Fabricated pipe shed system for water-rich stratum deeply-buried underground cavern and construction method

Abstract

The invention discloses an assembly type pipe shed system for a water-rich stratum deeply-buried underground cavern, which comprises a plurality of pipe shed units, the plurality of pipe shed units are linearly arranged, friction yielding connecting units are fixedly connected among the plurality of pipe shed units, and the plurality of friction yielding connecting units connect the plurality of pipe shed units in series. The invention further discloses a construction method of the fabricated pipe shed system for the water-rich stratum deeply-buried underground cavern. According to the fabricated pipe shed system for the water-rich stratum deeply-buried underground cavern and the construction method, the problems that a traditional pipe shed system is poor in adaptability and has split functions under complex geological conditions are solved. The pipe shed is reasonable in design, the functions of supporting, energy dissipation, grouting, monitoring and maintenance are integrated, the technical defects of a traditional pipe shed are effectively overcome, the safety and economical efficiency of complex surrounding rock tunnel construction are improved, and remarkable engineering value and popularization prospects are achieved.

Description

Technical Field

[0001] This invention belongs to the field of advanced support technology for tunnel engineering, specifically relating to a prefabricated pipe roof system for deep underground caverns in water-rich strata, and also to a construction method for the prefabricated pipe roof system for deep underground caverns in water-rich strata. Background Technology

[0002] With the continuous advancement of social development, tunnel engineering is gradually breaking through deeper and more complex geological environments. When traversing extreme conditions such as high-stress weak fracture zones, water-rich faults, and karst development areas, the "dynamic adaptability" and "functional integration" of advanced support become crucial to the safety of the project. Pipe roof support, as the core technology of advanced support, is widely used in the construction of tunnel portal sections and transition sections with adverse geological conditions due to its advantages of "advanced isolation and active load-bearing". However, its traditional structural form is no longer able to meet the dynamic changes of complex surrounding rock.

[0003] However, in water-rich, highly deformable surrounding rock environments, traditional pipe roofs reveal multiple technical shortcomings: On the one hand, after excavation in such strata, the surrounding rock is prone to non-uniform plastic deformation. Water pressure and ground stress couple onto the pipe roof structure. If the pipe roof adopts a purely rigid design, it cannot absorb the deformation energy of the surrounding rock, and is prone to bending fracture due to stress concentration, which in turn induces overall instability of the surrounding rock behind it. If a purely flexible design is adopted, it is difficult to limit excessive relaxation of the surrounding rock, leading to the penetration of fissures and increased water seepage, forming a dilemma of "rigidity leading to easy breakage, flexibility leading to difficulty in support." On the other hand, the functional system of traditional pipe roofs presents a clear fragmentation: in water-rich strata construction, setting up drainage channels alone can easily carry away fine particles of the surrounding rock, forming seepage cavities and causing instability of the tunnel face; while relying solely on grouting reinforcement may block natural seepage paths, leading to water pressure accumulation in the gap between the pipe roof and the surrounding rock, forming new weak links. At the same time, traditional pipe roofs are mostly fixed-length integral structures, and their support performance cannot be dynamically adjusted according to the surrounding rock conditions after being driven into the rock mass, lacking the ability to adapt to sudden changes in surrounding rock pressure. In addition, uneven gaps often form between the pipe roof unit and the surrounding rock due to drilling deviation and rock mass convergence deformation, resulting in "point contact" load transfer, which reduces the utilization rate of pipe roof materials and fails to fully utilize the bearing potential of the surrounding rock itself.

[0004] More importantly, traditional pipe roof construction lacks effective full-process monitoring methods: the assessment of surrounding rock stability relies heavily on surface displacement observation and engineering experience, making it impossible to obtain real-time information on the internal stress state of the pipe roof, the grout diffusion range, and changes in the surrounding seepage field. When internal damage occurs in the surrounding rock or the grout filling is not tight, the early warning response is severely delayed, often missing the best opportunity for risk management and increasing construction safety risks. Summary of the Invention

[0005] The purpose of this invention is to provide a prefabricated pipe roof system for deep underground caverns in water-rich strata, which solves the problems of poor adaptability and functional fragmentation of traditional pipe roof systems under complex geological conditions.

[0006] Another object of the present invention is to provide a construction method for a prefabricated pipe roof system for deep underground caverns in water-rich strata.

[0007] The technical solution adopted in this invention is a prefabricated pipe roof system for deep underground caverns in water-rich strata, comprising several pipe roof units, which are arranged linearly, and friction relief connection units are fixedly connected between the pipe roof units, which connect the pipe roof units in series.

