[0027] (B.4) Secondary empty push of the shield machine and steering of the rear supporting trolley;

[0028] After the empty push construction of the left line of the shield is completed, the rear supporting trolley will be separated section by section according to the order of exiting the tunnel. After the empty push construction of the right line of the shield is completed, it will be lifted section by section to the right line starting boundary of the tunnel for assembly using a crawler crane.

[0029] As a preferred embodiment of the above scheme, in step (A.1), the following steps are performed:

[0030] (A.1.1) Clean the base surface;

[0031] (A.1.2) Chiseling, cleaning and straightening of the original reserved steel bars; use an electric pick to chisel, with the depth controlled at 8-12mm, remove all the floating slurry and soft layer on the concrete surface, expose most of the coarse aggregate, and ensure that the roots of the aggregates are clean and moist, but no water should accumulate until the new concrete is poured;

[0032] (A.1.3) The surveyors first measured and laid out the two sides of the platform, measuring and laying out an arc section every 2 meters. Eight control piles were arranged in each section, with 1#, 2#, 5#, and 6# as boundary lines, and 3#, 4#, 7#, and 8# as rail surfaces. The control piles were driven into the base of the platform using Φ16 steel bars and wrapped with cement mortar;

[0033] (A.1.4) After the steel bars are tied, the embedded steel plates are positioned so that the embedded steel plates are in an “n” shape as a whole;

[0034] (A.1.5) Pre-buried PVC pipe: φ110 PVC pipe is buried before pouring the pedestal, which is used for the later installation of φ100 through-rod to provide the shield machine with air thrust reaction force; the PVC pipe is 21.5cm away from the pre-buried steel plate, and the horizontal spacing between each PVC pipe is 5cm and the vertical spacing is 1.5m.

[0035] (A.1.6) Setting up the mold and re-measuring;

[0036] (A.1.7) Concrete pouring: Before pouring concrete, check and measure the elevation of the pouring surface, moisten the roughened surface, pour the concrete to a thickness of 980mm, and use an insert vibrator to compact it. The vibration time should be until no bubbles or floating slurry are generated on the surface. Be careful to avoid segregation due to excessive vibration of the concrete. The concrete should be smoothed in time before final setting. The flatness after molding should be within ±1cm. The concrete strength grade is C35.

[0037] (A.1.8) After the concrete is poured, it must be smoothed, trimmed and watered in a timely manner for 14 days.

[0038] More preferably, in step (A.1), three PVC pipes are buried in a row on the empty derivation table at intervals of 80 cm.

[0039] It is further preferred that, in step (A.4), before the empty push, at least two wedge-shaped steel plates are welded on one side of the shield body, adjacent to the tracks on both sides of the empty push guide platform, as a device to prevent the shield machine from rolling sideways, and are cut off before approaching the receiving bracket after the empty push is completed.

[0040] Beneficial effects of the present invention:

[0041] (1) A row of PVC pipes is buried every 80±10 cm on the air-pushing guide table in the extension direction of the mining method tunnel, which is used to install the through rods and the steel frame to form a reaction frame in the later stage. A reaction block is welded on both sides of the shield tail and the shield shell. The jack is placed between the reaction frame and the reaction block to give the shield machine an air-pushing reaction force. The interval between two adjacent rows of PVC pipes is regarded as a cycle advance. After each cycle advance, the reaction frame is taken out from the previous row of PVC pipes and inserted into the next row of PVC pipes to carry out the next cycle advance of air-pushing until the entire mining method tunnel section is completed. The construction is convenient and fast, and can meet the air-pushing requirements of the mining method tunnel section with a large longitudinal slope.

[0042] (2) The traditional shield turning method uses the construction method of disassembling the shield and then hoisting it. It requires a 450-ton crane to disassemble and hoist it. The construction is time-consuming and labor-intensive, and the hoisting requires a 450-ton crane. This method uses the overall translation and steering of the shield machine mainframe, and the rear supporting trolley is hoisted by a 300-ton crane, which reduces the number of hoisting and disassembling of the shield machine, reduces welding and cutting of lifting lugs, and shortens the construction period from the original 40 days to 7 days, which not only shortens the construction period but also reduces the construction cost. The traditional construction method of disassembling and hoisting the shield machine will inevitably damage the shield mechanism accessories during the disassembly and assembly of the shield machine mainframe. However, the overall translation and steering of the shield machine mainframe does not require disassembly and assembly, which greatly reduces the probability of damage to the shield mechanism accessories. In addition, the shield body is separated from the rear supporting trolley and turned separately. After the left-line empty pushing construction of the shield body is completed, the rear supporting trolley is separated section by section according to the order of exiting the tunnel, and after the right-line empty pushing construction of the shield body is completed, it is lifted section by section to the right-line starting boundary of the tunnel by a crawler crane for assembly, instead of assembling the shield body and the rear supporting trolley immediately after the turning is completed. This can save space and time occupied by the tunnel entrance. The shield body can be assembled after the right-line empty pushing in time, which can free up the tunnel entrance for other construction in time, which is more efficient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The structure of an empty derivation table.

