Large-span river-crossing air rib air film and construction method thereof and river channel site enclosure

Abstract

The present application relates to large-span river-crossing air rib air film and its construction method and river site enclosure. The large-span river-crossing air rib air film is arched, transversely crosses the river, and is connected to the river-side foundations at both ends. A platform scaffold is erected in the river channel / foundation pit during construction. The top of the platform scaffold is connected to the river-side foundations at both sides to form a work surface for laying the air ribs before inflation. The laying and inflation of the air ribs are carried out based on the work surface. An auxiliary air bag is laid in the transverse middle part of the work surface so that each air rib can be pressed on the auxiliary air bag after laying. The inflation of the air ribs and the auxiliary air bag is carried out simultaneously during the inflation and arching, so that the auxiliary air bag is placed under the middle part of the air rib, avoiding the air rib from being dead-folded, and the air rib air film reaches the set arched state. The present application can realize more than 60 meters.

Description

Technical Field

[0001] This invention relates to large-span cross-river air-ribbed membrane structures, their construction methods, and their application in riverbank protection. Background Technology

[0002] Air-ribbed membrane structures are commonly used for the enclosure of narrow construction sites such as river channels, especially those requiring access or passage from both ends. Each air rib of the membrane is fixed to one end on each side of the construction site, forming an arched enclosure structure. This effectively prevents dust and noise from spreading to the surrounding area, allowing construction equipment to enter, exit, and pass through the arched structure and the two ends of the enclosed river channel. Because this enclosure system is easy to construct, has a short construction period, and the air-ribbed membrane structure can be reused, it has found good application in river and subway construction projects. However, for large-span (e.g., total span of 80 meters or 60 meters) cross-river air-supported membrane structures, at least two technical challenges are faced. First, air-supported membrane structures usually need to be laid on a flat surface and inflated. If laid in the riverbed, inflation will cause the middle of the air-supported membrane structure to bulge downwards, making it impossible to form an arched structure with the middle bulging upwards. Second, even if the air-supported membrane structure is laid on a flat surface, due to the large span, during the upward arching process at both ends, the middle of the air rib (the transverse middle of the air-supported membrane structure) remains on the ground under its own weight, gradually forming dead folds. Under the constraints of the inflation equipment and the pressure resistance of the air ribs currently used in practice, it is impossible to eliminate these dead folds and support the air ribs by relying solely on inflation. Summary of the Invention

[0003] The purpose of this invention is to provide a construction method for large-span cross-river air-supported membrane structures and air-supported membrane enclosures for large-span river construction sites, so as to construct air-supported membrane structures for large-span river construction sites.

[0004] The technical solution of the present invention is: a large-span cross-river air-ribbed membrane, which is formed by connecting several arched air ribs in sequence (connected in sequence through the sides) and is arched. The feature is that the air-ribbed membrane spans the river laterally, and its two ends are respectively connected to the foundation on both sides of the river.

[0005] Furthermore, the total span of the arched air rib air membrane is no less than 60 meters.

[0006] Preferably, spiral ground stakes (or spiral piles) are provided on the foundation on both sides of the river channel. The top of the spiral ground stake is provided with an air rib connector (e.g., a pull ring). Both ends of the arched air rib are provided with several ground stake connectors (e.g., shackles). The ground stake connectors at each end of the air rib are connected to the corresponding air rib pull rings on the corresponding ground stakes through connecting straps, thereby realizing the connection (soft connection) of the arched air ribs on the foundation on both sides of the river channel.

[0007] The distribution of the ground stake connectors at either end of the air rib should meet the requirements of a stable connection. The distribution of the corresponding ground stakes and the corresponding air rib connectors on the ground stakes should be adapted to the connection with the connecting strip of the corresponding ground stake connector to avoid excessive twisting of the air ribs due to the connection.

[0008] Preferably, the outer side of the arched air rib air membrane is covered with a membrane material (which may be referred to as the outer membrane), and the membrane material is connected to the arched air ribs that constitute the arched air rib air membrane through connectors, thereby connecting the membrane material to the arched air rib air membrane.

[0009] Preferably, both sides of the arched air rib are provided with connectors for connecting with adjacent arched air ribs, and the corresponding connectors on adjacent arched air ribs are connected by connecting strips, thereby realizing the connection (soft connection) between the arched air ribs.

