Integrated construction method for continuous grooving and pouring of underground anti-impact wall

Abstract

The invention discloses an integrated construction method for continuous grooving and pouring of an underground anti-impact wall, and relates to the technical field of continuous grooving construction of the underground anti-impact wall, and the construction method comprises the following construction steps: constructing a guide wall through a guiding and grooving system, and excavating a groove section; a positioning pre-embedded connection system is arranged on the wall surface of the groove section to form a reinforcing layer; the performance of the retaining wall slurry in the groove is kept stable by using the dynamic slurry management system; after grooving is completed, rapid hole cleaning, reinforcement cage installation and synchronous concrete pouring are sequentially executed, the positioning pre-buried connection system comprises a positioning pre-buried net, a grouting channel and extension fibers, and the extension fibers are connected with conical barbs and anchored to the groove wall. The underground scour prevention wall has the advantages that the firmness and the stability of the underground scour prevention wall structure are improved, and the phenomena of soil layer softening, collapse or quicksand are effectively prevented.

Description

Technical Field

[0001] This invention relates to the technical field of continuous trenching construction of underground erosion control walls, and in particular to an integrated construction method for continuous trenching and grouting of underground erosion control walls. Background Technology

[0002] In the field of underground engineering, such as large-scale water conservancy and hydropower projects, mining operations, and tunnel construction, underground erosion barriers are considered a crucial geotechnical structure. Their core function is to effectively resist water erosion, maintain the long-term stability of the foundation, and prevent soil loss or liquefaction.

[0003] However, traditional methods for constructing underground erosion barriers have several inherent limitations. First, trench excavation and slurry injection for wall protection are usually carried out as separate steps. This sequential operation mode is prone to causing insufficient stability of the trench wall during the construction phase, especially under geological conditions with high groundwater levels or weak and unconsolidated soil layers, where the risks are particularly significant.

[0004] Secondly, existing construction techniques face challenges in constructing robust and continuous structural interfaces. This often results in a lack of sufficient integrity between adjacent wall units or between the wall and the surrounding rock, thereby reducing the overall structural strength of the system. This structural discontinuity increases the risk of water seepage (leakage) and potential structural failures (such as local collapse or excessive deformation), especially when the system needs to withstand long-term external hydrostatic pressure or geological loads.

[0005] Furthermore, in traditional solutions, the combined effect between the temporary support mortar and permanent reinforcement components (such as steel cages) is often insufficient. This poor synergy hinders the effective transfer of loads, thereby weakening the overall stability of the completed trench section and the finished wall's resistance to various external static and dynamic water loads. Summary of the Invention

[0006] This application provides an integrated construction method for continuous trenching and grouting of underground erosion walls, which improves the robustness and stability of the underground erosion wall structure and effectively prevents soil softening, collapse, or quicksand phenomena.

[0007] This application provides an integrated construction method for continuous trenching and grouting of underground erosion control walls, which adopts the following technical solution: An integrated construction method for continuous trenching and grouting of underground anti-scouring walls includes the following steps: constructing a guide wall and excavating trench sections using a guiding and trenching system; setting a positioning pre-embedded connection system on the trench section wall to form a reinforcement layer; using a mud dynamic management system to maintain the stability of the mud performance within the trench wall; and sequentially performing rapid hole cleaning, reinforcement cage installation, and simultaneous concrete grouting after trenching is completed. The positioning pre-embedded connection system includes a positioning pre-embedded mesh, grouting channels, and extended fibers, wherein the extended fibers are connected with conical barbs and anchored to the trench wall.

[0008] Preferably, the positioning pre-embedded mesh forms a honeycomb structure inside, the honeycomb structure is composed of a plurality of regular hexagonal tension holes, the tension holes are connected to the grouting channel and are connected to the extended fiber.

[0009] Preferably, the extended fiber has a root-like divergent structure, and its interior is provided with a divergent channel communicating with the grouting channel. Under the grouting pressure, the divergent channel drives the extended fiber to expand and extend outward.

[0010] Preferably, the tapered barbs at the ends of the extended fibers have a backward-sloping ratchet structure, and the barbs are made of a hard material and penetrate the soil of the trench wall under grouting pressure to form a mechanical interlock.

[0011] Preferably, the mud dynamic management system includes a circulation purification device, a regeneration treatment device, and a mud proportioning device. The regeneration treatment device restores the mud performance to a preset standard range by supplementing bentonite, soda ash, and CMC.

[0012] Preferably, the regeneration treatment device detects the viscosity, density, and pH value of the purified mud and replenishes bentonite, soda ash, and CMC in a preset ratio to maintain the mud wall protection function.

[0013] Preferably, the rapid hole cleaning and rebar cage installation system includes a sediment thickness detector, an automatic verticality monitoring module, and temporary fixing facilities, wherein the verticality monitoring module provides real-time feedback of the rebar cage's posture data.

[0014] Preferably, the automatic verticality monitoring module includes a tilt sensor and a wireless transmission device, wherein the tilt sensor is installed on the top of the rebar cage and is linked to the crane operation terminal.

[0015] Preferably, the synchronous concrete pouring system adopts a segmented guide pipe assembly arranged along the central axis of the reinforcing cage, and the guide pipe interface is provided with a sealing ring and connected to the bolts via a flange.

[0016] Preferably, the top of the guide wall cooperates with the top fixing component of the positioning pre-embedded mesh to form a horizontal reference surface, and the inner guide surface of the guide wall maintains a predetermined gap with the running trajectory of the trenching equipment to constrain longitudinal offset.

