One-well three-machine shield staggered direction large split launching construction method

Abstract

The invention relates to a one-well three-machine shield staggered large split launching construction method, which comprises the following steps of: firstly, hoisting a 1 # shield tunneling machine into a well through a crawler crane, and launching the 1 # shield tunneling machine after assembling and debugging; then, the crawler crane is transferred to the field, the second shield tunneling machine is hoisted to the well, and the second shield tunneling machine is started after assembling and debugging; and after the 1 # shield tunneling machine or the 2 # shield tunneling machine conducts tunneling for 100 rings, starting of the 3 # shield tunneling machine is conducted. According to the one-well three-machine shield staggered direction large split launching construction method, the launching requirement of multiple shield machines of the ultra-deep circular small vertical shaft is met by adopting an underground trolley stacking mode, and the problems that pipeline extension from the ground is not economical, high-altitude operation pipelines are difficult to install and fix, and the pressure of pressurized pipelines is unstable are solved.

Description

Technical Field

[0001] The invention relates to the field of shield split launching, in particular to a "one shaft and three machines" shield staggered large split launching construction method. Background Art

[0002] After nearly 200 years of development, shield technology has developed towards deeper and larger working shafts. The circular shaft support structure can convert the horizontal soil pressure outside the foundation pit into radial pressure acting on the circular horizontal support, which can exert the arch effect and make full use of the compressive properties of concrete, effectively reducing the deformation of the surrounding soil during foundation pit excavation. It has been widely used at home and abroad.

[0003] There are two main starting methods: one is the overall starting, that is, the front and rear guide tunnels are set at the bottom of the well. When the length of the guide tunnel reaches a certain requirement, the shield machine body and other supporting equipment are hoisted into the starting well together, and excavation begins after assembly and debugging. The other is the split starting, that is, when the shield starting well is small, the shield body or part of the trolley is hoisted into the starting well first, and the other part of the trolley is placed on the ground. The excavation begins forward by extending the pipeline, and when the shield excavation reaches the length that can put the trolley and its supporting equipment in, the supporting trolley is hoisted into the well for the second start according to the overall starting mode.

[0004] Ultra-deep circular shaft (e.g., the inner diameter of the 1# working shaft in this project is 33m, the outer diameter is 36m, and the shaft depth is about 63m. It consists of 24 zigzag underground continuous walls with a wall thickness of 800mm. It is equipped with 10 inner ring beams and 1 ring plate support. The net width of the axis of the working shaft underground tunnel is 17.78m, and the maximum horizontal width is 31m.) The split start of shield machines has always been a difficult problem in the industry, and the "one shaft, three machines" shield machine staggered large split start is rare at home and abroad. "One shaft, three machines": 3 shield machines are started from the same working shaft. Staggered means: the left line starts for large mileage, and the right line starts for small mileage. Large split start means that the supporting trolley behind the shield machine is hoisted underground. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a "one shaft, three machines" shield staggered large-split starting construction method. In projects such as urban subways, water conservancy tunnels, and integrated pipeline corridors, when the small site cannot meet the conventional split starting with the trolley placed on the ground and the working shaft is also used as a two-way starting working shaft, this method can effectively solve the technical problems of the narrow site being unable to meet the subsequent supporting trolley arrangement, avoiding the uneconomical extension of pipelines from the ground, the difficulty in installing and fixing pipelines for high-altitude operations, the unstable pressure of pressurized pipelines, and the split starting of multiple shield machines in one shaft.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: A "one well, three machines" shield machine staggered large-scale split start construction method, comprising: 1) Construction sequence: 1# shield machine and 2# shield machine start separately in staggered directions; first hoist 1# shield machine down the well, assemble and debug before starting; then, crawler crane transfers to hoist 2# shield machine down the well, assemble and debug before starting separately; after 1# shield machine or 2# shield machine has excavated 100 rings, 3# shield machine starts separately; the advantage of this construction method is that the assembly and debugging of 3# shield machine will not affect the excavation construction of 1# shield machine or 2# shield machine; 2) Reinforcement of the starting end: In order to ensure the safety of the 1# shield machine, the 2# shield machine and the 3# shield machine entering the tunnel, the normal excavation direction and the water-stopping effect of the tunnel entrance, according to the design requirements, the strata within a certain range should be reinforced and water-stopped before the three groups of shield machines enter the tunnel to ensure the safe entry of the shield machines; 3) Layout of ground monitoring points in the starting section: Starting from the starting end, each section is marked as a section with a certain length. Multiple monitoring points are arranged in each section. Adjacent monitoring points in the same section are kept at a certain distance. This can more comprehensively obtain data such as deformation and displacement of the ground in the starting section to ensure construction safety and project quality. 4) Placement and positioning of the starting frame: The starting frame adopts a steel structure to bear the gravity of the shield machine and the friction during advancement; 5) Shield assembly and debugging: After the corresponding shield machine is assembled, it can be debugged without load; after the no-load debugging is qualified, load debugging can be carried out; 6) Rear supporting trolley hoisting and pipeline connection: The rear supporting trolleys are placed on the trolley brackets respectively.

[0007] 1) After the lifting of TBM 1# was completed, the crawler crane was transferred to lift TBM 2# down into the well; after TBM 1# completed +100 rings of excavation, it was stopped to reorganize TBM 6 and TBM 7, change the slag outlet, water pipes and high-voltage cables, and resume excavation. At the same time, TBM 3# was assembled and debugged to ensure that the construction of the three TBMs would not affect each other.

