Water-rich sand layer tunnel face pretreatment steel sleeve shield tunneling machine wall grinding receiving construction method

Abstract

The invention discloses a water-rich sand layer tunnel face pretreatment steel sleeve shield tunneling machine wall grinding receiving construction method. The method comprises the following steps that S1, shield tunneling machine tool configuration optimization is conducted; s2, a shield receiving steel sleeve is assembled; s3, diaphragm wall joint profile steel detection; s4, grouting reinforcement is conducted on the tunnel face; s5, the profile steel is chiseled away; s6, steel sleeve filling; s7, wall grinding tunneling control of the shield tunneling machine; and S8, the grouting sealing ring and the steel sleeve are dismantled. Through cooperation of the hobbing cutter and the tearing cutter, the construction requirement that a shield tunneling machine cutter cuts underground diaphragm wall steel bars and concrete is met, underground diaphragm wall joint profile steel is chiseled away in the early stage, shield receiving is conducted through the steel sleeve, and the torque is too large in the process that a textile shield tunneling machine grinds an underground diaphragm wall; according to the principle of low rotating speed, low speed and small thrust, tunneling parameters of the shield tunneling machine are reasonably formulated, grouting and ring sealing operation at the back of the duct piece wall of the shield receiving end are well done, the steel sleeve is dismantled, and the safety of shield receiving in the high-risk geological environment of the water-rich sand layer is smoothly guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of shield construction, and specifically relates to a construction method for receiving a shield machine by grinding a wall with a pre-treated working face steel sleeve in a water-rich sand layer. Background Art

[0002] With the rapid development of urban construction and the surging demand for urban underground space development and rail transit construction, the shield method has been widely used due to its advantages such as high construction efficiency and small environmental impact. At the same time, there will also be a working condition where the construction of the previous station is completed and the reserved line interface of the planned line is well prepared.

[0003] When using the conventional shield receiving method in a water-rich sand layer, the construction risk is high, and there are construction risks such as water gushing, sand gushing, and collapse of the end soil body. In order to ensure the safety of shield receiving construction, the steel sleeve method is generally used for shield receiving construction. However, the diaphragm wall adopts a reinforced concrete structure, and the shield machine is equipped with a soft soil cutter head, which cannot safely cut the joint steel of the diaphragm wall and the reinforcement of the large-diameter diaphragm wall, posing a safety hazard.

[0004] Therefore, we propose a construction method for receiving a shield machine by grinding a wall with a pre-treated working face steel sleeve in a water-rich sand layer to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to solve the above deficiencies and provide a construction method for receiving a shield machine by grinding a wall with a pre-treated working face steel sleeve in a water-rich sand layer.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: A construction method for receiving a shield machine by grinding a wall with a pre-treated working face steel sleeve in a water-rich sand layer, including the following steps:

[0007] S1. Optimization of shield machine tool configuration: Tearing knives are evenly distributed on the cutter head of the shield machine, and multiple evenly distributed hob cutters are added to the cutter head of the shield machine;

[0008] S2. Assembly of shield receiving steel sleeve: The components of the shield receiving steel sleeve include a transition steel ring, a steel sleeve body, an end cover, a base, and a reaction frame. Assemble and reinforce the shield receiving steel sleeve;

[0009] S3. Detection of joint steel of diaphragm wall: Initially locate the joint position through the design drawings and construction records, and then find the position of the joint steel by the electromagnetic induction method;

[0010] S4. Grouting reinforcement of the working face: Adopt a plum blossom arrangement of 3 rows of grouting holes around the chiseling of the joint steel. The spacing of the grouting holes is 0.8 m, and the horizontal grouting reinforcement depth is 2.5 m from the soil-facing side of the diaphragm wall;

[0011] S5. Section steel removal: Conduct exploratory hole inspection on the reinforcement of the diaphragm wall at the heading face to confirm the reinforcement condition. After ensuring that there is no water seepage or sand leakage in the exploratory holes, remove the section steel at the joint in segments.

[0012] S6. Steel sleeve filling: After the removal of the section steel at the joint is completed, backfill the steel sleeve. Connect the ground and the steel sleeve through a muck filling and conveying pipe. Set a funnel on the ground and directly convey the muck from the funnel into the steel sleeve.