[0044] Figure 2 It is a top view of the installation of shield machine and reaction frame on the empty derivation platform.

[0045] Figure 3 The structure of the embedded steel plate on the empty derivation platform.

[0046] Figure 4 This is the construction layout drawing of the empty derivation platform.

[0047] Figure 5 A top view of the receiving bracket.

[0048] Figure 6 The shield body is in the state after stepping onto the receiving bracket.

[0049] Figure 7 Schematic diagram of shield translation and steering. DETAILED DESCRIPTION

[0050] The present invention will be further described below by way of embodiments and in conjunction with the accompanying drawings:

[0051] A method for construction of large longitudinal slope empty pushing and translation transfer of a mining method tunnel section shield, comprising two parts: large longitudinal slope empty pushing (A) and translation transfer (B).

[0052] Among them, (A) the shield tunneling of the mining method tunnel section with large longitudinal slope empty pushing includes the following steps:

[0053] (A.1) Construction of empty derivation table.

[0054] Combination Figure 1 , Figure 2 As shown, after the construction of the mining method tunnel is completed, an empty push guide platform is constructed at the bottom of the tunnel. Before the guide platform is cast, a row of PVC pipes is buried on the guide platform every 80±10cm along the extension direction of the mining method tunnel, which is used for the later installation of the through rod 2 to provide the shield machine 3 with empty push reaction force.

[0055] The empty guide platform 1 adopts a reinforced concrete structure. After the steel bars (not shown in the figure) are tied, the buried position of the PVC pipe is measured and set out. The PVC pipe is reinforced with front and rear wires. The bottom of the PVC pipe is tied with a plastic bag to ensure that concrete does not invade the pipe to avoid the inability to install the core rod 2 later. The PVC pipe and the steel bars are tied and reinforced, and multiple reinforcements are adopted from top to bottom. After that, the guide platform is cast. After the guide platform is cast, the shield machine sliding guide rails 4 are installed on both sides of the guide platform, and they are fixed to the embedded steel plates 5 on both sides of the guide platform with rail clamps (such as Figure 3 As shown in FIG. 1 , the embedded steel plate is fixed on the steel bars of the empty derivation platform 1. The embedded steel plate 5 is preferably in an "n" shape, and the two legs have outer flanges.

[0056] In step (A.1), proceed as follows:

[0057] (A.1.1) Clean the base surface of the pedestal.

[0058] Clean the mud and floating slag on the base surface, and transport the abandoned slag to the slag yard manually with the help of loaders.

[0059] (A.1.2) Roughen, clean and straighten the original reserved steel bars.

[0060] After cleaning the base surface of the pedestal, use an electric pick to chisel it. The chiseling should be light and delicate, and the depth should be controlled at 8-12mm to achieve the required effect, preferably 10mm. At the same time, remove all the floating slurry and soft layer on the surface of the concrete, and most of the coarse aggregate is exposed, and the aggregate exposure reaches 75%. Be careful not to loosen the coarse aggregate, avoid strip, point or pit-shaped chiseling, and point chiseling can be used as appropriate where the construction is difficult. After the floating slurry and the soft layer on the surface are removed, most of the coarse aggregate is exposed. In order to ensure the aggregate strength requirements before the new concrete is poured and achieve the chiseling effect, it is necessary to rinse with water, clean up the floating slurry and residue, and ensure that the root is clean and moist, but there must be no water accumulation until the new concrete is poured, and it must be maintained on site in combination with maintenance.

[0061] (A.1.3) The surveyors first measured and laid out the two sides of the platform, planning to make every 12 meters a construction section. A circular section was measured and laid out every 2 meters, and 8 control piles were arranged in each section. 1#, 2#, 5#, and 6# were the boundary lines, and 3#, 4#, 7#, and 8# were the rail surfaces. Figure 4As shown, the control piles are driven into the base of the pedestal using Φ16 steel bars and wrapped with cement mortar.

