Freezing bedrock outer layer gabion cage grouting integral type well wall construction system

Abstract

The invention relates to the technical field of ore resource utilization, in particular to a frozen bedrock outer layer gabion cage grouting integral well wall construction system. According to the technical scheme, the frozen bedrock outer layer gabion cage grouting integral type well wall building system comprises a gabion cage structure module, a filler supply and preprocessing module, a guide grouting system module, a sealing and forming maintenance module and a construction monitoring and data integration module; according to the scheme, firstly, the low-cost gabion metal net cage is used as a flexible framework, iron ore tailings or coal gangue block stones which are originally difficult to treat are used as main filling materials, expensive concrete is replaced, resource utilization of solid waste is achieved, and the cost of raw materials is greatly reduced; the problems that a pure gabion structure is poor in integrity and internal materials are prone to weathering and loss are effectively solved through the auxiliary guide pipe pre-embedding and subsequent pressure grouting processes.

Description

Technical Field

[0001] This invention relates to the field of mineral resource utilization technology, and in particular to an integral wellbore construction system for gabion cage grouting in the outer layer of frozen bedrock. Background Technology

[0002] The inner well wall of the frozen bedrock section serves as the main load-bearing permanent support structure, while the outer well wall plays a temporary support role, only playing a certain role in the early stage of construction. As a thick-walled cylindrical structure, the well shaft is mainly supported by the inner well wall, while the outer well wall experiences less stress and has good strength stability after the bedrock is frozen.

[0003] Existing technologies commonly employ monolithic cast plain concrete or reinforced concrete support methods when constructing the outer well wall in frozen bedrock sections. However, the outer well wall is essentially a temporary support structure, whose core function is limited to maintaining the local stability of the frozen wall after excavation during the short construction period before the construction of the permanent inner well wall. The load it bears is far lower than that of a permanent structure. Traditional concrete support does not distinguish between this fundamental difference between temporary and permanent structures, and directly adopts high-standard building materials and complex processes similar to those used in permanent structures. This results in a large amount of high-grade cement, aggregates, and steel bars being consumed in a short-term, limited-stress component, leading to significant waste of building materials and excessively high project costs.

[0004] To address the aforementioned issues, this solution first utilizes low-cost gabion mesh cages as a flexible framework, replacing expensive concrete with iron ore tailings or coal gangue boulders, which are typically difficult to process. This achieves resource utilization of solid waste and significantly reduces raw material costs. Second, through pre-embedded auxiliary conduits and subsequent pressure grouting, after the initial support structure composed of the flexible framework and waste filler is formed, grout is injected to fill all the gaps between the boulders. This transforms the originally loose filler into a dense structure with integrity and strength after solidification, effectively solving the problems of poor integrity and easy weathering and loss of internal materials in simple gabion structures. This enables the gabion structure to withstand the mechanical properties required for temporary support, thereby significantly reducing project costs. Summary of the Invention

[0005] To overcome the limitations of existing technologies that commonly employ monolithic cast plain concrete or reinforced concrete support methods when constructing the outer well wall in frozen bedrock sections, it is important to understand that the outer well wall is essentially a temporary support structure. Its core function is limited to maintaining the local stability of the frozen wall after excavation during the short construction period before the permanent inner well wall is constructed. The load it bears is far lower than that of a permanent structure. Traditional concrete support does not distinguish between this fundamental difference between temporary and permanent structures and directly uses high-standard building materials and complex processes similar to those used for permanent structures. This results in a large amount of high-grade cement, aggregates, and steel bars being consumed in a short-term, low-stress component, leading to significant waste of building materials and excessively high project costs.

[0006] The technical solution of this invention is: an integral wellbore construction system for gabion cage grouting in the outer layer of frozen bedrock, comprising the following modules: Gabion cage structural modules: used to form the skeleton of the well wall, constrain the internal filling material, provide initial support force, and together with the grouting body, form the final integral structure; Filler supply and pretreatment module: Used to supply and process solid waste used as filler material for gabion cages; Grouting system module: used to achieve controlled and uniform injection of grout into the gaps between the filling materials inside the gabion cage; Sealing and curing module: used to seal the outer surface of the gabion cage before grouting to prevent grout loss, and to provide suitable conditions for grout curing after grouting; Construction monitoring and data integration module: used for real-time monitoring and data collection of the entire construction process.

[0007] As a preferred embodiment, the gabion cage structure module includes: A11: Cage unit, including wire mesh, mesh nodes, and reinforcing ribs, used to form a container for holding the filler material and to connect the solidified body after grouting into a whole; A12: Connection unit, including binding wire, connecting ring and spiral fastener, used to connect adjacent gabion cages to ensure the integrity and stability of the entire gabion cage structure during the construction phase; A13: Corrosion Reinforcement Unit, including PVC / PE coating, anode protection block and anti-corrosion coating spraying equipment, is used to specially treat or add a protective layer to the gabion cage metal mesh to resist the downhole corrosive environment and extend the structural life.

[0008] Preferably, the packing supply and pretreatment module includes: A21: Pre-treatment unit, including vibrating screen, jaw crusher and flushing nozzle, used to screen, crush or wash raw iron ore tailings or coal gangue to remove excessively fine powder and impurities and obtain boulders of suitable particle size; A22: Conveying unit, including belt conveyor, underground silo and controllable unloading hopper, used to transport pre-treated qualified stones to the underground construction face and put them into gabion cages; A23: Metering and filling control unit, including a weighing sensor, filling height scale and compaction vibrator, used to control filling speed and density to prevent gabion cage deformation.

