A method for synchronous construction of a double-cavity ventilation shaft body secondary lining and a mid-plate

Abstract

The present application relates to the technical field of ventilation shaft construction, and particularly relates to a method for synchronous construction of a double-cavity ventilation shaft body secondary lining and a middle partition plate, which comprises the following steps: S1: construction preparation, well bottom assembly of a hydraulic self-elevating shaft secondary lining and a middle partition plate synchronous construction formwork; S2: secondary lining of the shaft body, binding of the middle partition plate steel bars and pouring of concrete; S3: climbing of the hydraulic self-elevating shaft secondary lining and the middle partition plate synchronous construction formwork; S4: demolding concrete modification and maintenance; S5: construction of a secondary lining middle partition plate surface thermal insulation layer; and S6: demolding of the hydraulic self-elevating shaft secondary lining and the middle partition plate synchronous construction formwork at a well head. The present application has simple assembly technology and fast construction speed, and can shorten the well construction period. The present application relies on a climbing rod embedded on the secondary lining of the shaft body and the middle partition plate to automatically climb, thereby saving the use cost of multiple winches, stabilizers and other equipment, reducing the construction cost during the construction of the secondary lining of the shaft body and the middle partition plate, and improving the economic benefits. The present application realizes synchronous lining of the secondary lining of the shaft body and the middle partition plate.

Description

Technical Field

[0001] This invention relates to the field of ventilation shaft construction technology, and in particular to a method for the simultaneous construction of the secondary lining and the central partition of a double-cavity ventilation shaft. Background Technology

[0002] In recent years, the construction of high-grade highways in my country has accelerated, and ventilation shafts are installed in all extra-long tunnels to improve the tunnel environment and safety. Functionally, tunnel ventilation shafts are often dual-purpose, meaning they have a central partition inside their circular cross-section, dividing the shaft into two equal or four unequal sections to meet the air supply and exhaust needs of both directions of traffic in the highway tunnel. In some extra-long highway tunnels, to effectively alleviate ventilation pressure during long-distance, single-ended excavation, ventilation shafts are used as air supply tunnels, and their "chimney" effect effectively reduces ventilation pressure during the main tunnel construction.

[0003] Each shaft is designed as a "dual-chamber" ventilation shaft, with a concrete partition of a certain thickness installed in the middle. This partition achieves both air supply and exhaust within the shaft. However, the construction of the partition requires advanced technical expertise. If the partition is prefabricated and then installed from the bottom up after the secondary lining of the shaft is completed, it will inevitably prolong the construction period, increase construction costs, and raise safety risks. Therefore, selecting the appropriate construction formwork and construction method is a pressing issue that needs to be addressed in the construction of ventilation shafts. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a method for simultaneous construction of the secondary lining and the middle partition of a dual-cavity ventilation shaft.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for simultaneous construction of the secondary lining and intermediate diaphragm of a dual-chamber ventilation shaft includes the following steps: S1: Construction preparation, assembly of the bottom of the well bottom for the synchronous construction template of the hydraulic self-elevating well casing secondary lining and middle diaphragm plate; S2: Secondary lining of the well body, binding of the reinforcement of the middle diaphragm and pouring of concrete; S3: Hydraulic self-elevating well casing secondary lining and diaphragm synchronous construction formwork climbing; S4: Finishing and curing of demolded concrete; S5: Construction of the thermal insulation layer on the surface of the secondary lining diaphragm; S6: The hydraulic self-elevating well casing secondary lining and middle diaphragm are constructed simultaneously, and the formwork is removed at the wellhead. Repeat steps S2 to S4 above to complete the simultaneous construction of the secondary lining and the middle partition plate of the wellbore from bottom to top, from the bottom of the well to the wellhead.

[0006] Furthermore, in step S1, the hydraulic self-elevating well casing secondary lining and diaphragm synchronous construction template includes a steel template for pouring concrete for the well casing secondary lining and diaphragm, multiple first and second supports set on the top of the steel template for climbing the steel template, several ball bearing hydraulic jacks, a radial steel truss, and an upper steel truss and a lower platform for construction workers. The upper steel truss is fully covered with scaffold boards or checkered steel plates and can be used as an upper platform for construction workers. The lower platform is a finishing platform used for repairing the outer surface of the concrete after demolding. The first support is an "F" shaped structure, with a receiving groove for accommodating the ball bearing hydraulic jacks at the upper end. The lower end of the first support is used for pouring the secondary lining of the well casing. The second support is an "open" shaped structure, with a receiving groove for accommodating the ball bearing hydraulic jacks at the middle of the upper end of the second support. The lower end of the second support is wrapped with the diaphragm for pouring the diaphragm concrete.