[0017] In summary, this application has the following beneficial effects: 1. By seamlessly integrating five systems—guiding and trenching, positioning and pre-embedded connection system, mud dynamic management, rapid hole cleaning and rebar cage installation, and synchronous concrete pouring—this invention achieves a fully integrated process for continuous trenching and pouring construction of underground anti-scour walls. This method can complete trenching, positioning and reinforcement, hole cleaning, rebar cage hoisting, and concrete pouring within a single construction cycle, reducing waiting time between processes and significantly improving construction efficiency and wall accuracy. The guiding and trenching system ensures the verticality and positional accuracy of the trench segments; the mud dynamic management system maintains stable wall performance and improves mud recycling rate; the rapid hole cleaning and rebar cage installation system completes sediment removal and precise rebar cage placement in a short time; and the newly added automatic verticality monitoring and sediment thickness data recording functions enable full traceability of quality; the synchronous concrete pouring system ensures a tight bond between the concrete and the trench wall and prevents defects. Through the synergistic effect of these four systems, this invention effectively reduces the risks of hole collapse and deviation, ensures stable and controllable wall quality, and improves construction safety and economy.

[0018] 2. By coordinating high-precision guide walls with a hydraulic grab trenching machine in the guiding and trenching system, reinforced concrete guide walls are constructed at precise positions on both sides of the anti-scour wall construction axis. The inner side of the guide wall serves as the guiding surface for the trenching equipment, while the outer side contacts the undisturbed soil to provide lateral support. A steel reinforcement skeleton is laid inside the guide wall, and the soil is backfilled and compacted to form an integral support. During the trenching process, the grab trenching machine is lowered along the channel between the guide walls. The grab guide component maintains the designed gap with the inner wall of the guide wall to reduce trench wall tilting caused by uneven ground or mechanical deviation. The verticality and trench wall condition are checked and adjusted during construction to ensure that the trench section cross-sectional dimensions, position, and verticality meet the design requirements.

[0019] 3. The entire process of the dynamic mud management system involves circulation, purification, and regeneration. The dynamic mud management system consists of a fresh mud preparation and storage device, a circulation and purification device, a performance regeneration device, and delivery pipelines. It monitors mud performance in real time throughout the entire trenching process and uses a circulation pump to transport the mud to the purification device to remove sand and sediment. After purification, bentonite, soda ash, and carboxymethyl cellulose are added according to the test results to bring the performance close to the standard of fresh mud. This purified mud is then mixed with new mud for use, maintaining overall performance stability, effectively reducing the risk of trench wall collapse, improving mud utilization, and providing stable operating conditions for subsequent processes.

[0020] 4. The system seamlessly integrates rapid borehole cleaning with the continuous installation of the reinforcing cage. Immediately after trenching is completed, the borehole cleaning equipment is activated, using a mud circulation and purification device to remove sediment from the bottom of the trench and maintain a stable mud level. The reinforcing cage, prefabricated off-site, is transported to the site in sections. A guiding device lowers it along the centerline of each trench section to the design elevation, and temporary fixings are used to connect it to the guide wall or pre-installed supports to prevent displacement or tilting before concrete pouring. This system achieves a tight connection between borehole cleaning and reinforcing cage installation, shortening mud retention time and minimizing performance degradation.

[0021] 5. The positioning and pre-embedded connection system connects the guiding and trenching system and the mud dynamic management system. The positioning and pre-embedded connection system is used to improve the strength and stability of the trench wall after the guiding and trenching system has formed the trench, and it works in conjunction with the wall protection mud injected in the subsequent mud dynamic management system and the concrete pouring of the synchronous concrete pouring system. This means that it can better integrate with the subsequent materials to form a more robust and durable overall structure.

[0022] 6. The pre-embedded positioning mesh, through its tension pores and honeycomb structure, enhances the strength and stability of the trench wall. Combined with the protective slurry, it effectively prevents slurry loss, forming a dense and strongly adhesive mud cake to prevent sediment deposition. Meanwhile, the extended fibers, as a flexible structure, connect to the grouting channels through their internal divergent channels. Under external force, they can expand and extend outwards, penetrating deep into the micropores and irregular surfaces of the trench wall, forming a widely distributed and interwoven solidified body. This effectively strengthens the bond between the pre-embedded positioning mesh and the trench wall, reduces local stress concentration, and improves overall stability. Combined with the conical barb design, the barbs, when the extended fibers extend, can pierce the trench wall material and generate a ratchet effect, further increasing the contact area and mechanical interlocking strength, thereby significantly improving the overall structure's pull-out and shear resistance. These components work together to ensure the robustness and stability of the underground erosion control wall structure, effectively preventing soil softening, collapse, or quicksand phenomena. Attached Figure Description

[0023] Figure 1 This is a construction flowchart in this embodiment; Figure 2 This is an overall layout structure diagram of the positioning and pre-embedded connection system in this embodiment; Figure 3 This is a partial cross-sectional view of the positioning and pre-embedded connection system in this embodiment; Figure 4 This is in this embodiment Figure 3 Enlarged structural diagram at point A in the middle; Figure 5 This is a flowchart of the mud preparation process in this embodiment; Figure 6 This is a flowchart of the mud separation and treatment process in this embodiment; Explanation of reference numerals in the attached drawings: 1. Channel section; 2. Positioning pre-embedded mesh; 3. Pipeline grout conveying device; 4. Fixing component; 5. Tension hole; 6. Extended fiber; 7. Barb. Detailed Implementation

[0024] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content. Example

[0025] This invention discloses an integrated construction method for continuous trenching and grouting of underground erosion control walls, such as... Figure 1 As shown, this repair process achieves efficient workflow and comprehensive quality control by completing trenching, hole cleaning, rebar cage hoisting, and concrete pouring within the same construction cycle. Figure 1 As shown, it includes a guiding and trenching system, a positioning and pre-embedded connection system, a mud dynamic management system, a rapid hole cleaning and rebar cage installation system, and a synchronous concrete pouring system.