[0062] (A.1.4) After the steel bars are tied, the embedded steel plates are positioned, and the embedded steel plates are in an "n" shape as a whole.

[0063] Rebar binding is carried out according to the measurement and layout data. The main reinforcement is made of φ16 threaded steel bars and anchored to the side wall and the reserved bottom steel bars of the pedestal. The steel bars on the straight wall are embedded 24cm into the pedestal base surface by planting steel bars. The spacing between steel bars is 20cm. The distribution bars are made of φ12 threaded steel bars and arranged at a spacing of 20cm. The steel bars are connected by binding.

[0064] After the steel bars are tied, the embedded steel plates are positioned. The size of the embedded steel plates is 30*30cm, and the spacing between the steel plates is 60cm. The fixed position of the plates is measured and laid out. The steel plates are installed by pulling wires to ensure that the steel plates are on the same surface. After the steel plates are embedded, they must be reviewed by the project department's precision measurement team before they can be erected and poured.

[0065] (A.1.5) Pre-buried PVC pipe: φ110 PVC pipe is buried before pouring the pedestal, which is used for the later installation of φ100 through-rod to provide empty thrust reaction force for the shield machine.

[0066] (A.1.6) Setting up the mold and re-measuring;

[0067] The formwork of the empty derivation platform is made of wood, the height of the bamboo plywood is 802mm, the bottom of the formwork is temporarily supported by 20 threaded steel implanted in the inverted arch, and the top of the formwork is fixed to the poured low side wall with tension screws. After the formwork is installed, the installation quality is fully checked, and square wood is used to make three groups of horizontal tie supports and fix them, and two horizontal supports are made in the middle of the square wood for reinforcement. After retesting and passing, concrete pouring is carried out.

[0068] (A.1.7) Concrete pouring: concrete is transported by mixing station and transported to the construction site by mixer truck. Concrete is transported to the mold through the chute. Before pouring concrete, the elevation of the pouring surface is checked and measured, and the roughened surface is moistened. The pouring thickness is 980mm. The insert vibrator is used to vibrate and compact the concrete. The vibration time is until no bubbles or floating slurry are generated on the surface. Pay attention to avoid segregation caused by excessive vibration time of concrete. The concrete should be smoothed in time before final setting. The flatness after molding is required to be within ±1cm. The concrete strength grade is C35.

[0069] (A.1.8) After the concrete is poured, it must be smoothed, trimmed and watered in a timely manner for 14 days.

[0070] In step (A.1), it is best to bury three PVC pipes in a row on the empty derivation table every 80 cm.

[0071] (A.2) Shield reception.

[0072] Before the shield machine steps onto the guide platform, the cutterhead is rotated, for example, by 30°. In the later stage of the empty push construction, it is strictly forbidden to rotate the cutterhead. The four side rollers close to the sliding guide rail are removed. The above measures are adopted to prevent the cutterhead from gnawing the rail during the empty push. Then start the shield machine, assemble the pipe segments, push the shield machine onto the shield machine sliding guide rail of the guide platform, and complete the reception.

[0073] (A.3) Install the reaction device.

[0074] Multiple through-rods 2 are welded and fixed to the industrial steel frame 6 as a reaction frame. The industrial steel frame 6 adopts an I-beam structure and is welded in front of the through-rods 2. The empty derivation platforms on the left and right sides are each equipped with a reaction frame. It should be ensured that the width of the industrial steel frame 6 is greater than the lateral span of all through-rods 2 on one side. The through-rods 2 are inserted into a pre-buried row of PVC pipes, and a reaction block 7 is welded on each side of the left and right sides of the shield tail shield shell.

[0075] (A.4) Shield tunnelling and guide platform backfilling.

[0076] The jack 8 is placed between the reaction frame and the reaction block 7, and combined with the hydraulic jack at the bottom of the shield itself, they are pushed together to increase the empty pushing speed. The interval between two adjacent rows of PVC pipes is a cycle footage for repeated pushing. After each cycle footage, the reaction frame is taken out from the previous row of PVC pipes and inserted into the next row of PVC pipes to push the next cycle footage until the entire mining method tunnel section is pushed, and then the guide platform is backfilled.

[0077] Preferably, in step (A.4), before the dry push, at least two wedge-shaped steel plates are welded on one side of the shield body, adjacent to the tracks on both sides of the dry push guide platform, as a device to prevent the shield machine from rolling sideways, and are cut off before approaching the receiving bracket after the dry push is completed.