[0013] S7. Shield tunneling control against the wall: The shield tunneling parameters follow the principle of "low rotation speed, low speed, and small thrust". During tunneling, strictly control the muck output per ring, and match the propulsion speed with the muck output to avoid ground heave and subsidence caused by overexcavation or under-excavation.

[0014] S8. Grouting for sealing the ring and removal of the steel sleeve: When the shield machine is 20 - 30 rings away from the heading face, conduct secondary grouting for sealing the ring behind the segments. Check for no water seepage through the segment exploratory holes and the screw conveyor. The shield machine continues to push forward until the shield tail is separated from the formed segments. Weld an arc-shaped steel plate between the last segment and the extended steel ring at the portal. After welding is completed, remove the steel sleeve.

[0015] Furthermore, in step S7, the shield tunneling parameters are adjusted according to the section. During the tunneling in the reinforced area, the propulsion speed is 20 - 30 mm / min, the cutterhead rotation speed is 1.0 - 1.2 r / min, and the thrust is 1000 - 1300 T.

[0016] During the process of cutting and grinding the diaphragm wall, the propulsion speed is 2 - 5 mm / min, the cutterhead rotation speed is 0.8 - 1.0 r / min, and the thrust is 800 - 1000 T.

[0017] During the tunneling in the steel sleeve, the propulsion speed is 10 - 20 mm / min, the cutterhead rotation speed is 0.6 - 0.8 r / min, and the thrust is 600 - 800 T.

[0018] Furthermore, in step S1, the quantity ratio of the hob to the ripping tool is greater than 1:2.

[0019] Furthermore, in step S3, the specific electromagnetic induction method used is as follows: Use an electromagnetic induction instrument to conduct grid scanning along the center of the design drawing of the section steel at the diaphragm wall joint at an interval of 0.5 m, and judge the position of the metal section steel through the abnormal magnetic field signal, mark the suspected points, and verify them by combining multi-directional scanning.

[0020] Furthermore, after step S3, verify the position of the section steel at the diaphragm wall joint through the drilling verification method. Drill small holes (hole diameter 50 mm) at the suspected points of the metal section steel to confirm the accurate position of the joint section steel.

[0021] Further, in the step S4, the slurry used for grouting is injected with single-fluid cement slurry and double-fluid cement + water glass slurry. The single-fluid slurry is used to diffuse and consolidate the grouting reinforcement range, and the double-fluid slurry is used to reinforce and consolidate the periphery of the chiseled joint steel section.

[0022] Further, the water-cement ratio of the single-fluid slurry is: water:cement = 1:1, the volume ratio of the cement slurry to the water glass solution in the double-fluid slurry is 1:1, and the volume ratio of the water glass solution is: water:water glass = 3:1.

[0023] Further, after the step S5, it is necessary to weld the steel mesh in time and use double-fast cement for plugging to ensure that there is no water seepage or sand gushing.

[0024] Further, after the step S6, check the sealing performance of the steel sleeve after filling. Remove the muck filling and conveying pipe, seal the top of the steel sleeve, and check the sealing performance of the steel sleeve by injecting water and pressurizing. Weld and plug the leakage points of the steel sleeve in time to confirm that the sealing performance check of the steel sleeve meets the requirements for shield machine reception.

[0025] Further, in the step S8, the secondary grouting slurry used for the secondary grouting seal ring operation is a double-fluid slurry composed of a cement slurry and a water glass solution with a volume ratio of 1:1. The water-cement ratio in the cement slurry is 1:1, and the volume ratio of water to water glass in the water glass solution is 1:1.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention optimizes the cutter configuration of the shield machine. Through the cooperation of the hob and the ripping cutter, it meets the construction requirements of the shield machine for cutting the diaphragm wall steel bars and concrete. And by removing the joint steel section of the diaphragm wall in advance and receiving the shield through the steel sleeve, it prevents the torque from being too large during the process of the shield machine grinding the diaphragm wall. The tunneling parameters of the shield machine are reasonably formulated according to the principle of "low rotation speed, low speed, and small thrust", and the post-grouting and seal ring operation of the segment wall behind the shield receiving end are well done, and the steel sleeve is removed, which successfully ensures the safety of shield machine reception in the high-risk geological environment of water-rich sandy stratum. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0029] Figure 1 It is a schematic flow chart of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The following will describe the technical solutions in the embodiments of the present invention in a clear and complete manner in combination with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0031] Please refer to Figure 1 , the construction method for the grinding wall reception of the steel sleeve shield machine for the pretreatment of the water-rich sand layer face of the present invention includes the following steps:

[0032] S1. Optimization of the cutter configuration of the shield machine. Tearing cutters are evenly distributed on the cutter head of the shield machine, and multiple evenly distributed hob cutters are added to the cutter head of the shield machine.

