Counter-pressure jacking filling construction method for constant-flow water karst cave
Through phased backpressure hoisting and dynamic sealing of water balloons, the problems of low backfilling density and high leakage risk of regular flowing water caves are solved, and efficient, economical and environmentally friendly cave backfilling is achieved to meet the tunnel waterproofing requirements.
Patent Information
- Application Number
- CN202510546833.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-28
- Publication Date
- 2025-08-15
AI Technical Summary
The backfill density of the often flowing water caves is low, the leakage risk is high, and the construction efficiency is poor, and traditional treatment methods are difficult to effectively solve.
The staged backpressure lift filling method is adopted, and the principle of water pressure self-compression is used to backfill concrete layer by layer through the embedded pump pipe and water-blocking ball system, and combined with multiple pump pipes to coordinate drainage, so as to achieve self-compression and precise sealing of concrete.
It significantly improves the backfill density and impermeability resistance, shortens the construction cycle, reduces costs, reduces environmental pollution, and meets the waterproofing requirements of tunnel operations.
Smart Images
Figure CN120487236A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a back-pressure jacking filling construction method for a constant-flow water cave. Background Art
[0002] With the rapid development of my country's transportation infrastructure, more and more new tunnels are being built. When encountering a karst cave with constant water flow, curtain grouting is often used in combination with the tunnel drainage system for treatment. However, as the solid crystals in the cave and the sediment in the fissure water are discharged, the tunnel drainage system is usually blocked, causing excessive water pressure and multiple leaks and water gushing from the bottom plate. This will not only damage the road surface and affect driving safety, but also make the subsequent remediation work difficult and costly. Therefore, the current measure of exposing the cave and draining the water is mainly used for treatment. When treating the karst cave with constant water flow after excavation and exposure, the backfill density of the karst cave with constant water flow is a major technical problem. Summary of the Invention
[0003] In response to the above problems, the present invention provides a construction method for back-pressure jacking and backfilling of a constant-flow water cave. Based on the principle of water pressure self-compacting, a staged back-pressure jacking and backfilling method is adopted to effectively solve the problems pointed out in the background technology.
[0004] The technical solution adopted in the present invention is: A back-pressure jacking filling construction method for a constant-flow water cave comprises the following steps: 1) Install temporary drainage pipes: drain the cave's regular water through temporary drainage pipes to create a dry construction space; 2) Install permanent drainage pipes, n pre-buried pump pipes and a water-blocking ball traction system: The permanent drainage pipe is used to drain the cave's regular water after construction is completed. The n pre-buried pump pipes are gradually raised in height inside the cave. The n pre-buried pump pipes are 1# pump pipe, 2# pump pipe...n# pump pipe, where n is an integer greater than or equal to 2. Drainage pipe traction ropes are pre-buried inside the permanent drainage pipes. Pump pipe traction ropes are pre-buried inside all pre-buried pump pipes, namely 1# pump pipe traction rope, 2# pump pipe traction rope...n# pump pipe traction rope. The end of the drainage pipe traction rope inside the cave is fixed to the water-blocking ball. The end of the 1# pump pipe traction rope inside the cave is directly fixed to the counterweight ball. The ends of the 2# pump pipe traction rope...n# pump pipe traction rope inside the cave are respectively put on the 1# pump pipe traction rope through 2# ring...n# ring. The counterweight ball is fixed to the bottom of the water-blocking ball. 3) Initial support construction: installation of steel arch frame, steel mesh and iron gauze, and sprayed concrete sealing are carried out in sequence in the cave; 4) Water-blocking ball plugging and back-pressure lifting and backfilling: 41). Plugging the pipe opening of the m# pump pipe: If m is 1, pull the traction rope of the 1# pump pipe to make the water-blocking ball naturally block the pipe opening of the m# pump pipe in the karst cave. If m≠1, first pull the traction rope of the m# pump pipe, pull the traction rope of the 1# pump pipe into the m# pump pipe, and then pull the traction rope of the 1# pump pipe in the m# pump pipe to make the water-blocking ball naturally block the pipe opening of the m# pump pipe in the karst cave. When the following conditions are met, proceed to the next step: If m≠n, there is continuous flowing water from the (m + 1)# pump pipe. If m=n, there is continuous flowing water from the permanent drain pipe. 42). Using the m# pump pipe for concrete pumping: Open the stop valve on the m# pump pipe, start the concrete pump truck, and send the concrete into the bottom of the karst cave through the m# pump pipe. The concrete first pushes open the water-blocking ball and then gradually rises from the bottom of the water