[0009] Preferably, the grouting system module includes: A31: Conduit unit, including auxiliary conduit with perforated holes, conduit connector, and conduit positioning frame, for pre-embedding during gabion cage assembly as a channel for slurry delivery and distribution; A32: Grouting unit, including grout mixer, grout storage tank, grouting pump and pressure gauge, is responsible for preparing and storing grout and injecting it into the conduit under pressure; A33: Grouting lifting and monitoring unit, including a liftable grouting pipe, depth indicator, flow meter and pressure sensor, for lifting the grouting pipe as the grouting surface rises, and monitoring grouting pressure, flow rate and range to prevent grout loss or incomplete filling.

[0010] As a preferred embodiment, the sealing and molding curing module includes: A41: Surface sealing layer unit, including a sprayer, a sealing slurry tank, and a smoothing tool, used to spray or coat a layer of fast-setting material onto the outer surface of the gabion cage before grouting to form a grout barrier; A42: Slurry curing unit, including temperature sensors, humidity control devices, and curing agent spraying equipment, for providing and controlling an environment conducive to slurry hydration, setting, and strength development; A43: Forming inspection unit, including ultrasonic testing instrument, rebound hammer and core drilling machine, used to inspect the quality of the formed monolithic well wall after grouting consolidation.

[0011] In A41, a layer of dense wire mesh can also be placed on the outside of the gabion cage as a grout barrier layer.

[0012] As a preferred option, the construction monitoring and data integration module includes: A51: Structural monitoring unit, including strain gauges, displacement sensors, and convergence meters, used to monitor the displacement, strain, and stress state of the gabion cage-grouting integrated structure during and after construction; A52: Environmental monitoring unit, including temperature and humidity sensors, water level gauges, and gas detectors, is used to monitor downhole temperature, humidity, and water inflow environmental parameters, and to assess their impact on construction and quality. A53: Data acquisition and processing unit, including data acquisition unit, industrial computer, monitoring software platform and large display screen, is used to collect data from various sensors, process, analyze and store data, and display construction status and structural health status through a visual interface.

[0013] A gabion cage grouting integral wellbore construction system for frozen bedrock outer layer includes the following steps during operation: S11: Repair and lay out the frozen bedrock well walls and treat solid waste filler material to prepare the base surface and materials for the installation of gabion cage structure; S12: Install and connect gabion cages layer by layer along the shaft outline, simultaneously extend the internal guide pipes, and fill and initially compact iron ore tailings or coal gangue boulders into each cage layer until the design elevation is reached; S13: After spraying a sealing layer onto the surface of the formed structure, pressure grouting is performed through a pre-embedded conduit system to bond the internal discrete stones into a whole, and after curing, the final complete well wall structure is formed.

[0014] Preferably, the construction preparation and base surface treatment include the following steps: S21: Before construction, use an ultrasonic detector and temperature sensor to scan the formed frozen bedrock well wall in detail, record its outline flatness, surface temperature distribution and frozen soil strength data, and use a pneumatic pick to trim obviously protruding frozen rock according to the scan results, mark local depression areas and plan filling schemes; S22: At the well site, iron ore tailings or coal gangue are transported to the pre-processing workshop. First, oversized materials are crushed by a jaw crusher, and then graded and screened by a multi-layer vibrating screen to remove fine particles and powder with a particle size of less than 2cm. Finally, qualified boulders with a particle size mainly concentrated in the range of 5-15cm are obtained. The sieved boulders are then sprayed and washed to remove the surface soil and easily weathered debris. S23: Plan and organize the gabion assembly area, the temporary storage area for pre-treated boulders, and the grouting station site near the wellhead. Use lifting equipment to safely transport rolled gabion mesh, binding wire, prefabricated perforated auxiliary guide pipes, and grouting pipe materials to the underground construction platform. At the same time, load the pre-treated boulders into a special bucket for lowering. S24: Lower a plumb line from the fixed reference point at the wellhead to determine the center point of the well. Using this center point as the center, and based on the designed inner radius of the outer well wall, use a laser pointer to clearly mark the entire installation outline on the frozen bedrock well wall. Make a cross section every 3 meters as the inner control edge line for the gabion cage installation. S25: At the designed elevation at the bottom of the well, first lay a layer of early-strength cement mortar about 5cm thick as a leveling layer, and calibrate it with a spirit level. Install an adjustable ring positioning steel frame along the outline. The steel frame is connected to the well wall anchoring point through a telescopic support rod to constrain the position and verticality of the first layer of gabion cages. S26: The pre-connected single-layer gabion cages above ground are hoisted to the bottom of the well, unfolded and closed around the positioning frame to form a ring-shaped first layer. At the central axis position in the width direction of the cage, PVC auxiliary guide pipes with dense perforations are vertically installed at the designed intervals. The bottom of the guide pipes is temporarily fixed to the bottom mesh of the cage with steel wire, and the top is 45-50cm higher than the upper edge of the cage. S27: The safety officer inspects the stability of the hoisting platform, the communication system, the ventilation, and the emergency equipment. The technical supervisor gives a final technical briefing to all work teams, clarifying the high-altitude construction parameters, filling standards, grouting ratio, and key quality control points for this section, and signs to confirm.