[0010] The construction method of any large-span cross-river air rib air membrane disclosed in this invention involves setting up a platform scaffold (used as a platform scaffold) in the riverbed / foundation pit. The top scaffold boards of the platform scaffold are connected to the foundations on both sides of the riverbed to form (together form) a working surface (which can be roughly flat) for laying the air ribs before inflation. The air ribs are then laid and inflated and arched based on this working surface.

[0011] Preferably, before laying each air rib flat on the working surface, the auxiliary airbag is first laid in the transverse middle of the working surface so that each air rib can press on the auxiliary airbag after being laid flat. When inflating to form an arch, the auxiliary airbag is inflated first. After the auxiliary airbag inflates to a certain height, the air ribs and auxiliary airbags are inflated in tandem. Alternatively, the auxiliary airbags and each air rib are inflated simultaneously at the beginning so that the auxiliary airbag is under the middle of the air rib to avoid dead bending of the air rib. After the auxiliary airbag is inflated, the air rib may or may not reach the target state (e.g., the design height, the set arch shape). If the air rib reaches the target state, the air rib inflation is stopped. If the air rib does not reach the target state, the air rib inflation continues until the air rib reaches the target state. The auxiliary airbag is a cylindrical airbag, set longitudinally (the airbag axis is longitudinal and perpendicular to the axis of the individual arched air rib).

[0012] Typically, the auxiliary airbags should be long enough (with a sufficiently large actual longitudinal span) to simultaneously lift all the air ribs during inflation. If necessary, multiple shorter auxiliary airbags can be arranged closely together or spaced apart within a certain limit to ensure that the area lifted after inflation covers all the air ribs. Since the air ribs are interconnected, in practice, a small number of air ribs are not affected by the auxiliary airbags and do not substantially hinder the arching of the entire air rib membrane.

[0013] Preferably, the number of auxiliary airbags is one or multiple in parallel (e.g., two or three).

[0014] Preferably, the number of auxiliary airbags is one or three arranged side by side. The diameter of the auxiliary airbag located in the center laterally (a single auxiliary airbag, or the middle auxiliary airbag among three auxiliary airbags) (in the longitudinally positioned posture, it is the height when fully inflated / vertical dimension, that is, the maximum height that can lift the air rib membrane) is 40%-80% of the design height of the air rib membrane, for example, 40%, 50%, 60%, 70%, 80%. If the auxiliary airbag is too small, it will be difficult to effectively arch the membrane; if it is too large, it will significantly increase the cost.

[0015] The river channel construction site retaining structure is composed of any of the large-span cross-river air-ribbed membrane structures disclosed in this invention, with or without a liftable soundproof soft curtain at any of its ends.

[0016] The beneficial effects of this invention are as follows: Because a platform scaffold is set up within the riverbed / construction pit, and the top surface of the platform scaffold connects to the ground on both sides of the riverbed or construction pit, the pre-inflated air-rib membrane can be laid as if on flat ground, avoiding the obstruction of the riverbed or pit to the inflation arching. Because auxiliary airbags are laid under the air-rib membrane, they are inflated in tandem with the air ribs during inflation, lifting the transverse middle of the air-rib membrane through the auxiliary airbags, achieving a roughly balanced arching of each part of the air rib, avoiding arching failure due to dead bends. Based on the applicant's engineering practice, the construction method of this invention can realize the construction of an 80-meter span air-rib membrane across a river, effectively solving the long-standing technical difficulty of constructing air-rib membranes with spans exceeding 60 meters. Furthermore, the construction cost and construction period are significantly better than other large-span air-rib membrane construction methods still under exploration. Attached Figure Description

[0017] Figure 1 This is a structural diagram of the large-span cross-river air-supported membrane structure when the arching is completed (with auxiliary airbags not removed and platform scaffolding not dismantled);

[0018] Figure 2 yes Figure 1 The illustrated embodiment is a structural diagram of the arching process;

[0019] Figure 3 This is another structural diagram of the large-span cross-river air rib air membrane arching completed (with auxiliary airbags not removed and platform scaffolding not dismantled);

[0020] Figure 4 This is a flowchart of the construction process for a large-span, cross-river air-supported membrane structure.