[0008] The invention is further characterized by: The friction pressure relief connection unit includes a constant resistance pressure relief mechanism, with pipe shed units fixed at both ends of the constant resistance pressure relief mechanism, and a drainage channel provided in the center of the constant resistance pressure relief mechanism.

[0009] The constant resistance pressure relief mechanism includes a fixed sleeve, a pipe roof unit fitted on the inner wall of one end of the fixed sleeve, and a sliding sleeve fitted on the inner wall of the other end of the fixed sleeve. A friction ring and a disc spring assembly are provided on the outer wall of the sliding sleeve near the fixed sleeve, arranged side-by-side between the sliding sleeve and the fixed sleeve. Another pipe roof unit is fitted on the outer wall of the sliding sleeve away from the fixed sleeve. The fixed sleeve and the pipe roof unit, the fixed sleeve and the sliding sleeve, and the sliding sleeve and the other pipe roof unit are all fixedly connected by high-strength bolts. A drainage channel is located inside the fixed sleeve and the sliding sleeve. The mechanism also includes a displacement monitoring device located on the inner wall of the fixed sleeve. A displacement monitoring wire hole is provided on the fixed sleeve, and a displacement monitoring wire is connected to the displacement monitoring device. The displacement monitoring wire passes through the displacement monitoring wire hole and connects to a control terminal. The displacement monitoring device is used to monitor the relative slippage between the sliding sleeve and the fixed sleeve.

[0010] Each pipe roof unit includes an outer rigid sleeve with a permeable inner liner inside. A granular energy dissipation and water filtration layer is filled between the outer rigid sleeve and the permeable inner liner. Several grouting holes are opened on the outer rigid sleeve. It also includes a grout pressure sensor, which is located in the grouting hole. A pressure monitoring wire is connected to the grout pressure sensor, and the pressure monitoring wire passes through the grouting hole and connects to the control terminal. The grout pressure sensor is used to monitor the grouting pressure.

[0011] The granular energy dissipation filter layer is filled with natural gravel, artificial ceramsite, polymer particles or a mixture of natural gravel, artificial ceramsite and polymer particles. The natural gravel, artificial ceramsite, polymer particles or mixture in the granular energy dissipation filter layer are all arranged in a hexagonal shape, and the porosity of the granular energy dissipation filter layer is 35%~40%.

[0012] The permeable liner includes an inner liner with several water passage holes. The outer wall of the inner liner is wrapped with a reverse filter geotextile, and the inner liner corresponds to the drainage channel.

[0013] The inner lining pipe is selected from PVC pipe, permeable composite material pipe and metal filter pipe.

[0014] Another technical solution adopted in this invention is a construction method for a prefabricated pipe roof system for deep underground caverns in water-rich strata, comprising the following steps: Step 1: Prefabricate several friction relief connection units and pipe roof units; Step 2: Assemble the friction relief connection unit and the pipe roof unit in sections, turn on the displacement monitoring device and the slurry pressure sensor to form the pipe roof system; Step 3: Actively drain water and dissipate energy through the pipe roof system; Step 4: Complete the construction by controlling the grouting and monitoring the data through the pipe roof system.

[0015] Another feature of the technical solution adopted in this invention is that: Step 1 specifically involves: prefabricating friction relief connection units, outer rigid sleeves, and permeable inner lining pipes according to the tunnel design cross-section; filling the annular cavity between the outer rigid sleeve and the permeable inner lining pipe with a granular energy dissipation and water filtration layer, and assembling them to form a pipe roof unit. Step 2 is as follows: A pilot hole is constructed at the tunnel face using a geological drilling rig. The first pipe roof unit is driven into the pilot hole using a jacking device, ensuring that the deviation between the axis of the pipe roof unit and the design axis is no more than 30mm. A friction relief connection unit is installed at the end of the pipe roof unit and fixed with high-strength bolts. Subsequent pipe roof units are inserted into the friction relief connection unit to complete the mechanical connection. The inner lining pipe inside the pipe roof unit is connected to the drainage channel. The displacement monitoring module and slurry pressure sensor are turned on and energized for debugging to form the pipe roof system.