[0026] The guiding and trenching system, positioning and pre-embedded connection system, mud dynamic management system, rapid hole cleaning and rebar cage installation system, and synchronous concrete pouring system are interconnected. Specifically, firstly, the guiding and trenching system uses a high-precision guide wall in conjunction with a hydraulic grab trenching machine equipped with real-time verticality monitoring and automatic correction functions to ensure the accuracy of trench wall formation and reduce the accumulation of deviations. Secondly, the mud dynamic management system monitors the mud density, viscosity, and pH value in real time during trenching and maintains stable wall protection performance through circulation purification and regeneration replenishment, reducing the risk of hole collapse and leakage. Thirdly, the rapid hole cleaning and rebar cage installation system immediately performs efficient hole cleaning and mud replacement after trenching is completed, and hoists the rebar cage into place in a short time, shortening the mud residence time and reducing performance degradation. Finally, the synchronous concrete pouring system immediately lays out ducts and continuously pours concrete after the rebar cage is positioned. Combined with reasonable duct layout and burial depth control, it ensures a tight bond between the concrete and the trench wall and prevents duct blockage.

[0027] S1: Specific operation of the guiding and trenching system; When setting up the guide and trenching system at the construction site, the first step is to accurately construct reinforced concrete guide walls on both sides of the planned construction axis of the seepage barrier (or underground continuous wall).

[0028] The aforementioned reinforced concrete guide wall adopts a "┓┏" shaped cross-section, with a horizontal thickness of approximately 300mm, a vertical thickness of approximately 200mm, an overall height of approximately 1600mm, and an internal clear width of approximately 1250mm. The inner side of the guide wall is specifically designed as a precise guiding surface for the trenching equipment, effectively limiting the entry and exit trajectory and posture of the grab bucket. Its outer side directly contacts the undisturbed soil, playing a crucial role in lateral support and position determination.

[0029] The internal structure of the guide wall is reinforced by a longitudinal and transverse steel reinforcement cage, with horizontal and vertical bars tied together at even intervals. To ensure structural durability, the thickness of the steel reinforcement protective layer is controlled at approximately 50mm. This internal reinforcement design aims to ensure that the guide wall maintains its structural integrity and prevents deformation when subjected to the mechanical loads and hydrostatic pressure of the slurry generated during trenching.

[0030] After the guide wall construction is completed, its outer area needs to be backfilled and compacted with soil to form a unified external support system. Simultaneously, the inner side of the guide wall will form a precise and closed guide slot. The top surface of the guide wall will undergo meticulous leveling to provide a flat and stable reference surface for the smooth operation of the trenching equipment. To facilitate construction measurement and precise control, the top surface will also be clearly marked with the trench segment number and elevation information.

[0031] The trenching operation takes place within a precise channel defined by the guide wall. The grab-type trenching machine is lowered vertically along this channel, with its guide components maintaining a precisely designed clearance from the inner wall of the guide wall. This configuration effectively ensures that the equipment maintains a stable operating trajectory both longitudinally and laterally, thereby minimizing trench wall tilting caused by geological heterogeneity or equipment operating deviations.

[0032] During excavation, the grab bucket's lower end efficiently cuts the soil layer through precise control of cutting depth and speed. The cut soil is then mixed with the wall-supporting slurry within the trench and lifted to the ground along with the grab bucket. This soil is immediately dumped onto transport vehicles and quickly removed from the construction area to prevent it from settling at the bottom of the trench and affecting subsequent processes. Throughout the trenching process, professionals continuously and meticulously monitor and record the verticality and overall condition of the trench walls, adjusting the equipment's operating posture as needed based on real-time feedback to ensure that the flatness of the trench walls and the verticality of trench section 1 strictly meet design specifications.

[0033] Throughout the construction cycle, the guide wall plays a crucial role. It not only precisely defines the operating range of the trenching equipment but also stabilizes the boundary of the mud surface, thus ensuring the continuous and effective functioning of the mud wall support. The bottom elevation of the guide wall is precisely aligned with the designed trench bottom elevation, effectively eliminating the risk of mud leakage from the bottom.

[0034] In summary, throughout the excavation of Section 1, the guide wall provided stable rigid constraints and precise positional control; the trenching equipment was responsible for the precise cutting and cross-sectional shaping of the soil layers; and the wall-supporting slurry formed a water-resistant filter cake on the trench wall, effectively suspending sediment. These three elements worked synergistically and efficiently in both space and time, ensuring that the cross-sectional dimensions, positional accuracy, and verticality of Section 1 strictly met design and construction specifications. This integrated control system laid a solid and stable foundation for subsequent key processes such as slurry performance regulation, borehole cleaning, and precise installation of the reinforcing cage.

[0035] S2: Positioning and pre-embedded connection system; The positioning and pre-embedded connection system is used to connect the guiding and trenching system and the mud dynamic management system. After the guiding and trenching system has formed the trench, the positioning and pre-embedded connection system is used to improve the strength and stability of the trench wall and to work in synergy with the wall protection mud injected in the subsequent mud dynamic management system and the concrete pouring of the synchronous concrete pouring system. This means that it can better integrate with subsequent materials to form a more robust and durable overall structure.