[0008] 2) In the process, the starting end is reinforced by WSS backward grouting, with a reinforcement range of 7m-9m. The vertical reinforcement range is based on the rock surface line of the boundary section. Only the fully strongly weathered surrounding rock is reinforced, and the medium and slightly weathered rock surfaces are not reinforced. Before starting, water exploration is carried out on the tunnel portal to check the reinforcement effect of the starting end. If the water exploration effect is not good, horizontal grouting or ground rotary spraying and multiple spraying reinforcement are adopted.

[0009] 3) In the starting section, ground monitoring points are arranged, starting from the starting end, with a section every 30m. 9 monitoring points are arranged in each section. The aperture of each monitoring point is 150mm, and the monitoring points in the same section are 5m apart. The measuring points are covered with protective covers, with an aperture of not less than 150mm and a hole depth of 1000mm. The marking points are made of φ18 threaded steel bars with a length greater than 80cm. After the measuring point holes are placed, concrete is poured at the bottom and coarse sand is filled in the middle to ensure the stability of the measuring points.

[0010] 4), before installing the starting frame, the surveying team first fixes two horizontal control points on the bottom plate of the starting shaft, and accurately locates the left and right positions of the starting frame according to the measurement and layout; then determines the distance between the trolley bracket and the steel ring of the steel tunnel door; then, the starting frame is installed at the predetermined position as required, and is reviewed by the surveying team. After completing the positioning, the starting frame is fixed.

[0011] 6) The rear supporting trolley is hoisted and connected with pipelines, including: 6.1) The temporary bridge of the 1# shield machine is connected to the first shield of the 1# shield machine, and the 1# trolley, 2# trolley, 3# trolley and 4# trolley of the 1# shield machine are placed underground; 6.2) Remove the foam and grease system on the original bridge and assemble them on the temporary bridge; 6.3) The frame of the No. 4 trolley and the connecting bridge frame are placed on the ground. The No. 6 and No. 7 trolleys will not enter the field for the time being and will enter the field when the marshaling is completed. 6.4) The extended pipeline is stored on the platform at the bottom of the No. 2 trolley in the mine. The vertical transportation uses a gantry crane to unload slag and materials; the horizontal transportation uses a winch + flat plate + small earth bucket; 6.5) The first phase extension pipeline of No. 1 shield machine; 6.6) After the lifting of the 1# shield machine is completed, the crawler crane will be transferred to the site to lift the 2# shield machine down into the well; 6.7) The shield of the No. 2 shield machine is assembled in the pit, and the temporary bridge is connected to the second shield of the No. 2 shield machine; 6.8) After the No. 1 trolley of the No. 1 shield machine enters the hole, the No. 2, No. 3, No. 4, and No. 1 trolleys of the No. 2 shield machine are lowered into the well in sequence, and are placed on top of the No. 2 shield machine trolley bracket, and the pipelines are connected. The No. 5 trolley, No. 6 trolley, and the connecting bridge are placed on the ground; 6.9) The extended pipeline is stored on the bottom platform of No. 2² trolley in the mine. The vertical transportation uses gantry crane to unload slag and materials; the horizontal transportation uses winch + flat plate + small earth bucket; 6.10) The first phase extension pipeline of No. 2 shield machine; 6.11) The No. 3 shield machine connecting bridge, No. 1³ trolley and No. 2³ trolley are stored in the tunnel; 6.12) Store the No. 3³ and No. 4 trolleys underground; when the No. 3 shield machine is being assembled and debugged, the shield and trolleys of the No. 1 shield machine have all entered the hole. At this time, some trolleys of the No. 3 shield machine are stacked on the trolley bracket of the No. 1 shield machine, and the No. 5 and No. 6 trolleys are placed on the ground; 6.13) Remove the wellhead horse stool and track, and position and reinforce the lower starting bracket; 6.14) The lower shield body is assembled and the shield tail needs to be welded in pieces down to the well; 6.14) Connect the extension pipeline and start debugging; 6.15) Electric car marshaling and turnout laying.

[0012] The trolley bracket includes at least one layer of bracket units, and the bracket unit includes two rows of left and right vertical columns, and the two rows of vertical columns are respectively connected into a whole through a first longitudinal support and a second longitudinal support. The top ends of the two rows of vertical columns are connected by multiple groups of transverse supports and longitudinal supports to form a support platform; the support platform includes a second transverse support, and the second transverse support and the second longitudinal support are connected to form a frame, and the frame is reinforced by a transversely arranged first transverse support, a third transverse support and a longitudinally arranged third longitudinal support, and a support plate is fixed on the upper end face of the frame.

[0013] Passages are fixed on the left and right sides of the support platform, and guardrails are fixed on both sides of the upper ends of the support platform and the passages.

[0014] The vertical columns of each layer of bracket units and the first longitudinal support, the second longitudinal support, the vertical columns and the channel, the channel and the support platform, and the adjacent upper and lower layers of bracket units are all installed and fixed by bolt assemblies equipped with elastic media, flat media and nuts; the number of bracket units is 1-5 layers, and the bottom ends of the vertical columns of each layer of bracket units and the second longitudinal support are provided with installation holes; the bracket units on the bottom layer are reinforced by pre-buried ground anchor bolts. The present invention provides a "one well, three machines" shield machine staggered large-scale split initial construction method, which has the following technical effects: 1) By adopting the trolley bracket, it can not only effectively solve the problem that the narrow ground of the existing circular working well construction site cannot meet the requirements of the rear supporting trolley arrangement, avoid the problems of uneconomical extension of pipelines from the ground, difficulty in installing and fixing pipelines at high altitude, and unstable pressure of pressurized pipelines. At the same time, it can also solve the problem of N (1≤N≤4) shield machines being launched separately in the same working well due to the tight construction period. In this project, the main rear supporting trolleys of the shield are stacked on the starting trolley bracket at the bottom of the well, which improves the utilization rate of the limited space in the well, reduces the labor intensity, and reduces the cost investment.