and gradually spreads to fill the entire bottom of the karst cave. The concrete forms self-compacting concrete under the action of water pressure. While the concrete is being sent: If m<n, the continuous flowing water in the karst cave will drain from the (m + 1)# pump pipe. When there is concrete flowing out of the (m + 1)# pump pipe, stop the concrete pumping and close the stop valve of the m# pump pipe at the same time. If m=n, the continuous flowing water in the karst cave will drain from the permanent drain pipe. When there is concrete flowing out of the permanent drain pipe, stop the concrete pumping and close the stop valve of the m# pump pipe at the same time. The initial value of m is 1. When m<n, let m=m + 1 and repeat step 4). When m=n, proceed to the next step. 5). Recycling the water-blocking ball and cleaning the pipeline: Use the drainage traction rope to take out the water-blocking ball and the counterweight ball from the permanent drain pipe, and clean the inside of the permanent drain pipe and all the embedded pump pipes.
[0005] Preferably, the heights of the pipe openings of the 1# pump pipe, 2# pump pipe... n# pump pipes in the karst cave gradually increase by a height difference of a meters, and the pipe opening of the 1# pump pipe in the karst cave is located at the bottom of the karst cave. The pipe opening of the permanent drain pipe in the karst cave is a meters higher than the pipe opening of the n# pump pipe.
[0006] Preferably, a is 2.
[0007] Preferably, when starting the concrete pump truck for concrete pumping in step 42), pull the traction rope of the drain pipe to make the water-blocking ball leave the concrete filling area.
[0008] Preferably, the stop valve on the embedded pump pipe is located at the outer end of the embedded pump pipe, and the concrete pump truck is connected to the embedded pump pipe through the stop valve.
[0009] Through innovative technologies such as staged backpressure jacking, dynamic plugging with water-blocking balls, and coordinated drainage of multiple pump pipes, the present invention systematically solves problems such as low compactness of backfilling in karst caves with continuous flowing water, high leakage risk, and poor construction efficiency. Its technical effects are significantly better than traditional methods in terms of compactness, impermeability, economy, and environmental protection, and have broad engineering application prospects.
[0010] The innovative features of the present invention are as follows: 1. Staged back pressure lifting and backfilling technology: By backfilling concrete layer by layer in stages (n≥2), the water pressure generated by the constant flow of water in the cave drives the self-compacting filling of concrete. During each backfill, the water pressure gradient is controlled by the height difference (e.g., 2 meters) of the pre-buried pump pipes (1# to n# pump pipes), and the concrete is lifted layer by layer until the cave is completely filled. Traditional methods of backfilling in one go are prone to erosion by water flow, resulting in cement slurry loss and the formation of leakage channels. The staged lifting technology can dynamically adjust the water pressure and filling speed to ensure uniform and dense concrete and avoid slurry loss. 2. Water-blocking ball dynamic blocking and traction system: A combination of a water-isolating ball and a counterweight ball is used, and the blocking and release of the pump pipe opening are controlled by a traction rope. The water-isolating ball naturally blocks the pump pipe opening due to the gravity of the counterweight ball. When the concrete is lifted, the water-isolating ball is automatically pushed open, achieving precise blocking and filling synchronization. Traditional blocking methods (such as grouting plugs) are prone to failure due to water pressure fluctuations, resulting in concrete loss or loose blocking. The water-isolating ball system achieves adaptive sealing through mechanical linkage, significantly improving reliability. 3. Coordinated design of embedded pump pipe and permanent drainage pipe: Permanent drainage pipes and pre-buried pump pipes are arranged in layers (with the 1# pump pipe at the lowest and the n# pump pipes rising gradually), forming a "low-in, high-out" drainage and filling path. During backfilling, constant water is discharged through the high-level pump pipes or permanent drainage pipes, preventing water flow from interfering with concrete filling. Traditional drainage systems are separated from backfill construction, which can easily lead to water pressure accumulation due to poor drainage. Collaborative design ensures smooth drainage and controllable water pressure throughout the construction process. 4. Multi-level linkage mechanism of traction rope: Except for the 1# pump pipe traction rope, the other pump pipe traction ropes are connected to the 1# pump pipe traction rope through rings to achieve rapid switching of the water-blocking balls among multiple pump pipes. During operation, only the target pump pipe traction rope needs to be pulled to complete the position adjustment of the water-blocking ball, so that the 1# pump pipe traction rope is transferred to the target pump pipe, and the target pump pipe traction rope is taken out at the same time to avoid the target pump pipe traction rope being buried in the concrete during concrete filling. The multi-level linkage mechanism simplifies the operation process and improves construction efficiency.
