Method for constructing tunnel lining waterstop

Abstract

The application relates to the technical field of tunnel engineering waterproof construction, and discloses a tunnel lining waterstop construction method, which comprises the following steps: cleaning and welding a waterstop joint; positioning the waterstop along a preset line of a lining formwork, applying tension through cooperation of a steel bar fixing point and a tension clamp, and controlling the gap between the waterstop and the formwork to be less than or equal to 0.5 mm; installing an anchor at the bottom of the waterstop, pressing the lower edge of the waterstop by means of the vertical flange of the anchor, and embedding the horizontal flange into concrete; laying a flexible isolation film based on silica gel on both sides of the waterstop, and connecting an inflatable expansion strip at the top of the waterstop; injecting nano epoxy resin into a micro channel, dynamically adjusting the injection pressure and the air pressure of the inflatable expansion strip, and curing the nano epoxy resin until the filling rate of the nano epoxy resin reaches 95% and the air pressure is stable; and finally, pouring concrete, adjusting the top pressure of the formwork on the waterstop through a hydraulic top pressing module, and removing the pressure after the concrete is initially cured. The application is mainly used for improving the waterproof sealing performance and structural stability of the joint of a tunnel lining.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel engineering waterproof construction, and more particularly to a method for constructing a tunnel lining waterstop. Background Art

[0002] The construction of tunnel lining waterstops presents key challenges that impact waterproofing effectiveness. Traditional methods of installing waterstops make it difficult to precisely control the gap between the waterstop and the lining formwork, leading to localized gaps or uneven fit. These gaps can cause the waterstop to shift or become partially suspended during concrete pouring, weakening its sealing effectiveness. Secondly, insufficient anchoring at the bottom of the waterstop can cause the lower edge to warp under the flow pressure of the concrete, creating seepage channels. Furthermore, the lack of effective real-time monitoring and dynamic control of the sealing resin injection process around the waterstop makes it difficult to ensure that the resin fully fills all micro-gaps and cures evenly, compromising the integrity and bond strength of the final sealing layer. Finally, during concrete pouring and applying top pressure to secure the waterstop, the integrated top pressure method can lead to uneven force distribution across the waterstop. Insufficient localized pressure can reduce the securing effect, while excessive localized pressure can damage the waterstop material. Previous attempts to address these issues, such as simply increasing the density of anchor points or increasing the top pressure, have often encountered difficulties such as increased operational complexity, low efficiency, and potential physical damage to the waterstop. Summary of the Invention

[0003] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0004] Another object of the present invention is to provide a method for constructing a tunnel lining waterstop, which solves the technical problems in traditional processes of gaps and poor sealing leading to leakage during installation of the waterstop.

[0005] In order to achieve these objects and other advantages according to the present invention, a method for constructing a tunnel lining waterstop is provided, which comprises the following steps:

[0006] Step 1: Clean the surface of the waterstop joint and weld the joint;

[0007] Step 2: Position the waterstop along the preset installation line of the lining formwork and fix it with steel bar fixing points; use tension clamps to apply tension between adjacent fixing points to ensure that the gap between the waterstop and the lining formwork is ≤0.5mm;

[0008] Step 3: Install L-shaped anchors at 50cm intervals at the bottom of the waterstop, embedding the horizontal flange in the concrete and pressing the vertical flange against the bottom edge of the waterstop;

[0009] Step 4: Lay a silicone-based flexible isolation membrane on both sides of the waterstop to cover the exposed surface of the waterstop; set a microchannel on the surface of the silicone-based flexible isolation membrane; connect an inflatable expansion strip to the top of the silicone-based flexible isolation membrane, and embed pressure sensors in the inflatable expansion strip and at the end of the microchannel;

[0010] Step 5: Inject a nano-epoxy resin with a viscosity of 800±200cps and a mass concentration of 2±0.5wt% of KH-550 silane coupling agent into the isolation membrane microchannel, and maintain a basic air pressure of 5kPa in the inflatable expansion bar; when the pressure at the end of the microchannel is less than 0.25MPa, the nano-epoxy resin injection pressure is increased in steps of 0.1MPa / 5s; when the pressure of the inflatable expansion bar is greater than 5.5kPa, the pressure is automatically relieved to 4.8kPa; when the nano-epoxy resin filling rate reaches 95% and the air pressure fluctuation is less than 0.2kPa / s, maintain the parameters until the nano-epoxy resin is cured;

[0011] Step 6: After the nano-epoxy resin is cured, pour the lining concrete. Use the hydraulic top pressure module to adjust the top pressure of the formwork on the waterstop to 0.1-0.3 MPa in different areas. Release the top pressure after the concrete has initially set, and remove the tension clamp and formwork after the strength reaches the standard.

[0012] Preferably, in the tunnel lining waterstop construction method, in step 2, an adjustable support frame is added between adjacent fixed points, and the support frame consists of a vertical screw and a horizontal support plate; a ball bearing is embedded in the surface of the horizontal support plate to contact the back of the waterstop, and the bottom of the vertical screw is fixed to the lining formwork through a threaded sleeve; a dividing plate is provided on the top of the vertical screw, and the height scale is calibrated on the outer wall of the threaded sleeve; a disc spring pre-tightening mechanism is installed between the horizontal support plate and the vertical screw; a flexible silicone pad is bonded to the back of the horizontal support plate, and the contour corrugation of the back of the waterstop is molded on its surface; during construction, the height of the horizontal support plate is adjusted by manually rotating the threaded sleeve based on the real-time reading of the laser rangefinder, so that the gap between the waterstop and the formwork is ≤0.5mm.

[0013] Preferably, in the tunnel lining waterstop construction method, the microchannel in step five adopts a segmented variable diameter structure: it is divided into three sections from the injection port to the end, and the cross-sectional diameters are 6 mm, 5 mm, and 4 mm respectively; a conical transition section is set between adjacent sections, and a spiral guide groove is set on the inner wall of the transition section; a pressure monitoring point is added 10 cm downstream of each diameter change point, and when the pressure drop rate of any monitoring point is greater than 0.02 MPa / s, the auxiliary injection port closest to the monitoring point is started, and diluted epoxy resin is injected into the auxiliary injection port, where the diluted epoxy resin is a mixture of nano-epoxy resin and 0.1wt% nano-alumina.

[0014] Preferably, in the tunnel lining waterstop construction method, a honeycomb aluminum buffer layer is installed on the top pressure surface of the hydraulic top pressure module in step six, and the pore density of the honeycomb aluminum buffer layer is 20 to 30 pores / cm²; the honeycomb aluminum pores of the honeycomb aluminum buffer layer are filled with silicone foam, and the outer side of the honeycomb aluminum buffer layer is composited with an orthogonal laminated carbon fiber mesh; before the top pressure operation, the honeycomb aluminum buffer layer is pre-compressed to 75% of the original thickness, and a limit column array is set between the honeycomb aluminum buffer layer and the top pressure surface.

[0015] Preferably, in the tunnel lining waterstop construction method, the inflatable expansion strip in step five is connected to a mechanical pressure balancing device, which includes a bellows compensator and a lever counterweight mechanism; food-grade glycerin is filled in the bellows, and the free end of the bellows is connected to a vertical guide rod; a lever is hinged at the top of the vertical guide rod, one end of the lever is fixed with a counterweight block, and the other end is provided with an adjustable weight slide rail; when the pressure fluctuation of the inflatable expansion strip is greater than 0.05kPa, the bellows is telescoped to drive the vertical guide rod to move, and the counterweight block is triggered to rise and fall through the imbalance of the lever; a metal sintered filter element is provided between the bellows and the inflatable expansion strip.

[0016] Preferably, in the tunnel lining waterstop construction method, the L-shaped anchor in step three is pre-installed on the rigid positioning grid, the rigid positioning grid is a truss structure with a width of 50 cm, a closed-cell foamed silicone layer is bonded to the back of the rigid positioning grid, and a criss-cross pressure relief groove is opened on the surface of the closed-cell foamed silicone layer; adjustable legs are installed at both ends of the rigid positioning grid, and the bottom of the legs have a magnetic base; a conical guide sleeve is embedded in the anchor slot, and the rigid positioning grid is pressed against the lining template during installation, and the legs are locked after calibration with a spirit level.

[0017] Preferably, the tunnel lining waterstop construction method is characterized in that phase change microcapsules are uniformly dispersed in the silica gel foam, and the preparation method is as follows: paraffin wax, nano-alumina powder and polyethylene glycol are melt-blended at a mass ratio of 100:1.5-2.5:0.5 at 120-140°C, and emulsified by high-speed shearing to form a dispersed phase with a particle size of ≤10μm; melamine resin is used as the shell material, and microencapsulation is carried out by in-situ polymerization at pH=4.5-5.5 to form microcapsules with a core material phase change temperature of 45-60°C; the mass proportion of the microcapsules in the silica gel foam is 8-12%.