[0036] like Figure 2 As shown, the positioning and pre-embedded connection system includes a mortar mixing device, a grouting pipeline device 3, and a positioning and pre-embedded net 2. After the trench section 1 is excavated and formed, the positioning and pre-embedded net 2 is inserted into the trench by an underwater robot connected to its bottom. Under the traction of the underwater robot, the positioning and pre-embedded net 2 is made to adhere to the trench wall and is positioned at the trench opening by the fixing part 4 at the top of the positioning and pre-embedded net 2. The positioning and pre-embedded net 2 has a grouting channel inside, and the grouting channel inside the positioning and pre-embedded net 2 is connected to the output end of the mortar mixing device through the grouting pipeline device 3. The mortar mixing device is used to mix mortar of appropriate concentration and inject it into the interior of the positioning and pre-embedded net 2 through the grouting pipeline device 3, so that the positioning and pre-embedded net 2 extends and lays flat on the trench wall. After the mortar in the grouting channel solidifies, a reinforcement layer is formed on the trench wall, which matches the subsequent wall protection mud and further plays a role in reinforcement.

[0037] like Figure 2 As shown, after the excavation of section 1 is completed, the trench is typically filled with slurry to maintain stability. Traditionally, precise trench wall reinforcement at this stage is very difficult. This method uses an underwater robot to guide and position a pre-embedded mesh 2 into the trench, ensuring it precisely adheres to the trench wall. Once the pre-embedded mesh 2 is in place, pre-mixed mortar is injected into the grouting channels inside the mesh via a pipeline grouting device 3. The pressure of the mortar causes the mesh to expand outward, compacting it more tightly and adhering it to the trench wall. The injected mortar gradually solidifies within the mesh, forming a reinforcement layer with a certain strength and density. This reinforcement layer effectively binds together the originally loose or easily collapsible trench wall soil, enhancing the integrity and stability of the trench wall from the inside out.

[0038] like Figure 2 As shown, the resulting reinforcement layer not only provides support itself but also integrates with the subsequently injected wall-protecting mortar. This means it can better bond with subsequent materials, forming a more robust and durable overall structure.

[0039] like Figure 2 As shown, pre-reinforcing the trench walls can significantly reduce the risk of trench wall collapse during construction, improving the safety of on-site operations. Simultaneously, the increased stability of the trench walls shortens the slurry maintenance time, accelerating the subsequent lowering of the reinforcing cage and concrete pouring, thereby improving overall construction efficiency.

[0040] Furthermore, traditional wall-forming slurry or final concrete comes into direct contact with the original soil, which may affect the interface quality due to the inhomogeneity or local collapse of the original soil. The reinforcement layer formed by this method provides a uniform and stable interface, and enhances the overall strength and stability of the subsequent concrete pouring and curing. It can better transfer the load of the final erosion barrier to the surrounding soil, and improve the overall performance and long-term durability of the erosion barrier against water erosion.

[0041] Finally, the reinforcement layer formed by the embedded mesh and the cured mortar is like putting a "lining" on the excavated trench wall. This "lining" not only enhances the strength of the trench wall, but may also play a certain role in isolation, reducing the exchange of moisture between the concrete and the original soil during subsequent concrete pouring, which is conducive to the uniform curing of the concrete.

[0042] like Figure 2 As shown, the interior of the pre-embedded positioning mesh 2 forms several hexagonal tension holes 5. These tension holes 5 create a honeycomb-like tension area on the tank wall, meaning the pre-embedded mesh itself may bear a certain amount of tension. This tension, combined with the honeycomb structure, further enhances the stability and impermeability of the mud cake. It helps to establish a stronger bond between the tank wall and the mud cake, reducing mud loss. In the mud dynamic management system described below, the wall-protecting mud works synergistically to form a mud cake and suspend sediment within the tension area of ​​the pre-embedded positioning mesh 2.

[0043] like Figure 2 As shown, this honeycomb structure possesses excellent mechanical properties, effectively dispersing stress and providing a physical support and anchoring interface for subsequent cake formation. When wall-protecting slurry with appropriate rheological properties (such as bentonite slurry) is injected into the trench, the solid particles in the slurry (such as bentonite) will penetrate towards the trench wall along with the slurry.

[0044] like Figure 2As shown, the honeycomb structure of the positioning pre-embedded mesh 2 acts like a precision sieve and skeleton. It can trap solid particles in the mud and guide these particles to be uniformly deposited on the surface of the mesh and within its pores, forming a dense and strongly adhesive mud cake. This positioning pre-embedded mesh 2 provides a stable "foundation" for the mud cake, making it less susceptible to erosion or peeling.

[0045] like Figure 2 As shown, the mud dynamic management system ensures that the performance of the wall protection mud (such as density, viscosity, thixotropy, filtrate loss, etc.) is always at its optimal state.

[0046] Once a stable mud cake forms within the tension zone of the pre-embedded mesh 2, it effectively prevents excessive loss of the mud liquid phase to the surrounding soil layers. This allows the mud in the trench to maintain its designed rheological properties, thereby effectively suspending the excavated sediment (soil chips, gravel, etc.) in the mud and carrying it out of the trench through the mud circulation system, preventing sediment from accumulating at the bottom of the trench.

[0047] By forming a strong and uniform mud cake on the trench wall, excessive water in the mud is effectively prevented from seeping into the surrounding soil layers, thus preventing soil softening, collapse, or quicksand, and significantly improving the overall stability of the trench wall. The pre-embedded mesh structure provides additional physical support and anchoring for the mud cake, making it stronger and less prone to falling off, further enhancing the seepage prevention and wall protection effects.

[0048] like Figure 3 As shown, the positioning pre-embedded mesh 2 has extendable, root-like, radiating fibers 6 on one side near the trench wall. These fibers 6 are flexible and have root-like radiating channels inside, which connect to the grouting channels within the positioning pre-embedded mesh 2. Under the pressure of the mortar, the flexible fibers 6 expand and extend outwards due to the increased internal pressure. They gradually extend and diffuse towards the trench wall, penetrating into the tiny pores, cracks, or irregular surfaces inside the trench wall. Once the fibers 6 are fully extended and inside the trench wall, the injected mortar gradually solidifies. After solidification, the fibers 6 are tightly bonded to the trench wall material, forming a widely distributed and interwoven solidified body. This structure is similar to countless tiny anchor points penetrating deep into the trench wall, thus achieving a firm fixation of the positioning pre-embedded mesh 2 and a stable effect through this "root-like growth behavior."