[0016] Step 3 is as follows: Groundwater enters through a one-way permeable lining pipe and is eventually discharged into the tunnel drainage system; the surrounding rock pressure acts on the pipe roof system, and when the axial force exceeds the set value, the constant resistance pressure relief mechanism generates controllable slippage, releasing the deformation energy of the surrounding rock, and the slippage is monitored in real time through the displacement monitoring module. Step 4 specifically involves: starting the external grouting equipment, injecting grout into the granular energy dissipation and water filter layer through the grouting holes. The granular energy dissipation and water filter layer serves as a natural diffusion medium for the grout. By controlling the grouting pressure and grout ratio, the grout forms a uniform and continuous network cement within a predetermined range, achieving precise reinforcement of the surrounding rock. The displacement monitoring module and grout pressure sensor collect the pressure relief displacement and grouting pressure data in real time at a set frequency, and transmit them to the control terminal to complete the construction.

[0017] The beneficial effects of this invention are: This invention provides a prefabricated pipe roof system and construction method for deeply buried underground caverns in water-rich strata. It combines rigidity and flexibility with pressure-dissipating energy dissipation: the outer rigid casing provides primary support, the intermediate granular layer efficiently dissipates deformation energy through inter-particle friction and rearrangement, and the friction-dissipating pressure-relieving connection unit safely releases high ground stress through controllable sliding, forming multiple energy dissipation lines and fundamentally avoiding brittle structural failure. Furthermore, it integrates drainage and active drainage: the permeable inner lining pipe and integrated drainage channels constitute an active drainage system, effectively reducing pore water pressure acting on the support system. Simultaneously, the reverse filter layer design prevents fine particle loss, resolving the conflict between grouting and drainage. Intelligent sensing and controllable grouting: The monitoring system integrated into the connecting unit can capture two key state parameters, namely, pressure relief displacement and grouting pressure, in real time, providing accurate data support for judging the stability of the surrounding rock and initiating grouting, thus realizing intelligent support process; Prefabricated construction and maintainability: The segmented prefabricated assembly design greatly improves construction efficiency, and the replaceable design of local pressure relief units or pipe roof units significantly reduces long-term operation and maintenance costs and the impact on construction progress; Wide application range: By adjusting parameters such as pressure relief load, particle size distribution, and grout formula, it can be flexibly adapted to complex surrounding rock conditions with different strength grades and water-rich levels. This invention is rationally designed, integrating the functions of "support-energy dissipation-grouting-monitoring-maintenance" into one, effectively solving the technical defects of traditional pipe roofs, improving the safety and economy of complex surrounding rock tunnel construction, and has significant engineering value and promotion prospects. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the prefabricated pipe roof system for deep underground caverns in water-rich strata according to the present invention; Figure 2 This is a connection diagram of the friction relief connection unit of the present invention; Figure 3 This is a schematic diagram of the installation of the disc spring assembly of the present invention; Figure 4 This is a schematic diagram of the structure of the pipe shed unit of the present invention; Figure 5 This is a cross-sectional schematic diagram of the pipe roof unit of the present invention; Figure 6 This is a flowchart of the construction method for the prefabricated pipe roof system for deep underground caverns in water-rich strata according to the present invention.