[0018] Preferably, in the tunnel lining waterstop construction method, the surface of the carbon fiber mesh is treated with argon plasma at a power of 300 to 500 W for 60 to 90 seconds; then the carbon fiber mesh is treated under a vacuum of ≤10 -3 Under Pa conditions, vapor phase grafting was performed with glycidyl methacrylate as the grafting monomer, and the grafting rate was ≥3.5μmol / m 2After grafting, an aluminum oxide reflective layer is deposited on the surface of the carbon fiber mesh. The deposition temperature is 290-310°C, the deposition time is 30-45s, and the mesh is preheated to 250°C±10°C and kept warm for 2 minutes before deposition. After deposition, nitrogen is introduced and cooled to <80°C at a rate of ≥15°C / s. The thickness of the reflective layer is 80-120nm, the crystal phase is γ-Al2O3, and the surface roughness of the reflective layer is Ra≤0.15μm.

[0019] Preferably, in the tunnel lining waterstop construction method, a hemispherical tungsten alloy cap is welded to the end of the limit column, and a micro-pit array is processed on the surface of the cap body by nanosecond pulse laser, and the laser parameters are: wavelength 1064nm, pulse energy 8-12mJ, repetition frequency 20kHz; micro-pit depth 20-50μm, diameter 80-150μm, micro-pit edge curvature radius ≥5μm; the micro-pit distribution density is calculated from the center of the cap body to the edge according to the function ρ=ρ0[1-(r / R) 2 ] Gradient decreasing, where ρ0 is the density of the cap body center 120 ~ 150 pits / mm 2 , r is the distance from the center, and R is the curvature radius of the cap body.

[0020] The present invention has at least the following beneficial effects:

[0021] 1. The tunnel lining waterstop construction method provided by the present invention improves the reliability of waterproof sealing and the controllability of construction quality. It is achieved specifically through multiple synergistic effects. First, the tension is accurately applied by a tension clamp and combined with the steel bar fixing point to ensure that the waterstop fits tightly with the lining formwork. The gap is strictly controlled within an extremely small range, which fundamentally reduces the risk of slurry infiltration or waterstop displacement during concrete pouring, laying the foundation for forming a continuous sealing interface. Secondly, the L-shaped anchors are installed at a specific spacing, and their vertical flanges effectively constrain the lower edge of the waterstop. The horizontal flanges are reliably anchored in the concrete, jointly resisting the buoyancy or disturbance generated by the flow of concrete, and preventing the bottom of the waterstop from warping and forming a leakage channel. In addition, the innovative silicone-based flexible isolation membrane system combined with the intelligently controlled resin injection process is the key: the flexible isolation membrane covers the exposed surface of the waterstop and presets microchannels, and cooperates with the inflatable expansion strips and embedded pressure sensors to form a real-time perception and feedback control network for the resin filling process. By dynamically adjusting the injection pressure and the air pressure of the expansion strip (e.g., stepped pressurization and automatic pressure relief), it can proactively adapt to complex gap morphologies, ensuring that the high-viscosity modified nano-epoxy resin fully fills all microscopic voids and achieves a high filling rate. Furthermore, it solidifies under stable conditions, ultimately forming a dense, high-bonding, continuous sealing layer, significantly improving the long-term waterproofing performance of the joint. Finally, the zone-adjustable hydraulic top pressure module applies optimized, controllable top pressure to the waterstop after concrete pouring. This pressure range effectively ensures the precise positioning and close contact of the waterstop before the initial setting of the concrete, while also avoiding local overpressure damage to the material through zone control. Pressure is released at the appropriate time, ensuring the ultimate bonding quality between the waterstop and the concrete.

[0022] 2. The present invention further introduces an adjustable support frame system (comprising a vertical screw, horizontal support plate, ball bearings, disc springs, and a flexible silicone cushioning layer), which effectively supplements the precision control of the center gap. This support frame allows for precise height adjustment. Its ball bearings and flexible silicone cushioning layer (molded with corrugations) significantly reduce friction with the back of the waterstop and provide uniform support. Combined with the preloaded effect of the disc springs, this effectively offsets local deformation or disturbances during construction. With the assistance of a laser rangefinder, manual and convenient high-precision dynamic maintenance of the gap between the waterstop and the formwork at each point along its length can be achieved, significantly enhancing the reliability and stability of the fit accuracy even under complex contours.

[0023] 3. This invention improves upon the mechanical pressure-balancing device (bellows compensator and lever counterweight mechanism), providing a robust, externally independent solution for stabilizing the expansion strip's air pressure. By utilizing the volume changes of the glycerin within the bellows to respond to air pressure fluctuations and utilizing the lever counterweight mechanism for automatic balancing (raising and lowering the counterweight), this device quickly and effectively suppresses pressure fluctuations, maintaining the base pressure within a very narrow range. This ensures constant contact pressure between the isolation membrane system, the waterstop, and the formwork during resin filling, creating more stable boundary conditions for uniform resin filling and curing. A metal sintered filter element ensures the purity of the system's internal media and reliable operation.

[0024] 4. This invention also optimizes the materials and structures of key components, resulting in synergistic benefits. Phase-change microcapsules (core material: a mixture of paraffin wax, nano-alumina, and polyethylene glycol; shell material: melamine resin) prepared using a specific ratio and process are introduced into the silicone foam of the honeycomb aluminum buffer layer. These microcapsules undergo phase changes in response to changes in construction ambient temperature or the heat of concrete hydration, absorbing or releasing heat. This effectively mitigates the thermal stress induced by localized temperature fluctuations on the buffer layer and surrounding materials (particularly the resin and concrete to be cured), thereby improving the thermal stability and durability of the system. Argon plasma treatment, vapor-phase grafting with glycidyl methacrylate, and the deposition of a γ-Al₂O₃ reflective layer on the carbon fiber mesh surface significantly enhance the interfacial bonding strength and chemical corrosion resistance between the carbon fiber mesh and the honeycomb aluminum buffer layer and the external environment. The highly reflective alumina layer, in particular, helps reflect some heat, further aiding thermal management. Precision laser machining creates a micro-dimpled array with a specific gradient distribution on the tungsten alloy cap at the end of the limiter post. This structural optimization significantly increases the effective friction coefficient of the contact surface and absorbs part of the energy through the deformation of micro-pits during the top pressing process, providing a more controllable and gradual contact stress transfer, effectively preventing accidental slippage or stress concentration between the limit column and the buffer layer or formwork during the top pressing operation or concrete expansion, and improving the overall control accuracy and safety of the top pressing system.

[0025] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the embodiments so that those skilled in the art can implement the invention with reference to the description.

[0027] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0028] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0029] The present invention provides a tunnel lining waterstop construction method, which comprises the following steps:

[0030] Step 1: Clean the surface of the waterstop joint and weld the joint;

[0031] Step 2: Position the waterstop along the preset installation line of the lining formwork and fix it with steel bar fixing points; use tension clamps to apply tension between adjacent fixing points to ensure that the gap between the waterstop and the lining formwork is ≤0.5mm;

[0032] Step 3: Install L-shaped anchors at 50cm intervals at the bottom of the waterstop, embedding the horizontal flange in the concrete and pressing the vertical flange against the bottom edge of the waterstop;

[0033] Step 4: Lay a silicone-based flexible isolation membrane on both sides of the waterstop to cover the exposed surface of the waterstop; set a microchannel on the surface of the silicone-based flexible isolation membrane; connect an inflatable expansion strip to the top of the silicone-based flexible isolation membrane, and embed pressure sensors in the inflatable expansion strip and at the end of the microchannel;

[0034] Step 5: Inject a nano-epoxy resin with a viscosity of 800±200cps and a mass concentration of 2±0.5wt% of KH-550 silane coupling agent into the isolation membrane microchannel, and maintain a basic air pressure of 5kPa in the inflatable expansion bar; when the pressure at the end of the microchannel is less than 0.25MPa, the nano-epoxy resin injection pressure is increased in steps of 0.1MPa / 5s; when the pressure of the inflatable expansion bar is greater than 5.5kPa, the pressure is automatically relieved to 4.8kPa; when the nano-epoxy resin filling rate reaches 95% and the air pressure fluctuation is less than 0.2kPa / s, maintain the parameters until the nano-epoxy resin is cured;

[0035] Step 6: After the nano-epoxy resin is cured, pour the lining concrete. Use the hydraulic top pressure module to adjust the top pressure of the formwork on the waterstop to 0.1-0.3 MPa in different areas. Release the top pressure after the concrete has initially set, and remove the tension clamp and formwork after the strength reaches the standard.