[0007] It also includes multiple climbing rods embedded in the secondary lining concrete and the middle diaphragm concrete respectively. The first support, the second support, the ball bearing hydraulic jack and the climbing rod together form the climbing system of the hydraulic self-elevating well secondary lining and the middle diaphragm synchronous construction formwork; the first support, the ball bearing hydraulic jack and the climbing rod constitute the climbing system of the hydraulic self-elevating well secondary lining, and the second support, the ball bearing hydraulic jack and the climbing rod constitute the climbing system of the middle diaphragm.

[0008] Both the first and second supports are equipped with ball bearing hydraulic jacks at their upper ends. One end of the climbing rod is embedded in the secondary lining concrete or the middle diaphragm concrete, and the other end of the climbing rod passes through the center of the ball bearing hydraulic jack and is lifted by several ball bearing hydraulic jacks.

[0009] Furthermore, any adjacent climbing pole joints are staggered by a distance of not less than 100cm in the vertical direction. Adjacent climbing poles have the same radial specifications but different axial lengths. The climbing poles are made of φ48.3×3.5 seamless steel pipe. The first batch of climbing poles embedded in the secondary lining concrete and the intermediate diaphragm concrete has at least four specifications. The four types of climbing poles have the same diameter but different lengths, and climbing poles 12 of the same specifications as those below are welded on top.

[0010] Furthermore, in step S1, the assembly sequence of the hydraulic self-elevating wellbore secondary lining and intermediate diaphragm synchronous construction template at the bottom of the well is as follows: S101: Assembly of the upper steel truss, lower steel truss, and main truss; S102: Assembly of the first and second supports, and installation of the ball-bearing hydraulic jack; S103: Installation of the climbing pole; S104: No-load test; S105: Joint acceptance inspection by all parties; S106: After the sliding membrane climbs to the preset height, the lower platform will be installed. During the climbing process, the climbing rod is welded together from several vertically connected rods. When the first climbing rod is installed at the bottom of the well, a steel plate is welded to its bottom end face. The climbing rod is also equipped with a limiting device to synchronize the lifting height of several ball-bearing hydraulic jacks. The steel plate increases the contact area and force-bearing area, and the limiting device ensures that the ball-bearing jacks are at the same height after each lifting segment, preventing tilting of the hydraulic integral sliding formwork.

[0011] Furthermore, in step S2, a working platform controlled by a hoist is installed above the steel formwork. This working platform is used for tying the reinforcing bars for the secondary lining of the well shaft and pouring concrete for the secondary lining and the central diaphragm. A safety platform is erected above the working platform to prevent falling objects from endangering the safety of construction workers.

[0012] When tying the first section of reinforcing bars at the bottom of the well, the tying height of the secondary lining reinforcing bars should not be lower than the height of the working platform. As the hydraulic self-elevating well secondary lining and diaphragm synchronous construction formwork climbs and the hoisting platform is raised, construction workers tie the secondary lining reinforcing bars on the working platform. The tying height of the diaphragm reinforcing bars is higher than the top surface of the construction formwork. As the hydraulic self-elevating well secondary lining and diaphragm synchronous construction formwork climbs, construction workers tie the diaphragm reinforcing bars on the upper platform. The tying height of the first section of the secondary lining and diaphragm reinforcing bars should be higher than the height of the working platform. Subsequently, as the hydraulic self-elevating well secondary lining and diaphragm synchronous construction formwork climbs and the hoisting platform is raised, the reinforcing bars are tied on the working platform. This can reduce the load on the hydraulic self-elevating well secondary lining and diaphragm synchronous construction formwork.

[0013] Furthermore, in step S2, the concrete includes a bottom-discharge bucket, a collection hopper installed on the working plate, and multiple placing pipes. After the concrete is mixed at the wellhead mixing plant, it is lowered into the bottom-discharge bucket through a chute. The bottom-discharge bucket is vertically transported to the collection hopper and then evenly, layeredly, and symmetrically placed into the formwork through multiple placing pipes. Before pouring concrete, the aggregate hopper and distribution pipe need to be lubricated with mortar. During the concrete pouring process, multiple immersion vibrators are used to vibrate the concrete. The outer walls of the multiple fabric tubes are equipped with cushioning devices; The diameter of the fabric tube is ≥200mm; The concrete is early-strength concrete.