[0078] A row of PVC pipes is buried every 80±10cm on the air-pushing guide table in the extension direction of the mining method tunnel, which is used to install the through rods and the industrial steel frame to form a reaction frame in the later stage. A reaction block is welded on both sides of the left and right sides of the shield tail and shield shell. The jack is placed between the reaction frame and the reaction block to give the shield machine an air-pushing reaction force. The interval between two adjacent rows of PVC pipes is a cycle advance for repeated advancement. After each cycle advance, the reaction frame is taken out from the previous row of PVC pipes and inserted into the next row of PVC pipes to carry out the next cycle advance of air-pushing until the entire mining method tunnel section is completed. The construction is convenient and fast, and can meet the air-pushing requirements of the mining method tunnel section with a large longitudinal slope.

[0079] (B) The translation transition part includes the following steps:

[0080] (B.1) Steering platform construction.

[0081] The exit ground of the mining method tunnel section is broken and excavated, a steel mesh is laid on the bottom plate, and steel embedded parts are configured, which are cast in one step using concrete. Then the platform steel plate is laid, the steel plate joints are welded and polished, and the platform steel plate is welded and fixed to the concrete steel embedded parts to prevent horizontal displacement of the platform steel plate during the horizontal pushing process of the shield machine.

[0082] (B.2) Receive bracket installation.

[0083] The receiving bracket is welded on the platform steel plate, and the rail surface height of the receiving bracket is 10 to 20 mm lower than the guide rail of the guide platform to prevent the bracket from slipping when the shield machine steps on the receiving bracket. Figure 5 , Figure 6 As shown, the receiving bracket is a welded frame structure with an arc-shaped top, and the arc shape of the top just matches the bottom contour of the shield body.

[0084] (B.3) Shield body translation and steering, such as Figure 7 shown.

[0085] Preparation before turning: Separate the front and rear supporting trolleys of the receiving bracket on the shield machine, weld and fix the rear receiving bracket on the shield machine to the receiving bracket, cut off the welding between the receiving bracket and the platform steel plate, and apply oil, such as butter, on the platform steel plate.

[0086] Turn to the first step: first use the guide platform concrete 9 to provide reaction force, install two jacks 8, and move the shield body and the receiving bracket longitudinally as a whole; then weld the jack force support pier (not shown in the figure) on the platform steel plate 10, and move the shield body and the receiving bracket longitudinally as a whole again; move forward longitudinally twice, such as Figure 7 As shown in a.

[0087] The second step of turning: In order to ensure that the shield screw machine can follow the turning and prevent collision with the open hole, a jack bearing pier (not shown in the figure) is welded on the platform steel plate, and the shield body and the receiving bracket are moved horizontally as a whole by the jack to enter the turning construction. Figure 7 (b) as shown;

[0088] The third step of steering: After the shield body is translated into place, the steering construction begins. Use two jacks on the left and right sides that are staggered front and back to push the receiving bracket to form a rotating force couple. During the rotation process, observe the position of the screw machine. After rotating to a certain angle, stop rotating and start to translate the bracket. After repeated rotation and translation, the screw machine is ready for overall rotation. Figure 7 (c) as shown;

[0089] Step 4 of turning: Rotate the shield as a whole until it turns 180 degrees. At this time, the front of the shield faces the direction of the secondary excavation. Figure 7 (d) as shown;

[0090] Step 5: Weld the jack reaction support on the platform steel plate on one side of the receiving bracket, and use the hydraulic jack to push the shield and the receiving bracket to the right line starting axis after multiple horizontal pushes. Figure 7 (e) as shown;

[0091] The sixth step of steering: weld the jack reaction pier on the platform steel plate behind the receiving bracket, use the hydraulic jack to push the shield and the receiving bracket to the right line starting tunnel entrance after multiple longitudinal pushes, complete the steering, cut off the welding between the shield machine and the receiving bracket, and prepare for the right line empty push tunnel. Figure 7 (f) shown.

[0092] (B.4) Secondary empty push of the shield machine and steering of the rear supporting trolley;

[0093] After the empty push construction of the left line of the shield is completed, the rear supporting trolley will be separated section by section according to the order of exiting the tunnel. After the empty push construction of the right line of the shield is completed, it will be lifted section by section to the right line starting boundary of the tunnel for assembly using a crawler crane.