[0015] Preferably, the following steps are included when assembling gabion cages layer by layer and filling them with solid waste: S31: Adjust the fine-tuning bolts on the ring positioning frame to ensure that the inner side of the first layer of gabion cages is tightly attached to the outline marked by laser, and that the upper surface of the cage is horizontal. Use a special double-strand steel wire twisting and binding tool to firmly bind all contact nodes between the side nets, end nets, and cover nets of adjacent gabion cages to form a continuous bottom unit; S32: Using a small grab bucket or a controllable unloading funnel on the underground hoisting platform, pre-treated stones are evenly filled into the first layer of gabion cages. A layered feeding method is used during filling; feeding is paused every 28-30cm, and workers use steel rods to tamp the stones in the cages, causing them to interlock and reducing large gaps. The filling is continued until the stones are slightly below the top edge of the cage. S33: Hoist the second layer of gabion cages onto the filled first layer, align the edges, and first tightly connect the vertical edge mesh of the upper and lower layers of gabion cages with binding wire, with a spacing of no more than 15cm. Then, screw the top of the auxiliary conduit pre-embedded in the first layer to the new conduit of the same specification through the sleeve joint. S34: Repeat the above filling and extension operations. After each layer of filling is completed, check the gabion for bulging or deformation and reinforce it with steel wire in a timely manner. Extend the auxiliary guide pipes section by section as the construction layer height increases, always keeping the top higher than the current construction surface, until the design elevation of this construction section is reached; S35: When filling to the top layer of gabion cages, fill the stones to be level with the top of the cage. Use stones with slightly smaller diameters to level the surface, check whether the top is relatively flat, and then re-check the binding quality of all exposed gabion mesh nodes; S36: After the construction section is completed, remove the internal positioning frame, and use a plumb line at the center of the shaft and a steel ruler to comprehensively measure the radius, verticality, and roundness of the formed gabion cage structure. For any local deviations exceeding the allowable value, correct and reinforce by adding external tie wires or locally supplementing mesh. S37: Before grouting, an endoscope is lowered through a pre-reserved auxiliary guide tube or a heavy hammer detection method is used to check the filling density and gaps of the stones in the gabion cages at different locations.

[0016] Preferably, the grouting consolidation and curing process includes the following steps: S41: Using a dedicated shotcrete machine, the cement paste or cement mortar mixed according to the design ratio is evenly sprayed onto the outer surface of the formed gabion cage structure. The spraying is carried out in two layers. The first layer covers the mesh, and the second layer is thickened to form a continuous, crack-free, dense, and sealed shell of 1.5-2.0cm. S42: After spraying, the construction area should be kept warm and moisturized. After the sealant has fully hardened, tap the surface lightly with a small hammer to check for hollow spots or cracks. Mark any defective areas and re-spray them. S43: At the ground grouting station, cement-based grouting material is prepared according to the design. Appropriate amounts of water-reducing agent and expanding agent can be added to improve fluidity and micro-expansion. Before pumping each batch of grout, its density, fluidity and initial setting time must be tested to ensure that the grout performance meets the requirements for long-distance diffusion and filling in the gaps between boulders. S44: Lead the high-pressure pipeline of the surface grouting pump down into the well through the wellbore hanging system, connect it to the grouting perforated pipe inserted at the bottom of the auxiliary guide pipe, start the grouting pump, and begin grouting at a lower pressure. Observe whether there is grout seepage near the guide pipe opening to confirm the diffusion path of the grout in the filling body; S45: After confirming that the grout has begun to spread, adopt a bottom-up and layered grouting method. When the grout level reaches a certain height through the observation hole or based on the grouting volume, stop grouting, raise the grouting pipe a certain distance, and then continue grouting. Repeat this operation until the grout flows out steadily from the uppermost auxiliary guide pipe or the preset vent overflow hole. S46: Throughout the grouting process, a designated person records in real time the grouting pressure, grouting flow rate, cumulative grouting volume, as well as the lifting height and time of the grouting pipe for each grouting hole. The system is dynamically adjusted based on feedback, and the maximum pressure does not exceed the design limit to prevent damage to the sealing layer or gabion cage. S47: When all grouting holes have reached the completion standard, stop grouting, pull out the grouting pipe, and immediately seal the auxiliary guide pipe opening with a pre-prepared wooden plug or special pipe cap. The grouting structure needs to be cured in a frozen low temperature environment for no less than 7 days. During this period, avoid collisions or the next high-level tunneling operation. After the core test shows that the strength meets the standard, a complete integral outer well wall is formed.

[0017] The beneficial effects of this invention are: Existing technologies commonly employ monolithic cast plain concrete or reinforced concrete support methods when constructing the outer well wall in frozen bedrock sections. However, the outer well wall is essentially a temporary support structure. Its core function is limited to maintaining the local stability of the frozen wall after excavation during the brief construction period before the permanent inner well wall is constructed. The load it bears is far lower than that of a permanent structure. Traditional concrete support does not distinguish this fundamental difference between temporary and permanent structures, directly using high-standard building materials and complex processes similar to those used for permanent structures. This results in a large amount of high-grade cement, aggregates, and steel reinforcement being consumed in a short-term, low-stress component, leading to significant material waste and excessively high project costs. This solution first utilizes low-cost... Gabion metal mesh cages serve as a flexible skeleton, using iron ore tailings or coal gangue boulders, which are originally difficult to process, as the main filling material, replacing expensive concrete. This achieves the resource utilization of solid waste and significantly reduces raw material costs. Secondly, through the process of pre-embedded auxiliary conduits and subsequent pressure grouting, after the initial support structure composed of the flexible skeleton and waste filling material is formed, grout is injected to fill all the gaps between the boulders. This transforms the originally loose filling material into a dense structure with integrity and strength after solidification, effectively solving the problems of poor integrity and easy weathering and loss of internal materials in simple gabion stone cage structures. This enables the gabion stone cage to bear the mechanical properties required for temporary support, thereby significantly reducing the project cost. Attached Figure Description