[0033] S2. Assembly of the shield receiving steel sleeve. The components of the shield receiving steel sleeve include a transition steel ring, a steel sleeve main body, an end cover, a base, and a reaction frame. Assemble and reinforce the shield receiving steel sleeve.

[0034] S3. Detection of the section steel at the diaphragm wall joint. Initially locate the joint position through the design drawings and construction records, and then find the position of the section steel through the electromagnetic induction method.

[0035] S4. Grouting reinforcement of the face. Adopt a plum blossom layout with 3 rows of grouting holes around the chiseling of the section steel. The spacing of the grouting holes is 0.8 m, and the horizontal grouting reinforcement depth is 2.5 m on the soil-facing side of the diaphragm wall.

[0036] S5. Chiseling of the section steel. Make inspection holes for the reinforcement situation of the diaphragm wall at the face to confirm the reinforcement situation. After confirming that there is no water seepage or sand leakage in the inspection holes, chisel the section steel in segments, and it is necessary to weld the steel mesh in time and use double-fast cement for plugging to ensure no water seepage or sand gushing.

[0037] S6. Filling of the steel sleeve. After the chiseling of the section steel is completed, backfill the steel sleeve. Connect the ground and the steel sleeve through the muck filling and conveying pipe. A funnel is set on the ground, and the muck is directly conveyed from the funnel into the steel sleeve.

[0038] S7. Control of the grinding wall tunneling of the shield machine. The shield tunneling parameters follow the principle of "low rotation speed, low speed, and small thrust". During tunneling, strictly control the muck output of each ring, and make the propulsion speed match the muck output to avoid ground heave and subsidence caused by overexcavation or under-excavation.

[0039] S8. Grouting for sealing the ring and removing the steel sleeve. When the shield machine is 20 - 30 rings away from the working face, secondary grouting for sealing the ring is carried out behind the segment. The secondary grouting slurry used for the secondary grouting for sealing the ring is a double - liquid slurry composed of a cement slurry and a water glass solution with a volume ratio of 1:1. The water - cement ratio in the cement slurry is 1:1, and the volume ratio of water to water glass in the water glass solution is 1:1. After checking through the segment inspection holes and the screw conveyor and finding no water leakage, the shield machine continues to push forward. When the tail of the shield machine is separated from the formed segments, an arc - shaped steel plate is welded between the last segment and the extended steel ring of the portal. After the welding is completed, the steel sleeve is removed.

[0040] In one embodiment, in the S7 step, the shield tunneling parameters are adjusted according to the section. During the tunneling in the reinforcement area, the propulsion speed is 20 - 30 mm / min, the cutterhead rotation speed is 1.0 - 1.2 r / min, and the thrust is 1000 - 1300 T.

[0041] During the cutting of the diaphragm wall, the propulsion speed is 2 - 5 mm / min, the cutterhead rotation speed is 0.8 - 1.0 r / min, and the thrust is 800 - 1000 T.

[0042] During the tunneling in the steel sleeve, the propulsion speed is 10 - 20 mm / min, the cutterhead rotation speed is 0.6 - 0.8 r / min, and the thrust is 600 - 800 T.

[0043] In one embodiment, in the S1 step, the quantity ratio of the hob to the ripping cutter is greater than 1:2. With such a design, by setting the hob, during the cutting of the reinforced concrete of the diaphragm wall, the torque of the shield machine can be reduced, preventing the shield machine from experiencing sudden torsion. And when the quantity ratio of the hob to the ripping cutter is greater than 1:2, the tunneling torque of the shield machine can be effectively reduced.