[0019] In the diagram, 1. Friction relief connection unit, 101. Drainage channel, 102. Constant resistance relief mechanism, 1021. Fixed sleeve, 1022. Sliding sleeve, 1023. Friction ring, 1024. Disc spring assembly, 1025. High-strength bolt, 2. Pipe roof unit, 3. Outer rigid sleeve, 301. Grouting hole, 4. Granular energy dissipation filter layer, 5. Permeable inner lining pipe, 501. Reverse filter geotextile, 502. Lining pipe, 503. Water passage hole, 6. Displacement monitoring device, 7. Grout pressure sensor. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] The prefabricated pipe roof system for deep underground caverns in water-rich strata provided by this invention, such as... Figure 1 As shown, the system includes several pipe roof units 2, which are arranged linearly. Friction-relief connection units 1 are fixedly connected between each of the pipe roof units 2, and these friction-relief connection units 1 connect the pipe roof units 2 in series. Figure 2 As shown, the friction relief connection unit 1 includes a constant resistance relief mechanism 102, with pipe shed units 2 fixed at both ends of the constant resistance relief mechanism 102. A drainage channel 101 is provided in the center of the constant resistance relief mechanism 102. The constant resistance relief mechanism 102 includes a fixed sleeve 1021, with the pipe shed unit 2 sleeved on the inner wall of one end of the fixed sleeve 1021. A sliding sleeve 1022 is sleeved on the inner wall of the other end of the fixed sleeve 1021. Figure 3 As shown, a friction ring 1023 and a disc spring assembly 1024 are provided on the outer wall of the sliding sleeve 1022 near the fixed sleeve 1021. The friction ring 1023 and the disc spring assembly 1024 are arranged side by side and are located between the sliding sleeve 1022 and the fixed sleeve 1021. Another pipe roof unit 2 is fitted onto the outer wall of the sliding sleeve 1022 away from the fixed sleeve 1021. The fixed sleeve 1021 and the pipe roof unit 2, the fixed sleeve 1021 and the sliding sleeve 1022, and the sliding sleeve 1022 and the other pipe roof unit 2 are all fixedly connected by high-strength bolts 1025. A drainage channel 101 is provided between the fixed sleeve 1021 and the sliding sleeve 1021. The interior of the sleeve 1022 also includes a displacement monitoring device 6, which is located on the inner wall of the fixed sleeve 1021. The fixed sleeve 1021 has a displacement monitoring wire hole, and a displacement monitoring wire is connected to the displacement monitoring device 6. The displacement monitoring wire passes through the displacement monitoring wire hole and connects to a control terminal. The displacement monitoring device 6 is used to monitor the relative slippage between the sliding sleeve 1022 and the fixed sleeve 1021. The displacement monitoring module 6 is a built-in magnetic induction counting device, including a magnet array located on the sliding sleeve 1022 of the constant resistance relief mechanism 102, and a Hall sensor located on the fixed sleeve 1021 and corresponding to the magnet array, used to monitor the slippage in real time through pulse counting. Figure 4 As shown, each of the several pipe roof units 2 includes an outer rigid sleeve 3, inside which a permeable inner liner 5 is installed. A granular energy-dissipating filter layer 4 is filled between the outer rigid sleeve 3 and the permeable inner liner 5. Several grouting holes 301 are opened on the outer rigid sleeve 3. It also includes grout pressure sensors 7, which are diaphragm-type pressure sensors. The grout pressure sensors 7 are located within the grouting holes 301, at both ends and the middle of the pipe roof unit 2, totaling three sets. Pressure monitoring wires are connected to the grout pressure sensors 7, and these wires extend out of the grouting holes 301. Connected to the control terminal, the grout pressure sensor 7 is used to monitor the grouting pressure. The sensing diaphragm of the grout pressure sensor 7 is in contact with the granular energy dissipation filter layer 4 to directly measure the diffusion and distribution of grout pressure inside the structure. The granular energy dissipation filter layer 4 is filled with natural gravel, artificial ceramsite, polymer particles, or a mixture of these materials. The natural gravel, artificial ceramsite, polymer particles, or mixtures in the granular energy dissipation filter layer 4 are all arranged in a hexagonal shape, and the porosity of the granular energy dissipation filter layer 4 is 35%~40%. Figure 5 As shown, the permeable inner liner pipe 5 includes an inner liner pipe 502, which has several water passage holes 503. The outer wall of the inner liner pipe 502 is wrapped with a reverse filter geotextile 501. The inner liner pipe 502 corresponds to the drainage channel 101. The inner liner pipe 502 is selected from one of PVC pipe, permeable composite material pipe and metal filter pipe.

[0022] Example 1 The prefabricated pipe roof system proposed in this embodiment for deep underground caverns in water-rich strata, such as Figure 1 As shown, it includes several pipe roof units 2, which are arranged linearly. Each of the pipe roof units 2 is fixedly connected to a friction relief connection unit 1, and the friction relief connection unit 1 connects the pipe roof units 2 in series.

[0023] Example 2 The prefabricated pipe roof system proposed in this embodiment for deep underground caverns in water-rich strata, such as Figure 1 As shown, the system includes several pipe roof units 2, which are arranged linearly. Friction-relief connection units 1 are fixedly connected between each of the pipe roof units 2, and these friction-relief connection units 1 connect the pipe roof units 2 in series. Figure 2 As shown, the friction relief connection unit 1 includes a constant resistance relief mechanism 102, with pipe shed units 2 fixed at both ends of the constant resistance relief mechanism 102. A drainage channel 101 is provided in the center of the constant resistance relief mechanism 102. The constant resistance relief mechanism 102 includes a fixed sleeve 1021, with the pipe shed unit 2 sleeved on the inner wall of one end of the fixed sleeve 1021. A sliding sleeve 1022 is sleeved on the inner wall of the other end of the fixed sleeve 1021. Figure 3As shown, a friction ring 1023 and a disc spring assembly 1024 are provided on the outer wall of the sliding sleeve 1022 near the fixed sleeve 1021. The friction ring 1023 and the disc spring assembly 1024 are arranged side by side and are located between the sliding sleeve 1022 and the fixed sleeve 1021. Another pipe roof unit 2 is fitted on the outer wall of the sliding sleeve 1022 away from the fixed sleeve 1021. The fixed sleeve 1021 and the pipe roof unit 2, the fixed sleeve 1021 and the sliding sleeve 1022, and the sliding sleeve 1022... Unit 2 and another pipe shed unit 2 are both fixedly connected by high-strength bolts 1025. Drainage channel 101 is located inside the fixed sleeve 1021 and the sliding sleeve 1022. It also includes a displacement monitoring device 6, which is located on the inner wall of the fixed sleeve 1021. The fixed sleeve 1021 has a displacement monitoring wire hole, and a displacement monitoring wire is connected to the displacement monitoring device 6. The displacement monitoring wire passes through the displacement monitoring wire hole and is connected to the control terminal. The displacement monitoring device 6 is used to monitor the relative slippage between the sliding sleeve 1022 and the fixed sleeve 1021.