[0011] The beneficial effects of the present invention are as follows: 1. Significantly improved backfill density: Utilizing the principle of self-compacting under hydraulic pressure, concrete is evenly distributed at the bottom of the cave, achieving a filling rate of over 98% and a void ratio of ≤3% (the void ratio of the traditional grouting method is ≥8%). Actual measured data: Geological radar testing shows that there are no void defects in the filled area, and the density meets the first-level waterproofing standard. 2. Excellent anti-seepage performance: The staged jacking combined with self-compacting concrete forms a continuous dense structure with a water seepage rate of ≤0.1L / m²·d (conventional methods ≥0.5L / m²·d). Water injection tests have shown that there are no leakage points after the cave is backfilled, meeting the waterproof requirements for long-term tunnel operation. 3. Construction efficiency and cost optimization: Phased backfill and rapid switching of water-blocking balls shorten the construction period by 30% and reduce overall costs by 25%; 4. Enhanced environmental protection and safety: zero concrete waste (100% utilization rate), centralized wastewater treatment to avoid pollution of surrounding water bodies; mechanical linkage of traction ropes to reduce high-risk manual operations; 5. Adapt to complex cave conditions: By adjusting the number of pump tubes (n value) and the height difference (a value), it can adapt to caves of different sizes (small to large) and water flow conditions. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 This is a construction principle diagram of Example 1; Figure 2 It is a structural diagram of the water-isolating ball traction system; 1. Permanent drainage pipe, 2. 1# pump pipe, 3. 2# pump pipe, 4. 3# pump pipe, 5. 4# pump pipe, 6. Drain pipe traction rope, 7. 1# pump pipe traction rope, 8. 2# pump pipe traction rope, 9. 3# pump pipe traction rope, 10. 4# pump pipe traction rope, 11. Water-blocking ball, 12. Counterweight ball, 13. 2# ring, 14. 3# ring, 15. 4# ring, 16. Stop valve. DETAILED DESCRIPTION
[0013] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.
[0014] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.
[0015] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise explicitly specified.
[0016] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.
[0017] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.
[0018] The present invention will be further described in detail below through specific embodiments with reference to the accompanying drawings. Example
[0019] like Figure 1-2 As shown, when n=4, the construction method of the present invention is described in detail, that is, four pre-buried pump pipes are used to fill the concrete in four times.
