Integral reinforcing method of steel sleeve for shield receiving

Abstract

The invention discloses an integral reinforcing method of a steel sleeve for shield receiving, and relates to the technical field of shield receiving, the integral reinforcing method of the steel sleeve for shield receiving comprises the following steps: installing the steel sleeve for shield receiving; a plurality of steel pipe supports are arranged between a steel sleeve rear end cover of the shield receiving steel sleeve and a receiving well bottom plate; leakage of weld joints and joints is checked; the shield receiving steel sleeve is filled with muck excavated by a shield; enabling the shield to enter a receiving section; and after the shield tail of the shield is separated from the tunnel portal, double-liquid slurry is injected through the pipe piece grouting holes, and overall reinforcement of the steel sleeve for shield receiving is completed. The steel sleeve for shield receiving is formed through flange sectional type connection, shield thrust is dispersed through counter-force supporting, sealing detection and muck filling are combined, the stability of the steel sleeve in a high-pressure sand layer is ensured, and the risk of water gushing and sand gushing is avoided. And the higher bearing and stability requirements in the shield receiving process are met.

Description

Technical Field

[0001] The invention relates to the technical field of shield receiving technology, in particular to an integral reinforcement method for a steel sleeve for shield receiving. Background Art

[0002] Shield construction technology is widely used as a key tool in tunnel construction. When the shield machine reaches the receiving stage, the soil surrounding the tunnel opening must be reinforced with a pre-buried steel sleeve to ensure the shield machine's safe and stable entry into the receiving shaft. Current steel sleeve reinforcement methods typically use simple reinforced concrete structures. However, as shield machines grow in size and geological conditions become more complex, this simple structure struggles to meet the higher load-bearing and stability requirements. Summary of the Invention

[0003] The main purpose of the present invention is to propose a method for integrally reinforcing a steel sleeve for receiving a shield, aiming to meet higher load-bearing and stability requirements during the shield receiving process.

[0004] To achieve the above-mentioned purpose, the present invention proposes a method for integrally reinforcing a shield receiving steel sleeve, comprising:

[0005] Install the shield receiving steel sleeve;

[0006] A plurality of steel pipe supports are arranged between the rear end cover of the steel sleeve of the shield receiving steel sleeve and the bottom plate of the receiving well, and the plurality of steel pipe supports are fixed to the bottom plate by planting steel bars;

[0007] Fill the shield receiving steel sleeve with water to 1m above the joint, let it stand for 1 hour, then pressurize it to 1 bar, and check for leakage in the welds and joints;

[0008] Filling the shield receiving steel sleeve with the slag excavated by the shield;

[0009] Allowing the shield machine to enter the receiving section;

[0010] After the tail of the shield machine is separated from the tunnel portal, double-liquid slurry is injected through the grouting holes of the segments to seal the tunnel portal, thereby completing the overall reinforcement of the shield machine receiving steel sleeve.

[0011] In one embodiment, the step of installing the shield receiving steel sleeve includes:

[0012] Install the sleeve;

[0013] An upper groove is formed on the outer side of the sleeve, and a lower groove is formed on the inner side of the sleeve to form a transition ring groove;

[0014] The transition ring is installed by utilizing the transition ring groove, and the gap between the ring plate of the tunnel door and the transition ring is filled and fully welded;

[0015] The rear end cover of the steel sleeve is installed on the sleeve to form the steel sleeve for receiving the shield.

[0016] In one embodiment, the steps of providing a plurality of steel pipe supports between the rear end cover of the steel sleeve of the shield receiving steel sleeve and the bottom plate of the receiving shaft, and fixing the plurality of steel pipe supports to the bottom plate by planting reinforcement bars include:

[0017] A plurality of steel pipe supports are provided between the rear end cover of the steel sleeve for receiving the shield and the bottom plate of the receiving well;

[0018] Drilling a plurality of holes corresponding to the plurality of steel pipe supports at preset positions on the bottom plate of the receiving well;

[0019] Installing the rebar-embedded steel plate using the drilled holes;

[0020] The ends of the plurality of steel pipe supports are fully welded to the embedded steel plates using triangular ribs to form reaction supports.