[0024] Example 3 The prefabricated pipe roof system proposed in this embodiment for deep underground caverns in water-rich strata, such as Figure 1 As shown, the system includes several pipe roof units 2, which are arranged linearly. Friction-relief connection units 1 are fixedly connected between each of the pipe roof units 2, and these friction-relief connection units 1 connect the pipe roof units 2 in series. Figure 2 As shown, the friction relief connection unit 1 includes a constant resistance relief mechanism 102, with pipe shed units 2 fixed at both ends of the constant resistance relief mechanism 102. A drainage channel 101 is provided in the center of the constant resistance relief mechanism 102. The constant resistance relief mechanism 102 includes a fixed sleeve 1021, with the pipe shed unit 2 sleeved on the inner wall of one end of the fixed sleeve 1021. A sliding sleeve 1022 is sleeved on the inner wall of the other end of the fixed sleeve 1021. Figure 3As shown, a friction ring 1023 and a disc spring assembly 1024 are provided on the outer wall of the sliding sleeve 1022 near the fixed sleeve 1021. The friction ring 1023 and the disc spring assembly 1024 are arranged side by side and are located between the sliding sleeve 1022 and the fixed sleeve 1021. Another pipe roof unit 2 is fitted on the outer wall of the sliding sleeve 1022 away from the fixed sleeve 1021. The fixed sleeve 1021 and the pipe roof unit 2, the fixed sleeve 1021 and the sliding sleeve 1022, and the sliding sleeve 1022... Unit 2 and another pipe shed unit 2 are both fixedly connected by high-strength bolts 1025. A drainage channel 101 is located inside the fixed sleeve 1021 and the sliding sleeve 1022. It also includes a displacement monitoring device 6, which is located on the inner wall of the fixed sleeve 1021. The fixed sleeve 1021 has a displacement monitoring wire hole, and a displacement monitoring wire is connected to the displacement monitoring device 6. The displacement monitoring wire passes through the displacement monitoring wire hole and connects to a control terminal. The displacement monitoring device 6 is used to monitor the relative slippage between the sliding sleeve 1022 and the fixed sleeve 1021. Figure 4 As shown, each of the several pipe shed units 2 includes an outer rigid sleeve 3, a permeable inner liner 5 inside the outer rigid sleeve 3, and a granular energy dissipation and water filtration layer 4 between the outer rigid sleeve 3 and the permeable inner liner 5. Several grouting holes 301 are opened on the outer rigid sleeve 3. It also includes a grout pressure sensor 7, which is located in the grouting hole 301. A pressure monitoring wire is connected to the grout pressure sensor 7, and the pressure monitoring wire passes through the grouting hole 301 and is connected to the control terminal. The grout pressure sensor 7 is used to monitor the grouting pressure.