[0018] Figure 1 The diagram shown is a schematic of the framework of an integral wellbore construction system for gabion cage grouting in the outer layer of frozen bedrock according to the present invention. Figure 2 The diagram shows the construction preparation and base surface treatment process of an integral well wall construction system for gabion cage grouting in frozen bedrock according to the present invention. Figure 3 The diagram shown is a schematic of the gabion cage layer-by-layer assembly and solid waste filling process of an integral well wall construction system for frozen bedrock outer layer gabion cage grouting according to the present invention. Figure 4 The diagram shows the grouting, consolidation, and curing process of an integral wellbore construction system for the outer layer of frozen bedrock using gabion cages, according to the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Please see Figure 1-4 This invention provides an embodiment: a gabion cage grouting integral wellbore construction system for frozen bedrock outer layer, comprising the following modules: Gabion cage structural modules: used to form the skeleton of the well wall, constrain the internal filling material, provide initial support force, and together with the grouting body, form the final integral structure; Filler supply and pretreatment module: Used to supply and process solid waste used as filler material for gabion cages; Grouting system module: used to achieve controlled and uniform injection of grout into the gaps between the filling materials inside the gabion cage; Sealing and curing module: used to seal the outer surface of the gabion cage before grouting to prevent grout loss, and to provide suitable conditions for grout curing after grouting; Construction monitoring and data integration module: used for real-time monitoring and data collection of the entire construction process.

[0021] As a preferred embodiment, the gabion cage structure module includes: A11: Cage unit, including wire mesh, mesh nodes, and reinforcing ribs, used to form a container for holding the filler material and to connect the solidified body after grouting into a whole; A12: Connection unit, including binding wire, connecting ring and spiral fastener, used to connect adjacent gabion cages to ensure the integrity and stability of the entire gabion cage structure during the construction phase; A13: Corrosion Reinforcement Unit, including PVC / PE coating, anode protection block and anti-corrosion coating spraying equipment, is used to specially treat or add a protective layer to the gabion cage metal mesh to resist the downhole corrosive environment and extend the structural life.

[0022] Preferably, the packing supply and pretreatment module includes: A21: Pre-treatment unit, including vibrating screen, jaw crusher and flushing nozzle, used to screen, crush or wash raw iron ore tailings or coal gangue to remove excessively fine powder and impurities and obtain boulders of suitable particle size; A22: Conveying unit, including belt conveyor, underground silo and controllable unloading hopper, used to transport pre-treated qualified stones to the underground construction face and put them into gabion cages; A23: Metering and filling control unit, including a weighing sensor, filling height scale and compaction vibrator, used to control filling speed and density to prevent gabion cage deformation.

[0023] Preferably, the grouting system module includes: A31: Conduit unit, including auxiliary conduit with perforated holes, conduit connector, and conduit positioning frame, for pre-embedding during gabion cage assembly as a channel for slurry delivery and distribution; A32: Grouting unit, including grout mixer, grout storage tank, grouting pump and pressure gauge, is responsible for preparing and storing grout and injecting it into the conduit under pressure; A33: Grouting lifting and monitoring unit, including a liftable grouting pipe, depth indicator, flow meter and pressure sensor, for lifting the grouting pipe as the grouting surface rises, and monitoring grouting pressure, flow rate and range to prevent grout loss or incomplete filling.

[0024] As a preferred embodiment, the sealing and molding curing module includes: A41: Surface sealing layer unit, including a sprayer, a sealing slurry tank, and a smoothing tool, used to spray or coat a layer of fast-setting material onto the outer surface of the gabion cage before grouting to form a grout barrier; A42: Slurry curing unit, including temperature sensors, humidity control devices, and curing agent spraying equipment, for providing and controlling an environment conducive to slurry hydration, setting, and strength development; A43: Forming inspection unit, including ultrasonic testing instrument, rebound hammer and core drilling machine, used to inspect the quality of the formed monolithic well wall after grouting consolidation.

[0025] In A41, a layer of fine-mesh wire mesh can also be placed on the outside of the gabion cage as a grout-blocking layer. As a preferred option, the construction monitoring and data integration module includes: A51: Structural monitoring unit, including strain gauges, displacement sensors, and convergence meters, used to monitor the displacement, strain, and stress state of the gabion cage-grouting integrated structure during and after construction; A52: Environmental monitoring unit, including temperature and humidity sensors, water level gauges, and gas detectors, is used to monitor downhole temperature, humidity, and water inflow environmental parameters, and to assess their impact on construction and quality. A53: Data acquisition and processing unit, including data acquisition unit, industrial computer, monitoring software platform and large display screen, is used to collect data from various sensors, process, analyze and store data, and display construction status and structural health status through a visual interface.

[0026] A gabion cage grouting integral wellbore construction system for frozen bedrock outer layer includes the following steps during operation: S11: Repair and lay out the frozen bedrock well walls and treat solid waste filler material to prepare the base surface and materials for the installation of gabion cage structure; S12: Install and connect gabion cages layer by layer along the shaft outline, simultaneously extend the internal guide pipes, and fill and initially compact iron ore tailings or coal gangue boulders into each cage layer until the design elevation is reached; S13: After spraying a sealing layer onto the surface of the formed structure, pressure grouting is performed through a pre-embedded conduit system to bond the internal discrete stones into a whole, and after curing, the final complete well wall structure is formed.