[0020] A back-pressure jacking filling construction method for a constant-flow water cave comprises the following steps: 1) Install temporary drainage pipes: Install temporary drainage pipes at the lowest point of the cave, extending to the drainage ditch outside the tunnel. Use the temporary drainage pipes to drain the cave's regular water, creating a dry construction space. Submersible pumps can be used to assist drainage and improve drainage efficiency. 2) Install permanent drainage pipes, 4 pre-buried pump pipes and water-isolating ball traction system: Pre-buried DN150 stainless steel drainage pipes at the bottom of the cave with a slope of ≥3%. The pipe mouth is set slightly above the target concrete pouring surface in the cave, and the end is connected to the main drainage system of the tunnel. The permanent drainage pipe is used to drain the cave's regular water after the construction is completed. The 4 pre-buried pump pipes are arranged longitudinally in the cave. The 4 pre-buried pump pipes are 1# pump pipe, 2# pump pipe, 3# pump pipe, and 4# pump pipe, and the pipe mouth of 1# pump pipe is the lowest and is located at the bottom of the cave. The pipe mouths of 2# pump pipe, 3# pump pipe, and 4# pump pipe are successively increased with a height difference of 2 meters. The pipe mouth of the permanent drainage pipe in the cave is 2 meters higher than the pipe mouth of 4# pump pipe. Pre-buried drainage pipe traction ropes are installed in the permanent drainage pipes. 1# pump pipe traction rope, 2# pump pipe traction rope, 3# pump pipe traction rope and 4# pump pipe traction rope are pre-buried in the 3# pump pipe and 4# pump pipe respectively. The end of the drainage pipe traction rope located in the cave is fixed on the water-isolating ball. The end of the 1# pump pipe traction rope located in the cave is directly fixed on the counterweight ball. The ends of the 2# pump pipe traction rope, 3# pump pipe traction rope and 4# pump pipe traction rope located in the cave are respectively sleeved on the 1# pump pipe traction rope through the 2# ring, 3# ring and 4# ring. The diameters of the 2# ring, 3# ring and 4# ring increase gradually, so that when the 2# pump pipe traction rope, 3# pump pipe traction rope and 4# pump pipe traction rope are pulled in sequence, the rings are pulled in order from small to large to avoid the rings from getting stuck with each other, and the counterweight ball is fixed at the bottom of the water-isolating ball. 3) Initial support construction: The steel arch frame is installed in sequence in the cave: the initial support steel arch frame is installed, the distance between the arch top and the cave roof is ≤100mm, fixed by locking anchor rods, and the longitudinal connecting reinforcement is welded densely to ensure overall stability; Installation of steel mesh and iron gauze: double-layer steel mesh is laid close to the steel arch frame, and the outer side is covered with dense iron gauze, which is fixed with U-shaped buckles. The overlap length of the iron gauze is ≥100mm, and the edges are welded and sealed; Shotcrete sealing: Wet spraying C25 concrete (thickness ≥150mm), spraying in two layers, interval time ≤2h, curing for 72 hours, and then proceed to the next process after the strength is ≥15MPa; 4) Water-blocking ball plugging and back-pressure lifting and backfilling: 41) Seal the outlet of the 1# pump pipe: Pull the traction rope of the 1# pump pipe to make the water-isolating ball naturally block the outlet of the 1# pump pipe in the cave. When water flows out of the 2# pump pipe, proceed to the next step. 42) Pumping concrete using pump pipe 1: Open the stop valve on pump pipe 1, start the concrete pump, and pump concrete into the bottom of the cave through pump pipe 1. At the same time, pull the drain pipe traction rope to move the water-blocking ball away from the concrete filling area. The pulling distance can be set to a, for example, 2 meters in this embodiment. The concrete first pushes the water-blocking ball away, then gradually rises from the bottom of the water, gradually spreading and filling the entire bottom of the cave. Under the action of water pressure, the concrete forms self-compacting concrete. As the concrete is pumped in, the constant flow water in the cave will be discharged from pump pipe 2. When concrete flows out of pump pipe 2, stop pumping the concrete, and close the stop valve of pump pipe 1 to proceed to the next step. 43) Seal the outlet of the 2# pump pipe: First pull the traction rope of the 2# pump pipe, pull the traction rope of the 1# pump pipe into the 2# pump pipe, and then pull the traction rope of the 1# pump pipe inside the 2# pump pipe to make the water-blocking ball naturally block the outlet of the 2# pump pipe in the cave. When water flows out of the 3# pump pipe, proceed to the next step; 44) Pumping concrete using pump pipe 2: Open the stop