[0049] By extending and diverging like a root system, the contact area between the embedded mesh and the trench wall and the number of anchor points are increased, allowing the embedded mesh to be more firmly fixed within the trench wall and significantly enhancing overall stability. The flexible extended fiber 6 can better adapt to the microscopic unevenness or cracks of the trench wall, penetrating into the fine structure of the trench wall to achieve a tighter and more effective bond, compensating for the shortcomings of rigid anchors on irregular trench wall interfaces.

[0050] Moreover, the root-like distributed anchoring method evenly distributes the fixing force over a wider area of ​​the trench wall, effectively avoiding localized stress concentration that may occur with traditional point anchoring, thereby reducing the risk of localized cracking or damage to the trench wall. The distributed anchoring structure can not only effectively resist pull-out forces perpendicular to the trench wall, but also better resist shear forces parallel to the trench wall through its diffusion and embedding effects.

[0051] like Figure 3 and Figure 4 As shown, the ends of the extensible, root-like, radiating fibers 6 are connected to conical barbs 7. These barbs 7 are made of hard steel, possessing sufficient strength and rigidity to pierce the soil within the trench wall with sharp conical structures, much like drill bits or nails, when the fibers 6 are stretched under pressure. The conical structure, combined with the barb 7 design, makes it easier for them to penetrate forward under pressure. Once penetrated, the barbs 7 have backward-sloping hooks, creating a ratchet effect. When attempting to pull them out, these barbs 7 tightly grip the surrounding soil or material, forming a strong mechanical interlock. After the barbs 7 penetrate the trench wall material, they not only increase the contact area with the material, but more importantly, they generate strong shear resistance, compressive resistance, and localized material engagement with the material, far exceeding simple surface friction.

[0052] The flexible structure of the extended fiber 6 ensures the distributed transmission of anchoring force and adaptability to the irregularity of the trench wall. Meanwhile, the hard steel barbs 7 at the ends provide strong, localized, and extremely high pull-out resistance rigid anchoring at each dispersed anchoring point, forming a robust "point-to-point" grip.

[0053] Once the hardened steel barbs 7 penetrate the trench wall material, their unique geometry makes them extremely difficult to pull out, providing pull-out resistance far exceeding that of simple friction or grout coagulation, ensuring that the embedded mesh will not easily detach under vertical tension. Furthermore, for trench wall materials such as soil, loose rock layers, or materials with low strength, simple grout diffusion may not provide a sufficiently strong anchorage. The barbs 7 can directly penetrate and grip these materials, greatly improving the fixing effect under these conditions. Once the barbs 7 penetrate the trench wall, even if the grout mortar has not fully cured, they immediately provide a certain mechanical fixing force, laying the foundation for subsequent structural stability. The strong mechanical locking provided by the barbs 7 ensures that the positioning embedded mesh 2 maintains a stable anchorage even under adverse conditions such as long-term stress, vibration, or water erosion, extending the service life of the structure.

[0054] S3: Mud Dynamic Management System; The dynamic mud management system plays a crucial role in stabilizing the trench walls and preventing leakage and collapse during continuous trenching and grouting construction of scour walls. It maintains the stability of mud performance throughout the entire construction process through dynamic circulation and regeneration. The dynamic mud management system consists of a fresh mud preparation and storage device, a circulation and purification device, a performance regeneration device, and mud delivery pipelines. It relies on mud tanks, mud pumps, and delivery hoses to connect and coordinate all components.

[0055] like Figure 5 and Figure 6 As shown, before construction, initial wall-protecting mud was prepared in a fresh mud pit according to the geological conditions. The mud preparation was carried out using a high-speed rotary mixer. First, a CMC solution was prepared and allowed to stand for 5 hours. Then, water and bentonite were added to the mixing drum and stirred for 5 minutes. Next, the CMC solution was added and stirring continued for 10 minutes. Finally, soda ash was added and stirred until homogeneous. The mixture was then placed in a storage tank and allowed to stand for 24 hours to allow the bentonite to fully hydrate. The materials used per 1000 kg of water were 85 kg of bentonite (200 mesh), 1.8 kg of soda ash, and 0.8 kg of CMC. The prepared fresh mud had the following performance indicators: specific gravity 1.05–1.15, viscosity 18–25 seconds, pH 8–9, water loss ≤30 ml / 30 min, and mud cake thickness ≤1 mm, meeting the requirements for wall protection.

[0056] The mud pit capacity design is based on the excavation volume of standard trench section 1, V1 = 28.5 × 6 × 1.2 = 205 m³, and the reserve volume V2 = 164 m³, the circulating regeneration treatment tank capacity V3 = 307 m³, and the injection waste mud volume V4 = 38.4 m³. It is determined that each work area will be equipped with two new 164 m³ mud tanks and a total mud pit with a capacity of V ≥ V3 + V4 = 345 m³ to ensure the continuity of supply and recovery. During trenching operations, mud is injected into trench section 1 through a delivery pipeline, with the liquid level always higher than the groundwater level, creating hydrostatic pressure on the trench walls. As excavation progresses, the mud, carrying cutting soil and sand, is transported to the circulating mud pit via a mud circulation pump and then enters the mud purification device. Mechanical separation removes the mixed sand and sediment, and the properties of the purified mud are adjusted according to the test results.