[0021] In one embodiment, water is injected into the shield receiving steel sleeve to 1 m above the joint, and after standing for 1 hour, the pressure is increased to 1 bar. The steps of checking the welds and joints for leakage include:

[0022] Pump water into the sleeve through the dewatering well until the water level reaches 1m above the middle joint of the sleeve, and observe leakage after standing for 1 hour;

[0023] Use an air compressor to pressurize to 1 bar and maintain the pressure for 30 minutes to detect leakage at the flange, weld and the reaction support connection. Install a dial indicator and a strain gauge on the surface of the entire shield receiving steel sleeve to detect the displacement of the entire shield receiving steel sleeve during the pressurization process.

[0024] In one embodiment, before the step of filling the shield receiving steel sleeve with the slag excavated by the shield, the method for integrally reinforcing the shield receiving steel sleeve further comprises:

[0025] Adding foaming agent and bentonite to the slag excavated by the shield to obtain improved slag;

[0026] The improved slag is injected into the shield receiving steel sleeve under pressure.

[0027] In one embodiment, after the shield tail of the shield machine is separated from the tunnel portal, the steps of injecting double-liquid slurry through the segment grouting holes to seal the tunnel portal and completing the overall reinforcement of the shield receiving steel sleeve include:

[0028] The double-liquid slurry is prepared by using cement slurry and water glass slurry;

[0029] The double-liquid slurry is injected three times from bottom to top through the segment grouting holes to seal the tunnel door and complete the overall reinforcement of the shield receiving steel sleeve.

[0030] In one embodiment, the steps of providing a plurality of steel pipe supports between the rear end cover of the steel sleeve of the shield receiving steel sleeve and the bottom plate of the receiving shaft, and fixing the plurality of steel pipe supports to the bottom plate by planting reinforcement bars include:

[0031] A plurality of steel pipe supports are arranged between the rear end cover of the steel sleeve of the shield receiving steel sleeve and the bottom plate of the receiving well, and the plurality of steel pipe supports are fixed to the bottom plate by planting steel bars;

[0032] Multiple steel lateral supports are provided on both sides of the shield receiving steel sleeve, and the installation height of the multiple steel lateral supports is 300mm from the bottom of the cylinder bracket;

[0033] The ends of the multiple horizontal supports of the steel sections are welded with 20mm thick steel plates and tightened against the side walls and longitudinal beams of the foundation pit.

[0034] In one embodiment, the step of installing the shield receiving steel sleeve includes:

[0035] Carrying out triaxial mixing pile construction on the receiving shaft of the shield;

[0036] Carry out jet grouting construction at the joints between mixing piles and ground-connected walls to form reinforced soil;

[0037] Performing unconfined compressive strength testing on the reinforced soil;

[0038] Install the shield receiving steel sleeve.

[0039] In one embodiment, after the step of installing the shield receiving steel sleeve, the shield receiving steel sleeve integral reinforcement method further comprises:

[0040] A grouting pipe is reserved outside the embedded ring of the tunnel portal.

[0041] In one embodiment, after the tail of the shield machine is separated from the tunnel portal, dual-liquid slurry is injected through the segment grouting holes to seal the tunnel portal. After the step of integrally reinforcing the shield receiving steel sleeve is completed, the method for integrally reinforcing the shield receiving steel sleeve further includes:

[0042] If the shield receiving steel sleeve is deformed, reinforcing ribs are welded at the deformed flange.