[0014] Furthermore, in step S3, the formwork climbing step for the synchronous construction of the hydraulic self-elevating well casing secondary lining and diaphragm is as follows: S301: Extend the climbing pole upwards; S302: Ball-type hydraulic jacks climb upwards; In step S301, the bottom end of the newly extended climbing rod is narrowed, with a narrowing length of not less than 50mm and an outer diameter of φ39mm×3.5mm after treatment. When several climbing rods are extended, the narrowed end is inserted into the exposed steel pipe of the lower section and welded firmly. The joints of two adjacent climbing rods are staggered vertically by at least 100cm. After the upper and lower climbing rods are firmly welded, it can be ensured that the ball bearing hydraulic jack can climb smoothly and without obstruction at the joint of the upper and lower climbing rods. When extending the upper and lower climbing rods, it must be ensured that the upper and lower climbing rods are on the same axis, and the straightness deviation of the upper and lower climbing rods should not be greater than 1 / 1000.

[0015] In step S301, the hydraulic circuits of several ball-bearing hydraulic jacks, including an oil pump, main oil pipes, and branch oil pipes, are assembled in a two-stage parallel configuration. One oil pump branches out six main oil pipes, and each main oil pipe branches out five branch oil pipes. These branch oil pipes are connected in parallel to several ball-bearing hydraulic jacks. A parallel branch hydraulic circuit system is formed using braided high-pressure hoses and various distributors. The system is divided into three zones (A, B, and C) according to the partition, and the pipe lengths are kept as similar as possible during pipe routing. Pipe fittings, distributors, needle valves, and limit switches are provided as needed.

[0016] Furthermore, in step S3, after the hydraulically self-elevating shaft lining and diaphragm synchronous construction template climbs to a height H, an installation plate for assembling the insulation layer of the shaft lining and diaphragm is assembled at the bottom of the shaft. This plate is then lifted using a winch via wire ropes and a sheave. The distance between the installation plate and the bottom of the construction template is ≥20m. Insulation boards are installed on the surface of the shaft lining and diaphragm using a keel. A derrick is erected directly above the shaft, and a sheave is installed on the derrick. The installation plate is connected to the winch via wire ropes, and the winch vertically lifts and moves the installation plate.

[0017] Furthermore, in step S6, the demolding sequence of the hydraulic self-elevating wellbore secondary lining and intermediate diaphragm synchronous construction formwork at the wellhead is as follows: S601: Remove the oil pump, main oil pipe and branch oil pipe; S602: Removal of construction formwork; S603: Remove the upper and lower steel trusses; S604: Remove the lower platform installed on the first or second bracket.

[0018] The lower platform is used to repair the honeycomb-like pitted surface of the concrete after the slipform is demolded. It is mainly connected to the middle diaphragm formwork by channel steel and is firmly connected by high-strength bolts.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. The assembly process of this invention is simple and the construction speed is fast, which can shorten the well construction cycle; 2. This invention relies on climbing rods embedded in the secondary lining and diaphragm of the well to climb independently, saving the cost of using multiple winches, stabilizing machines and other equipment, reducing the construction cost during the construction of the secondary lining and diaphragm of the well, and improving economic benefits. 3. This invention achieves simultaneous lining of the secondary lining and the central diaphragm of the well body, resulting in better structural stability and firmness of the central diaphragm and the secondary lining concrete of the well body, and thus has excellent seismic performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the simultaneous construction of the secondary lining and the central diaphragm of the well shaft; Figure 2 This is a cross-sectional view of the template for the synchronous construction of the secondary lining and middle diaphragm of a hydraulic self-elevating well. Figure 3 This is a cross-sectional view of the second support at the diaphragm. Figure 4 This is a cross-sectional view of the F-support at the secondary lining concrete section. Figure 5 This is a diagram showing the distribution of the oil injection pipe and branch pipes for a ball bearing jack. Attached diagram labels: 1-Derrick, 2-Windlock, 3-Wire rope, 4-Head sheave, 5-Primary lining cast concrete, 6-Secondary lining concrete, 7-Intermediate diaphragm concrete, 8-Safety disc, 9-Working disc, 10-Lower platform, 11-Installation disc, 12-Climbing pole, 13-First support, 14-Second support, 15-Upper steel truss, 16-Lower steel truss, 17-Ball bearing hydraulic jack, 18-Bottom discharge bucket, 19-Collection hopper, 20-Putting pipe, 21-Steel formwork, 22-Radial steel truss, 23-Oil pump, 24-Main oil pipe, 25-Branch oil pipe. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0022] Example 1 like Figure 1 , 2 As shown in Figures 3, 4, and 5, the present invention discloses a method for simultaneous construction of the secondary lining and intermediate diaphragm of a double-cavity ventilation shaft, comprising the following steps: S1: Construction preparation, assembly of the bottom of the well bottom for the synchronous construction template of the hydraulic self-elevating well casing secondary lining and middle diaphragm plate; S2: Secondary lining of the well body, binding of the reinforcement of the middle diaphragm and pouring of concrete; S3: Hydraulic self-elevating well casing secondary lining and diaphragm synchronous construction formwork climbing; S4: Finishing and curing of demolded concrete; S5: Construction of the thermal insulation layer on the surface of the secondary lining diaphragm; S6: The hydraulic self-elevating well casing secondary lining and middle diaphragm are constructed simultaneously, and the formwork is removed at the wellhead. Repeat steps S2 to S4 above to complete the simultaneous construction of the secondary lining and the middle partition plate of the wellbore from bottom to top, from the bottom of the well to the wellhead.