[0057] Although the purified circulating mud removes solid impurities, the content of bentonite, soda ash, and CMC decreases due to contact with soil, groundwater, and harmful ions in concrete, weakening its wall-protecting performance. To restore performance, bentonite, soda ash, and CMC are added during the regeneration process according to test results, or concentrated fresh mud is directly mixed into the purified mud and stirred by a mud pump to bring its performance indicators close to the standards of fresh mud. The regenerated mud is not used alone but is mixed with fresh mud to maintain overall performance stability.

[0058] Throughout the construction process, the mud dynamic management system and the positioning and pre-embedded connection system complement each other: the guide wall defines the boundary of the mud surface, the trenching equipment provides precise shaping, the mud wall protection forms a water-proof layer and suspends sediment on the positioning and pre-embedded mesh 2 on the trench wall surface, and the circulation and regeneration device maintains stable performance. Through this system, the collapse rate of the trench wall can be effectively reduced under different geological conditions, the mud utilization rate and construction quality can be improved, and stable operating conditions can be provided for subsequent hole cleaning, reinforcement cage installation and concrete pouring.

[0059] S4: Rapid Hole Cleaning and Reinforcing Cage Installation System After the excavation of Section 1 is completed and the depth and cross-sectional dimensions are confirmed to meet the design requirements, the rapid borehole cleaning and rebar cage installation system is immediately activated to complete the removal of sediment and precise placement of the rebar cage in the shortest possible time, thereby ensuring the stability of the trench wall and preventing significant degradation of the mud performance. The system mainly consists of borehole cleaning equipment, mud circulation and purification devices, rebar cage prefabrication and hoisting equipment, guiding and positioning devices, and temporary fixing facilities. All components are spatially connected through pipelines, lifting tools, measurement baselines, and guiding components, forming a continuous operation chain in time sequence.

[0060] The borehole cleaning operation is carried out under the action of mud slurry wall protection. A cleaning pump and its inlet / outlet mud slurry pipelines, installed above section 1 of the trench, pump the mud slurry mixed with sediment from the bottom of the trench to a mud circulation tank. After the sand and sediment are removed by a separation device, the purified mud slurry is returned to the trench through the delivery pipeline, achieving circulating cleaning. A high-precision sediment thickness detector is introduced during the cleaning process, along with a data recording module, to monitor and record the sediment thickness at the bottom of the trench in real time. When the sediment thickness meets the design and specification requirements, the cleaning is immediately stopped, and the mud slurry level is kept stable. The sediment thickness curve is simultaneously archived, forming a traceable quality record, providing data for subsequent engineering inspection and quality management. In this process, the mud circulation and purification device and the cleaning equipment form a closed loop, preventing the mud performance from declining due to sediment accumulation and creating clean conditions for mud replacement during the subsequent concrete pouring stage.

[0061] The reinforcing cage is prefabricated off-site according to the design drawings and transported to the site in sections. Before hoisting, a crane operating platform and guiding device are set up above the guide wall. The guiding device is laid out along the centerline of section 1 of the trench, corresponding to the reference surface at the top of the guide wall, to ensure the verticality of the reinforcing cage during the lowering process. During the hoisting operation, an automatic verticality monitoring module is installed on the reinforcing cage. The module consists of an inclination sensor and a wireless data transmission device, which provides real-time feedback on the cage's attitude to the crane operator. When a tilting trend is detected, the system immediately issues a warning signal, allowing the operator to adjust the hoisting posture in time to prevent collision with the trench wall or torsional deformation. When the bottom of the reinforcing cage approaches the design elevation of the trench bottom, the position and height are confirmed by a measuring device. Then, temporary fixing facilities are used to connect the upper end of the reinforcing cage to the guide wall or pre-set supports to prevent displacement or tilting before concrete pouring.

[0062] In the overall collaboration of the system, the hole cleaning equipment and mud circulation purification device are put into operation before the steel cage hoisting, ensuring that the sediment at the bottom of the trench is thoroughly removed and the mud performance meets the wall protection standards; the automatic verticality monitoring module and the guiding device work together to keep the steel cage within the design range in both vertical and horizontal positions; the temporary fixing facilities maintain the stability of the steel cage throughout the grouting process, and at the same time, with the function of archiving sediment thickness data, the quality of the whole process can be traced and precisely controlled.

[0063] S5: Synchronous Concrete Pouring System After the reinforcing cage is installed and its position and verticality are confirmed to meet design requirements through measurement, the synchronous concrete pouring process begins immediately. First, the mixing plant produces concrete according to the designed mix proportions and transports it to the site. On-site testing of performance parameters such as slump and temperature is conducted, and pouring can only proceed after these parameters are confirmed to be acceptable. Before pouring, the segmented, assembled guide pipes are lowered from top to bottom along the central axis of the reinforcing cage to approximately 300mm from the bottom of the trench. Each section of the guide pipe is connected by flanges and sealing bolts, and sealing rings are installed at the joints to prevent grout leakage. The upper end of the guide pipe is connected to the feed hopper, and a gate at the bottom of the feed hopper controls the feeding speed. After lowering, clean water or cement slurry with the same mix proportion as the concrete is injected into the guide pipe to lubricate it, reducing resistance and preventing segregation caused by direct contact between the concrete and the slurry.

[0064] When the pouring officially begins, the first batch of concrete is slowly poured into the feed hopper. Under its own weight, it enters the tremie pipe and exits from the bottom, directly contacting the slurry at the bottom of the tank to displace it. The slurry rises along section 1 of the tank and flows through the overflow outlet into the recovery pipeline, where it is transported to the slurry tank for purification and reuse. Throughout the pouring process, the bottom of the tremie pipe is always buried at least 2 meters in the poured concrete to prevent slurry backflow or the formation of interlayers. As the concrete level rises, operators adjust the tremie pipe's lifting height synchronously based on measurement readings and the amount of slurry recovered, ensuring that the concrete pouring speed matches the slurry displacement speed and preventing uneven stress on the tank walls due to fluid level fluctuations.