[0043] The technical solution of this invention defines the steel sleeve structure, support system, and construction process. It forms a shield receiving steel sleeve through segmented flange connections, utilizes reaction force support to disperse the shield thrust, and combines seal testing and slag filling to ensure the stability of the steel sleeve in the high-pressure sand layer, avoiding the risk of water and sand gushing. This meets the higher load-bearing and stability requirements during the shield receiving process. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0045] Figure 1 This is a flow chart of an embodiment of a method for integrally reinforcing a shield receiving steel sleeve provided by the present invention.

[0046] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0048] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0049] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0050] Shield construction technology is widely used as a key tool in tunnel construction. When the shield machine reaches the receiving stage, the soil surrounding the tunnel opening must be reinforced with a pre-buried steel sleeve to ensure the shield machine's safe and stable entry into the receiving shaft. Current steel sleeve reinforcement methods typically use simple reinforced concrete structures. However, as shield machines grow in size and geological conditions become more complex, this simple structure struggles to meet the higher load-bearing and stability requirements.

[0051] In order to solve this technical problem, the present invention proposes a method for integrally reinforcing a shield receiving steel sleeve.

[0052] See also Figure 1 In one embodiment of the present invention, the method for integrally reinforcing the shield receiving steel sleeve includes:

[0053] Step S10, installing the shield receiving steel sleeve;

[0054] Step S20, arranging a plurality of steel pipe supports between the rear end cover of the steel sleeve for receiving the shield and the bottom plate of the receiving shaft, and fixing the plurality of steel pipe supports to the bottom plate by planting steel bars;

[0055] Step S30: inject water into the shield receiving steel sleeve to 1 m above the joint, let it stand for 1 hour, then pressurize it to 1 bar, and check for leakage in the welds and joints;

[0056] Step S40, filling the shield receiving steel sleeve with the slag excavated by the shield;

[0057] Step S50, making the shield machine enter the receiving section;

[0058] In step S60, after the tail of the shield machine is separated from the tunnel portal, double-liquid slurry is injected through the grouting holes of the segments to seal the tunnel portal, thereby completing the overall reinforcement of the shield machine receiving steel sleeve.

[0059] It should be noted that the shield reception in this application refers to the reception of the head of the shield machine.

[0060] Specifically, (1) Steel sleeve structure installation: The steel sleeve consists of a transition ring (1 section), a cylinder (4 sections), and an end cover (1 section), with a total length of 13500 mm, an inner diameter of 9150 mm, and an outer diameter of 9510 mm. The cylinder is welded with 20 mm thick steel plates, and longitudinal and annular ribs (20 mm thick, 150 mm high, and 550*600 mm apart) are set on the periphery. The adjacent two sections of the cylinder are connected by flanges made of 40 mm thick steel plates. The cylinders are connected by M30 8.8 grade bolts, and 8 mm thick rubber pads are embedded between the flanges.

[0061] (2) Reaction support setting: 9 Φ609*16mm steel pipe supports are set between the rear end cover of the steel sleeve and the bottom plate of the receiving well. The supports and the bottom plate are fixed by planting steel bars (Φ38 round steel, depth 280mm, 10 pieces / group), and the supports are welded to 20*700*800mmQ235B steel plates;

[0062] (3) Leakage test: Pour water into the steel sleeve to 1m above the joint, let it stand for 1 hour, then pressurize it to 1 bar, and check for leakage in the welds and joints;

[0063] (4) Filling: Use shield excavated soil to fill the steel sleeve, and the soil is injected through the ground funnel and conveying pipeline. The filling volume is ≥830m 3 ;

[0064] (5) Shield tunneling control: After the shield enters the receiving section, the tunneling speed is gradually reduced from 50-70 mm / min to 2-5 mm / min, and the soil bin pressure is reduced from 2.0-2.5 bar to 0.6-0.8 bar;

[0065] (6) Tunnel porthole sealing: After the shield tail is separated from the tunnel porthole, cement-water glass double liquid slurry (cement slurry: water glass slurry = 1:1, grouting pressure ≤ 5 bar) is injected through the grouting hole of the pipe segment.