[0027] Preferably, the construction preparation and base surface treatment include the following steps: S21: Before construction, use an ultrasonic detector and temperature sensor to scan the formed frozen bedrock well wall in detail, record its outline flatness, surface temperature distribution and frozen soil strength data, and use a pneumatic pick to trim obviously protruding frozen rock according to the scan results, mark local depression areas and plan filling schemes; S22: At the well site, iron ore tailings or coal gangue are transported to the pre-processing workshop. First, oversized materials are crushed by a jaw crusher, and then graded and screened by a multi-layer vibrating screen to remove fine particles and powder with a particle size of less than 2cm. Finally, qualified boulders with a particle size mainly concentrated in the range of 5-15cm are obtained. The sieved boulders are then sprayed and washed to remove the surface soil and easily weathered debris. S23: Plan and organize the gabion assembly area, the temporary storage area for pre-treated boulders, and the grouting station site near the wellhead. Use lifting equipment to safely transport rolled gabion mesh, binding wire, prefabricated perforated auxiliary guide pipes, and grouting pipe materials to the underground construction platform. At the same time, load the pre-treated boulders into a special bucket for lowering. S24: Lower a plumb line from the fixed reference point at the wellhead to determine the center point of the well. Using this center point as the center, and based on the designed inner radius of the outer well wall, use a laser pointer to clearly mark the entire installation outline on the frozen bedrock well wall. Make a cross section every 3 meters as the inner control edge line for the gabion cage installation. S25: At the designed elevation at the bottom of the well, first lay a layer of early-strength cement mortar about 5cm thick as a leveling layer, and calibrate it with a spirit level. Install an adjustable ring positioning steel frame along the outline. The steel frame is connected to the well wall anchoring point through a telescopic support rod to constrain the position and verticality of the first layer of gabion cages. S26: The pre-connected single-layer gabion cages above ground are hoisted to the bottom of the well, unfolded and closed around the positioning frame to form a ring-shaped first layer. At the central axis position in the width direction of the cage, PVC auxiliary guide pipes with dense perforations are vertically installed at the designed intervals. The bottom of the guide pipes is temporarily fixed to the bottom mesh of the cage with steel wire, and the top is 45-50cm higher than the upper edge of the cage. S27: The safety officer inspects the stability of the hoisting platform, the communication system, the ventilation, and the emergency equipment. The technical supervisor gives a final technical briefing to all work teams, clarifying the high-altitude construction parameters, filling standards, grouting ratio, and key quality control points for this section, and signs to confirm.

[0028] Preferably, the following steps are included when assembling gabion cages layer by layer and filling them with solid waste: S31: Adjust the fine-tuning bolts on the ring positioning frame to ensure that the inner side of the first layer of gabion cages is tightly attached to the outline marked by laser, and that the upper surface of the cage is horizontal. Use a special double-strand steel wire twisting and binding tool to firmly bind all contact nodes between the side nets, end nets, and cover nets of adjacent gabion cages to form a continuous bottom unit; S32: Using a small grab bucket or a controllable unloading funnel on the underground hoisting platform, pre-treated stones are evenly filled into the first layer of gabion cages. A layered feeding method is used during filling; feeding is paused every 28-30cm, and workers use steel rods to tamp the stones in the cages, causing them to interlock and reducing large gaps. The filling is continued until the stones are slightly below the top edge of the cage. S33: Hoist the second layer of gabion cages onto the filled first layer, align the edges, and first tightly connect the vertical edge mesh of the upper and lower layers of gabion cages with binding wire, with a spacing of no more than 15cm. Then, screw the top of the auxiliary conduit pre-embedded in the first layer to the new conduit of the same specification through the sleeve joint. S34: Repeat the above filling and extension operations. After each layer of filling is completed, check the gabion for bulging or deformation and reinforce it with steel wire in a timely manner. Extend the auxiliary guide pipes section by section as the construction layer height increases, always keeping the top higher than the current construction surface, until the design elevation of this construction section is reached; S35: When filling to the top layer of gabion cages, fill the stones to be level with the top of the cage. Use stones with slightly smaller diameters to level the surface, check whether the top is relatively flat, and then re-check the binding quality of all exposed gabion mesh nodes; S36: After the construction section is completed, remove the internal positioning frame, and use a plumb line at the center of the shaft and a steel ruler to comprehensively measure the radius, verticality, and roundness of the formed gabion cage structure. For any local deviations exceeding the allowable value, correct and reinforce by adding external tie wires or locally supplementing mesh. S37: Before grouting, an endoscope is lowered through a pre-reserved auxiliary guide tube or a heavy hammer detection method is used to check the filling density and gaps of the stones in the gabion cages at different locations.

[0029] Preferably, the grouting consolidation and curing process includes the following steps: S41: Using a dedicated shotcrete machine, the cement paste or cement mortar mixed according to the design ratio is evenly sprayed onto the outer surface of the formed gabion cage structure. The spraying is carried out in two layers. The first layer covers the mesh, and the second layer is thickened to form a continuous, crack-free, dense, and sealed shell of 1.5-2.0cm. S42: After spraying, the construction area should be kept warm and moisturized. After the sealant has fully hardened, tap the surface lightly with a small hammer to check for hollow spots or cracks. Mark any defective areas and re-spray them. S43: At the ground grouting station, cement-based grouting material is prepared according to the design. Appropriate amounts of water-reducing agent and expanding agent can be added to improve fluidity and micro-expansion. Before pumping each batch of grout, its density, fluidity and initial setting time must be tested to ensure that the grout performance meets the requirements for long-distance diffusion and filling in the gaps between boulders. S44: Lead the high-pressure pipeline of the surface grouting pump down into the well through the wellbore hanging system, connect it to the grouting perforated pipe inserted at the bottom of the auxiliary guide pipe, start the grouting pump, and begin grouting at a lower pressure. Observe whether there is grout seepage near the guide pipe opening to confirm the diffusion path of the grout in the filling body; S45: After confirming that the grout has begun to spread, adopt a bottom-up and layered grouting method. When the grout level reaches a certain height through the observation hole or based on the grouting volume, stop grouting, raise the grouting pipe a certain distance, and then continue grouting. Repeat this operation until the grout flows out steadily from the uppermost auxiliary guide pipe or the preset vent overflow hole. S46: Throughout the grouting process, a designated person records in real time the grouting pressure, grouting flow rate, cumulative grouting volume, as well as the lifting height and time of the grouting pipe for each grouting hole. The system is dynamically adjusted based on feedback, and the maximum pressure does not exceed the design limit to prevent damage to the sealing layer or gabion cage. S47: When all grouting holes have reached the completion standard, stop grouting, pull out the grouting pipe, and immediately seal the auxiliary guide pipe opening with a pre-prepared wooden plug or special pipe cap. The grouting structure needs to be cured in a frozen low temperature environment for no less than 7 days. During this period, avoid collisions or the next high-level tunneling operation. After the core test shows that the strength meets the standard, a complete integral outer well wall is formed.