valve on pump pipe 2, start the concrete pump, and pump concrete into the bottom of the cave through pump pipe 2. At the same time, pull the drain pipe traction rope to move the water-blocking ball away from the concrete filling area. The pulling distance can be set to a, for example, 2 meters in this embodiment. The concrete first pushes the water-blocking ball away, then gradually rises from the bottom of the water, gradually spreading and filling the entire bottom of the cave. Under the action of water pressure, the concrete forms self-compacting concrete. As the concrete is pumped in, the constant flow water in the cave will be discharged from pump pipe 3. When concrete flows out of pump pipe 3, stop pumping the concrete, and close the stop valve of pump pipe 2 to proceed to the next step. 45) Seal the outlet of the 3# pump pipe: First pull the traction rope of the 3# pump pipe, pull the traction rope of the 1# pump pipe into the 3# pump pipe, and then pull the traction rope of the 1# pump pipe inside the 3# pump pipe to make the water-blocking ball naturally block the outlet of the 3# pump pipe in the cave. When water flows out of the 4# pump pipe, proceed to the next step; 46) Pumping concrete using pump pipe 3: Open the stop valve on pump pipe 3, start the concrete pump, and pump concrete into the bottom of the cave through pump pipe 3. At the same time, pull the drain pipe traction rope to move the water-blocking ball away from the concrete filling area. The pulling distance can be set to a, for example, 2 meters in this embodiment. The concrete first pushes the water-blocking ball away, then gradually rises from the bottom of the water, gradually spreading and filling the entire bottom of the cave. Under the action of water pressure, the concrete forms self-compacting concrete. As the concrete is pumped in, the constant flow water in the cave will be discharged from pump pipe 4. When concrete flows out of pump pipe 4, stop pumping the concrete, and close the stop valve of pump pipe 3 to proceed to the next step. 47) Seal the outlet of the 4# pump pipe: First pull the 4# pump pipe traction rope, pull the 1# pump pipe traction rope into the 4# pump pipe, and then pull the 1# pump pipe traction rope inside the 4# pump pipe to make the water-blocking ball naturally block the outlet of the 4# pump pipe in the cave. When water flows out of the permanent drainage pipe, proceed to the next step; 48) Pumping concrete using pump pipe 4: Open the stop valve on pump pipe 4, start the concrete pump, and pump concrete into the bottom of the cave through pump pipe 4. At the same time, pull the drain pipe traction rope to move the water-blocking ball away from the concrete filling area. The pulling distance can be set to a, for example, 2 meters in this embodiment. The concrete first pushes the water-blocking ball away, then gradually rises from the bottom of the water, gradually spreading and filling the entire bottom of the cave. Under the action of water pressure, the concrete forms self-compacting concrete. As the concrete is pumped in, the permanent water in the cave will be discharged from the permanent drain pipe. When concrete flows out of the permanent drain pipe, stop pumping the concrete, close the stop valve of pump pipe 4, and proceed to the next step. 5) Water-blocking ball recovery and pipe cleaning: Use the drainage traction rope to remove the water-blocking ball and the counterweight ball from the permanent drainage pipe, clean the inside of the permanent drainage pipe and all embedded pump pipes, and flush with a high-pressure water gun when necessary.
[0021] In this embodiment, the stop valve on the embedded pump pipe is located at the outer end of the embedded pump pipe. The concrete ground pump is connected to the embedded pump pipe through the stop valve. The stop valve is an anti-backflow stop valve with an anti-backflow function. When pumping concrete into the cave, it ensures the jacking and pressing effect of the concrete.
[0022] The present invention is based on the two core principles of "water pressure self-compacting" and "staged counter-pressure jacking". Through the pre-buried pump pipe, dynamic sealing of water-blocking balls and the traction rope linkage system, it can achieve efficient and dense backfilling of caves with constant water flow. Specifically, the reverse water pressure is formed by the constant water flow in the cave, and the concrete is lifted layer by layer to fill the cave. The pump pipe sealing and release are precisely controlled by the water-blocking balls to ensure uniform diffusion of concrete and no slurry loss.
[0023] Finally, it should be noted that the above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and is subject to numerous variations. All variations that can be directly derived or conceived by a person of ordinary skill in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.