[0023] In step S1, the hydraulic self-elevating shaft secondary lining and diaphragm synchronous construction template includes a steel template 21 for pouring concrete 7 for the shaft secondary lining and diaphragm, multiple first supports 13 and second supports 14 set on the top of the steel template 21 for climbing the steel template 21, several ball bearing hydraulic jacks 17, a radial steel truss 22, and an upper steel truss 15 and a lower platform 10 for construction workers to work on. The upper steel truss 15 is fully covered with scaffold boards or checkered steel plates and can be used as an upper platform for construction workers. The lower platform 10 is a finishing platform used for repairing the outer surface of the concrete after demolding. Specifically, the first support 13 has an "F" shaped structure, with a receiving groove for accommodating the ball-bearing hydraulic jack 17 at the upper end of the first support 13, and the lower end of the first support 13 is used for the pouring of the secondary lining of the well body; the second support 14 has an "open" shaped structure, with a receiving groove for accommodating the ball-bearing hydraulic jack 17 at the middle of the upper end of the second support 14, and the lower end of the second support 14 is wrapped with a middle partition plate for the pouring of the middle partition plate concrete 7.

[0024] It also includes multiple climbing rods 12 embedded inside the secondary lining concrete 6 and the intermediate diaphragm concrete 7, respectively. The first support 13, the second support 14, the ball-bearing hydraulic jack 17, and the climbing rods 12 together form the climbing system for the hydraulic self-elevating well casing secondary lining and intermediate diaphragm synchronous construction formwork. Specifically, the first support 13, the ball-bearing hydraulic jack 17, and the climbing rods 12 constitute the climbing system for the hydraulic self-elevating well casing secondary lining, and the second support 14, the ball-bearing hydraulic jack 17, and the climbing rods 12 constitute the climbing system for the intermediate diaphragm.

[0025] The upper ends of the first support 13 and the second support 14 are both equipped with ball bearing hydraulic jacks 17. One end of the climbing rod 12 is embedded in the interior of the secondary lining concrete 6 or the middle diaphragm concrete 7, and the other end of the climbing rod 12 is inserted into the center of the ball bearing hydraulic jack 17 and exposed at a certain height. It climbs by relying on several ball bearing hydraulic jacks 17.

[0026] Any adjacent climbing pole 12 joints shall be staggered by at least 100cm in the vertical direction. Adjacent climbing poles 12 shall have the same radial specifications but different axial lengths. The climbing poles 12 shall be constructed of φ48.3×3.5 seamless steel pipe. Specifically, at least four specifications of climbing poles 12 shall be initially embedded inside the secondary lining concrete 6 and the intermediate diaphragm concrete 7. These four types of climbing poles 12 shall have the same diameter but different lengths, and climbing poles 12 of the same specifications shall be welded above and below them. Simultaneously, the number of support pole joints at the same height shall not exceed 1 / 4 of the total number of joints. The purpose of using different lengths for adjacent climbing poles 12 is that the joint locations are weak points under stress; staggered joints ensure good component performance, uniform stress distribution, and improved safety and stability. The outer diameter of the climbing pole 12 is 48.3mm, and the wall thickness is 3.5mm.

[0027] In step S1, the assembly sequence of the hydraulic self-elevating wellbore secondary lining and intermediate diaphragm synchronous construction template at the bottom of the well is as follows: S101: Assembly of the main trusses, including the upper steel truss 15 and the lower steel truss 16; S102: Assembly of the first support 13 and the second support 14, and installation of the ball-type hydraulic jack 17; S103: Installation of climbing pole 12; S104: No-load test; S105: Joint acceptance inspection by all parties; S106: After the sliding membrane rises to the preset height, the installation of the lower platform 10 begins; During the climbing process, the climbing rod 12 is welded together from several vertically connected climbing rods 12. When the first climbing rod 12 is installed at the bottom of the well, a steel plate is welded to its bottom end face. The climbing rod 12 is also equipped with a limiting device for synchronizing the lifting height of several ball-bearing hydraulic jacks 17. Specifically, the steel plate increases the contact area and the force-bearing area, and the limiting device ensures that the several ball-bearing jacks are at the same height after each lifting segment, preventing the hydraulic integral sliding formwork from tilting.