[0065] As the concrete surface approaches the top of the guide wall, the lifting speed of the tremie pipe is gradually reduced until the concrete overflows from the top of the guide wall and forms a dense and flat surface, completing the pouring. During the pouring process, a designated person records the tremie pipe embedment depth, lifting height, concrete volume, and mud recovery volume in real time to ensure the entire process is continuous and uninterrupted. This system maintains dynamic coordination with the mud dynamic management system during operation, promptly recovering and purifying the displaced mud. Simultaneously, it coordinates with the precise positioning during the reinforcement cage installation stage to ensure the reinforcement cage remains in its designed position during pouring. Through this sequential, parameter-controlled construction method, efficient mud replacement and resource recovery can be achieved while ensuring concrete density and wall quality, completing the final transformation from trench segment 1 formation to structural wall completion.

[0066] Working Principle: First, the guiding and trenching system is activated. A reinforced concrete guide wall with a "┓┏" shaped cross-section (approximately 300mm thick, 1600mm high, and 1250mm wide) is precisely constructed along the construction axis. This guide wall provides a rigid guide opening, stabilizes the mud surface boundary, and provides a reference platform for equipment operation. Under the strict constraint of the guide wall, the hydraulic grab trenching machine excavates vertically, with real-time monitoring and automatic correction to ensure the vertical accuracy and dimensions of the trench wall meet requirements. The excavated soil is mixed with the wall-protecting mud and then lifted and transported away, reducing sedimentation at the bottom of the trench.

[0067] Then, after the trench section 1 is excavated and formed, the positioning and pre-embedded connection system is immediately deployed. This system uses an underwater robot to pull and attach the positioning and pre-embedded net 2 with its built-in grouting channel to the trench wall, and positions it at the trench opening using the top fixing member 4. The positioning and pre-embedded net 2 features a unique honeycomb-shaped tension hole design 5.

[0068] Subsequently, the positioning and pre-embedded connection system injects the proportioned mortar into the grouting channel of the pre-embedded mesh through the pipeline grouting device 3. The grouting pressure causes the pre-embedded mesh to expand outward, more tightly compacting the trench wall.

[0069] Simultaneously, the flexible, root-like, radiating extended fibers 6 of the pre-embedded mesh facing the trench wall, along with their hardened steel conical barbs 7 at their ends, work under the pressure of the mortar: the flexible fibers extend and penetrate into the tiny pores of the trench wall, while the barbs 7 at their ends pierce into the soil, forming a strong mechanical interlocking effect similar to a ratchet. After the mortar cures, a reinforcement layer is formed on the trench wall, consisting of the pre-embedded mesh, extended fibers 6, barbs 7, and cured mortar. This layer greatly enhances the integrity and stability of the trench wall and provides a uniform, high-strength interface with microscopic anchoring points, laying the foundation for subsequent mud wall protection and concrete bonding.

[0070] Subsequently, the mud dynamic management system became fully operational, working in conjunction with the positioning and pre-embedded connection system to maintain trench wall stability. This system operates on a dynamic, cyclical basis. First, before construction, prepare fresh mud (specific gravity 1.05~1.15, viscosity 18~25 seconds, etc.) precisely according to the formula (water + bentonite + soda ash + CMC) and store it.

[0071] During the trenching process, fresh or recycled mud is injected into the trench, and the liquid level is higher than the groundwater level to form hydrostatic pressure to protect the wall.

[0072] Subsequently, the mud containing cutting soil and sand is pumped out by a circulating pump and enters a mud purification device to remove sediment.

[0073] Then, the purified mud enters the regeneration process, where bentonite, soda ash, or CMC (or concentrated fresh mud) are added according to the test results to restore its performance to near the standard of fresh mud.

[0074] Finally, the recycled mud is reinjected into the tank for reuse. The key is that as the mud flows within the tank, its solid particles are effectively trapped and deposited on the surface and in the gaps of the honeycomb tension holes 5 of the pre-embedded mesh 2, forming a uniform, dense, and strongly adhesive mud cake. This mud cake, relying on the physical support and anchoring provided by the pre-embedded mesh, significantly enhances the tank wall's ability to prevent seepage, provide stable support, and suspend sediment. The mud tank capacity design ensures the continuity and sufficient reserve of the entire circulation process.

[0075] Once the trench is completed and confirmed, the rapid hole cleaning and rebar cage installation system is immediately activated: First, a closed-loop circulation system is formed through the hole cleaning pump and pipelines to extract the slurry containing sediment from the bottom of the trench. After the sediment is removed by a purification device, the clean slurry is pumped back into the trench. At the same time, a high-precision sediment thickness detector monitors the sediment thickness at the bottom of the trench in real time. Hole cleaning is stopped once the standard is reached to ensure the cleanliness of the bottom of the trench.

[0076] Then, the prefabricated steel cages from off-site are lowered using an on-site crane. Before hoisting, a guide device is installed on top of the guide wall to ensure centerline alignment.

[0077] During the lowering process, the automatic verticality monitoring module on the steel cage detects the cage's posture in real time, provides immediate feedback to the operator, and makes timely adjustments to prevent collisions with the trench walls or tilting.

[0078] When the bottom of the rebar cage is close to the design elevation, after precise positioning, use temporary fixing facilities to firmly lock its upper end to the guide wall or support to prevent displacement or tilting in subsequent processes.