[0066] The technical solution provided by this invention defines the steel sleeve structure, support system, and construction process. A segmented flange connection forms the shield receiving steel sleeve, utilizing reaction support to disperse the shield thrust. Combined with seal testing and soil filling, this ensures the steel sleeve's stability in the high-pressure sand layer, minimizing the risk of water and sand gushing. This approach meets the higher load-bearing and stability requirements during the shield receiving process.

[0067] In an embodiment of the present invention, the step of installing the shield receiving steel sleeve includes:

[0068] Step S11, installing the sleeve;

[0069] Step S12, opening an upper half groove on the outer side of the sleeve and opening a lower half groove on the inner side of the sleeve to form a transition ring groove;

[0070] Step S13, installing the transition ring using the transition ring groove, and filling and fully welding the gap between the ring plate of the tunnel door and the transition ring;

[0071] Step S14, installing the rear end cover of the steel sleeve on the sleeve to form the shield receiving steel sleeve.

[0072] Specifically, the welding of the transition ring and the portal embedded steel ring includes the following steps:

[0073] (a) Transition ring groove design: the upper groove is opened on the outside of the sleeve, and the lower groove is opened on the inside;

[0074] (b) Transition ring positioning: Use a laser rangefinder to calibrate the deviation between the center line of the steel sleeve and the axis of the portal to ≤ 2 mm;

[0075] (c) Gap filling: For areas where the gap between the tunnel door ring plate and the transition ring is greater than 3mm, 16mm thick steel plates are used to fill the gap and fully weld it. The welds must pass the magnetic particle inspection.

[0076] This embodiment solves the sealing failure problem caused by the pre-embedded deformation of the tunnel door through groove optimization and gap filling welding, ensures the rigid connection between the transition ring and the tunnel door steel ring, and improves the compressive strength.

[0077] In an embodiment of the present invention, the steps of arranging a plurality of steel pipe supports between the rear end cover of the steel sleeve of the shield receiving steel sleeve and the bottom plate of the receiving shaft, and fixing the plurality of steel pipe supports to the bottom plate by planting reinforcement bars include:

[0078] Step S21, arranging a plurality of steel pipe supports between the rear end cover of the steel sleeve for receiving the shield and the bottom plate of the receiving shaft;

[0079] Step S22, drilling a plurality of holes corresponding to the plurality of steel pipe supports at preset positions on the bottom plate of the receiving well;

[0080] Step S23, installing the rebar-embedded steel plate using the drilled holes;

[0081] Step S24, the ends of the plurality of steel pipe supports are fully welded to the embedded steel plates using triangular ribs to form reaction supports.

[0082] Specifically, the anchoring of the reaction support includes:

[0083] (a) Bottom plate opening: Drill a Φ40mm hole with a depth of 300mm at the preset position of the bottom plate of the receiving well;

[0084] (b) Rebar grouting: Use epoxy resin adhesive to fix Φ38 round steel, and the pull-out strength after curing should be ≥150kN;

[0085] (c) Support welding: The support end of the steel pipe is fully welded to the embedded steel plate using a triangular reinforcement plate (20mm thick), and the weld height is ≥12mm.

[0086] This embodiment uses the reinforcement process to enhance the connection strength between the base plate and the support, disperse the axial tension of the shield thrust (≤3000t) on the steel sleeve, and prevent the support from slipping.

[0087] In an embodiment of the present invention, the steps of injecting water into the shield receiving steel sleeve to 1 m above the joint, leaving it to stand for 1 hour, and then pressurizing it to 1 bar, and inspecting the welds and joints for leakage include:

[0088] Step S31, pumping water through a dewatering well into the sleeve until the water level reaches 1 meter above the middle joint of the sleeve, and then observing for leakage after standing for 1 hour;

[0089] Step S32: Use an air compressor to pressurize to 1 bar and maintain the pressure for 30 minutes to detect the leakage of the flange, weld and the reaction support connection, and install a dial indicator and a strain gauge on the surface of the shield receiving steel sleeve as a whole to detect the displacement of the shield receiving steel sleeve as a whole during the pressurization process.