[0028] In step S2, a working platform 9, controlled by a hoist, is installed at a certain height on the top of the steel formwork 21. The working platform 9 is used for binding the reinforcing bars for the secondary lining of the well body and pouring the concrete 7 for the secondary lining and the middle diaphragm plate. Specifically, a safety platform 8 is erected above the working platform 9 to prevent falling objects from endangering the safety of construction personnel.

[0029] When tying the first section of reinforcing bars at the bottom of the well, the tying height of the secondary lining reinforcing bars should not be lower than the height of the working platform 9. As the hydraulic self-elevating well secondary lining and diaphragm synchronous construction formwork climbs and the hoisting platform is raised, construction workers tie the secondary lining reinforcing bars on the working platform 9. The tying height of the diaphragm reinforcing bars is higher than the top surface of the construction formwork. As the hydraulic self-elevating well secondary lining and diaphragm synchronous construction formwork climbs, construction workers tie the diaphragm reinforcing bars on the upper platform. Specifically, the tying height of the first section of the secondary lining and diaphragm reinforcing bars should be higher than the height of the working platform 9. Subsequently, as the hydraulic self-elevating well secondary lining and diaphragm synchronous construction formwork climbs and the hoisting platform is raised, the reinforcing bars are tied on the working platform 9. This can reduce the load on the hydraulic self-elevating well secondary lining and diaphragm synchronous construction formwork.

[0030] In step S2, the concrete includes a bottom-discharge bucket 18, a collection hopper 19 installed on the working plate 9, and multiple placing pipes 20. After the concrete is mixed at the wellhead mixing plant, it is lowered into the bottom-discharge bucket 18 through a chute. The bottom-discharge bucket 18 is vertically transported into the collection hopper 19, and then evenly, layeredly, and symmetrically placed into the formwork through the multiple placing pipes 20.

[0031] Before pouring concrete, the aggregate hopper 19 and the placing pipe 20 need to be lubricated with mortar. Specifically, lubrication reduces the friction between the concrete and the surfaces of the aggregate hopper 19 and the placing pipe 20, thereby reducing the possibility of concrete sticking to the surface; the lubricating effect of the mortar reduces blockage of the concrete in the placing pipe 20, ensuring smooth flow of the concrete; mortar lubrication improves the fluidity and pumpability of the concrete, which is beneficial for uniform pouring and filling of the concrete; lubrication reduces wear on the aggregate hopper 19 and the placing pipe 20, extending their service life.

[0032] During concrete pouring, multiple immersion vibrators are used to compact the concrete. Specifically, the purpose of vibration is to eliminate air bubbles and voids in the concrete, improving its density and uniformity, thereby increasing its strength and durability.

[0033] The outer walls of the multiple placing booms 20 are equipped with cushioning devices. Specifically, to protect the outer walls of the placing booms 20 and the surrounding structures, soft cushioning materials such as rubber or foam are installed on the outer walls of the placing booms 20. The function is to reduce the impact force during concrete pouring, as the placing booms 20 may collide with the surrounding formwork or supporting structures, thus preventing damage to the placing booms 20 and the structures. Simultaneously, the cushioning devices help prevent loose particles or debris from entering the placing booms 20, reducing the possibility of blockage and ensuring continuous concrete flow. Furthermore, the placing booms 20 may need to move or rotate during concrete pouring; the cushioning devices reduce friction between the placing booms 20 and the surrounding structures, making movement smoother.

[0034] The diameter of the fabric tube 20 is ≥200mm.

[0035] The concrete is early-strength concrete. Specifically, early-strength concrete is a special type of concrete that exhibits rapid early strength development. This type of concrete can reach relatively high strength in the early stages after pouring (usually within a few hours), making it more suitable for projects that need to be put into use as soon as possible or have a tight construction schedule.

[0036] In step S3, the formwork climbing steps for the synchronous construction of the hydraulic self-elevating well casing secondary lining and intermediate diaphragm are as follows: S301: Extend the climbing pole upwards 12; S302: Ball-type hydraulic jack 17 climbs upwards; In step S301, the bottom end of the newly extended climbing rod 12 is narrowed, with a narrowing length of not less than 50mm and an outer diameter of φ39mm×3.5mm after treatment. When several climbing rods 12 are extended, the narrowed end is inserted into the exposed steel pipe of the lower section and welded firmly. The joints of two adjacent climbing rods 12 are staggered vertically by at least 100cm. Specifically, after the upper and lower climbing rods 12 are firmly welded, it can be ensured that the ball bearing hydraulic jack 17 can climb smoothly and without obstruction at the joint of the upper and lower climbing rods 12. When extending the upper and lower climbing rods 12, it must be ensured that the upper and lower climbing rods 12 are on the same axis, and the straightness deviation of the upper and lower climbing rods 12 should not be greater than 1 / 1000.