[0030] Example 1 Background: This embodiment is applied to the construction project of a secondary vertical shaft in a large coal mine. The shaft needs to pass through a water-rich bedrock layer with a thickness of more than 150 meters. The design adopts the freezing method for construction. Traditionally, the outer temporary shaft wall of this frozen bedrock section is planned to be poured with C30 plain concrete. It is expected that the amount of concrete used will be large and the cost will be high. Moreover, it cannot accommodate the mountains of coal gangue waste accumulated in the mining area. The construction unit decided to use the frozen bedrock outer layer gabion cage grouting integral shaft wall construction system described in this invention. An industrial test was conducted in the section of the shaft with a depth of -300 meters to -350 meters to verify the feasibility and economy of using coal gangue as the main material to construct a temporary support structure.

[0031] Implementation steps: First, construction preparation and base treatment were carried out. At the bottom working face of the target construction section, technicians used an explosion-proof ultrasonic detector to scan the frozen bedrock well wall in a circumferential direction, and obtained the outline point cloud data of the well wall. It was confirmed that its average temperature was stable below -10℃ and the frozen soil strength met the requirements. According to the scanning results, frozen rock protruding more than 10 cm was trimmed with a hand-held pneumatic pick, and three large depression areas were marked. At the same time, in the ground industrial square, the coal gangue from the mining area stockpile was transported to the pre-processing line. First, the large pieces with a particle size of more than 30 cm were crushed by a jaw crusher. Then, they were screened by a double-layer vibrating screen to strictly remove debris and powder with a particle size of less than 2 cm. Finally, about 120 cubic meters of qualified gangue blocks with a particle size concentrated between 5 and 15 cm were obtained, and the surface dust was washed off by a spray system. Subsequently, the gabion cage structure was assembled layer by layer and filled with gangue. At the bottom of the prepared well, workers first laid a 5-centimeter-thick layer of early-strength cement mortar for leveling. Then, along the design net radius outline projected by the laser pointer, they installed an adjustable ring-shaped positioning steel frame consisting of six arc-shaped plates. The single-layer galvanized Galfan gabion cages, pre-connected above ground, were then hoisted down into the well, unfolded around the positioning frame, and closed into a ring-shaped first layer. At the center line of each gabion cage width, a PVC auxiliary guide pipe with densely perforated holes was vertically installed every 1 meter. The bottom of the guide pipe... The gabion cage is temporarily fixed, with the top extending 50 centimeters above the cage body. Using the grab bucket on the underground hoist, pre-treated coal gangue boulders are filled into the first layer of cages in layers. The filling is paused every 30 centimeters, and workers use steel rods to tamp the filling to achieve initial compaction, until the filling reaches 5 centimeters from the top of the cage. After completion, the second layer of gabion cages is hoisted and its side netting is tightly tied to the bottom layer. Auxiliary guide pipes are then connected, and the filling and heightening process is repeated until the entire 50-meter-high gabion cage structure is assembled and filled, ultimately forming a 50-meter-high cylindrical gangue-filled gabion cage temporary structure. Finally, grouting consolidation and curing were carried out. On the outer surface of the formed gabion structure, a two-layer sealing layer of cement mortar mixed with a quick-setting agent was sprayed using a wet shotcrete machine, with a total thickness controlled at 2 cm. After 24 hours of curing, a tight seal was formed. At the ground grouting station, a cement grout with a water-cement ratio of 0.5, mixed with a water-reducing agent and a micro-expansion agent, was prepared. Its flowability was tested to be greater than 300 mm. The grouting pipe was lowered into the bottom auxiliary conduit through a high-pressure pipeline suspended from the well wall, and grouting began with an initial pressure of 0.4 MPa. The process employs a bottom-up, segmented lifting technique, lifting the grouting pipe approximately every 3 meters of grouting height. This is monitored in real time by pressure sensors and flow meters installed on the guide pipes. Once the grout has steadily overflowed from the top guide pipe opening and stabilized for 10 minutes, grouting is stopped, and all pipe openings are immediately sealed. The grouting structure was cured in the low-temperature environment of the wellbore for 7 days. Subsequently, core sampling was conducted, and the average compressive strength of the core samples reached 15 MPa, meeting the design requirements for temporary support. This successfully formed an integral frozen bedrock outer layer well wall.

[0032] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A gabion cage grouting integral wellbore construction system for frozen bedrock outer layer; characterized in that: It consists of the following modules: Gabion cage structural modules: used to form the skeleton of the well wall, constrain the internal filling material, provide initial support force, and together with the grouting body, form the final integral structure; Filler supply and pretreatment module: Used to supply and process solid waste used as filler material for gabion cages; Grouting system module: used to achieve controlled and uniform injection of grout into the gaps between the filling materials inside the gabion cage; Sealing and curing module: used to seal the outer surface of the gabion cage before grouting to prevent grout loss, and to provide suitable conditions for grout curing after grouting; Construction monitoring and data integration module: used for real-time monitoring and data collection of the entire construction process.