[0090] Specifically, the sealing test is:

[0091] (a) Water injection test: Pump water from the dewatering well and inject it into the steel sleeve until the water level reaches 1m above the middle joint of the sleeve. Leave it for 1 hour and observe for leakage.

[0092] (b) Air pressure test: Use an air compressor to pressurize to 1 bar, maintain the pressure for 30 minutes, and check the leakage of flanges, welds and reaction support connections to ≤0.1L / min;

[0093] (c) Strain monitoring: A dial indicator (5 mm range, 0.5 mm accuracy) and a strain gauge are installed on the surface of the steel sleeve. The displacement during pressurization is ≤1.5 mm.

[0094] This embodiment ensures the sealing of the steel sleeve under high-pressure environment through dual detection combined with real-time monitoring, and avoids leakage due to local deformation.

[0095] More specifically, monitoring points were arranged as follows: strain gauges (1m apart) and dial indicators (6 groups) were installed on the surface of the steel sleeve to transmit data to the monitoring platform in real time;

[0096] Warning threshold: When the displacement is ≥2mm or the strain value is ≥500με, a level 1 alarm is triggered;

[0097] Linkage control: After the alarm is triggered, the shield thrust is automatically adjusted to below 2000t, and the backup dewatering well (well depth 47m, dewatering rate ≥5m) is started. 3 / h).

[0098] In an embodiment of the present invention, before the step of filling the shield receiving steel sleeve with the slag excavated by the shield, the method for integrally reinforcing the shield receiving steel sleeve further comprises:

[0099] Step S301, adding a foaming agent and bentonite to the muck excavated by the shield tunneling to obtain improved muck;

[0100] Step S302: injecting the improved slag into the shield receiving steel sleeve under pressure.

[0101] Specifically, the filling step includes:

[0102] (a) Slag soil improvement: Add foaming agent (mass ratio 1:50) and bentonite (mass ratio 1:20) to the slag soil, and control the moisture content to 18% to 22%;

[0103] (b) Transportation and pressurization: The slag is injected into the steel sleeve through a φ200mm spiral conveying pipe, and the air pressure in the pipe is maintained at 0.3-0.5 bar;

[0104] (c) Compacting: Every 2m 3 After the slag is removed, a high-pressure water gun (pressure ≥ 1MPa) is used for impact compaction, and the density is ≥ 90%.

[0105] This embodiment improves the fluidity of the slag and compacts it in layers to fill the gaps in the steel sleeve, forming a homogeneous support body and reducing the vibration of the cylinder during shield advancement.

[0106] In an embodiment of the present invention, after the shield tail of the shield machine is separated from the tunnel portal, the steps of injecting double-liquid slurry through the segment grouting holes to seal the tunnel portal and completing the overall reinforcement of the shield receiving steel sleeve include:

[0107] Step S61, preparing the dual-liquid slurry using cement slurry and water glass slurry;

[0108] Step S62: inject the double-liquid slurry three times from bottom to top through the segment grouting holes to seal the tunnel door and complete the overall reinforcement of the shield receiving steel sleeve.

[0109] Specifically, the tunnel gate sealing grouting includes:

[0110] (a) Slurry ratio: Cement slurry (PO 42.5 cement 100 parts, water 100 parts) and water glass slurry (modulus 2.8-3.2, concentration 35Be', water glass 100 parts, water 100 parts) were mixed in a 1:1 volume ratio;

[0111] (b) Grouting sequence: 3 injections from bottom to top, with the first injection volume ≥ 6m 3 , the final grouting pressure is 2~2.5bar;

[0112] (c) Setting time control: initial setting time 30 seconds, final setting time ≤ 20 seconds.

[0113] This embodiment uses dual-liquid slurry ratio optimization and sequential grouting to quickly seal the tunnel portal gap and prevent soil and water loss.