[0094] The traditional shield turning method uses the construction method of hoisting after disassembling the shield. It requires a 450-ton crane to disassemble and hoist it. The construction is time-consuming and labor-intensive, and the hoisting requires a 450-ton crane. This method uses the overall translation and steering of the shield machine mainframe, and the rear supporting trolley is hoisted by a 300-ton crane, which reduces the number of hoisting and disassembling of the shield machine, reduces welding and cutting of lifting ears, and shortens the construction period from the original 40 days to 7 days, which not only shortens the construction period but also reduces construction costs. The traditional construction method of hoisting after disassembling the shield will inevitably damage the shield mechanism accessories during the disassembly and assembly of the shield mainframe. However, the overall translation and steering of the shield machine mainframe does not require disassembly and assembly, which greatly reduces the probability of damage to the shield mechanism accessories. In addition, the shield body is separated from the rear supporting trolley and turned separately. After the left-line empty pushing construction of the shield body is completed, the rear supporting trolley is separated section by section according to the order of exiting the tunnel, and after the right-line empty pushing construction of the shield body is completed, it is lifted section by section to the right-line starting boundary of the tunnel by a crawler crane for assembly, instead of assembling the shield body and the rear supporting trolley immediately after the turning is completed. This can save space and time occupied by the tunnel entrance. The shield body can be assembled after the right-line empty pushing in time, which can free up the tunnel entrance for other construction in time, which is more efficient and quick.

Claims

1. A method for construction of shield tunnel section with large longitudinal slope empty pushing and translation transfer, comprising two parts: shield tunnel section with large longitudinal slope empty pushing and translation transfer, characterized in that: (A) The shield tunneling process of the mining method tunnel section with large longitudinal slope includes the following steps: (A.1) Construction of empty derivation platform; After the construction of the mining tunnel is completed, an empty guide platform is constructed at the bottom of the tunnel. Before the guide platform is cast, a row of PVC pipes is buried on the guide platform every 80±10cm along the extension direction of the mining tunnel, which is used for the later installation of through-hole rods to provide the shield machine with empty thrust reaction force. After the steel bars are tied, the buried position of the PVC pipe is measured and marked, and the front and rear wires are used to reinforce the PVC pipe. The bottom of the PVC pipe is tied with plastic bags to ensure that concrete does not invade the pipe to avoid the failure to install through-hole rods in the later stage. The PVC pipe and the steel bars are tied and reinforced, and multiple reinforcements are adopted from top to bottom. After the guide platform is cast, the shield machine sliding rails are installed on both sides of the guide platform, and they are fixed to the embedded steel plates on both sides of the guide platform with rail clamps; (A.2) Shield receiving; The cutterhead should be rotated before the shield machine steps onto the guide platform. It is strictly forbidden to rotate the cutterhead during the later stage of empty push construction. The four side rollers close to the sliding guide rail should be removed to prevent the cutterhead from gnawing the rail. Then the shield machine should be started, the pipe segments should be assembled, and the shield machine should be pushed onto the guide platform rail to complete the reception. (A.3) Install the reaction device; Multiple through-rods are welded and fixed to the steel frame as reaction frames. The guide platforms on the left and right sides are each equipped with a reaction frame. The through-rods are inserted into a row of pre-buried PVC pipes, and a reaction block is welded on each side of the left and right sides of the shield shell at the shield tail. (A.4) Shield tunneling and guide platform backfilling; The jack is placed between the reaction frame and the reaction block, and combined with the hydraulic jack at the bottom of the shield itself, they are pushed together to increase the empty pushing speed, and the interval between two adjacent rows of PVC pipes is regarded as a cycle footage for repeated pushing. After each cycle footage, the reaction frame is taken out from the previous row of PVC pipes and inserted into the next row of PVC pipes to push the next cycle footage until all the empty pushing of the mining method tunnel section is completed, and then the guide platform is backfilled; (B) The translation transition includes the following steps: (B.1) Steering platform construction; The ground at the exit of the mining tunnel section is excavated, a steel mesh is laid on the bottom plate, and embedded steel parts are configured, which are then cast in one step using concrete. Then the platform steel plate is laid, and the joints of the steel plates are welded and polished flat. The platform steel plate is welded and fixed to the embedded concrete steel parts to prevent the platform steel plate from horizontal displacement during the horizontal pushing process of the shield machine. (B.2) Receiving bracket installation; Weld the receiving bracket on the platform steel plate. The receiving bracket rail surface height is 10-20mm lower than the guide rail of the guide platform to prevent the bracket from slipping when the shield machine steps on the receiving bracket. (B.3) Shield translation and steering; Preparation before turning: Separate the front and rear supporting trolleys of the receiving bracket on the shield machine, weld and fix the receiving bracket on the shield machine, cut off the welding between the receiving bracket and the platform steel plate, and apply oil on the platform steel plate; The first step of turning: first, use the guide platform concrete to provide reaction force, install two jacks, and move the shield body and the receiving bracket longitudinally as a whole; then weld the jack force piers on the platform steel plate, and move the shield body and the receiving bracket longitudinally as a whole again; The second step of turning: In order to ensure that the shield screw machine can follow the turning and prevent collision with the open hole during turning, the jack bearing pier is welded on the platform steel plate, and the shield body and the receiving bracket are horizontally translated as a whole to start the turning construction; The third step of steering: after the shield body is translated into place, the steering construction begins. Use two jacks on the left and right sides that are staggered front and back to push the bracket to form a rotating force couple. During the rotation process, observe the position of the screw machine. After rotating to a certain angle, stop rotating and start to translate the bracket. After repeated rotation and translation, the screw machine is ready for overall rotation. Step 4 of turning: Rotate the shield as a whole until it turns 180 degrees, with the front of the shield facing the direction of the secondary excavation. Step 5: Weld the jack reaction support on the platform steel plate on one side of the receiving bracket, and use the hydraulic jack to push the shield and the receiving bracket to the right line starting axis after multiple horizontal pushes; The sixth step of steering: weld the jack reaction pier on the platform steel plate behind the receiving bracket, use the hydraulic jack to push the shield body and the receiving bracket to the entrance of the right line starting tunnel after multiple longitudinal pushes, complete the steering, cut off the welding between the shield machine and the receiving bracket, and prepare for the right line empty push tunnel; (B.4) Secondary empty push of the shield machine and steering of the rear supporting trolley; After the empty push construction of the left line of the shield is completed, the rear supporting trolley will be separated section by section according to the order of exiting the tunnel. After the empty push construction of the right line of the shield is completed, it will be lifted section by section to the right line starting boundary of the tunnel for assembly using a crawler crane.