[0036] Traditional installation relies on manual pressing or simple fixing, which can lead to loose fit between the waterstop and the formwork. Local gaps (often greater than 1mm) can easily occur, and when concrete is poured, slurry seeps into the gaps, causing the waterstop to shift or become suspended, creating a risk of water seepage. Conventional anchors are spaced too far apart (>80cm) or the clamping force is insufficient, resulting in bottom anchor failure. Under the impact of concrete flow, the lower edge of the waterstop can easily tilt upward and move out of its intended position. Manual resin injection cannot sense the filling status in real time, and the sealing resin filling is uncontrollable. Unfilled gaps, trapped bubbles, or excessive pressure can damage the waterstop, resulting in a discontinuous sealing layer after curing. Integral top pressure can easily cause local overpressure (>0.5MPa) or underpressure (<0.05MPa) in the waterstop. Overpressure causes material deformation, the top pressure process is rough, and underpressure reduces bonding strength.

[0037] Existing technology uses a "fixed clip + manual resin infusion + overall mechanical top-pressing" process. Its limitations include: gap control relies on worker experience, making it impossible to quantitatively test the fit; the anchor is a single-point U-shaped clamp, which only constrains the middle of the waterstop and is prone to warping at the edges; the resin injection endpoint is determined empirically, resulting in poor filling uniformity; and the top-pressing process uses a jack for overall pressure application, resulting in uneven pressure distribution.

[0038] The above technical solution systematically solves the above problems through the coordination of quantitative tension control, distributed anchoring, intelligent filling regulation and partitioned top pressure.

[0039] A tension clamp is a clamping device that can apply continuous tension. The clamp has serrated anti-slip grooves and the tension is adjusted by a screw mechanism.

[0040] The L-shaped anchor is a right-angle component formed by one-time stamping of 304 stainless steel. The horizontal flange is 5cm long and 3mm thick, with anti-pullout barbs; the vertical flange is 2cm high and 2mm thick, with a rounded edge at the top.

[0041] The silicone-based flexible isolation membrane is a reinforced silicone sheet with a thickness of 0.8 mm and a tensile strength of ≥8 MPa. The surface is hot-pressed by a mold to form a continuous microchannel with a semicircular cross-section (1.2 mm deep and 2 mm wide).

[0042] The inflatable expansion strip is a Φ8mm rubber hollow tube with built-in mesh reinforcement fiber, and the bursting pressure is greater than 0.8MPa.

[0043] The hydraulic jacking module consists of an array of independently controlled plunger cylinders, with a single cylinder stroke of 50mm and an adjustable output force of 0-50kN.

[0044] In the technical solution, after cleaning the welded joint, the laser marking of the lining formwork is used to lay the waterproof tape. Steel reinforcement fixing points are set every 1.5 m, and U-shaped clamps are used to lock the flanges of the waterproof tape. Tension clamps are installed between adjacent fixing points: the clamp jaws are engaged with the edges of the waterproof tape, the handle is rotated to make the tension gauge show 0.15-0.25 kN, and then the gap between the formworks is detected with a feeler gauge until it is less than or equal to 0.5 mm, and then the clamp is locked. The technical solution quantifies the tension to eliminate local loosening and prevent concrete from entering the gap.

[0045] In the technical solution, L-shaped anchors are driven into the bottom of the waterproof tape every 50 cm. Special installation tools are used to vertically nail the horizontal flanges of the anchors into the formwork, ensuring that the vertical flanges tightly press the lower edge of the waterproof tape, and there is no visible gap. After anchoring, the waterproof tape is tapped gently, and there is no loosening sound. The technical solution resists the upward force of the concrete by mechanical constraint and eliminates the risk of bottom warping.

[0046] In the technical solution, after laying the isolation film, the injection equipment is connected, and when started, the inflation strip is inflated to a basic pressure of 5 kPa. Modified nano epoxy resin (viscosity 800 cps ± 10%) is pumped into the micro-channel, and the initial injection pressure is 0.2 MPa. When the end pressure sensor is less than 0.25 MPa, the control system increases the pressure by 0.1 MPa every 5 seconds; if the inflation strip pressure is greater than 5.5 kPa, the pressure relief valve is automatically opened to 4.8 kPa. After the filling rate reaches 95% and the air pressure fluctuation tends to be stable, the parameters are maintained for 120 minutes until solidification. The dynamic pressure adjustment adapts to the gap shape, ensuring that the resin is filled without dead angles. After pouring the concrete, the hydraulic pressure module is started. The lining formwork is divided into 2 m long control sections along the longitudinal direction, and the pressure of each section is independently adjusted to the range of 0.15-0.25 MPa. After the pressure is stable, it is left to stand until the concrete surface is initially set (no trace with a finger).

[0047] The technical solution can balance the pressure to protect the structure of the waterproof tape, improve the uniformity of the concrete bond, and achieve millimeter-level adhesion between the entire length of the waterproof tape and the formwork, eliminating sealing failure caused by gaps; the bottom anchoring system effectively suppresses fluid dynamic disturbance and maintains the stability of the spatial position of the waterproof tape; the resin filling process forms a defect-free sealing layer through pressure closed-loop control, significantly improving the bonding strength; and the partitioned pressure avoids local stress concentration and ensures the integrity of the interface between the waterproof tape and the concrete.

[0048] The technical solution converts the manual experience-dependent links in traditional processes into controllable engineering technologies through quantifiable operation steps and special components, significantly reducing construction variability while ensuring reliability.

[0049] In another technical solution, the tunnel lining waterstop construction method is as follows: in step 2, an adjustable support frame is added between adjacent fixed points, and the support frame consists of a vertical screw and a horizontal support plate; a ball bearing is embedded on the surface of the horizontal support plate to contact the back of the waterstop, and the bottom of the vertical screw is fixed to the lining formwork through a threaded sleeve; a dividing plate is set on the top of the vertical screw, and the height scale is calibrated on the outer wall of the threaded sleeve; a disc spring pre-tightening mechanism is installed between the horizontal support plate and the vertical screw; a flexible silicone pad is bonded to the back of the horizontal support plate, and the surface of the flexible silicone pad is molded with a corrugated contour of the back of the waterstop; during construction, the height of the horizontal support plate is adjusted by manually rotating the threaded sleeve based on the real-time reading of the laser rangefinder, so that the gap between the waterstop and the formwork is ≤0.5mm.

[0050] The above technical solution primarily addresses the underlying flaws in gap control. Specifically, in curved lining or long-distance construction, it's difficult to maintain a uniform fit between the waterstop and the formwork using tension clamps alone. Traditional temporary supports suffer from the following drawbacks: Metal brackets directly push against the back of the waterstop, creating rigid contact at the support point. This concentrated localized pressure can easily damage the rubber material or cause corrugated deformation of the waterstop, increasing the gap. Adjusting the height of a specific point can cause chained displacement in adjacent areas due to structural interference, requiring repeated calibration and resulting in low efficiency. Vibrations during concrete pouring or people stepping on them can easily cause minor settlement of the support frame, leading to the recurrence of gaps.

[0051] Existing technology uses a "simple triangular support rod + manual jackscrew" support method. Its limitations include: the top of the support rod is a flat plate that contacts the back of the waterstop, resulting in high friction and uneven pressure distribution; height adjustment relies on the rotation of the jackscrew, without a preload buffer mechanism, resulting in poor fine-tuning accuracy; and the lack of a contour-adaptive design makes it easy for the corrugated parts of the waterstop to become suspended.

[0052] To address the above problems, the above technical solution integrates three elements: flexible support, pre-tightening and gap elimination, and contour matching to achieve dynamic gap stability under construction disturbance.

[0053] The adjustable support frame is a lifting mechanism consisting of a vertical screw and a horizontal support plate. The vertical screw thread lead is 2mm and the stroke is 0-100mm.

[0054] The ball bearing is embedded in the axial thrust bearing on the surface of the horizontal support plate, with the exposed ball top height of 1.5mm and can roll freely 360°.

[0055] The disc spring preload mechanism is installed in the laminated spring group between the horizontal support plate and the vertical screw rod, with an initial preload of 50N and a maximum compression of 3mm.

[0056] The flexible silicone cushion layer is a 5mm thick molded silicone sheet with a surface that replicates the corrugation on the back of the waterstop and a Shore hardness of 40A.

[0057] Install the support frame between adjacent rebar fixing points. First, weld the threaded sleeve to the pre-set position on the lining formwork. Then, screw the vertical screw into the sleeve until it reaches the center. Attach the horizontal support plate to the top of the vertical screw through the center screw hole. Install the disc spring assembly and lock nut in sequence. Adjust the threaded sleeve so that the horizontal support plate is initially close to the back of the waterstop (with a gap of approximately 10 mm). The modular design allows for quick assembly and disassembly, and the foundation height can be roughly adjusted.