[0015] 2) Arranging three shield machines to start in staggered directions in one working shaft at the same time greatly shortened the total construction period and accelerated the project progress. Effectively utilizing the limited working shaft space, achieving the coordinated operation of multiple shield machines, and improving the utilization rate of underground space.

[0016] 3) By adopting the starting end reinforcement, the safety of the shield machine entering the tunnel, the normal excavation direction and the water-stopping effect of the tunnel entrance are guaranteed.

[0017] 4) By real-time monitoring of ground deformation, settlement, etc., potential safety hazards such as ground collapse and building tilt can be discovered in time, so that corresponding preventive and remedial measures can be taken to protect the lives and property of construction workers, surrounding buildings and the public. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is a schematic diagram of the overall structure of the trolley bracket in the present invention.

[0019] Figure 2 It is a left view of the trolley bracket in the present invention (in the figure, ①, ②, ③, ④ respectively represent four-layer bracket units from bottom to top).

[0020] Figure 3 It is a front view of the trolley bracket in the present invention.

[0021] Figure 4 Schematic diagram of a single-layer trolley bracket in the present invention (middle layer).

[0022] Figure 5 Schematic diagram of a single-layer trolley bracket in the present invention (bottom layer).

[0023] Figure 6 for Figure 5 A local enlarged schematic diagram of point A in the middle.

[0024] Figure 7 This is a state schematic diagram (top view) of step 1 of the present invention.

[0025] Figure 8 This is a state schematic diagram (front view) of step 1 of the present invention.

[0026] Fig. 9 Schematic diagram of the state of step 2 of the present invention (top view).

[0027] Fig.10 This is a state schematic diagram (front view) of step 2 of the present invention.

[0028] Fig.11 This is a state schematic diagram (top view) of step 3 of the present invention.

[0029] Fig.12 This is a state schematic diagram (top view) of step 4 of the present invention.

[0030] Fig.13 This is a state schematic diagram (top view) of step 5 of the present invention.

[0031] Fig.14 This is a state schematic diagram (top view) of step 6 of the present invention.

[0032] Fig.15 This is a state schematic diagram (front view) of step 6 of the present invention.

[0033] Fig.16 This is a state schematic diagram (top view) of step 7 of the present invention.

[0034] In the figure: connecting bolt 1, vertical column 2, diagonal brace 3, ladder 4, first longitudinal support 5, second longitudinal support 6, third longitudinal support 7, first transverse support 8, second transverse support 9, third transverse support 10, passage 11, guardrail 12, horse stool platform 13, extended pipeline storage area 14, temporary bridge 15, 1# shield machine, 2# shield machine, connecting bridge 18, gantry crane 19, machine head 20, bucket truck 21, gantry crane slag discharge channel 22, 3# shield machine. DETAILED DESCRIPTION

[0035] like Figure 1-6 As shown, the trolley bracket includes at least one layer of bracket units. The bracket units can be set up in 1-5 layers according to the actual situation, as long as the shield starting requirements are met. Adjacent bracket units are connected by bolts and stacked from bottom to top. The height of each layer is different, from bottom to top, they are 3.45, 5.1, 5.5, and 5.2m respectively.

[0036] like Figure 4-5 As shown, each bracket unit includes multiple groups of vertical columns 2, and the vertical columns 2 are arranged side by side at intervals ( Figure 4 There are 3 vertical columns 2 on each side, and storage space is reserved. The middle of the adjacent vertical columns 2 on the left is connected by the first longitudinal support 5, and the top is connected by the second longitudinal support 6. The middle of the adjacent vertical columns 2 on the right is connected by the first longitudinal support 5, and the top is connected by the second longitudinal support 6. The middle of the two rows of second longitudinal supports 6 on the left and right sides is connected by the first transverse support 8, and the two ends are connected by the second transverse support 9. In order to further improve the strength, the first transverse support 8 and the second transverse supports 9 on both sides are connected by the third longitudinal support 7 and multiple third transverse supports 10.

[0037] The second longitudinal support 6, the third longitudinal support 7, the first transverse support 8, the second transverse support 9 and the third transverse support 10 at the top constitute a support platform, a plate is laid on the top of the support platform, and the rear supporting trolley is arranged on the support platform. The trolley weighs more than 50 tons and is heavy. It does not need to be fixed and can be placed stably on the support platform.

[0038] A guardrail 12 is fixed on the outside of the support platform to ensure safety.

[0039] In addition, a channel 11 is fixed outside the two rows of second longitudinal supports 6 on the left and right sides, and the lower end of the outer edge of the channel 11 is fixed to the vertical column 2 through the diagonal support 3. The channel 11 is provided to facilitate the horizontal passage of construction workers.

[0040] In addition, ladders 4 are vertically fixed outside the first longitudinal support 5 and the second longitudinal support 6, and the ladders 4 between the upper and lower adjacent bracket units are staggered. The ladders 4 are convenient for operators to go up and down the ladders.

[0041] In addition, when the components of each layer of bracket units and adjacent bracket units are detachably connected through bolt assemblies, elastic media, flat media and nuts are provided. The advantages of using elastic media and flat media are: the elasticity of the elastic washers is used to prevent loosening. After locking, this accessory can effectively prevent the screws from loosening through the elasticity of the elastic washers, thereby ensuring the stability of the connection. The flat media is used to protect the surface of the connected parts from damage.