2. The integral wellbore construction system for gabion cage grouting in frozen bedrock as described in claim 1, characterized in that: Gabion cage structural modules include: A11: Cage unit, including wire mesh, mesh nodes, and reinforcing ribs, used to form a container to hold the filler material and to connect the solidified body after grouting into a whole; A12: Connection unit, including binding wire, connecting ring and spiral fastener, used to connect adjacent gabion cages to ensure the integrity and stability of the entire gabion cage structure during the construction phase; A13: Corrosion Reinforcement Unit, including PVC / PE coating, anode protection block and anti-corrosion coating spraying equipment, is used to specially treat or add a protective layer to the gabion cage metal mesh to resist the downhole corrosive environment and extend the structural life.

3. The integral wellbore construction system for gabion cage grouting in frozen bedrock as described in claim 1, characterized in that: The packing supply and pretreatment module includes: A21: Pre-treatment unit, including vibrating screen, jaw crusher and flushing nozzle, used to screen, crush or wash raw iron ore tailings or coal gangue to remove excessively fine powder and impurities and obtain boulders of suitable particle size; A22: Conveying unit, including belt conveyor, underground silo and controllable unloading hopper, used to transport pre-treated qualified stones to the underground construction face and put them into gabion cages; A23: Metering and filling control unit, including a weighing sensor, filling height scale and compaction vibrator, used to control filling speed and density to prevent gabion cage deformation.

4. The integral wellbore construction system for gabion cage grouting in frozen bedrock as described in claim 1, characterized in that: The grouting system module includes: A31: Conduit unit, including auxiliary conduit with perforated holes, conduit connector, and conduit positioning frame, for pre-embedding during gabion cage assembly as a channel for slurry delivery and distribution; A32: Grouting unit, including grout mixer, grout storage tank, grouting pump and pressure gauge, is responsible for preparing and storing grout and injecting it into the conduit under pressure; A33: Grouting lifting and monitoring unit, including a liftable grouting pipe, depth indicator, flow meter and pressure sensor, for lifting the grouting pipe as the grouting surface rises, and monitoring grouting pressure, flow rate and range to prevent grout loss or incomplete filling.

5. The integral wellbore construction system for gabion cage grouting in the outer layer of frozen bedrock according to claim 1, characterized in that: The sealing and molding curing module includes: A41: Surface sealing layer unit, including a sprayer, a sealing slurry tank, and a smoothing tool, used to spray or coat a layer of fast-setting material onto the outer surface of the gabion cage before grouting to form a grout barrier; A42: Slurry curing unit, including temperature sensors, humidity control devices, and curing agent spraying equipment, for providing and controlling an environment conducive to slurry hydration, setting, and strength development; A43: Forming inspection unit, including ultrasonic testing instrument, rebound hammer and core drilling machine, used to inspect the quality of the formed monolithic well wall after grouting consolidation; In A41, a layer of dense wire mesh can also be placed on the outside of the gabion cage as a grout barrier layer.

6. The integral wellbore construction system for gabion cage grouting in frozen bedrock as described in claim 1, characterized in that: The construction monitoring and data integration module includes: A51: Structural monitoring unit, including strain gauges, displacement sensors, and convergence meters, used to monitor the displacement, strain, and stress state of the gabion cage-grouting integrated structure during and after construction; A52: Environmental monitoring unit, including temperature and humidity sensors, water level gauges, and gas detectors, is used to monitor downhole temperature, humidity, and water inflow environmental parameters, and to assess their impact on construction and quality. A53: Data acquisition and processing unit, including data acquisition unit, industrial computer, monitoring software platform and large display screen, is used to collect data from various sensors, process, analyze and store data, and display construction status and structural health status through a visual interface.

7. A gabion cage grouting integral wellbore construction system for frozen bedrock outer layer according to any one of claims 1-6, characterized in that: A gabion cage grouting integral wellbore construction system for frozen bedrock outer layer includes the following steps during operation: S11: Repair and lay out the frozen bedrock well walls and treat solid waste filler material to prepare the base surface and materials for the installation of gabion cage structure; S12: Install and connect gabion cages layer by layer along the shaft outline, simultaneously extend the internal guide pipes, and fill and initially compact iron ore tailings or coal gangue boulders into each cage layer until the design elevation is reached; S13: After spraying a sealing layer onto the surface of the formed structure, pressure grouting is performed through a pre-embedded conduit system to bond the internal discrete stones into a whole, and after curing, the final complete well wall structure is formed.

8. The integral wellbore construction system for gabion cage grouting in the outer layer of frozen bedrock according to claim 7, characterized in that: The following steps are included in the construction preparation and base surface treatment: S21: Before construction, use an ultrasonic detector and temperature sensor to scan the formed frozen bedrock well wall in detail, record its outline flatness, surface temperature distribution and frozen soil strength data, and use a pneumatic pick to trim obviously protruding frozen rock according to the scan results, mark local depression areas and plan filling schemes; S22: At the well site, iron ore tailings or coal gangue are transported to the pre-processing workshop. First, oversized materials are crushed by a jaw crusher, and then graded and screened by a multi-layer vibrating screen to remove fine particles and powder with a particle size of less than 2cm. Finally, qualified boulders with a particle size mainly concentrated in the range of 5-15cm are obtained. The sieved boulders are then sprayed and washed to remove the surface soil and easily weathered debris. S23: Plan and organize the gabion assembly area, the temporary storage area for pre-treated boulders, and the grouting station site near the wellhead. Use lifting equipment to safely transport rolled gabion mesh, binding wire, prefabricated perforated auxiliary guide pipes, and grouting pipe materials to the underground construction platform. At the same time, load the pre-treated boulders into a special bucket for lowering. S24: Lower a plumb line from the fixed reference point at the wellhead to determine the center point of the well. Using this center point as the center, and based on the designed inner radius of the outer well wall, use a laser pointer to clearly mark the entire installation outline on the frozen bedrock well wall. Make a cross section every 3 meters as the inner control edge line for the gabion cage installation. S25: At the designed elevation at the bottom of the well, first lay a layer of early-strength cement mortar about 5cm thick as a leveling layer, and calibrate it with a spirit level. Install an adjustable ring positioning steel frame along the outline. The steel frame is connected to the well wall anchoring point through a telescopic support rod to constrain the position and verticality of the first layer of gabion cages. S26: The pre-connected single-layer gabion cages above ground are hoisted to the bottom of the well, unfolded and closed around the positioning frame to form a ring-shaped first layer. At the central axis position in the width direction of the cage, PVC auxiliary guide pipes with dense perforations are vertically installed at the designed intervals. The bottom of the guide pipes is temporarily fixed to the bottom mesh of the cage with steel wire, and the top is 45-50cm higher than the upper edge of the cage. S27: The safety officer inspects the stability of the hoisting platform, the communication system, the ventilation, and the emergency equipment. The technical supervisor gives a final technical briefing to all work teams, clarifying the high-altitude construction parameters, filling standards, grouting ratio, and key quality control points for this section, and signs to confirm.