[0114] In an embodiment of the present invention, the steps of arranging a plurality of steel pipe supports between the rear end cover of the steel sleeve of the shield receiving steel sleeve and the bottom plate of the receiving shaft, and fixing the plurality of steel pipe supports to the bottom plate by planting reinforcement bars include:

[0115] Step S201: multiple steel pipe supports are provided between the rear end cover of the steel sleeve of the shield receiving steel sleeve and the bottom plate of the receiving shaft, and the multiple steel pipe supports are fixed to the bottom plate by planting steel bars;

[0116] Step S202: installing multiple steel lateral supports on both sides of the shield receiving steel sleeve, with the installation height of the multiple steel lateral supports being 300 mm from the bottom of the cylinder bracket;

[0117] Step S203: Weld the ends of the multiple sections of the horizontal support steel plates with 20 mm thick steel plates, and tighten them against the side walls and longitudinal beams of the foundation pit.

[0118] Specifically, the transverse reinforcement support is set:

[0119] (a) Support arrangement: 8 I20b steel transverse supports are installed on both sides of the steel sleeve, with a spacing of 1600 mm and a support height of 300 mm from the bottom of the cylinder bracket;

[0120] (b) End treatment: 20mm thick steel plates are welded to the ends of the steel sections, tightly pressed against the side walls and longitudinal beams of the foundation pit, with the contact area ≥95%;

[0121] (c) Dynamic adjustment: During the shield tunneling process, the support displacement is detected after each ring of excavation. If the displacement is ≥2mm, additional diagonal supports are added.

[0122] This embodiment utilizes lateral supports and reaction supports to form a spatial force system, thereby suppressing the lateral deformation of the steel sleeve and ensuring the accuracy of the shield axis (±20mm).

[0123] In an embodiment of the present invention, the step of installing the shield receiving steel sleeve includes:

[0124] Step S101, performing triaxial mixing pile construction on the receiving shaft of the shield machine;

[0125] Step S102, performing jet grouting at the joints between the mixing piles and the ground-connected wall to form a reinforced soil mass;

[0126] Step S103, performing unconfined compressive strength testing on the reinforced soil;

[0127] Step S104: installing the shield receiving steel sleeve.

[0128] Specifically, the end reinforcement includes:

[0129] (a) Triaxial mixing pile construction: pile diameter 850 mm, spacing 600 mm, cement content 10% in the weak reinforcement area (0-16 m), and 20% in the strong reinforcement area (16-40.4 m);

[0130] (b) High-pressure jet grouting reinforcement: Φ800mm jet grouting piles are constructed at the joints between the mixing piles and the ground-connected wall, with a cement slurry pressure of ≥30MPa and a lifting speed of 10cm / min;

[0131] (c) Core sampling test: The unconfined compressive strength of the reinforced soil is ≥1.2MPa, and the permeability coefficient is ≤1*10 -6 cm / s.

[0132] This embodiment forms a continuous water-stop curtain through layered reinforcement and joint reinforcement to block the water gushing channel in the sand layer.

[0133] In an embodiment of the present invention, after the step of installing the shield receiving steel sleeve, the shield receiving steel sleeve integral reinforcement method further comprises:

[0134] Step P10: reserve a grouting pipe outside the embedded ring of the tunnel portal.

[0135] Specifically, for emergency response to water and sand gushing: reserve grouting pipes (spacing 500mm) on the outside of the embedded ring of the tunnel portal, and inject polyurethane quick-setting slurry (liquid A: 100 parts of isocyanate, liquid B: 100 parts of polyether polyol) when leakage is found.

[0136] In an embodiment of the present invention, after the tail of the shield machine is separated from the tunnel portal, dual-liquid slurry is injected through the segment grouting holes to seal the tunnel portal, and after the step of integrally reinforcing the shield receiving steel sleeve is completed, the method for integrally reinforcing the shield receiving steel sleeve further includes:

[0137] Step S70: If the shield receiving steel sleeve is deformed, a reinforcing rib is welded at the deformed flange.