[0042] In addition, after the bottom bracket unit is in place, it is reinforced with pre-buried ground anchors, which can prevent the bracket from loosening.

[0043] In addition, the vertical column 2, diagonal brace 3, ladder 4, first longitudinal support 5, second longitudinal support 6, third longitudinal support 7, first transverse support 8, second transverse support 9, third transverse support 10 and channel 11 in the device are respectively made of Q345B, and the overall weight is about 60t.

[0044] The No. 1 working shaft of this project has an inner diameter of 33m, an outer diameter of 36m, and a depth of about 63m. It consists of 24 zigzag underground continuous walls with a wall thickness of 800mm, 10 inner ring beams and 1 ring plate support. The net width of the working shaft underground tunnel axis is 17.78m and the maximum horizontal width is 31m.

[0045] The circular shaft in the middle cannot meet the requirements of placing the trolley on the ground for split start due to the narrow site. The construction site limitations, the complexity of the working conditions, and the unpredictability of the geology make the construction organization design difficult, the cross construction difficult, and the safety risk at the start stage high. In addition, all three shield machines must be started within 70 days, which puts great pressure on the construction period.

[0046] In view of the above situation, the method of the present invention is adopted for construction, and the three shield machines can be started separately within the specified time node, and the project proceeds smoothly.

[0047] A "one well, three machines" shield machine staggered large-scale split start construction method, comprising: 1) Construction sequence: Shield machine #1 and shield machine #2 start separately in staggered directions.

[0048] First, the 1# shield machine will be hoisted down the well and started after assembly and debugging. Then the crawler crane will be transferred to the site to hoist the 2# shield machine down the well, and it will start separately after assembly and debugging. After the 1# shield machine or the 2# shield machine has excavated 100 rings, the 3# shield machine will start separately.

[0049] 2) Reinforcement of the starting end: In order to ensure the safety of the three groups of shield machines entering the tunnel, the normal excavation direction, and the water-stopping effect of the tunnel entrance, according to the design requirements, the strata within a certain range should be reinforced and water-stopped before the three groups of shield machines enter the tunnel.

[0050] 3) Arrangement of ground monitoring points in the starting section: starting from the starting end, there is a section every 30m, 9 monitoring points are arranged in each section, the aperture of each monitoring point is 150mm, and the distance between monitoring points in the same section is 5m.

[0051] 4) Placement and positioning of the starting frame: The starting frame adopts a steel structure, which mainly bears the gravity of the shield machine and the friction during advancement.

[0052] 5) Shield assembly and debugging: After the shield is assembled, no-load debugging can be carried out. After the no-load debugging is qualified, load debugging can be carried out.

[0053] 6) Rear supporting trolley hoisting and pipeline connection: The rear supporting trolleys are placed on the trolley brackets respectively.

[0054] In step 1), after the 1# shield machine is hoisted, the crawler crane is transferred to the site to hoist the 2# shield machine down into the well. After the 1# shield machine has completed +100 rings of excavation, it is stopped for reorganization, the slag outlet is changed, the water pipes and high-voltage cables are changed, and excavation is resumed. At the same time, the 3# shield machine is assembled and debugged.

[0055] In step 2), the WSS backward grouting reinforcement is used for the starting end of the shield tunnel, and the reinforcement range is 8m (the center line of the line). The vertical reinforcement range is based on the rock surface line of the boundary section. Only the fully weathered surrounding rock is reinforced, and the medium and slightly weathered rock surfaces are not reinforced. Before starting, water detection work is carried out on the tunnel portal to check the reinforcement effect of the end. If the water detection effect is not good, horizontal grouting or ground rotary spraying and re-spraying reinforcement is adopted.

[0056] In step 3), close to the starting point, there is a section every 30m, 9 monitoring points are arranged in each section, the aperture of each monitoring point is 150mm, and the monitoring points in the same section are 5m apart. The measuring points are covered with protective covers, the aperture shall not be less than 150mm, the hole depth shall be 1000mm, and the marking points shall be φ18 threaded steel bars with a length greater than 80cm. After the measuring point holes are placed, concrete is poured at the bottom and coarse sand is filled in the middle to ensure the stability of the measuring points.

[0057] In step 4), since the shield machine is heavy, the starting frame must have sufficient rigidity and strength. Before installing the starting frame. The surveying team first fixes two horizontal control points on the bottom plate of the starting shaft, and accurately locates the left and right positions of the starting frame according to the measurement and layout; determines the distance between the bracket and the steel ring of the steel tunnel gate according to the construction length of the tunnel gate steel ring, the length of the trolley bracket, the total length of the negative ring and the position of the reaction frame; considering the shield starting and the shield posture control entering the reinforcement area, to ensure that the shield advancement motion trajectory meets the construction requirements, the elevation of the starting bracket of the left and right line brackets of the shield is increased by 10mm~20mm to prevent the shield from falling. Then the starting frame is installed at the predetermined position as required, and the surveying team reviews it. After the positioning is completed, the starting frame is fixed.

[0058] In step 5), the main purpose of load debugging is to check the load capacity of various pipeline machine sealing equipment and to further improve the debugging work that cannot be completed by no-load debugging, so that each working system of the shield can reach the working state that meets the normal construction requirements.