[0044] In one embodiment, in the S3 step, the specific electromagnetic induction method used is as follows: Use an electromagnetic induction instrument to conduct grid scanning at an interval of 0.5 m along the center of the design drawing of the joint steel section of the diaphragm wall, and judge the position of the metal steel section through the magnetic field anomaly signal, mark the suspected points, and verify them by combining multi - direction scanning. With such a design, the electromagnetic induction method can achieve the rapid positioning of the shallow - layer (0 - 3 m) steel section joints, thereby further exploring the position of the joint steel section, and the risk of construction in the drilling area of the water - rich sand layer is relatively low.

[0045] In one embodiment, after the S3 step, the position of the joint steel section of the diaphragm wall is verified by the drilling verification method. Small holes (hole diameter 50 mm) are drilled at the suspected points of the metal steel section to confirm the accurate position of the joint steel section. With such a design, by drilling small holes at the suspected points of the metal steel section, the accurate position of the joint steel section can be determined, providing accurate information for subsequent grouting reinforcement and steel section chiseling, and facilitating the progress of subsequent processes.

[0046] In one embodiment, in the step S4, the slurry used for grouting is injected by using single-component cement slurry and cement + water glass two-component slurry. The single-component slurry is used to diffuse and consolidate the grouting reinforcement range, and the two-component slurry is used to reinforce and consolidate the periphery of the cut joint steel section. The water-cement ratio of the single-component slurry is: water:cement = 1:1. The volume ratio of the cement slurry to the water glass solution in the two-component slurry is 1:1, and the volume ratio of the water glass solution is: water:water glass = 3:1. With such a design, by setting the cooperation of the single-component slurry and the two-component slurry, the grouting reinforcement range can be diffused and consolidated, and the periphery of the cut joint steel section can be reinforced and consolidated, so as to meet the safety requirements for cutting the joint steel section and ensure the normal progress of the shield receiving operation by using the steel sleeve method in the water-rich sand layer.

[0047] In one embodiment, after the step S6, the sealing performance of the steel sleeve after filling is checked. The muck filling and conveying pipe is removed, and the top of the steel sleeve is closed. The sealing performance of the steel sleeve is checked by means of water injection and pressurization, and the leakage points of the steel sleeve are welded and blocked in time when found. With such a design, by checking the sealing performance of the steel sleeve, it can be ensured that the sealing performance of the steel sleeve meets the requirements for shield receiving, which is convenient for the shield receiving operation.

[0048] Preferably, in the step S8, before the shield tail of the shield machine exits the formed segment, the tensioning device for 10 segments at the receiving end needs to be installed to ensure that after the segments at the receiving end lose the jacking force, the segments are effectively tensioned, avoiding the risk of leakage between the segment ring joints.

[0049] After the arc-shaped steel plate at the shield receiving end portal is welded, the arc-shaped steel plate is quickly installed and a grouting ball valve is reserved. If there is a situation of water leakage, grouting plugging operation is carried out in time through the grouting ball valve.

[0050] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A construction method for receiving a steel sleeve shield machine wall by pre-treating the tunnel face in a water-rich sand layer, characterized in that: The steps include: S1. The shield machine cutter configuration is optimized. The shield machine cutter head is evenly distributed with tearing knives, and multiple evenly distributed roller cutters are added to the shield machine cutter head; S2. Assemble the shield receiving steel sleeve. The components of the shield receiving steel sleeve include a transition steel ring, a steel sleeve body, an end cover, a base and a reaction frame. Assemble and reinforce the shield receiving steel sleeve; S3. Detection of the joint steel of the ground-connected wall: preliminarily locate the joint position through the design drawings and construction records, and then find the joint steel position through electromagnetic induction method; S4, face grouting reinforcement, three rows of grouting holes are arranged in a plum blossom shape around the chiseled joint steel, the spacing between the grouting holes is 0.8m, and the horizontal grouting reinforcement depth is 2.5m from the soil surface of the ground-connected wall; S5. Remove the steel sections and drill holes to check the reinforcement of the face diaphragm wall. Confirm that there is no water seepage or sand leakage in the holes, and then remove the joint steel sections in sections. S6, steel sleeve filling: after the joint steel is chiseled out, the steel sleeve is backfilled. The ground and the steel sleeve are connected by a slag filling conveying pipe. A funnel is set on the ground to convey the slag directly from the funnel into the steel sleeve. S7. Shield machine wall grinding excavation control. The shield excavation parameters follow the principle of "low rotation speed, low speed, and small thrust". During excavation, the excavation volume of each ring is strictly controlled, and the advancement speed and excavation volume are matched to avoid ground heave and sinking caused by over-excavation or under-excavation; S8. Remove the grouting sealing ring and steel sleeve. When the shield machine is 20-30 rings away from the tunnel face, carry out secondary grouting sealing operation behind the segment wall. Check the segment exploration holes and screw conveyor to see if there is any water leakage. The shield machine continues to push. The shield tail of the shield machine is separated from the formed segment. An arc steel plate is welded between the last ring of the segment and the portal extension steel ring. After welding, remove the steel sleeve.