Claims
1. A back pressure jacking filling construction method for a constant flow water cave, characterized in that: It includes the following steps: 1). Install a temporary drain pipe: Drain the constant water flow in the karst cave through the temporary drain pipe to create a dry construction space. 2). Install a permanent drain pipe, n embedded pump pipes and a water-blocking ball traction system: The permanent drain pipe is used to drain the constant water flow in the karst cave after the construction is completed. The pipe orifice heights of the n embedded pump pipes in the karst cave gradually increase. The n embedded pump pipes are respectively 1# pump pipe, 2# pump pipe... n# pump pipe, where n is an integer greater than or equal to 2. Embed a drain pipe traction rope in the permanent drain pipe, and respectively embed pump pipe traction ropes in all the embedded pump pipes, namely 1# pump pipe traction rope, 2# pump pipe traction rope... n# pump pipe traction rope. The end of the drain pipe traction rope located in the karst cave is fixed on the water-blocking ball. The end of the 1# pump pipe traction rope located in the karst cave is directly fixedly connected to the counterweight ball. The ends of the 2# pump pipe traction rope... n# pump pipe traction ropes located in the karst cave are respectively sleeved on the 1# pump pipe traction rope through 2# rings... n# rings. The counterweight ball is fixed at the bottom of the water-blocking ball. 3). Initial support construction: Sequentially install steel arch frames, install steel bar meshes and iron wire meshes, and spray concrete for sealing in the karst cave. 4). Water-blocking ball plugging and backpressure jacking and backfilling: 41). Plugging the orifice of the m# pump pipe: If m is 1, pull the 1# pump pipe traction rope to make the water-blocking ball naturally block the orifice of the m# pump pipe in the karst cave. If m≠1, first pull the m# pump pipe traction rope, pull the 1# pump pipe traction rope into the m# pump pipe, and then pull the 1# pump pipe traction rope in the m# pump pipe to make the water-blocking ball naturally block the orifice of the m# pump pipe in the karst cave. When the following conditions are met, proceed to the next step: If m≠n, there is constant water flow out of the m + 1# pump pipe. If m=n, there is constant water flow out of the permanent drain pipe. 42). Pump concrete using the m# pump pipe: Open the stop valve on the m# pump pipe, start the concrete pump truck, and send the concrete into the bottom of the karst cave through the m# pump pipe. The concrete first pushes open the water-blocking ball, and then gradually jacks up from the bottom of the water, gradually spreads and fills the entire bottom of the karst cave. The concrete forms self-compacting concrete under the action of water pressure. While the concrete is being sent: If m < n, the constant water flow in the karst cave will drain out from the m + 1# pump pipe. When there is concrete flowing out of the m + 1# pump pipe, stop pumping concrete and at the same time close the stop valve of the m# pump pipe. If m=n, the constant water flow in the karst cave will drain out from the permanent drain pipe. When there is concrete flowing out of the permanent drain pipe, stop pumping concrete and at the same time close the stop valve of the m# pump pipe. The initial value of m is 1. When m < n, let m = m + 1, and repeat 4). When m=n, proceed to the next step. 5). Recover the water-blocking ball and clean the pipeline: Use the drainage traction rope to take out the water-blocking ball and the counterweight ball from the permanent drain pipe, and clean the interiors of the permanent drain pipe and all the embedded pump pipes.
2. A back pressure jacking filling construction method for a constant flow water cave according to claim 1, characterized in that: The pipe orifice heights of the 1# pump pipe, 2# pump pipe... n# pump pipes in the karst cave gradually increase by a height difference of a meters, and the pipe orifice of the 1# pump pipe in the karst cave is located at the bottom of the karst cave. The pipe orifice of the permanent drain pipe in the karst cave is a meters higher than the pipe orifice of the n# pump pipe.
3. A back pressure jacking filling construction method for a constant flow water cave according to claim 2, characterized in that: The a is 2.
4. The back-pressure jacking filling construction method for a constant-flow water cave according to claim 2 is characterized in that: Said 42) while starting the concrete pump to pump concrete, pull the drainage pipe traction rope to make the water-isolating ball leave the concrete filling area.
5. A back pressure jacking filling construction method for a constant flow water cave according to claim 4, characterized in that: The stop valve on the pre-buried pump pipe is located on the outer end of the pre-buried pump pipe, and the concrete floor pump is connected to the pre-buried pump pipe through the stop valve.