[0059] In step 6), the rear supporting trolley is hoisted and connected with the pipeline, which specifically includes: 6.1) The temporary bridge of No. 1 shield machine is connected with the shield body. The No. 1, No. 2, No. 3, No. 4 (circulating water system) and No. 5 trolleys of No. 1 shield machine are placed underground → The foam and grease systems on the original bridge are removed and assembled on the temporary bridge → The frame of No. 4 trolley and the connecting bridge frame are placed on the ground. Trolleys No. 6 and No. 7 will not enter the site for the time being and will enter the site when the group is formed → The extended pipeline is stored on the bottom platform of No. 2 trolley underground. The gantry crane is used for vertical transportation to unload slag and materials; the winch + flat plate + small earth bucket are used for horizontal transportation → The first stage of pipeline extension (starting).

[0060] 6.2) After the lifting of the 1# shield machine is completed, the crawler crane is transferred to the site for lifting and lowering into the well → the shield of the 2# shield machine is lowered into the well for assembly, and the temporary bridge of the 2# shield machine is connected to the shield → after the No. 1 trolley of the 1# shield machine enters the hole, the No. 2² trolley, No. 3² trolley, No. 4² trolley, and No. 1² trolley of the 2# shield machine are lowered into the well in turn, overlapped and placed at the original No. 1¹ trolley position, connected to the pipeline, and the No. 5¹ trolley, No. 6¹ trolley and the connecting bridge of the 2# shield machine are placed on the ground. (The trolleys will enter the site in batches as planned: connecting bridge; trolley No. 2², trolley No. 3², trolley No. 4², trolley No. 1²; trolley No. 5¹, trolley No. 6¹) → The extended pipeline is stored on the bottom platform of trolley No. 2² underground. The gantry crane is used for vertical transportation to unload slag and materials; the winch + flat plate + small earth bucket is used for horizontal transportation → The first stage extension pipeline of 2# shield machine (starting).

[0061] 6.3) The connecting bridge of the 23# shield machine 3#, the 1³ trolley and the 2³ trolley can all be stored in the tunnel (Shilong 1# working shaft - Shilong 2# working shaft section left line) → store the 3³ trolley and the 4³ trolley in the shaft, and place the 5³ trolley and the 6³ trolley on the ground → remove the wellhead horse stool and track, position and reinforce the lower starting bracket → assemble the lower shield body, and the shield tail needs to be welded in blocks in the shaft. (Whether the open tunnel completed by the start can be removed) → connect the extension pipeline, debug the start → battery car marshaling → turnout laying.

[0062] Example 1 Three EPB-TBM dual-mode shield machines are used for the initial operation of the 1# working shaft. Two EPB-TBM dual-mode shield machines with an excavation diameter of 9130mm are used in the direction of smaller mileage. One EPB-TBM dual-mode shield machine with an excavation diameter of 9140mm is used on the left line in the direction of larger mileage. After the section is connected, it will be transferred to the original launching shaft for the right line operation.

[0063] like Figure 7-16 As shown in the figure: A represents the first slag well, B represents the second slag well, C represents the first 500T crawler crane station, D represents the first 500T crawler crane station, E represents the trolley bracket, F represents the storage position during assembly, G represents the temporary storage position before entering the site, H represents the gantry crane, I represents the center line of the left tunnel, J represents the center line of the right tunnel, K represents the direction of Shiyan Center Station, L represents the direction of 2# working well, M represents 1# working well, 1a, 2a, 3a, 4a, 5a, 6a, 7a They represent trolley No. 1, 2, 3, 4, 5, 6 and 7 of TBM No. 1 respectively; 1b, 2b, 3b, 4b, 5b and 6b represent trolley No. 1, 2, 3, 4, 5 and 6 of TBM No. 2 respectively; 1c, 2c, 3c, 4c, 5c and 6c represent trolley No. 1, 2, 3, 4, 5 and 6 of TBM No. 2 respectively.

[0064] A "one well, three machines" shield machine staggered large-scale split start construction method, comprising the following steps: Step 1: Figure 7-8 As shown, the No. 1 shield machine is hoisted down into the well for assembly and debugging.

[0065] The operation process of the 1# shield machine in step 1 is as follows: S1.1.1: The first shield 16 of the No. 1 shield machine is assembled in the pit, the temporary bridge 15 is connected to the first shield 16, and the No. 1, No. 2, No. 3, and No. 4 trolleys (represented by 1a, 2a, 3a, and 4a, respectively) are placed on the trolley bracket in the No. 1 working pit (represented by M). The foam and grease system on the original bridge is removed and assembled on the temporary bridge 15.

[0066] S1.1.2: Trolley No. 5 (indicated by 5a) and connecting bridge 18 of No. 1 shield machine are placed on the ground, and Trolley No. 6 and Trolley No. 7 will not enter the site for the time being and will enter the site when the formation is completed.

[0067] S1.1.3: The extended pipeline is stored in the extended pipeline storage area 14, located on the horse stool platform 13 of the No. 1 working shaft. The vertical transportation uses a gantry crane 19 to unload slag and materials; the horizontal transportation uses a winch + flat plate + small earth bucket.

[0068] S1.1.4: The first phase of extended pipelines for TBM No. 1 (starting): from trolley No. 5 to trolley No. 4, about 85 meters; from trolley No. 4 to trolley No. 3, about 6.5 meters; from trolley No. 3 to trolley No. 2 (part of the pipeline), about 6.5 meters; from trolley No. 2 to trolley No. 1, the self-contained pipeline is used; from trolley No. 3 to the first shield body 16, about 120 meters; from trolley No. 2 to the first shield body 16, about 120 meters; from trolley No. 1 to the first shield body, about 50 meters.