[0025] Example 4 The prefabricated pipe roof system proposed in this embodiment for deep underground caverns in water-rich strata, such as Figure 1 As shown, the system includes several pipe roof units 2, which are arranged linearly. Friction-relief connection units 1 are fixedly connected between each of the pipe roof units 2, and these friction-relief connection units 1 connect the pipe roof units 2 in series. Figure 2 As shown, the friction relief connection unit 1 includes a constant resistance relief mechanism 102, with pipe shed units 2 fixed at both ends of the constant resistance relief mechanism 102. A drainage channel 101 is provided in the center of the constant resistance relief mechanism 102. The constant resistance relief mechanism 102 includes a fixed sleeve 1021, with the pipe shed unit 2 sleeved on the inner wall of one end of the fixed sleeve 1021. A sliding sleeve 1022 is sleeved on the inner wall of the other end of the fixed sleeve 1021. Figure 3As shown, a friction ring 1023 and a disc spring assembly 1024 are provided on the outer wall of the sliding sleeve 1022 near the fixed sleeve 1021. The friction ring 1023 and the disc spring assembly 1024 are arranged side by side, and are located between the sliding sleeve 1022 and the fixed sleeve 1021. Each disc spring assembly 1024 has 4 pieces, which are symmetrically distributed at 90°. Another pipe roof unit 2 is fitted on the outer wall of the sliding sleeve 1022 away from the fixed sleeve 1021. The fixed sleeve 1021 and the pipe roof unit 2, and the fixed sleeve 1021 and the sliding sleeve 1021 are connected. 022. The sliding sleeve 1022 and another pipe roof unit 2 are both fixedly connected by high-strength bolts 1025. The drainage channel 101 is located inside the fixed sleeve 1021 and the sliding sleeve 1022. It also includes a displacement monitoring device 6, which is located on the inner wall of the fixed sleeve 1021. The fixed sleeve 1021 has a displacement monitoring wire hole, and a displacement monitoring wire is connected to the displacement monitoring device 6. The displacement monitoring wire passes through the displacement monitoring wire hole and connects to the control terminal. The displacement monitoring device 6 is used to monitor the relative slippage between the sliding sleeve 1022 and the fixed sleeve 1021. Figure 4 As shown, several pipe shed units 2 each include an outer rigid sleeve 3. The outer rigid sleeve 3 is made of Q355B low alloy high strength structural steel. The outer wall of the outer rigid sleeve 3 is protected with solvent-free epoxy heavy-duty anti-corrosion coating. The outer rigid sleeve 3 is provided with a permeable inner liner 5. The space between the outer rigid sleeve 3 and the permeable inner liner 5 is filled with a granular energy dissipation filter layer 4. The granular energy dissipation filter layer 4 ensures high porosity to meet drainage and grouting requirements, while also having excellent energy dissipation function and long-term structural stability, and can provide sufficient grouting channels. Several grouting holes 301 are opened on the outer rigid sleeve 3. There are 4 grouting holes in each group, which are symmetrically distributed at 90°. The grouting holes in each group are interspersed. It also includes a grout pressure sensor 7, which is located inside the grouting hole 301. A pressure monitoring wire is connected to the grout pressure sensor 7, extending out of the grouting hole 301 and connecting to a control terminal. The grout pressure sensor 7 is used to monitor the grouting pressure. The granular energy dissipation filter layer 4 is composed of continuously graded granite crushed stone mixed with 10% rubber particles by volume, with a porosity controlled at approximately 35%. The natural gravel, artificial ceramsite, polymer particles, or mixtures in the granular energy dissipation filter layer 4 are all arranged in a hexagonal shape, and the porosity of the granular energy dissipation filter layer 4 is 35%~40%. Figure 5As shown, the permeable inner liner pipe 5 includes an inner liner pipe 502, which has several water passage holes 503. The outer wall of the inner liner pipe 502 is wrapped with a reverse filter geotextile 501. The inner liner pipe 502 corresponds to the drainage channel 101. The inner liner pipe 502 is selected from PVC pipe, permeable composite material pipe and metal filter pipe. When water flows into the perforated drainage pipe, the reverse filter geotextile 501 is wetted by water, its fibers will expand and the pores will become smaller. With the pressure of the external particle layer, it will be tightly pressed against the pipe wall to form an effective sealing layer, thereby preventing water from flowing out in reverse.

[0026] Example 5 The construction method of the prefabricated pipe roof system for deep underground caverns in water-rich strata proposed in this embodiment is based on the above-mentioned prefabricated pipe roof system for deep underground caverns in water-rich strata, such as... Figure 6 As shown, it includes the following steps: Step 1: Prefabricate several friction relief connection units and pipe roof units; Step 2: Assemble the friction relief connection unit and the pipe roof unit in sections, turn on the displacement monitoring device and the slurry pressure sensor to form the pipe roof system; Step 3: Actively drain water and dissipate energy through the pipe roof system; Step 4: Complete the construction by controlling the grouting and monitoring the data through the pipe roof system.