[0058] The operator uses a laser rangefinder to scan the gap between the waterstop and the formwork. When the gap at a certain point exceeds 0.5mm, the operator rotates the threaded sleeve corresponding to that point (each scale increment corresponds to 0.1mm of lift). As the horizontal support plate rises, the ball bearing contacts the back of the waterstop and rolls freely. The disc springs are compressed and deformed, storing preload. Adjustments are made continuously until the gap is achieved and the corrugated flexible silicone cushioning layer fully engages the back of the waterstop. In this technical solution, the rolling bearing eliminates frictional resistance, while the preloaded disc springs compensate for micro-deformations.

[0059] If an external impact causes the horizontal support plate to move downward during construction (such as concrete vibration), the disc spring releases its preload, pushing the support plate upward, and the ball bearings subsequently roll back into place. The flexible silicone underlayment's corrugated structure provides lateral restraint, preventing the waterstop from sliding laterally. An adaptive anti-backlash mechanism ensures consistent contact without manual intervention.

[0060] In the above technical solution, the ball bearing changes sliding friction into rolling friction to avoid dragging the water stop during adjustment to cause new gaps; the disc spring preload offsets the gap in the bracket system and absorbs the impact energy of construction; the molded silicone corrugation provides three-dimensional fit, eliminating the stress concentration of traditional rigid support; the dividing plate and laser ranging are linked to realize quantitative control of the gap, which significantly improves the accuracy.

[0061] This technical solution, through innovative mechanical structures, transforms discrete support points into an adaptive system with robust anti-disturbance capabilities, fundamentally resolving the industry's pain point of gap control in long-distance, variable-curvature working conditions. Compared to traditional rigid supports, this solution significantly reduces reliance on operator experience while maintaining accuracy.

[0062] In another technical solution, the tunnel lining waterstop construction method is described, and in step five, the microchannel adopts a segmented variable diameter structure: it is divided into three sections from the injection port to the end, and the cross-sectional diameters are 6 mm, 5 mm, and 4 mm respectively; a conical transition section is set between adjacent sections, and a spiral guide groove is set on the inner wall of the transition section; a pressure monitoring point is added 10 cm downstream of each diameter change point. When the pressure drop rate of any monitoring point is greater than 0.02 MPa / s, the auxiliary injection port closest to the monitoring point is started, and diluted epoxy resin is injected into the auxiliary injection port. The diluted epoxy resin is a mixture of nano-epoxy resin and 0.1 wt% nano-alumina.

[0063] The above technical solution primarily addresses inherent defects in the resin filling process. When filling long microchannels, traditional constant-diameter channels are prone to insufficient pressure at the end due to resin viscosity resistance, resulting in incomplete filling or the formation of bubbles. Sudden changes in local gaps (such as uneven templates) can trigger abnormal resin loss and a sudden drop in pressure within the channel. Existing technologies face two key bottlenecks: In constant-diameter channels, resin flow resistance increases with distance, and the end pressure is significantly lower than the inlet, making it difficult to drive resin to fully fill the distal micro-gaps. Furthermore, sudden resin leakage (such as a damaged isolation membrane) causes a pressure drop, making it difficult to quickly locate and remedy the leak, resulting in localized filling defects.

[0064] Existing technology uses a "single-diameter flow channel + manual pressure monitoring" approach. Its limitations include: For constant-diameter flow channels greater than 3 meters, the end fill rate is typically less than 85%; pressure monitoring is only performed at the inlet and end, failing to identify anomalies in the intermediate section; and when a leak occurs, injection must be stopped and investigated throughout the entire line, resulting in low efficiency and the tendency to create weak interface areas after repair.

[0065] The above technical solution maintains the pressure gradient through the variable diameter design of the flow channel, and establishes a distributed pressure monitoring and auxiliary injection linkage mechanism to achieve adaptive regulation of the filling process.

[0066] The microchannel with segmented variable diameter structure is divided into three continuous sections along the flow direction, with inner diameters of 6mm, 5mm and 4mm respectively, and the total length does not exceed 8m.

[0067] The tapered transition section is a truncated cone-shaped channel connecting adjacent diameter-reducing sections, with a taper angle of 15° and a length of 30 mm.

[0068] The continuous spiral ribs processed on the inner wall of the transition section of the spiral guide groove have a pitch of 8mm and a protrusion height of 0.4mm.

[0069] The basic components of the diluted epoxy resin are the same as those of the nano epoxy resin. 5% active diluent (glycidyl ether) and 0.1wt% nano alumina are added to the basic components to obtain the diluted epoxy resin.

[0070] In this technical solution, a segmented, variable-diameter microchannel is hot-pressed onto the surface of a silicone isolation membrane. Starting from the inlet, the first 6mm diameter channel is 2.5 meters long, connected via a tapered transition section to a 5mm diameter middle section (2 meters long), and then to a second transition section to a 4mm diameter final section (1.5 meters long). Each transition section has a left-handed spiral guide groove machined into the inner wall. A micro pressure sensor is embedded 10 cm downstream of each diameter change point. The channel's decreasing cross-sectional area compensates for pressure decay, and the spiral guide suppresses flow separation.

[0071] In the technical solution, the nano epoxy resin is pumped from the injection port with an initial pressure of 0.25 MPa. When the pressure drop rate of a certain monitoring point exceeds the set threshold value (such as the middle sensor > 0.02 MPa / s), the auxiliary injection port closest to the point is automatically opened. The auxiliary injection port is located 50 cm upstream of the abnormal point, and the dilution type epoxy resin is injected until the pressure of the monitoring point rises to the normal fluctuation range (± 0.01 MPa / s), and then the auxiliary injection is closed. Local rapid resin replenishment repairs pressure abnormalities and avoids full-line pump shutdown.

[0072] If the pressure continues to drop after auxiliary injection, the system determines that a major leak has occurred, automatically alarms and marks the fault section. Workers check the isolation membrane along the section and, after finding a break, use a pre-installed patch (silicone tape of the same material) to heat seal and restart auxiliary injection to complete filling.

[0073] The above technical solution can accurately locate the fault point and minimize the rework range. The variable-diameter flow channel design maintains similar resin flow shear rates in each section, reducing end pressure loss; the tapered transition section combined with the spiral guide groove eliminates vortexes caused by sudden changes in flow path, reducing the risk of bubble retention; the distributed pressure monitoring network captures local pressure abnormalities in real time, and the auxiliary injection system quickly responds to repair defects; the dilution resin is chemically compatible with the nano epoxy resin, and the nano alumina enhances the mechanical properties of the repair area, avoiding the formation of a weak interface.

[0074] The above technical solution solves the pressure equalization problem in long-distance micro-channel filling by combining fluid mechanics optimization and intelligent control. Compared with traditional equal-diameter flow channels, it significantly reduces the dependence on manual intervention while ensuring high filling rate, especially suitable for sealing operations on complex curved linings.

[0075] In another technical solution, the tunnel lining waterproof belt construction method, in step six, the top pressure surface of the hydraulic top pressure module is installed with a honeycomb aluminum buffer layer, and the hole density of the honeycomb aluminum buffer layer is 20-30 holes / cm²; the honeycomb aluminum buffer layer is filled with silicone foam in the honeycomb aluminum holes, and the outer side of the honeycomb aluminum buffer layer is compounded with an orthogonal layered carbon fiber net; before the top pressure operation, the honeycomb aluminum buffer layer is pre-compressed to 75% of the original thickness, and an array of limiting columns is arranged between the honeycomb aluminum buffer layer and the top pressure surface.

[0076] The above technical solution primarily addresses the pressure defects of the hydraulic jacking module. When adjusting the pressure in different zones of the traditional integral jacking system, the actual pressure on different parts of the waterstop is uneven due to differences in concrete fluidity and formwork deformation. Existing technology has the following key bottlenecks: When the rigid jacking surface directly contacts the formwork, local high points experience excessive pressure (far exceeding the set value), while low points experience insufficient pressure, causing overpressure and deformation in some areas of the waterstop or underpressure and detachment. The rapid pressure application of the jacking module generates a shock wave that can easily crack the edges of the brittle waterstop. If the formwork deforms slightly before the initial setting of the concrete, the rigid jacking system cannot adaptively compensate for the displacement, which can cause a sudden drop in pressure.

[0077] Existing technologies use a "metal pressure plate + rubber gasket" pressure interface. This has limitations: the rubber gasket expands laterally under pressure, reducing the effective pressure area; the gasket's fixed elastic modulus makes it difficult to adapt to different deformation zones; and without a pre-compression design, an impact peak still occurs at the initial contact moment.

[0078] The above technical solution achieves the unity of flexibility and controllability of pressure transmission through a gradient composite buffer layer and a pre-compression mechanism.

[0079] The honeycomb aluminum buffer layer is a 5052 aluminum alloy honeycomb core with a pore size of 1.2 mm and a density of 25 pores / cm 2 , core wall thickness 0.1mm.