[0037] In step S301, the hydraulic circuits of several ball-bearing hydraulic jacks 17, including an oil pump 23, main oil pipes 24, and branch oil pipes 25, are assembled in a two-stage parallel configuration. One oil pump 23 branches out six main oil pipes 24, and each main oil pipe 24 branches out five branch oil pipes 25. Several branch oil pipes 25 are connected in parallel to several ball-bearing hydraulic jacks 17. Specifically, N branch oil pipes 25 connected in parallel to N ball-bearing jacks can maintain a uniform oil supply to the N ball-bearing jacks, facilitating the adjustment of the lift difference among the N ball-bearing jacks. Specifically, the oil pump control console is a YKT-36 model, with main oil pipes 24 Φ16mm and branch oil pipes 25 Φ8mm. A parallel branch hydraulic circuit system is formed using steel wire braided high-pressure hoses and various distributors. The system is divided into three areas, A, B, and C, according to the partition plate, and the lengths of each oil circuit are made as similar as possible during pipe laying. Pipe fittings, oil separators, needle valves, and limit switches are provided as needed.

[0038] In step S3, after the hydraulic self-elevating shaft lining and diaphragm synchronous construction template climbs to a height H, an installation plate 11 for assembling the insulation layer of the shaft lining and diaphragm is assembled at the bottom of the shaft. This plate is then lifted using a winch 2 via a steel wire rope 3 and a sheave 4. The distance between the installation plate 11 and the bottom of the construction template is ≥20m. Specifically, insulation boards are installed on the surface of the shaft lining and diaphragm using a keel. A derrick 1 is erected directly above the shaft, and a sheave 4 is installed on the derrick 1. The installation plate 11 is connected to the winch 2 via a steel wire rope 3, and the winch 2 vertically lifts and moves the installation plate 11.

[0039] In step S6, the demolding sequence of the hydraulic self-elevating wellbore secondary lining and intermediate diaphragm synchronous construction formwork at the wellhead is as follows: S601: Remove oil pump 23, main oil pipe 24 and branch oil pipe 25; S602: Removal of construction formwork; S603: Remove the upper steel truss 15 and the lower steel truss 16; S604: Remove the lower platform 10 installed on the first support 13 or the second support 14. Specifically, the lower platform 10 is installed at the lower end of the first support 13 or the second support 14, and is located directly below the lower steel truss 16. The lower platform 10 is used to repair the honeycomb texture on the outer surface of the concrete after the slipform demolding. It is mainly connected to the middle diaphragm formwork through channel steel and is firmly connected by high-strength bolts.

[0040] Based on Example 1, this example presents the specific working principle of a method for simultaneous construction of the secondary lining and the middle diaphragm of a dual-cavity ventilation shaft.

[0041] The specific implementation principle and process are as follows: Construction formwork is installed inside the already completed primary lining concrete 5. Reinforcing bars are tied between the formwork and the primary lining concrete 5 before pouring the secondary lining and diaphragm concrete 7. Simultaneously, during the pouring of the secondary lining and diaphragm concrete 7, multiple metal climbing rods 12 are pre-embedded at certain intervals. After the first layer of concrete has fully set and reached the specified strength, a ball-bearing hydraulic jack 17 is passed through each metal climbing rod 12. The base of the ball-bearing hydraulic jack 17 is connected to the lifting frame at the top of the construction formwork using bolts. The construction formwork is then suspended on the cantilever beam of the lifting frame. The lifting support adopts a circumferential radial spatial frame structure, i.e., a radial steel truss 22. The construction formwork and the supporting frame are braced together using radial beams. To facilitate construction, scaffold boards are laid on top of the radial beams as an upper construction platform, with a lower platform 10 suspended below. All ball bearing hydraulic jacks 17 are connected to the hydraulic control system in parallel. While pouring concrete, the hydraulic control system is activated. Multiple ball bearing hydraulic jacks 17 use metal climbing rods 12 as climbing guides to drive the entire construction formwork to slide continuously from bottom to top along the concrete surface with a certain demolding strength and initial setting. During the sliding process, steel reinforcement binding, concrete pouring, climbing rod 12 extension, and demolding concrete repair operations are carried out simultaneously. The entire shaft secondary lining and the middle diaphragm concrete 7 are completed in a reciprocating cycle.