[0069] Step 2: If Figure 9-10 As shown in the figure, after the No. 1 shield machine was started, the No. 1 carriage entered the tunnel; and the No. 2 shield machine was hoisted down the shaft for assembly and debugging.

[0070] The operation process of the 1# shield machine in step 2 is as follows: S2.1.1: Shield machine No. 1 will start to excavate 1 ring per day. After starting, all 5 negative rings will be assembled with staggered joints. The upper part of the negative ring from -2 to -1 will not be assembled and will be supported by steel sections to facilitate excavation and material placement. S2.1.2: After the initial excavation is completed +2 rings, the battery car is marshaled into: 1 head 20 + 1 bucket flatbed car 21 for slag transportation, and the segment transportation is still carried out by flatbed car + winch; S2.1.3: After the initial excavation has completed the +15th ring, the pipeline of the No. 1 trolley is removed, and the No. 1 trolley is split into three parts (left, middle, and right). After entering the cave, the No. 1 trolley is assembled, and the No. 1 trolley is connected to the temporary bridge 15 and the pipeline is connected; S2.1.4: Second stage extension pipeline of No. 1 shield machine (after completing +15 rings): The distance from No. 2 trolley to No. 1 trolley is about 105 meters, and the No. 1 trolley to the first shield body 16 uses its own pipeline (no need to extend), and other pipelines remain unchanged.

[0071] The operation process of the 2# shield machine in step 2 (after the lifting of the 1# shield machine is completed, the crawler crane is transferred to lift the 2# shield machine down into the well) is as follows: S2.2.1: The second shield body 17 of the 2# shield machine is assembled in the well, and the temporary bridge 15 of the 2# shield machine is connected to the second shield body 17; S2.2.2: After the No. 1 trolley of the No. 1 shield machine enters the hole, the No. 2, No. 3, No. 4, and No. 1 trolley of the No. 2 shield machine are lowered into the well in sequence, and are placed on top of each other on the No. 2 trolley bracket, and the pipelines are connected. The No. 5, No. 6, and the connecting bridge 18 are placed on the ground; the No. 2, No. 3, No. 4, and No. 1 trolley; the No. 5, and No. 6 trolleys); S2.2.3: The extended pipeline is stored on the horse stool platform 13 at the bottom of the No. 2 trolley in the mine. The vertical transportation uses a gantry crane to unload slag and materials; the horizontal transportation uses a winch + flat plate + small earth bucket; S2.2.4: Extension pipeline of 2# shield machine (starting): from trolley 5² to trolley 4, about 85 meters; from trolley 4² to trolley 3², about 6.5 meters; from trolley 4² to trolley 2² (part of the pipeline), about 12.5 meters; from trolley 3² to trolley 2², about 6.5 meters; from trolley 3² to trolley 1² (part of the pipeline), about 12.5 meters; trolley 2² to trolley 1² uses its own pipeline; from trolley 3² to the second shield body 17, about 120 meters; from trolley 2² to the second shield body 17, about 120 meters; from trolley 1² to the second shield body 17, about 50 meters.

[0072] Step 3: If Fig.11 As shown in the figure, after the 1# shield machine completed the excavation of +50 rings, the negative ring of the reaction frame at the 1# shield machine was removed; the 2# shield machine completed the start, and the 1² trolley completed entering the tunnel.

[0073] The operation process of the 1# shield machine in step 3 is as follows: S3.1.1: After the 1# shield machine has excavated +50 rings, it will stop (100 meters), remove the reaction frame, negative ring, and extended pipeline, and lay the wellhead horse stool and track; hoist the 1¹ trolley and temporary bridge 15 out and place them on the ground site to prepare for the trolley assembly.

[0074] Taking the mode conversion position into comprehensive consideration, the trolley reorganization and mode conversion are performed together.

[0075] The operation process of the 2# shield machine in step 3 is as follows: S3.2.1: After the start of the 2# shield machine, the excavation will be carried out at the rate of 1 ring / day. The installation form and quantity of the starting negative ring are the same as those of the 1# shield machine; S3.2.2: After the initial excavation is completed +2 rings, the battery car is marshaled into: 1 head + 1 bucket flatbed car for soil transportation, and the segment transportation is still carried out by flatbed car + winch; S3.2.3: After the initial excavation has completed the +15 ring, the pipelines of the No. 1² trolley are removed, and the No. 1² trolley is split into three parts (left, middle, and right). After entering the cave, they are assembled and connected to the temporary bridge 15, and the pipelines are connected; S3.2.4: The second stage extension pipeline of 2# shield machine (after completing +15 rings): The distance from 2² trolley to 1² trolley is about 105 meters, and the self-contained pipeline (no extension is required) is used from 1² trolley to the second shield body 17, and other pipelines remain unchanged.

[0076] Step 4: Fig.12 As shown, the 1# shield machine's 1¹-5¹ trolleys were reorganized and excavation was resumed; the 2# shield machine completed excavation of +50 rings and removed the negative ring of the reaction frame.

[0077] The operation process of the 1# shield machine in step 4 is as follows: S4.1.1: Reorganize the connecting bridge, trolley No. 1 to trolley No. 5 in sequence, and change the belt conveyor and the excavation port to trolley No. 5 (space needs to be verified). After the pipeline is connected, resume excavation. The battery car formation is: 1 head 20 + 2 soil bucket trucks + 1 segment truck 23; Consider: Is there space on top of trolley No. 5 to install the belt conveyor driving wheel? S4.1.2: Resume excavation.