[0138] Specifically, emergency measures for steel sleeve deformation: 20mm thick reinforcing ribs (size 200*300mm) are welded at the deformed flange, and the weld height between the ribs and the cylinder is ≥15mm.

[0139] By reserving grouting channels and rapid response mechanisms, sudden risks during construction can be dealt with in a timely manner and the impact of accidents can be reduced.

[0140] As an example implementation, the steel sleeve was installed in sections using a 130t truck crane (operating radius 14m, lifting capacity 24.8t). First, the transition ring was positioned and welded to the pre-embedded steel ring at the portal. The lower half of the sleeve was then installed in sections, with rubber pads inserted and bolts tightened. The anchor bars for the reaction support were cured with epoxy resin adhesive to ensure a pullout strength of ≥150kN per bar. After the support and baseplate were welded, a full weld quality inspection was performed.

[0141] As another example, during a leak test, after water injection and pressure increased to 1 bar, a 0.05L / min leak was detected at the flange connection, which was resolved by re-tightening the bolts. During the filling process, the modified soil had a moisture content of 20%. Layered injection and water compaction were performed, resulting in a final density of 92%. A dual-liquid grouting system was used for tunnel portal sealing, with an initial setting time of 28 seconds. After grouting, no leakage was observed at the tunnel portal.

[0142] As another exemplary embodiment: After the transverse support was installed, the monitoring found that the displacement was 1.8mm. After adding two diagonal braces, the displacement was stable. The end reinforcement core test strength was 1.5MPa, and the permeability coefficient was 8*10 -7 During construction, a displacement warning was triggered, and the system automatically reduced the shield thrust to 1800t and activated the backup dewatering well, keeping the surface settlement within 25mm.

[0143] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformation made by using the contents of the present invention description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the scope of protection of the present invention.

Claims

1. A method for integrally reinforcing a shield receiving steel sleeve, characterized in that: include: Install the shield receiving steel sleeve; A plurality of steel pipe supports are arranged between the rear end cover of the steel sleeve of the shield receiving steel sleeve and the bottom plate of the receiving well, and the plurality of steel pipe supports are fixed to the bottom plate by planting steel bars; Fill the shield receiving steel sleeve with water to 1m above the joint, let it stand for 1 hour, then pressurize it to 1 bar, and check for leakage in the welds and joints; Filling the shield receiving steel sleeve with the slag excavated by the shield; Allowing the shield machine to enter the receiving section; After the tail of the shield machine is separated from the tunnel portal, double-liquid slurry is injected through the grouting holes of the segments to seal the tunnel portal, thereby completing the overall reinforcement of the shield machine receiving steel sleeve.

2. The method for integrally reinforcing a shield receiving steel sleeve according to claim 1, wherein: The steps of installing the shield receiving steel sleeve include: Install the sleeve; An upper groove is formed on the outer side of the sleeve, and a lower groove is formed on the inner side of the sleeve to form a transition ring groove; The transition ring is installed by utilizing the transition ring groove, and the gap between the ring plate of the tunnel door and the transition ring is filled and fully welded; The rear end cover of the steel sleeve is installed on the sleeve to form the steel sleeve for receiving the shield.

3. The method for integrally reinforcing a shield receiving steel sleeve according to claim 2, wherein: The steps of arranging a plurality of steel pipe supports between the rear end cover of the steel sleeve for receiving the shield and the bottom plate of the receiving shaft, and fixing the plurality of steel pipe supports to the bottom plate by planting steel bars include: A plurality of steel pipe supports are provided between the rear end cover of the steel sleeve for receiving the shield and the bottom plate of the receiving well; Drilling a plurality of holes corresponding to the plurality of steel pipe supports at preset positions on the bottom plate of the receiving well; Installing the rebar-embedded steel plate using the drilled holes; The ends of the plurality of steel pipe supports are fully welded to the embedded steel plates using triangular ribs to form reaction supports.