[0080] The silicone foam is an open-cell foamed silicone rubber that fills honeycomb pores, with a porosity of 85% and an anti-permanent deformation rate of ≤8%.

[0081] The orthogonal laminated carbon fiber mesh is a double-layer mesh woven from 0 / 90° oriented T300 carbon fiber bundles, with a single layer weight of 80g / m 2 .

[0082] The limiting column array is a carbide cylinder with a diameter of 3 mm and a height of 1.1 times the thickness of the buffer layer after pre-compression.

[0083] In the above technical solution, the preparation and installation of the honeycomb aluminum buffer layer specifically involves injecting silicone foam into the honeycomb aluminum pores and removing any excess material after curing. A carbon fiber mesh (with the fibers oriented parallel to the template edge) is composited with epoxy glue on the outside of the honeycomb aluminum buffer layer. Before installation, the honeycomb aluminum buffer layer is compressed to 75% of its original thickness using a press, then installed into the frame of the top-pressing module and limited on all sides by retaining edges. Limiting columns (50mm spacing) are evenly distributed between the top-pressing surface and the honeycomb aluminum buffer layer, with the column ends protruding 0.5mm above the surface of the honeycomb aluminum buffer layer. Pre-compression is set to eliminate initial assembly gaps, and limiting columns prevent excessive compression.

[0084] The aforementioned technical solution operates as follows: when the hydraulic system is activated to apply pressure in zones, the silicone foam in the buffer layer undergoes compression and deformation first. When the pressure reaches the lower limit (0.1 MPa), the limiting column begins to contact the pressure surface. As the pressure continues to increase to the upper limit (0.3 MPa), the carbon fiber mesh constrains the lateral expansion of the honeycomb aluminum, ensuring that pressure is evenly transmitted to the formwork through the foam. When concrete vibration causes micro-displacement of the formwork, the foam absorbs this displacement through elastic deformation, maintaining the pressure fluctuation within ±5% of the set value. The gradient deformation mechanism filters out pressure peaks and adaptively compensates for displacement.

[0085] In the above technical solution, pressure relief and recovery involve releasing the top pressure after the concrete initially sets. The honeycomb aluminum buffer layer, under the elastic action of the silicone foam, rebounds to its pre-compressed state (85% of its original thickness), and the limit posts disengage. Inspection of the honeycomb aluminum buffer layer confirms its acceptance and reusability if no permanent indentations are observed on its surface. This elastic recovery ensures reliability over repeated use.

[0086] The above technical solution has a honeycomb aluminum porous structure to disperse local concentrated stress and avoid indentation damage to the waterstop; the large deformation capacity of the silicone foam absorbs impact energy and protects the fragile parts of the waterstop; the carbon fiber mesh inhibits lateral expansion to ensure the stability of the effective top pressure area; the rigid constraint of the limit column prevents overpressure, and the pre-compression design eliminates action hysteresis; the overall rebound characteristics adapt to the dynamic construction environment and have the beneficial effect of extending the life of the components.

[0087] This technical solution, through material synthesis and structural innovation, transforms the jacking process from a rigid collision to a controllable elastic interaction. Compared to traditional gasket solutions, it significantly improves the uniformity and stability of pressure transmission, making it particularly suitable for refined jacking operations on curved linings or long-span tunnels.

[0088] In another technical solution, in the tunnel lining waterstop construction method, the inflatable expansion strip in step five is connected to a mechanical pressure balancing device, which includes a bellows compensator and a lever counterweight mechanism; food-grade glycerin is filled in the bellows, and its free end is connected to a vertical guide rod; a lever is hinged at the top of the vertical guide rod, one end of the lever is fixed with a counterweight block, and the other end is provided with an adjustable weight slide rail; when the pressure fluctuation of the inflatable expansion strip is greater than 0.05kPa, the bellows is extended and retracted to drive the vertical guide rod to move, and the counterweight block is triggered to rise and fall through the imbalance of the lever; a metal sintered filter element is provided between the bellows and the inflatable expansion strip.

[0089] Pressure control flaws in inflatable expansion bars: During the resin filling process, temperature fluctuations or deformation of the isolation membrane can easily cause small variations in air pressure (±0.1 kPa) within the inflatable expansion bar. Traditional electric pressure control systems have the following bottlenecks: the electric pump and sensor require continuous power, and the humid environment of the tunnel can easily cause circuit failures, leading to uncontrolled air pressure; the electronic control system has a delay in detecting and adjusting pressure fluctuations as small as 0.05 kPa, making it impossible to achieve real-time balancing; and the frequent activation and deactivation of the solenoid valve can easily cause pressure fluctuations, exacerbating unstable resin flow.

[0090] Existing technology uses a closed-loop system consisting of an electric air pump, a pressure sensor, and a PLC controller. This system has limitations: System failure during power outages poses a safety risk; The accuracy of detecting micro-pressure fluctuations is limited (typically >0.1 kPa), resulting in a 3-5 second lag in regulation; and Solenoid valve switching generates pressure steps that disrupt the resin filling interface.

[0091] The above technical solution uses a purely mechanical structure to achieve high-sensitivity micro-pressure self-balancing, eliminating dependence on external energy.

[0092] The bellows compensator is a phosphor bronze bellows with a wall thickness of 0.2mm and an effective area of ​​15cm 2 , axial stiffness 5N / mm.

[0093] The lever counterweight mechanism is an equal-arm lever (arm length ratio 1:1), and the fulcrum adopts sapphire bearings.

[0094] The vertical guide rod is a stainless steel rod with a diameter of 8 mm and a surface polished to Ra ≤ 0.2 μm.

[0095] The adjustable weight slide is an aluminum alloy track with a scale, and the weight movement resolution is 1mm.

[0096] In this technical solution, the lower end of the bellows is sealed to the inflation port of the inflatable expansion bar, and a vertical guide rod is fixed to the upper end. The top of the vertical guide rod is hinged to the midpoint of a lever. A basic counterweight (corresponding to 5kPa air pressure) is fixed to one end of the lever, and a sliding weight (initial position at zero) is set at the other end. The bellows is filled with food-grade glycerin, air bubbles are removed, and then sealed. A 5μm pore size 316L stainless steel sintered filter element is installed between the bellows and the inflatable expansion bar. The incompressibility of glycerin ensures accurate pressure transmission, and the filter element prevents impurities from entering the mechanical system.

[0097] In this technical solution, when the air pressure in the inflatable expansion bar increases by 0.05 kPa, the glycerin in the bellows is compressed, pushing the vertical guide rod upward. This raises the right side of the lever fulcrum, triggering an imbalance. Gravity forces the sliding weight to move distally along the rail until the lever is rebalanced. Conversely, when the air pressure decreases, the vertical guide rod moves downward, causing the left side of the lever to sink, and the weight slides toward the fulcrum to restore balance. Every 1 mm of weight movement corresponds to a 0.02 kPa adjustment in air pressure. The lever amplifies micro-displacements, and the weight's gravitational potential energy is converted into air pressure regulation power.

[0098] In the above technical solution, zero point calibration is performed before construction: after the inflatable expansion bar is inflated to 5kPa, the slide rail weight is adjusted to level the lever. If a sudden temperature change occurs during construction, the glycerin volume expansion is compensated by the bellows, and the filter element prevents gas reverse osmosis. The lever's rotational flexibility is regularly checked, and any contamination on the guide rod surface is removed. The fully enclosed mechanical structure resists environmental interference and requires minimal maintenance.

[0099] The above technical solution has the following beneficial effects: the bellows and glycerin combination system directly converts air pressure fluctuations into displacement with a sensitivity of 0.02kPa / mm; the lever counterweight mechanism automatically restores balance through weight displacement, eliminating air pressure fluctuations without delay; pure mechanical action avoids pressure steps and maintains the stability of the resin filling interface; no energy dependence ensures reliability in humid environments, and the sintered filter element extends the life of the system; the weight position is visualized as an air pressure indicator scale to assist manual monitoring.

[0100] This technical solution replaces electronic control with precision mechanical transmission, solving the challenge of reliable control in low-pressure environments. Compared to electric systems, it achieves a breakthrough in self-stabilizing operation in power-free and high-humidity conditions, significantly improving construction robustness in complex tunnel environments.

[0101] In another technical solution, in the tunnel lining waterstop construction method, the L-shaped anchor in step three is pre-installed on the rigid positioning grid. The rigid positioning grid is a truss structure with a width of 50 cm. A closed-cell foamed silicone layer is bonded to the back of the rigid positioning grid, and criss-cross pressure relief grooves are opened on the surface of the silicone layer. Adjustable legs are installed at both ends of the rigid positioning grid, and the bottom of the legs have a magnetic base. A conical guide sleeve is embedded in the anchor slot. During installation, the rigid positioning grid is pressed against the lining template, and the legs are locked after calibration with a spirit level.