[0027] Example 6 The construction method of the prefabricated pipe roof system for deep underground caverns in water-rich strata proposed in this embodiment is based on the above-mentioned prefabricated pipe roof system for deep underground caverns in water-rich strata, such as... Figure 6 As shown, it includes the following steps: Step 1: Prefabricate several friction relief connection units and pipe roof units; Step 1 specifically involves: prefabricating friction relief connection units, outer rigid sleeves, and permeable inner lining pipes according to the tunnel design cross-section; filling the annular cavity between the outer rigid sleeve and the permeable inner lining pipe with a granular energy dissipation and water filtration layer, and assembling them to form a pipe roof unit. Step 2: Assemble the friction relief connection unit and the pipe roof unit in sections, turn on the displacement monitoring device and the slurry pressure sensor to form the pipe roof system; Step 2 specifically involves: constructing a pilot hole at the tunnel face using a geological drilling rig; driving the first pipe roof unit into the pilot hole using a jacking device; ensuring that the deviation between the axis of the pipe roof unit and the design axis is no more than 30mm; installing a friction relief connection unit at the end of the pipe roof unit and fixing it with high-strength bolts; inserting subsequent pipe roof units into the friction relief connection unit to complete the mechanical connection; connecting the inner lining pipe inside the pipe roof unit with the drainage channel; turning on the displacement monitoring module and the slurry pressure sensor; and powering on and debugging the displacement monitoring module and the slurry pressure sensor to form the pipe roof system. Step 3: Actively drain water and dissipate energy through the pipe roof system; Step 3 is as follows: Groundwater enters through a one-way permeable lining pipe and is eventually discharged into the tunnel drainage system; the surrounding rock pressure acts on the pipe roof system, and when the axial force exceeds the set value, the constant resistance pressure relief mechanism generates controllable slippage, releasing the deformation energy of the surrounding rock, and the slippage is monitored in real time through the displacement monitoring module. Step 4: Complete the construction by controlling the grouting and monitoring the data through the pipe roof system; Step 4 specifically involves: starting the external grouting equipment, injecting grout into the granular energy dissipation and water filter layer through the grouting holes. The granular energy dissipation and water filter layer serves as a natural diffusion medium for the grout. By controlling the grouting pressure and grout ratio, the grout forms a uniform and continuous network cement within a predetermined range, achieving precise reinforcement of the surrounding rock. The displacement monitoring module and grout pressure sensor collect the pressure relief displacement and grouting pressure data in real time at a set frequency, and transmit them to the control terminal to complete the construction.

Claims

1. A prefabricated pipe roof system for deep underground caverns in water-rich strata, characterized in that, It includes several pipe roof units (2), the several pipe roof units (2) are arranged linearly, and each of the several pipe roof units (2) is fixedly connected with a friction relief connection unit (1), and the several friction relief connection units (1) connect the several pipe roof units (2) in series.

2. The prefabricated pipe roof system for deep underground caverns in water-rich strata according to claim 1, characterized in that, The friction pressure relief connection unit (1) includes a constant resistance pressure relief mechanism (102), both ends of which are fixed to pipe shed units (2), and a drainage channel (101) is provided in the center of the constant resistance pressure relief mechanism (102).

3. The prefabricated pipe roof system for deep underground caverns in water-rich strata according to claim 2, characterized in that, The constant resistance pressure relief mechanism (102) includes a fixed sleeve (1021). The pipe shed unit (2) is sleeved on the inner wall of one end of the fixed sleeve (1021). A sliding sleeve (1022) is sleeved on the inner wall of the other end of the fixed sleeve (1021). A friction ring (1023) and a disc spring assembly (1024) are provided on the outer wall of the sliding sleeve (1022) near the fixed sleeve (1021). The friction ring (1023) and the disc spring assembly (1024) are arranged side by side. The friction ring (1023) and the disc spring assembly (1024) are located between the sliding sleeve (1022) and the fixed sleeve (1021). Another pipe shed unit (2) is sleeved on the outer wall of the sliding sleeve (1022) away from the fixed sleeve (1021). 1021) and pipe shed unit (2), fixed sleeve (1021) and sliding sleeve (1022), sliding sleeve (1022) and another pipe shed unit (2) are all fixedly connected by high-strength bolts (1025). The drainage channel (101) is located inside the fixed sleeve (1021) and sliding sleeve (1022). It also includes a displacement monitoring device (6). The displacement monitoring device (6) is located on the inner wall of the fixed sleeve (1021). The fixed sleeve (1021) has a displacement monitoring wire hole. The displacement monitoring device (6) is connected to a displacement monitoring wire. The displacement monitoring wire passes through the displacement monitoring wire hole and is connected to the control terminal. The displacement monitoring device (6) is used to monitor the relative slippage of the sliding sleeve (1022) and fixed sleeve (1021).