[0078] The operation process of the 2# shield machine in step 4 is as follows: S4.2.1: Normal excavation.

[0079] Step 5: Fig.13 As shown, the No. 6 and No. 7 trolleys of the No. 1 shield machine have been reorganized and excavation has been resumed; the No. 1²-5² trolleys of the No. 2 shield machine have been reorganized and excavation has been resumed.

[0080] The operation process of the 1# shield machine in step 5 is as follows: S5.1.1: After the excavation is completed at +71 rings and the No. 5¹ trolley passes through the B shaft, the slag is discharged from the B shaft and the pipe segments are lowered; S5.1.2: After the excavation is completed +90 rings, the machine will be stopped, the No. 6¹ and No. 7 trolleys will be reorganized, the slag outlet will be changed, the water pipes and high-voltage cables will be changed, and the excavation will be resumed. After the excavation reaches 100 rings, the machine will be stopped for reorganization according to the actual situation.

[0081] The operation process of the 2# shield machine in step 5 is as follows: S5.2.1: After excavation is completed, the machine will be shut down at +56 ring, reaction frame, negative ring, extended pipeline will be dismantled, wellhead horse stool and track will be laid; trolley No. 1² and temporary bridge 15 will be hoisted out, and trolley reorganization will be prepared; S5.2.2: Reorganize the No. 18 to No. 6 trolleys of the connecting bridge in sequence and connect the pipelines. After completion, the battery car will be organized into: 1 locomotive + 2 earth bucket trucks + 1 segment transport.

[0082] Step 6: Figure 14-15 As shown, the trolley of the 3# shield machine is assembled down the shaft.

[0083] The operation process of the 1# shield machine in step 6 is as follows: S6.1.1: Excavation has completed +100 rings, and the connecting bridge 18 of the 3# shield machine, the 1³ trolley, and the 2³ trolley are all stored in the tunnel.

[0084] The operation process of the 2# shield machine in step 6 is as follows: S6.2.1: Normal excavation.

[0085] The operation process of the 3# shield machine in step 6 is as follows: S6.3.1: Lower trolley No. 2, trolley No. 1 and connecting bridge 18 into the well and store them in the tunnel; S6.3.2: Store trolleys 3³ and 4³ on the underground trolley tray, and place trolleys 5³ and 6³ on the ground.

[0086] Step 7: Fig.16 As shown, the third shield body 23 of the 3# shield machine is lowered into the well for assembly and debugging, and the start-up is completed.

[0087] The operation process of the 1# shield machine in step 7 is as follows: S7.1.1: Shield machine No. 1 discharges slag and materials from the second slag discharge shaft; battery cars are arranged in a row and excavate 2 rings per day.

[0088] The operation process of the 2# shield machine in step 7 is as follows: S7.2.1: The 2# shield machine discharges slag and materials from the 1# working shaft (indicated by M) and normally advances 1 ring / day.

[0089] The operation process of the 3# shield machine in step 7 is as follows: S7.3.1: Remove the wellhead horse stool platform and track, and lower the starting bracket for positioning and reinforcement; S7.3.2: The third shield 23 of the 3# shield machine is lowered for assembly, and the shield tail needs to be welded in sections down to the well. (Whether the open tunnel completed at the start can be dismantled); S7.3.3: Connect the extension pipeline and start commissioning; S7.3.4: Battery car marshaling; S7.3.5: Turnout laying.

Claims

1. A "one well, three machines" shield machine staggered large split initial construction method, characterized by: 1) Reinforcement of the starting end of the shield machine: Before the shield machine enters the tunnel, the ground within a certain range is reinforced and water-proofed; 2) The shield machine starts in the wrong direction: First, the 1# shield machine is hoisted down the well by a crawler crane, and after assembly and commissioning, the 1# shield machine starts to move; then, the crawler crane is transferred to the site to hoist the 2# shield machine down the well, and after assembly and commissioning, the 2# shield machine starts to move; after the 1# shield machine or the 2# shield machine has excavated 100 rings, the 3# shield machine starts to move; 3) Arrangement of ground monitoring points in the departure section: Close to the starting point, each interval of a certain length is recorded as a section, and multiple monitoring points are arranged in each section. Adjacent monitoring points in the same section maintain a certain distance; 4) Placement and positioning of the originating rack: The starting frame adopts a steel structure to bear the gravity of the shield machine and the friction during advancement; 5) Shield assembly and debugging: After the corresponding shield machine is assembled, it can be debugged without load; after the no-load debugging is qualified, load debugging will be carried out; 6) Rear supporting trolley hoisting and pipeline connection: The rear supporting trolleys are placed on the trolley brackets respectively.

2. According to claim 1, a "one well, three machines" shield staggered large-scale initial construction method is characterized by: 2) After the lifting of the No. 1 shield machine, the crawler crane was transferred to lift the No. 2 shield machine into the well; after the No. 1 shield machine completed +100 rings of excavation, it was stopped to reorganize the No. 6 and No. 7 trolleys, modify the slag outlet, change the water pipes and high-voltage cables, and resume excavation. At the same time, the No. 3 shield machine was assembled and debugged.

3. The "one well, three machines" shield machine staggered large-scale initial construction method according to claim 1 is characterized by: 1) In the process, the starting end is reinforced by WSS backward grouting, with a reinforcement range of 7m-9m. The vertical reinforcement range is based on the rock surface line of the boundary section. Only the fully strongly weathered surrounding rock is reinforced, and the medium and slightly weathered rock surfaces are not reinforced. Before starting, water exploration is carried out on the tunnel portal to check the reinforcement effect of the starting end. If the water exploration effect is not good, horizontal grouting or ground rotary spraying and multiple spraying reinforcement are adopted.