2. The water-rich sand layer tunnel face pretreatment steel sleeve shield machine grinding wall receiving construction method according to claim 1 is characterized in that: In the step S7, the shield tunneling parameters are adjusted according to the sections. During the tunneling reinforcement area, the advancing speed is 20-30 mm / min, the cutter head speed is 1.0-1.2 r / min, and the thrust is 1000-1300 T. During the process of cutting and grinding the ground connection wall, the advancement speed is 2-5mm / min, the cutter head speed is 0.8-1.0r / min, and the thrust is 800-1000T; During the steel sleeve excavation process, the advancement speed is 10-20mm / min, the cutter head speed is 0.6-0.8r / min, and the thrust is 600-800T.

3. The water-rich sand layer tunnel face pretreatment steel sleeve shield machine grinding wall receiving construction method according to claim 1 is characterized in that: In the step S1, the ratio of the number of the rolling cutters to the number of the tearing cutters is greater than 1:

2.

4. The water-rich sand layer tunnel face pretreatment steel sleeve shield machine grinding wall receiving construction method according to claim 1 is characterized in that: In the S3 step, the electromagnetic induction method used is specifically: using an electromagnetic induction instrument to perform grid scanning at intervals of 0.5m along the center of the ground-wall joint steel design drawing, and determine the position of the metal steel through abnormal magnetic field signals, mark suspected points, and verify them in combination with multi-directional scanning.

5. The water-rich sand layer tunnel face pretreatment steel sleeve shield machine grinding wall receiving construction method according to claim 4 is characterized in that: After the step S3, the position of the ground-connected wall joint steel is verified by drilling verification, and small holes are drilled at suspected points of the metal steel to confirm the accurate position of the joint steel.

6. The water-rich sand layer tunnel face pretreatment steel sleeve shield machine grinding wall receiving construction method according to claim 1 is characterized in that: In the step S4, the slurry used for grouting is injected using cement single-liquid slurry and cement + water glass double-liquid slurry. The single-liquid slurry is used to diffuse and consolidate the grouting reinforcement range, and the double-liquid slurry is used to reinforce and consolidate the surrounding area of ​​the chiseled joint steel.

7. The water-rich sand layer tunnel face pretreatment steel sleeve shield machine grinding wall receiving construction method according to claim 6 is characterized in that: The water-cement ratio of the single-liquid slurry is: water: cement = 1:1, the volume ratio of cement slurry to water glass solution in the double-liquid slurry is 1:1, and the volume ratio of the water glass solution is: water: water glass = 3:

1.

8. The water-rich sand layer tunnel face pretreatment steel sleeve shield machine grinding wall receiving construction method according to claim 1 is characterized in that: After the step S5, it is necessary to weld the steel mesh in time and use double-fast cement to seal it to ensure that there is no water seepage or sand gushing.

9. The water-rich sand layer tunnel face pretreatment steel sleeve shield machine grinding wall receiving construction method according to claim 1, characterized in that: After the S6 step, the sealing of the filled steel sleeve is checked, the slag filling conveying pipe is removed, the top of the steel sleeve is sealed, and the sealing of the steel sleeve is checked by water injection and pressurization. If any leakage points of the steel sleeve are found, they are welded and sealed in time to confirm that the sealing inspection of the steel sleeve meets the shield acceptance requirements.

10. The water-rich sand layer tunnel face pretreatment steel sleeve shield machine grinding wall receiving construction method according to claim 1, characterized in that: In the step S8, the secondary grouting slurry used in the secondary grouting ring sealing operation is a double liquid slurry formed by mixing cement slurry and water glass solution in a volume ratio of 1:1, the water-cement ratio in the cement slurry is 1:1, and the volume ratio of water to water glass in the water glass solution is 1:1.

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