[0079] Finally, after the reinforcing cage is installed in place and confirmed to be correct, the synchronous concrete pouring system is seamlessly connected: First, qualified concrete is transported to the site, and its slump and other properties are checked. Then, the segmented guide pipes are lowered along the center of the reinforcing cage to a point approximately 300mm from the bottom of the trench, connected and sealed, and then connected to the feed hopper. After lowering, the pipes are lubricated with clean water or cement slurry.

[0080] Then, the pouring officially began. The first batch of concrete was slowly poured into the hopper, and by its own weight, it entered the duct and was discharged from the bottom, replacing the mud in the tank. The replaced mud overflowed from the tank opening into the recycling pipeline and was sent to the mud tank for purification and regeneration.

[0081] During the pouring process, the key is to keep the bottom of the tremie pipe embedded at least 2 meters into the poured concrete. The tremie pipe is then raised synchronously and at a uniform speed according to the rising rate of the concrete surface. This ensures that the concrete continuously falls to replace the slurry, preventing slurry mixing, layering, or blockage of the tremie pipe.

[0082] Finally, as the concrete surface approaches the top of the guide wall, the lifting speed is slowed down until the concrete overflows from the top of the guide wall, forming a flat and dense surface. Key parameters (depth, lifting volume, volume, and amount of recycled grout) are recorded throughout the process to ensure continuous control.

[0083] This integrated construction method for continuous trenching and grouting of underground erosion control walls first involves precise trenching using a guide wall and trenching system; then, a positioning and pre-embedded system pre-reinforces the trench walls to form an ideal interface; simultaneously, a mud system enables dynamic wall protection and sediment suspension and removal; immediately after trenching, efficient hole cleaning and precise hoisting and fixing of the reinforcing cage are performed; finally, continuous and controlled concrete pouring effectively replaces and recycles the mud. Each system is tightly integrated in time, interdependent in space (e.g., the guide wall is the foundation for equipment operation and measurement positioning; the pre-embedded mesh is key to optimizing the mud cake and strengthening the interface; mud circulation connects hole cleaning and concrete replacement), and functionally interconnected (e.g., hole cleaning creates conditions for reinforcing cage installation, and reinforcing cage positioning is a prerequisite for concrete pouring). Through real-time parameter monitoring and closed-loop control, efficient, stable, and high-quality operation is achieved throughout the entire process from trenching to wall construction.

[0084] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An integrated construction method for continuous trenching and grouting of underground erosion control walls, characterized in that, The construction steps include: constructing a guide wall and excavating a trench section (1) through a guide and trenching system; setting a positioning pre-embedded connection system on the wall of the trench section (1) to form a reinforcement layer; using a mud dynamic management system to maintain the stability of the mud performance of the trench wall; and performing rapid hole cleaning, steel cage installation and synchronous concrete pouring in sequence after the trench is completed. The positioning pre-embedded connection system includes a positioning pre-embedded mesh (2), a grouting channel and an extension fiber (6). The extension fiber (6) is connected with a conical barb (7) and anchored to the trench wall.

2. The integrated construction method for continuous trenching and grouting of underground erosion control walls according to claim 1, characterized in that, The positioning pre-embedded mesh (2) forms a honeycomb structure inside, which is composed of several regular hexagonal tension holes (5). The tension holes (5) are connected to the grouting channel and are connected to the extended fiber (6).

3. The integrated construction method for continuous trenching and grouting of underground erosion control walls according to claim 2, characterized in that, The extended fiber (6) has a root-like divergent structure and has a divergent channel inside that communicates with the grouting channel. Under the grouting pressure, the divergent channel drives the extended fiber (6) to expand and extend outward.

4. The integrated construction method for continuous trenching and grouting of underground erosion control walls according to claim 3, characterized in that, The tapered barbs (7) at the end of the extended fiber (6) have a backward-sloping ratchet structure. The barbs (7) are made of hard material and penetrate the soil of the trench wall under the grouting pressure to form a mechanical interlock.

5. The integrated construction method for continuous trenching and grouting of underground erosion control walls according to claim 1, characterized in that, The mud dynamic management system includes a circulation purification device, a regeneration treatment device, and a mud proportioning device. The regeneration treatment device restores the mud performance to a preset standard range by supplementing bentonite, soda ash, and CMC.

6. The integrated construction method for continuous trenching and grouting of underground erosion control walls according to claim 5, characterized in that, The regeneration treatment device detects the viscosity, density, and pH value of the purified mud and replenishes bentonite, soda ash, and CMC in a preset ratio to maintain the mud's wall-protecting function.

7. The integrated construction method for continuous trenching and grouting of underground erosion control walls according to claim 1, characterized in that, The rapid hole cleaning and rebar cage installation system includes a sediment thickness detector, an automatic verticality monitoring module, and temporary fixing facilities. The verticality monitoring module provides real-time feedback on the rebar cage's posture data.

8. The integrated construction method for continuous trenching and grouting of underground erosion control walls according to claim 7, characterized in that, The automatic verticality monitoring module includes a tilt sensor and a wireless transmission device. The tilt sensor is installed on the top of the steel cage and is linked to the crane operation terminal.

9. The integrated construction method for continuous trenching and grouting of underground erosion control walls according to claim 1, characterized in that, The synchronous concrete pouring system uses segmented guide pipe assemblies arranged along the central axis of the reinforcing cage. The guide pipe interfaces are equipped with sealing rings and connected to the bolts via flanges.

10. The integrated construction method for continuous trenching and grouting of underground erosion control walls according to claim 1, characterized in that, The top of the guide wall and the top fixing part (4) of the positioning pre-embedded net (2) cooperate to form a horizontal reference surface. The inner guide surface of the guide wall maintains a predetermined gap with the running trajectory of the trenching equipment to constrain longitudinal offset.

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