[0102] The above technical solution mainly addresses the accuracy defects in the installation of L-shaped anchors: the traditional single-point anchoring method has the following key bottlenecks: manual point-by-point measurement of 50cm intervals is time-consuming and prone to cumulative errors, resulting in uneven density of anchors and weakening the overall constraint effect; during manual knocking installation, the pressure of the vertical flange on the lower edge of the waterstop fluctuates with the strength of the workers, and insufficient local compression can easily form micro gaps; the impact force of concrete pouring may push unfixed anchors to tilt and lose their compression function.

[0103] Existing technology uses a "tape measure positioning + manual hammering" anchoring process. This has limitations: Recalibration with a tape measure is required after every five to six anchors are installed, resulting in a cumulative error of up to ±3cm; hammering force cannot be quantified, leading to a high risk of localized deformation of the waterstop; and anchors are fixed independently, making lateral concrete flow prone to causing overall displacement.

[0104] The above technical solution realizes fast and accurate installation and anti-disturbance locking of anchor groups through an integrated rigid positioning grid.

[0105] The rigid positioning grid is a lightweight aluminum alloy truss with a width of 50 cm. The upper chord is an I-beam and the lower chord is equipped with a dovetail slot.

[0106] The closed-cell foamed silicone layer is a low compression permanent deformation silicone foam with a thickness of 8mm, and a well-shaped pressure relief groove with a depth of 2mm and a width of 3mm on the surface.

[0107] The tapered guide sleeve is a hardened steel sleeve embedded in the anchor slot, with an upper diameter of 12mm, a lower diameter of 8mm, and a polished inner wall.

[0108] The magnetic base is a leg bottom plate embedded with NdFeB permanent magnets, with an adsorption force of ≥300N.

[0109] In the above technical solution, the pre-assembly of the rigid positioning grid involves inserting the horizontal flanges of the L-shaped anchors into the slots of the lower chord of the rigid positioning grid outside the work surface, using the tapered guide sleeves to limit the position. After verifying that the tops of the vertical flanges of all anchors are flush, a closed-cell silicone foam layer is applied to the back of the rigid positioning grid to ensure unobstructed pressure relief grooves. The height of the outriggers is adjusted until the vertical flanges of the anchors are 5 mm below the lower edge of the waterstop. This pre-assembly eliminates individual component positioning errors, and the silicone layer cushions the impact of subsequent compression.

[0110] In the above technical solution, on-site positioning and calibration are as follows: The rigid positioning grid is placed against the lining formwork, the legs are extended, and the magnetic base is attached to the steel formwork surface. A spirit level is used to check the longitudinal and transverse horizontality of the rigid positioning grid. Biaxial leveling (tolerance ≤ 1°) is achieved by rotating the legs for fine adjustment. After tightening the legs, lightly press the rigid positioning grid to observe the uniformity of the silicone layer's compression deformation. Magnetic fixation allows for rapid initial positioning, and biaxial leveling ensures consistent spatial alignment of the anchor groups.

[0111] In the above technical solution, anchor lock-in is achieved by using a dedicated press-in tool (with a pressure indicator) to align the tapered guide sleeve and press the anchor vertically downward until the horizontal flange is completely immersed in the formwork. The press-in force is controlled within the range of 0.8-1.2 kN. At this point, the vertical flange presses the lower edge of the waterstop upward by 0.5 mm, creating pre-compression. This process completes the installation of all anchors throughout the rigid positioning grid. The guide sleeve ensures vertical insertion into the formwork, and the quantitative pressure ensures uniform compression.

[0112] The above technical solution has the following beneficial effects: the rigid positioning grid truss rigidly maintains the precise relative position of the anchors within a width of 50 cm, and the spacing error is close to zero; the conical guide sleeve constrains the vertical movement trajectory of the anchors, eliminating compression failure caused by tilted installation; the closed-cell silicone layer absorbs the vibration energy of concrete pouring to prevent the rigid positioning grid from shifting; the magnetic base and adjustable legs achieve rapid leveling to adapt to curved formwork construction; the criss-cross decompression groove releases the compressive stress of the silicone layer to avoid long-term creep affecting positioning accuracy.

[0113] This technical solution, through the innovation of modular positioning tooling, transforms discrete anchoring operations into high-precision batch operations. Compared to traditional manual installation, it simultaneously solves the three major challenges of positioning accuracy, installation efficiency, and anti-disturbance stability, making it particularly suitable for the efficient construction of large-section tunnels.

[0114] In another technical solution, the tunnel lining waterstop construction method is described, and phase change microcapsules are uniformly dispersed in the silicone foam. The preparation method is: paraffin wax, nano-alumina powder and polyethylene glycol are melt-blended at a mass ratio of 100:1.5~2.5:0.5 at 120~140°C, and emulsified by high-speed shear to form a dispersed phase with a particle size of ≤10μm; melamine resin is used as the shell material, and microencapsulation is performed by in-situ polymerization at pH=4.5~5.5 to form microcapsules with a core material phase change temperature of 45~60°C; the mass proportion of microcapsules in the silicone foam is 8~12%.

[0115] The above technical solution is mainly aimed at the defects of the thermal stress adaptability of the buffer layer: when the heat of concrete hydration and changes in ambient temperature cause the formwork system to expand and contract, traditional homogeneous buffer materials are prone to two types of failure due to their fixed linear expansion coefficient: when the temperature rises suddenly, the buffer layer expands and squeezes the carbon fiber mesh, causing cracking of the composite interface or deformation of the honeycomb aluminum; when the temperature drops suddenly, the buffer layer shrinks, forming a micro gap between the top pressure surface, which weakens the pressure transmission efficiency.

[0116] The existing technology adopts the solution of "pure silicone foam filled with honeycomb aluminum". Its limitation is that the thermal expansion coefficient of silicone foam is 250×10 -6 / ℃, and a dimensional change of 0.25% occurs for every 10℃ change in temperature; after repeated thermal cycles, the foam exhibits permanent compression deformation and the cushioning performance decays; there is no active thermal management capability, and high temperature areas are prone to premature curing of the resin.

[0117] The above technical solution realizes adaptive regulation of the buffer layer temperature through the latent heat storage characteristics of phase change microcapsules.

[0118] Phase change microcapsules are microparticles with a paraffin-based mixed core material wrapped in a melamine resin shell, with a particle size of 5-8μm and a phase change temperature of 53±2℃.

[0119] Melt blending refers to mechanically stirring paraffin wax, nano-alumina powder and polyethylene glycol in a constant temperature reactor at 130° C. until they are completely miscible.

[0120] The in-situ polymerization method is a process in which melamine resin monomer is polymerized and coated on the surface of core material droplets in an acidic aqueous phase.

[0121] In this technical solution, refined paraffin wax (melting range 50-55°C), nano-alumina (particle size 30 nm), and polyethylene glycol 600 are added to a reactor in a mass ratio of 100:2:0.5. Emulsification is performed at 12,000 rpm for 20 minutes while in the molten state at 130°C, forming a dispersed phase emulsion with a particle size of ≤8 μm. The mixture is then transferred to a polymerization reactor, where pre-polymerized melamine resin is added and the pH is adjusted to 5.0. Microencapsulation is completed by reacting at 80°C for 3 hours. Filtering and drying yield a free-flowing powder. The nano-alumina enhances the thermal conductivity of the core material, while the polyethylene glycol improves the reversibility of the phase change.

[0122] In this technical solution, a 10wt% microcapsule powder is added to liquid silicone (a vinyl silicone oil containing hydrogen) and mechanically stirred for dispersion before being injected into the pores of the aluminum honeycomb. Curing is performed at 90°C with a blowing agent, uniformly distributing the microcapsules along the silicone cell walls. After being composited with a carbon fiber mesh, the entire structure is hot-pressed. This positions the microcapsules within the cell stress concentration zones, maximizing thermal management efficiency.

[0123] In this technical solution, when the heat of concrete hydration raises the buffer layer temperature to 53°C, the microcapsule core melts and absorbs heat, inhibiting the expansion of the silicone foam. When the temperature drops below 48°C, the core solidifies and releases heat, compensating for the silicone's contraction. Throughout this process, the buffer layer's dimensional change rate is reduced to less than 30% of that of a pure silicone system. The latent heat of phase change buffers sudden temperature changes, maintaining stable interfacial contact pressure.

[0124] The above technical solution has the following technical effects: liquid phase change absorbs or releases latent heat, smoothing out temperature fluctuations in the construction environment; nano-alumina improves the thermal conductivity of the core material and accelerates the phase change response speed; the microcapsule shell material is chemically compatible with the silica gel matrix, avoiding interface peeling failure; significantly reduces the performance degradation of the buffer layer caused by thermal cycling, extending its service life; and maintains the consistency of pressure transmission of the hydraulic top pressure module under variable temperature conditions.