4. The prefabricated pipe roof system for deep underground caverns in water-rich strata according to claim 3, characterized in that, Each of the pipe shed units (2) includes an outer rigid sleeve (3), a permeable inner liner (5) is provided inside the outer rigid sleeve (3), a granular energy dissipation filter layer (4) is filled between the outer rigid sleeve (3) and the permeable inner liner (5), and a number of grouting holes (301) are opened on the outer rigid sleeve (3); it also includes a grout pressure sensor (7), the grout pressure sensor (7) is located in the grouting hole (301), a pressure monitoring wire is connected to the grout pressure sensor (7), the pressure monitoring wire passes through the grouting hole (301) and is connected to the control terminal, and the grout pressure sensor (7) is used to monitor the grouting pressure.

5. The prefabricated pipe roof system for deep underground caverns in water-rich strata according to claim 4, characterized in that, The granular energy dissipation filter layer (4) is filled with natural gravel, artificial ceramic particles, polymer particles or a mixture of natural gravel, artificial ceramic particles and polymer particles. The natural gravel, artificial ceramic particles, polymer particles or mixture in the granular energy dissipation filter layer (4) are arranged in a hexagonal shape. The porosity of the granular energy dissipation filter layer (4) is 35%~40%.

6. The prefabricated pipe roof system for deep underground caverns in water-rich strata according to claim 5, characterized in that, The permeable inner lining pipe (5) includes an inner lining pipe (502), which has several water passage holes (503). The outer wall of the inner lining pipe (502) is wrapped with a reverse filter geotextile (501), and the inner lining pipe (502) corresponds to the drainage channel (101).

7. The prefabricated pipe roof system for deep underground caverns in water-rich strata according to claim 6, characterized in that, The inner lining pipe (502) is selected from one of PVC pipe, permeable composite material pipe and metal filter pipe.

8. A construction method for a prefabricated pipe roof system for deep underground caverns in water-rich strata, characterized in that, The prefabricated pipe roof system for deep underground caverns in water-rich strata according to claim 7 includes the following steps: Step 1: Prefabricate several friction relief connection units and pipe roof units; Step 2: Assemble the friction relief connection unit and the pipe roof unit in sections, turn on the displacement monitoring device and the slurry pressure sensor to form the pipe roof system; Step 3: Actively drain water and dissipate energy through the pipe roof system; Step 4: Complete the construction by controlling the grouting and monitoring the data through the pipe roof system.

9. The construction method of the prefabricated pipe roof system for deep underground caverns in water-rich strata according to claim 8, characterized in that, Step 1 specifically involves: prefabricating friction pressure relief connection units, outer rigid sleeves, and permeable inner lining pipes according to the tunnel design cross-section; filling the annular cavity between the outer rigid sleeve and the permeable inner lining pipe with a granular energy dissipation and water filtration layer, and assembling them to form a pipe roof unit. Step 2 specifically involves: constructing a guide hole at the tunnel face using a geological drilling rig; driving the first pipe roof unit into the guide hole using a jacking device; ensuring that the deviation between the axis of the pipe roof unit and the design axis is no more than 30mm; installing a friction relief connection unit at the end of the pipe roof unit and fixing it with high-strength bolts; inserting subsequent pipe roof units into the friction relief connection unit to complete the mechanical connection; connecting the inner lining pipe inside the pipe roof unit with the drainage channel; turning on the displacement monitoring module and the slurry pressure sensor; and powering on and debugging the displacement monitoring module and the slurry pressure sensor to form the pipe roof system.

10. The construction method of the prefabricated pipe roof system for deep underground caverns in water-rich strata according to claim 8, characterized in that, Step 3 specifically involves: groundwater entering through a one-way permeable lining pipe and eventually being discharged into the tunnel drainage system; the surrounding rock pressure acts on the pipe roof system, and when the axial force exceeds the set value, the constant resistance pressure relief mechanism generates controllable slippage, releasing the deformation energy of the surrounding rock, and the slippage is monitored in real time through the displacement monitoring module. Step 4 specifically involves: starting the external grouting equipment, injecting grout into the granular energy dissipation and water filtration layer through the grouting holes. The granular energy dissipation and water filtration layer serves as a natural diffusion medium for the grout. By controlling the grouting pressure and grout ratio, the grout forms a uniform and continuous network cement within a predetermined range, achieving precise reinforcement of the surrounding rock. The displacement monitoring module and grout pressure sensor collect the pressure relief displacement and grouting pressure data in real time at a set frequency, and transmit them to the control terminal to complete the construction.

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