4. The "one well, three machines" shield machine staggered large-scale initial construction method according to claim 1 is characterized by: 3) In the starting section, ground monitoring points are arranged, starting from the starting end, with a section every 30m. 9 monitoring points are arranged in each section. The aperture of each monitoring point is 150mm, and the monitoring points in the same section are 5m apart. The measuring points are covered with protective covers, with an aperture of not less than 150mm and a hole depth of 1000mm. The marking points are made of φ18 threaded steel bars with a length greater than 80cm. After the measuring point holes are placed, concrete is poured at the bottom and coarse sand is filled in the middle to ensure the stability of the measuring points.

5. The "one well, three machines" shield machine staggered large-scale initial construction method according to claim 1 is characterized by: 4), before installing the starting frame, the surveying team first fixes two horizontal control points on the bottom plate of the starting shaft, and accurately locates the left and right positions of the starting frame according to the measurement and layout; then determines the distance between the trolley bracket and the steel ring of the steel tunnel door; then, the starting frame is installed at the predetermined position as required, and is reviewed by the surveying team. After completing the positioning, the starting frame is fixed.

6. The "one well, three machines" shield machine staggered large-scale initial construction method according to claim 1 is characterized by: 6) The rear supporting trolley is hoisted and connected with pipelines, including: 6.1) The temporary bridge of the 1# shield machine is connected to the first shield of the 1# shield machine, and the 1# trolley, 2# trolley, 3# trolley and 4# trolley of the 1# shield machine are placed underground; 6.2) Remove the foam and grease system on the original bridge and assemble them on the temporary bridge; 6.3) The frame of the No. 4 trolley and the connecting bridge frame are placed on the ground. The No. 6 and No. 7 trolleys will not enter the field for the time being and will enter the field when the marshaling is completed. 6.4) The extended pipeline is stored on the platform at the bottom of the No. 2 trolley in the mine. The vertical transportation uses a gantry crane to unload slag and materials; the horizontal transportation uses a winch + flat plate + small earth bucket; 6.5) The first phase extension pipeline of No. 1 shield machine; 6.6) After the lifting of the 1# shield machine is completed, the crawler crane will be transferred to the site to lift the 2# shield machine down into the well; 6.7) The shield of the No. 2 shield machine is assembled in the pit, and the temporary bridge is connected to the second shield of the No. 2 shield machine; 6.8) After the No. 1 trolley of the No. 1 shield machine enters the hole, the No. 2, No. 3, No. 4, and No. 1 trolleys of the No. 2 shield machine are lowered into the well in sequence, and are placed on top of the No. 2 shield machine trolley bracket, and the pipelines are connected. The No. 5 trolley, No. 6 trolley, and the connecting bridge are placed on the ground; 6.9) The extended pipeline is stored on the bottom platform of No. 2² trolley in the mine. The vertical transportation uses gantry crane to unload slag and materials; the horizontal transportation uses winch + flat plate + small earth bucket; 6.10) The first phase extension pipeline of No. 2 shield machine; 6.11) The No. 3 shield machine connecting bridge, No. 1³ trolley and No. 2³ trolley are stored in the tunnel; 6.12) Store the No. 3³ and No. 4 trolleys underground; when the No. 3 shield machine is being assembled and debugged, the shield and trolleys of the No. 1 shield machine have all entered the hole. At this time, some trolleys of the No. 3 shield machine are stacked on the trolley bracket of the No. 1 shield machine, and the No. 5 and No. 6 trolleys are placed on the ground; 6.13) Remove the wellhead horse stool and track, and position and reinforce the lower starting bracket; 6.14) The lower shield body is assembled and the shield tail needs to be welded in pieces down to the well; 6.14) Connect the extension pipeline and start debugging; 6.15) Electric car marshaling and turnout laying.

7. The "one well, three machines" shield machine staggered large-scale initial construction method according to claim 1 is characterized by: The trolley bracket comprises at least one layer of bracket units, the bracket unit comprises two rows of left and right vertical columns (2), the two rows of vertical columns (2) are respectively connected to form a whole through a first longitudinal support (5) and a second longitudinal support (6), and the top ends of the two rows of vertical columns (2) are connected through multiple groups of transverse supports and longitudinal supports to form a support platform; the support platform comprises a second transverse support (9), and the second transverse support (9) is connected with the second longitudinal support (6) to form a frame, the frame is reinforced by a transversely arranged first transverse support (8), a third transverse support (10) and a longitudinally arranged third longitudinal support (7), and a support plate is fixed to the upper end surface of the frame.

8. The "one well, three machines" shield machine staggered large-scale initial construction method according to claim 7 is characterized by: Passages (11) are fixed on the left and right sides of the support platform, and guardrails (12) are fixed on both sides of the upper ends of the support platform and the passage (11).

9. The "one well, three machines" shield machine staggered large-scale initial construction method according to claim 7 is characterized by: The vertical columns (2) of each layer of bracket units and the first longitudinal support (5), the second longitudinal support (6), the vertical columns (2) and the channel (11), the channel (11) and the support platform, and the adjacent upper and lower bracket units are all installed and fixed by bolt assemblies equipped with elastic media, flat media and nuts; the number of bracket units is 1-5 layers, and the bottom ends of the vertical columns (2) and the second longitudinal support (6) of each layer of bracket units are provided with installation holes; the bracket units at the bottom layer are reinforced by pre-buried ground anchor bolts.

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