4. The method for integrally reinforcing a shield receiving steel sleeve according to claim 3, wherein: The steps of injecting water into the shield receiving steel sleeve to 1m above the joint, leaving it to stand for 1 hour and then pressurizing it to 1 bar, and inspecting the welds and joints for leakage include: Pump water into the sleeve through the dewatering well until the water level reaches 1m above the middle joint of the sleeve, and observe leakage after standing for 1 hour; Use an air compressor to pressurize to 1 bar and maintain the pressure for 30 minutes to detect leakage at the flange, weld and the reaction support connection. Install a dial indicator and a strain gauge on the surface of the entire shield receiving steel sleeve to detect the displacement of the entire shield receiving steel sleeve during the pressurization process.

5. The method for integrally reinforcing a shield receiving steel sleeve according to claim 4, wherein: Before the step of filling the shield receiving steel sleeve with the slag excavated by the shield, the shield receiving steel sleeve integral reinforcement method further comprises: Adding foaming agent and bentonite to the slag excavated by the shield to obtain improved slag; The improved slag is injected into the shield receiving steel sleeve under pressure.

6. The method for integrally reinforcing a shield receiving steel sleeve according to claim 5, characterized in that: After the shield tail of the shield machine is separated from the tunnel portal, the steps of injecting double-liquid slurry through the segment grouting holes to seal the tunnel portal and complete the overall reinforcement of the shield receiving steel sleeve include: The double-liquid slurry is prepared by using cement slurry and water glass slurry; The double-liquid slurry is injected three times from bottom to top through the segment grouting holes to seal the tunnel door and complete the overall reinforcement of the shield receiving steel sleeve.

7. The method for integrally reinforcing a shield receiving steel sleeve according to claim 6, wherein: The steps of arranging a plurality of steel pipe supports between the rear end cover of the steel sleeve for receiving the shield and the bottom plate of the receiving shaft, and fixing the plurality of steel pipe supports to the bottom plate by planting steel bars include: A plurality of steel pipe supports are arranged between the rear end cover of the steel sleeve of the shield receiving steel sleeve and the bottom plate of the receiving well, and the plurality of steel pipe supports are fixed to the bottom plate by planting steel bars; Multiple steel lateral supports are provided on both sides of the shield receiving steel sleeve, and the installation height of the multiple steel lateral supports is 300mm from the bottom of the cylinder bracket; The ends of the multiple horizontal supports of the steel sections are welded with 20mm thick steel plates and tightened against the side walls and longitudinal beams of the foundation pit.

8. The method for integrally reinforcing a shield receiving steel sleeve according to any one of claims 1 to 7, characterized in that: The steps of installing the shield receiving steel sleeve include: Carrying out triaxial mixing pile construction on the receiving shaft of the shield; Carry out jet grouting construction at the joints between mixing piles and ground-connected walls to form reinforced soil; Performing unconfined compressive strength testing on the reinforced soil; Install the shield receiving steel sleeve.

9. The method for integrally reinforcing a shield receiving steel sleeve according to any one of claims 1 to 7, characterized in that: After the step of installing the shield receiving steel sleeve, the shield receiving steel sleeve integral reinforcement method further comprises: A grouting pipe is reserved outside the embedded ring of the tunnel portal.

10. The method for integrally reinforcing a shield receiving steel sleeve according to any one of claims 1 to 7, characterized in that: After the tail of the shield machine is separated from the tunnel portal, double-liquid slurry is injected through the segment grouting holes to seal the tunnel portal, and after the step of integrally reinforcing the shield receiving steel sleeve is completed, the method for integrally reinforcing the shield receiving steel sleeve further includes: If the shield receiving steel sleeve is deformed, reinforcing ribs are welded at the deformed flange.

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