[0042] The primary lining of the shaft was constructed using a "short excavation and short lining, mixed excavation and lining" operation. After reaching a certain height above the design elevation at the bottom of the shaft, the hydraulically retractable integral steel formwork for the primary lining was removed. The cyclical operation of "short-segment excavation and lining" for the primary lining was changed to a single-line operation of "long and short excavation and lining." Subsequently, the drilling and blasting method was used for excavation and support construction on both sides of the shaft. After the drilling and blasting method excavation and support construction reached 5m, the survey was carried out, and the secondary lining steel formwork and integral hydraulic slipform were assembled simultaneously. After the assembly was completed and inspected and accepted by all parties, the construction proceeded from the bottom of the shaft to the shaft opening in the following order: application of cement-based penetrating waterproof coating, reinforcement binding, concrete pouring, and formwork slipforming, until the design elevation at the shaft opening was reached, at which point the formwork was removed.

[0043] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A method for simultaneous construction of the secondary lining and intermediate diaphragm of a double-cavity ventilation shaft, characterized in that, Includes the following steps: S1: Construction preparation, assembly of the bottom of the well bottom for the synchronous construction template of the hydraulic self-elevating well casing secondary lining and middle diaphragm plate; S2: Secondary lining of the well body, binding of the reinforcement of the middle diaphragm and pouring of concrete; S3: Hydraulic self-elevating well casing secondary lining and diaphragm synchronous construction formwork climbing; S4: Finishing and curing of demolded concrete; S5: Construction of the thermal insulation layer on the surface of the secondary lining diaphragm; S6: The hydraulic self-elevating well casing secondary lining and middle diaphragm are constructed simultaneously, and the formwork is removed at the wellhead. The specific construction method of step S3 is as follows: after the hydraulic self-elevating shaft lining and the middle partition plate synchronous construction template climbs to a height H, an installation plate (11) for assembling the insulation layer of the shaft lining and the middle partition plate is assembled at the bottom of the shaft; a derrick (1) is erected directly above the shaft, and a sheave (4) is installed on the derrick (1); the installation plate (11) is connected to the winch (2) through a steel wire rope (3); the installation plate (11) is vertically lifted and moved under the action of the winch (2); the distance between the installation plate (11) and the bottom of the construction template is ≥20m; the insulation plate is installed on the surface of the shaft lining and the middle partition plate by means of a keel using the installation plate (11); The hydraulic self-elevating shaft lining and diaphragm synchronous construction template includes a steel template (21) for pouring concrete (7) for the shaft lining and diaphragm, multiple first supports (13) and second supports (14) set at the top of the steel template (21) for climbing the steel template (21), several ball-bearing hydraulic jacks (17), a radial steel truss (22), and an upper steel truss (15) and a lower platform (10) for construction workers. The first support (13) has an "F" shaped structure. The upper end of the first support is provided with a receiving groove for accommodating the ball-bearing hydraulic jacks (17), and the lower end of the first support... Used for the pouring operation of secondary lining of well body; the second support (14) is an "open" shaped structure, and a receiving groove for accommodating ball hydraulic jacks (17) is set in the middle of the upper end of the second support. The lower end of the second support is wrapped with a middle partition plate for the pouring operation of the middle partition plate concrete (7); the hydraulic oil circuits of several ball hydraulic jacks (17) are assembled in a two-stage parallel manner; the two-stage parallel manner is as follows: one oil pump (23) branches out six main oil pipes (24), each main oil pipe (24) branches out five branch oil pipes (25), and several branch oil pipes (25) are connected in parallel to several ball hydraulic jacks (17). Repeat steps S2 to S4 above to complete the simultaneous construction of the secondary lining and the middle partition plate of the wellbore from bottom to top, from the bottom of the well to the wellhead.

2. The method for simultaneous construction of the secondary lining and intermediate diaphragm of a double-cavity ventilation shaft according to claim 1, characterized in that: In step S1, the upper steel truss (15) is fully covered with scaffold boards or patterned steel plates and can be used as an upper platform for construction workers. The lower platform (10) is a finishing platform used for repairing the outer surface of the concrete after demolding. It also includes multiple climbing rods (12) embedded in the secondary lining concrete (6) and the middle diaphragm concrete (7) respectively. The first support (13), the second support (14), the ball bearing hydraulic jack (17) and the climbing rods (12) together form the climbing system of the hydraulic self-elevating well secondary lining and middle diaphragm synchronous construction template. The upper ends of the first support (13) and the second support (14) are equipped with ball bearing hydraulic jacks (17). One end of the climbing rod (12) is embedded in the interior of the secondary lining concrete (6) or the middle diaphragm concrete (7), and the other end of the climbing rod (12) passes through the center of the ball bearing hydraulic jack (17) and climbs by relying on several ball bearing hydraulic jacks (17).

3. The method for simultaneous construction of the secondary lining and intermediate diaphragm of a double-cavity ventilation shaft according to claim 2, characterized in that: The joints of any adjacent climbing poles (12) shall be staggered by a distance of not less than 100cm in the vertical direction. The adjacent climbing poles (12) shall have the same radial specifications but different axial lengths. The climbing poles (12) shall be made of φ48.3×3.5 seamless steel pipe.