[0125] This technical solution, through the design of functional composite materials, endows the buffer layer with active temperature adaptability. Compared with traditional homogeneous materials, this breakthrough solves the problem of uncontrolled thermal deformation in the high temperature and humidity environments of tunnels, providing reliable support for the precision top-pressing process.

[0126] In another technical solution, the tunnel lining waterstop construction method is as follows: the surface of the carbon fiber mesh is treated with argon plasma at a power of 300 to 500 W for 60 to 90 seconds; then the carbon fiber mesh is treated with argon plasma at a power of 300 to 500 W for 60 to 90 seconds; -3Under Pa conditions, vapor phase grafting was performed with glycidyl methacrylate as the grafting monomer, and the grafting rate was ≥3.5μmol / m 2 After grafting, an aluminum oxide reflective layer is deposited on the surface of the carbon fiber mesh. The deposition temperature is 290-310°C, the deposition time is 30-45s, and the mesh is preheated to 250°C±10°C and kept warm for 2 minutes before deposition. After deposition, nitrogen is introduced and cooled to <80°C at a rate of ≥15°C / s. The thickness of the reflective layer is 80-120nm, the crystal phase is γ-Al2O3, and the surface roughness of the reflective layer is Ra≤0.15μm.

[0127] The above technical solution mainly targets the environmental tolerance defects of carbon fiber mesh: In the high humidity and alkaline concrete environment of the tunnel, traditional carbon fiber mesh is prone to the following defects: due to the difference in thermal expansion coefficients between carbon fiber and silicone foam, interfacial stress accumulates under temperature cycles, leading to stratification; alkaline substances precipitated from concrete penetrate along the fiber bundles, catalyzing the hydrolysis of the epoxy resin matrix and reducing the mesh reinforcement effect; high-temperature radiation from hydration heat accelerates resin aging and weakens the structural integrity of the buffer layer.

[0128] Existing technology uses a "direct composite" approach using untreated carbon fiber mesh. Its limitations include: insufficient bonding strength with silicone due to the inert surface of the carbon fiber; a lack of a chemical barrier layer, resulting in a service life of less than two years in alkaline environments; and the high heat absorption of black carbon fiber, which exacerbates local temperature rise.

[0129] The above technical solution synergistically improves interface stability and environmental resistance through triple modification of surface activation, grafting and coating.

[0130] Argon plasma treatment is a process that uses inert gas glow discharge to generate highly active particles to bombard the material surface.

[0131] Vapor-phase grafting is a modification technology that allows gaseous monomers to react with active sites on the surface of a material in a vacuum environment.

[0132] The aluminum oxide reflective layer is a γ-crystalline aluminum oxide thin film formed by vapor deposition and has high infrared reflectivity.

[0133] The surface activation process involves placing a carbon fiber mesh in a vacuum chamber and introducing argon gas to a pressure of 10 Pa. A 400W radio frequency power is applied to ignite the plasma for 75 seconds. This treatment increases the oxygen content on the fiber surface to 18%, and nanoscale pits are formed. Plasma etching removes surface contaminants and increases reactive sites.

[0134] In the above technical solution, the specific steps of gas phase grafting strengthening are as follows: the activated carbon fiber mesh is moved into the grafting chamber and the vacuum is reduced to 0.001 Pa. Glycidyl methacrylate is introduced and heated to 85°C for 10 minutes. After the grafting is completed, the epoxy group density on the fiber surface reaches 4.2 μmol / m 2The epoxy monomer reacts with free radicals on the surface of the carbon fiber to form a chemically bonded transition layer.

[0135] In the above technical solution, during the reflective layer deposition process, the grafted fiber web is preheated to 255°C and held at this temperature for 2 minutes before being transferred to the deposition chamber. Trimethylaluminum vapor and oxygen are introduced, reacting at 300°C for 40 seconds to deposit γ-Al2O3. After deposition, the web is cooled to 70°C at a rate of 20°C / s with nitrogen, resulting in a continuous coating with a thickness of 100nm. Gradient temperature control eliminates thermal stress, and the γ-phase alumina crystal structure ensures high reflectivity.

[0136] The above technical solution has the following beneficial effects: plasma treatment slightly roughens the fiber surface, improving the mechanical bite strength; vapor-phase grafted epoxy groups cross-link with the silicone foam to achieve a chemical bond-enhanced interface; the γ-Al2O3 reflective layer blocks more than 90% of infrared radiation, reducing the risk of thermal damage; the dense crystal structure of alumina isolates water vapor and alkaline ion penetration; the surface roughness is optimized to Ra=0.12μm, maintaining a balance between coating adhesion and flexibility.

[0137] This technical solution, through multi-level surface engineering, creates a composite protection system, breaking through the application bottleneck of carbon fiber reinforcements in harsh environments. Compared to traditional untreated fibers, it significantly improves the service reliability of the buffer layer in coupled thermal, humid, and chemical environments, providing a key material guarantee for the long-life top pressure system.

[0138] In another technical solution, the tunnel lining waterstop construction method is described, the end of the limit column is welded with a hemispherical tungsten alloy cap, and the surface of the cap body is processed with a micro-pit array by nanosecond pulse laser, the laser parameters are: wavelength 1064nm, pulse energy 8-12mJ, repetition frequency 20kHz; the micro-pit depth is 20-50μm, the diameter is 80-150μm, and the curvature radius of the pit edge is ≥5μm; the micro-pit distribution density is from the center of the cap body to the edge according to the function ρ=ρ0[1-(r / R) 2 ] Gradient decreasing, where ρ0 is the density of the cap body center 120 ~ 150 pits / mm 2 , r is the distance from the center, and R is the curvature radius of the cap body.

[0139] The above technical solution is mainly aimed at the problem of contact failure at the end of the limit column: the traditional smooth spherical limit column has the following key bottlenecks during the dynamic top pressure process: the static friction coefficient between the smooth metal spherical surface and the carbon fiber mesh of the buffer layer is only 0.15-0.2. The lateral force generated by concrete vibration can easily cause the limit column to slip, resulting in misaligned top pressure transmission and stress concentration damage. When the local high-pressure contact point exceeds the yield limit of the buffer layer, it will cause permanent crushing of the honeycomb aluminum or tearing of the silicone foam; the top pressure impact energy is directly transmitted to the buffer layer, aggravating material fatigue.

[0140] Existing technology uses a "polished carbide hemispherical cap" design. Its limitations include: while the ultra-smooth surface reduces frictional resistance, it has weak anti-slip capabilities; concentrated contact stress is more than three times the local yield strength of the buffer layer; and there is no energy absorption mechanism, resulting in microcracks on the contact surface after long-term use.

[0141] The above technical solution achieves coordinated regulation of friction enhancement and stress dispersion through a gradient micro-pit array.

[0142] The micro-dimple array is a regular cluster of micro-holes machined into the surface of the tungsten alloy cap, with a depth-to-diameter ratio of 0.3-0.6. A gradient distribution pattern shows a continuously decreasing density of micro-dimples from the center of the cap to the edge. The nanosecond pulse laser is a short-pulse laser device with a pulse width of 10ns and a focused spot diameter of ≤20μm.

[0143] In this technical solution, a tungsten alloy cap is fixed to a five-axis laser processing table, with the center of the cap top set as the coordinate origin. Processing parameters at each point are calculated using a preset density function: high energy density (12mJ pulse energy) is used in the center to create a 50μm deep, 150μm diameter pit, while lower energy (8mJ) is used at the edges to create a 20μm deep, 80μm diameter pit. The laser beam is incident vertically and dynamically focused to track the surface, achieving a smooth transition with an 8μm radius of curvature at the pit edge.

[0144] Technical effect: Variable parameter processing adapts to changes in surface curvature and avoids sudden changes in edge stress.

[0145] In this technical solution, during the top-pressure process, the carbon fiber mesh in the buffer layer is embedded in micro-dimples, forming a mechanical interlock. During initial contact, the high-density dimples in the center provide high frictional resistance. As pressure increases, the sidewalls of the dimples elastically deform to absorb energy, while the low-density areas at the edges gradually contribute to the load. The gradient distribution of the dimples reduces the peak contact stress to 40% of that of a uniform sphere. Progressive contact expansion avoids stress concentration, and micro-deformation dissipates impact energy.

[0146] In this technical solution, when concrete vibration induces lateral forces, the carbon fiber bundles are drawn into the dimples, forming multiple anchor points. The optimized radius of curvature at the dimple edges prevents fiber damage. Experiments have shown that the micro-dimple array increases the static friction coefficient to above 0.45. Geometric interlocking and material interlocking synergistically mitigate the risk of slippage.