9. The integral wellbore construction system for gabion cage grouting in the outer layer of frozen bedrock according to claim 7, characterized in that: The following steps are included in the layer-by-layer assembly and solid waste filling of gabion cages: S31: Adjust the fine-tuning bolts on the ring positioning frame to ensure that the inner side of the first layer of gabion cages is tightly attached to the outline marked by laser, and that the upper surface of the cage is horizontal. Use a special double-strand steel wire twisting and binding tool to firmly bind all contact nodes between the side nets, end nets, and cover nets of adjacent gabion cages to form a continuous bottom unit; S32: Using a small grab bucket or a controllable unloading funnel on the underground hoisting platform, pre-treated stones are evenly filled into the first layer of gabion cages. A layered feeding method is used during filling; feeding is paused every 28-30cm, and workers use steel rods to tamp the stones in the cages, causing them to interlock and reducing large gaps. The filling is continued until the stones are slightly below the top edge of the cage. S33: Hoist the second layer of gabion cages onto the filled first layer, align the edges, and first tightly connect the vertical edge mesh of the upper and lower layers of gabion cages with binding wire, with a spacing of no more than 15cm. Then, screw the top of the auxiliary conduit pre-embedded in the first layer to the new conduit of the same specification through the sleeve joint. S34: Repeat the above filling and extension operations. After each layer of filling is completed, check whether the gabion is bulging or deformed, and reinforce and tighten it with steel wire in time. The auxiliary guide pipe is extended section by section as the construction layer height increases, always keeping the top higher than the current construction surface, until the design elevation of this construction section is reached; S35: When filling to the top layer of gabion cages, fill the stones to be level with the top of the cage. Use stones with slightly smaller diameters to level the surface, check whether the top is relatively flat, and then re-check the binding quality of all exposed gabion mesh nodes; S36: After the construction section is completed, remove the internal positioning frame, and use a plumb line at the center of the shaft and a steel ruler to comprehensively measure the radius, verticality, and roundness of the formed gabion cage structure. For any local deviations exceeding the allowable value, correct and reinforce by adding external tie wires or locally supplementing mesh. S37: Before grouting, an endoscope is lowered through a pre-reserved auxiliary guide tube or a heavy hammer detection method is used to check the filling density and gaps of the stones in the gabion cages at different locations.

10. The integral wellbore construction system for gabion cage grouting in the outer layer of frozen bedrock according to claim 7, characterized in that: The grouting, consolidation, and curing process includes the following steps: S41: Using a dedicated shotcrete machine, the cement paste or cement mortar mixed according to the design ratio is evenly sprayed onto the outer surface of the formed gabion cage structure. The spraying is carried out in two layers. The first layer covers the mesh, and the second layer is thickened to form a continuous, crack-free, dense, and sealed shell of 1.5-2.0cm. S42: After spraying, the construction area should be kept warm and moisturized. After the sealant has fully hardened, tap the surface lightly with a small hammer to check for hollow spots or cracks. Mark any defective areas and re-spray them. S43: At the ground grouting station, cement-based grouting material is prepared according to the design. Appropriate amounts of water-reducing agent and expanding agent can be added to improve fluidity and micro-expansion. Before pumping each batch of grout, its density, fluidity and initial setting time must be tested to ensure that the grout performance meets the requirements for long-distance diffusion and filling in the gaps between boulders. S44: Lead the high-pressure pipeline of the surface grouting pump down into the well through the wellbore hanging system, connect it to the grouting perforated pipe inserted at the bottom of the auxiliary guide pipe, start the grouting pump, and begin grouting at a lower pressure. Observe whether there is grout seepage near the guide pipe opening to confirm the diffusion path of the grout in the filling body; S45: After confirming that the grout has begun to spread, adopt a bottom-up and layered grouting method. When the grout level reaches a certain height through the observation hole or based on the grouting volume, stop grouting, raise the grouting pipe a certain distance, and then continue grouting. Repeat this operation until the grout flows out steadily from the uppermost auxiliary guide pipe or the preset vent overflow hole. S46: Throughout the grouting process, a designated person records in real time the grouting pressure, grouting flow rate, cumulative grouting volume, as well as the lifting height and time of the grouting pipe for each grouting hole. The system is dynamically adjusted based on feedback, and the maximum pressure does not exceed the design limit to prevent damage to the sealing layer or gabion cage. S47: When all grouting holes have reached the completion standard, stop grouting, pull out the grouting pipe, and immediately seal the auxiliary guide pipe opening with a pre-prepared wooden plug or special pipe cap. The grouting structure needs to be cured in a frozen low temperature environment for no less than 7 days. During this period, avoid collisions or the next high-level tunneling operation. After the core test shows that the strength meets the standard, a complete integral outer well wall is formed.

Images