4. The method for simultaneous construction of the secondary lining and intermediate diaphragm of a double-cavity ventilation shaft according to claim 2, characterized in that: In step S1, the assembly sequence of the hydraulic self-elevating wellbore secondary lining and intermediate diaphragm synchronous construction template at the bottom of the well is as follows: S101: Assembly of the main truss of the upper steel truss (15) and lower steel truss (16); S102: Assembly of the first bracket (13) and the second bracket (14), and installation of the ball-type hydraulic jack (17); S103: Installation of the climbing pole (12); S104: No-load test; S105: Joint acceptance inspection by all parties; S106: After the sliding membrane climbs to the preset height, the lower platform (10) will be installed. During the climbing process, the climbing rod (12) is welded together from several climbing rods (12) connected end to end. When the first climbing rod (12) is installed at the bottom of the well, a steel plate is welded to the bottom end face of the climbing rod (12). The climbing rod (12) is also equipped with a limiting device for synchronously raising the height of several ball-bearing hydraulic jacks (17).

5. The method for simultaneous construction of the secondary lining and intermediate diaphragm of a double-cavity ventilation shaft according to claim 2, characterized in that: In step S2, a working plate (9) controlled by a hanging plate is set above the steel template (21). The working plate (9) is used for the reinforcement binding of the secondary lining of the well body and the pouring of concrete (7) for the secondary lining and the middle partition plate of the well body. When the first section of steel reinforcement is tied at the bottom of the well, the tying height of the steel reinforcement of the secondary lining of the well body shall not be lower than the height of the working plate (9). As the hydraulic self-elevating well secondary lining and the middle partition plate synchronous construction template climbs and the hoisting plate is lifted, the construction personnel tie the secondary lining steel reinforcement on the working plate (9). The tying height of the middle partition plate steel reinforcement is higher than the top surface of the construction template. As the hydraulic self-elevating well secondary lining and the middle partition plate synchronous construction template climbs, the construction personnel tie the middle partition plate steel reinforcement on the upper platform.

6. The method for simultaneous construction of the secondary lining and intermediate diaphragm of a double-cavity ventilation shaft according to claim 1, characterized in that: In step S2, the concrete includes a bottom-discharge bucket (18), a collection hopper (19) installed on the working plate (9), and multiple placing pipes (20). After the concrete is mixed at the wellhead mixing plant, it is lowered into the bottom-discharge bucket (18) through a chute. The bottom-discharge bucket (18) is vertically transported into the collection hopper (19) and then evenly, layeredly, and symmetrically placed into the formwork through multiple placing pipes (20). Before concrete pouring, mortar is needed to lubricate the aggregate hopper (19) and the distribution pipe (20); During the concrete pouring process, multiple immersion vibrators are used to vibrate the concrete. The outer walls of the multiple fabric tubes (20) are equipped with cushioning devices; The diameter of the fabric tube (20) is ≥200mm; The concrete is early-strength concrete.

7. The method for simultaneous construction of the secondary lining and intermediate diaphragm of a double-cavity ventilation shaft according to claim 2, characterized in that: In step S3, the formwork climbing steps for the synchronous construction of the hydraulic self-elevating well casing secondary lining and intermediate diaphragm are as follows: S301: Extend the climbing pole upwards (12); S302: The ball-type hydraulic jack (17) climbs upward; In step S301, the bottom end of the newly extended climbing pole (12) is narrowed, the length of the narrowing treatment is not less than 50mm, and the outer diameter of the narrowed end is φ39mm×3.5mm. When several climbing poles (12) are extended, the narrowed end is inserted into the interior of the exposed steel pipe of the lower section and welded firmly. The joints of two adjacent climbing poles (12) are staggered vertically by at least 100cm. In step S301, there are oil pumps (23), main oil pipes (24) and branch oil pipes (25). One oil pump (23) branches out six main oil pipes (24), and each main oil pipe (24) branches out five branch oil pipes (25). Several branch oil pipes (25) are connected in parallel to several ball-type hydraulic jacks (17).

8. The method for simultaneous construction of the secondary lining and intermediate diaphragm of a double-cavity ventilation shaft according to claim 7, characterized in that: In step S6, the demolding sequence of the hydraulic self-elevating wellbore secondary lining and intermediate diaphragm synchronous construction formwork at the wellhead is as follows: S601: Remove the oil pump (23), main oil pipe (24) and branch oil pipe (25); S602: Removal of construction formwork; S603: Remove the upper steel truss (15) and the lower steel truss (16). S604: Remove the lower platform (10) installed on the first bracket (13) or the second bracket (14).

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