2. The method for shield tunneling with large longitudinal slope empty pushing and translation transfer construction according to claim 1 is characterized by: In step (A.1), proceed as follows: (A.1.1) Clean the base surface; (A.1.2) Chiseling, cleaning and straightening of the original reserved steel bars; use an electric pick to chisel, with the depth controlled at 8-12mm, remove all the floating slurry and soft layer on the concrete surface, expose most of the coarse aggregate, and ensure that the roots of the aggregates are clean and moist, but no water should accumulate until the new concrete is poured; (A.1.3) The surveyors first measured and laid out the two sides of the platform, measuring and laying out an arc section every 2 meters. Eight control piles were arranged in each section, with 1#, 2#, 5#, and 6# as boundary lines, and 3#, 4#, 7#, and 8# as rail surfaces. The control piles were driven into the base of the platform using Φ16 steel bars and wrapped with cement mortar; (A.1.4) After the steel bars are tied, the embedded steel plates are positioned so that the embedded steel plates are in an "n" shape as a whole; (A.1.5) Pre-buried PVC pipe: φ110 PVC pipe is buried before the pedestal is cast, which is used for the later installation of φ100 through-hole rod to provide the shield machine with empty thrust reaction force; (A.1.6) Model establishment and re-measurement; (A.1.7) Concrete pouring: Before pouring concrete, recheck and measure the elevation of the pouring surface, wet and roughen the surface, pour the concrete to a thickness of 980mm, and use an insert vibrator to compact the concrete. The vibrating time should be until no more bubbles or floating slurry are generated on the surface. Be careful to avoid segregation due to excessive vibration of the concrete. The concrete should be smoothed in time before final setting. The flatness after forming should be within ±1cm. The concrete strength grade is C35. (A.1.8) After the concrete is poured, it must be smoothed, trimmed and watered in a timely manner for 14 days.

3. The method for shield tunneling with large longitudinal slope empty pushing and translation transfer construction according to claim 1 is characterized by: In step (A.1), three PVC pipes are buried in a row on the guide platform at intervals of 80 cm.

4. The method for shield tunneling with large longitudinal slope empty pushing and translation transfer construction according to claim 1 is characterized in that: In step (A.4), before the dry push, no less than two wedge-shaped steel plates are welded on one side of the shield body, adjacent to the tracks on both sides of the dry push guide platform, as a device to prevent the shield machine from rolling sideways, and are cut off before approaching the receiving bracket after the dry push is completed.

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