[0147] The above technical solution has the following technical effects: the gradient density distribution matches the contact pressure field to avoid local overload damage to the buffer layer; the plastic deformation of the micro-pits absorbs the top pressure impact energy and reduces the accumulation of material fatigue; the multi-level mechanical anchoring effect significantly improves the ability to resist lateral slip; the smooth pit edges protect the structural integrity of the carbon fiber mesh; laser processing ensures the consistency of the microstructure morphology and maintains long-term service stability.

[0148] The technical scheme above converts the limiting column from a passive constraint element into an intelligent stress regulation interface through bionic microstructure design. Compared with a traditional smooth ball head, it has broken through the dynamic contact failure problem in a high-precision top pressure system and provides reliable guarantee for pressure control under complex working conditions.

[0149] The number of devices and the scale of processing described herein are intended to be illustrative of the application. Applications, modifications and variations of the application will be apparent to those skilled in the art.

[0150] Although embodiments of the present application have been disclosed in connection with the illustrative embodiments of the present application, it should be understood that the application can be practiced not only in the specific embodiments, but in other embodiments as well. This includes several possible variations on the inventive method and apparatus. It is therefore desired that what is claimed be supported by the application as broadly as reasonably possible.

Claims

1. A method for constructing a tunnel lining waterstop, characterized in that: The following steps are involved: Step 1: Clean the surface of the waterstop joint and weld the joint; Step 2: Position the waterstop along the preset installation line of the lining formwork and fix it with steel bar fixing points; use tension clamps to apply tension between adjacent fixing points to ensure that the gap between the waterstop and the lining formwork is ≤0.5mm; Step 3: Install L-shaped anchors at 50cm intervals at the bottom of the waterstop, embedding the horizontal flange in the concrete and pressing the vertical flange against the bottom edge of the waterstop; Step 4: Lay a silicone-based flexible isolation membrane on both sides of the waterstop to cover the exposed surface of the waterstop; set a microchannel on the surface of the silicone-based flexible isolation membrane; connect an inflatable expansion strip to the top of the silicone-based flexible isolation membrane, and embed pressure sensors in the inflatable expansion strip and at the end of the microchannel; Step 5: Inject a nano-epoxy resin with a viscosity of 800±200cps and a mass concentration of 2±0.5wt% of KH-550 silane coupling agent into the isolation membrane microchannel, and maintain a basic air pressure of 5kPa in the inflatable expansion bar; when the pressure at the end of the microchannel is less than 0.25MPa, the nano-epoxy resin injection pressure is increased in steps of 0.1MPa / 5s; when the pressure of the inflatable expansion bar is greater than 5.5kPa, the pressure is automatically relieved to 4.8kPa; when the nano-epoxy resin filling rate reaches 95% and the air pressure fluctuation is less than 0.2kPa / s, maintain the parameters until the nano-epoxy resin is cured; Step 6: After the nano-epoxy resin is cured, pour the lining concrete. Use the hydraulic top pressure module to adjust the top pressure of the formwork on the waterstop to 0.1-0.3 MPa in different areas. Release the top pressure after the concrete has initially set, and remove the tension clamp and formwork after the strength reaches the standard.

2. The method for constructing a tunnel lining waterstop according to claim 1, wherein: In step 2, an adjustable support frame is added between adjacent fixed points, and the adjustable support frame consists of a vertical screw and a horizontal support plate; a ball bearing is embedded on the surface of the horizontal support plate to contact the back of the waterstop, and the bottom of the vertical screw is fixed to the lining formwork through a threaded sleeve; a dividing plate is set on the top of the vertical screw, and the height scale is calibrated on the outer wall of the threaded sleeve; a disc spring pre-tightening mechanism is installed between the horizontal support plate and the vertical screw; a flexible silicone pad is glued to the back of the horizontal support plate, and the contour corrugation of the back of the waterstop is molded on the surface of the flexible silicone pad; during construction, the height of the horizontal support plate is adjusted by manually rotating the threaded sleeve based on the real-time reading of the laser rangefinder so that the gap between the waterstop and the formwork is ≤0.5mm.

3. The tunnel lining waterstop construction method according to claim 1, wherein: In step five, the microchannel adopts a segmented variable diameter structure: it is divided into three sections from the injection port to the end, with cross-sectional diameters of 6 mm, 5 mm, and 4 mm, respectively; a conical transition section is set between adjacent sections, and a spiral guide groove is set on the inner wall of the transition section; a pressure monitoring point is added 10 cm downstream of each diameter change point. When the pressure drop rate at any monitoring point is greater than 0.02 MPa / s, the auxiliary injection port closest to the monitoring point is started, and diluted epoxy resin is injected into the auxiliary injection port. The diluted epoxy resin is a mixture of nano-epoxy resin and 0.1wt% nano-alumina.

4. The tunnel lining waterstop construction method according to claim 1, characterized in that: In step six, a honeycomb aluminum buffer layer is installed on the top pressure surface of the hydraulic top pressure module, and the pore density of the honeycomb aluminum buffer layer is 20 to 30 pores / cm²; the honeycomb aluminum pores of the honeycomb aluminum buffer layer are filled with silicone foam, and the outer side of the honeycomb aluminum buffer layer is composited with an orthogonal laminated carbon fiber mesh; before the top pressure operation, the honeycomb aluminum buffer layer is pre-compressed to 75% of the original thickness, and a limit column array is set between the honeycomb aluminum buffer layer and the top pressure surface.

5. The tunnel lining waterstop construction method according to claim 1, characterized in that: In step 5, the inflatable expansion strip is connected to a mechanical pressure balancing device, which includes a bellows compensator and a lever counterweight mechanism; the bellows is filled with food-grade glycerin, and the free end of the bellows is connected to a vertical guide rod; A hinged lever is connected to the top of the vertical guide rod, with a counterweight fixed at one end and an adjustable weight slide at the other end. When the pressure fluctuation of the inflatable expansion strip exceeds 0.05kPa, the bellows expands and contracts to drive the vertical guide rod to move, triggering the counterweight to rise and fall through the imbalance of the lever. A metal sintered filter element is installed between the bellows and the inflatable expansion strip.

6. The tunnel lining waterstop construction method according to claim 1, characterized in that: In step three, the L-shaped anchors are pre-installed on the rigid positioning grid. The rigid positioning grid is a truss structure with a width of 50 cm. A closed-cell foam silicone layer is bonded to the back of the rigid positioning grid, and criss-cross pressure relief grooves are opened on the surface of the closed-cell foam silicone layer. Adjustable legs are installed at both ends of the rigid positioning grid, and the bottom of the legs have magnetic bases. A conical guide sleeve is embedded in the anchor slot. During installation, the rigid positioning grid is placed close to the lining template, and the legs are locked after calibration with a spirit level.

7. The method for constructing a tunnel lining waterstop according to claim 4, wherein: Phase-change microcapsules are uniformly dispersed in a silica gel foam. The preparation method comprises the following steps: paraffin wax, nano-alumina powder and polyethylene glycol are melt-blended at a mass ratio of 100:1.5-2.5:0.5 at 120-140°C, and emulsified at high speed shear to form a dispersed phase with a particle size of 10 μm or less; melamine resin is used as a shell material, and microencapsulation is carried out by in-situ polymerization at a pH of 4.5-5.5 to form microcapsules with a core material phase change temperature of 45-60°C; the mass proportion of the microcapsules in the silica gel foam is 8-12%.

8. The method for constructing a tunnel lining waterstop according to claim 7, wherein: The surface of the carbon fiber mesh is treated with argon plasma at a power of 300-500W for 60-90s; then the vacuum degree is ≤10 -3 Under Pa conditions, vapor phase grafting was performed with glycidyl methacrylate as the grafting monomer, and the grafting rate was ≥3.5μmol / m 2 After grafting, an aluminum oxide reflective layer is deposited on the surface of the carbon fiber mesh. The deposition temperature is 290-310°C, the deposition time is 30-45s, and the mesh is preheated to 250°C±10°C and kept warm for 2 minutes before deposition. After deposition, nitrogen is introduced and cooled to <80°C at a rate of ≥15°C / s. The thickness of the reflective layer is 80-120nm, the crystal phase is γ-Al2O3, and the surface roughness of the reflective layer is Ra≤0.15μm.

9. The method for constructing a tunnel lining waterstop according to claim 8, wherein: A hemispherical tungsten alloy cap was welded to the end of the limiting column. The surface of the cap was processed with a micro-pit array by nanosecond pulse laser. The laser parameters were as follows: wavelength 1064 nm, pulse energy 8-12 mJ, repetition frequency 20 kHz; micro-pit depth 20-50 μm, diameter 80-150 μm, and pit edge curvature radius ≥ 5 μm; the micro-pit distribution density from the center of the cap to the edge was calculated according to the function ρ = ρ0 [1-(r / R) 2 ] Gradient decreasing, where ρ0 is the density of the cap body center 120 ~ 150 pits / mm 2 , r is the distance from the center, and R is the curvature radius of the cap body.