[0021] Marked in the diagram: 10, slope protection pile; 20, platform scaffolding; 26, top scaffold board; 30, air rib air membrane; 40, auxiliary airbag. Detailed Implementation

[0022] The following uses the design parameters of a specific engineering project as an example to further illustrate the present invention. For different engineering projects / usage scenarios, the relevant parameters can be adjusted according to actual needs, and the specific implementation methods such as the connectors and connection methods used can also be adjusted according to actual needs.

[0023] See Figures 1 to 4 The construction method for air-supported membrane structures / air-supported structures for large-span river construction sites includes the following steps:

[0024] S1. Erect platform scaffolding

[0025] Erection sequence: Foundation treatment → Laying out lines according to the erection plan → Laying continuous scaffold boards → Placing longitudinal ground bracing → Erecting uprights one by one → Immediately fastening them to the longitudinal ground bracing → Installing transverse ground bracing and fastening it to the uprights or longitudinal ground bracing → Installing the first main horizontal bar → Installing the first secondary horizontal bar → Second main horizontal bar → Second secondary horizontal bar → Erecting temporary outriggers → Third and fourth main and secondary horizontal bars → Installing transverse diagonal bracing → Connecting uprights → Adding scissor bracing → Laying scaffold boards → Installing guardrails and toe boards → Hanging safety nets.

[0026] 1) Basic processing

[0027] The site for erecting platform scaffolding should be flat and firm, and should have waterproofing and drainage measures. The foundation should meet the following requirements:

[0028] ① The bearing capacity of the foundation of the platform scaffolding should be calculated separately based on the load on the platform scaffolding, the erection height, and the soil conditions of the erection site;

[0029] ② The bearing capacity of the foundation of the platform scaffolding must meet the standard value of the axial force transmitted from the superstructure to the top surface of the upright foundation. When the foundation cannot meet the bearing capacity requirements, reliable reinforcement measures should be taken.

[0030] 2) Measurement and positioning

[0031] Before installing the platform scaffolding system, the erection position should be pre-arranged. A total station should be used to locate the longitudinal and transverse spacing of the uprights on site according to the plan length. Control lines should be marked or strung on the ground for control. The purpose is to ensure that the scaffolding is erected accurately.

[0032] 3) Place the wooden blocks and adjustable base.

[0033] The contact surface between the platform scaffold base and the foundation should be flat and compact, without any gaps or warping. The platform scaffold base should be on the same horizontal plane. The elevation of the upright pad or the bottom surface of the base should preferably be 50mm to 100mm higher than the natural ground level.

[0034] The padding board should be a wooden padding board with a length of not less than 2 spans, a thickness of not less than 50mm, and a width of not less than 200mm.

[0035] 4) Frame installation

[0036] ① Longitudinal and transverse sweeping bars

[0037] The longitudinal sweeping rods are fixed to the uprights 20cm from the top of the base using right-angle fasteners, while the transverse sweeping rods are fixed to the uprights immediately below the longitudinal sweeping rods using right-angle fasteners. When there is a significant height difference between the uprights, the sweeping rods are staggered, with the higher longitudinal sweeping rod extending two spans towards the lower part and fixed to the upright.

[0038] ② Erecting poles

[0039] Except for the top step of the top floor, all other joints on each floor and at each step must be connected using butt couplers. Uprights and horizontal members must be connected using right-angle couplers. Joints should be staggered, with two adjacent upright joints avoiding the same span and staggered by at least 50cm in height. The center distance of each joint from the main node should not exceed 1 / 3 of the step distance. When uprights overlap at the top, the overlap length should be no less than 1m, and it must be secured with three equally spaced swivel couplers. The distance from the edge of the end coupler cover plate to the end of the overlapping longitudinal horizontal member should be no less than 100mm.

[0040] ③ Main horizontal bar

[0041] The main horizontal bar is placed below the secondary horizontal bar, inside the column; it is fastened to the column with right-angle couplers, and its length should not be less than 3 spans or less than 4.5m; the main horizontal bar should be continuously arranged around the same level.

[0042] The main horizontal members are extended using butt couplers, which should be staggered. The joints of two adjacent longitudinal main horizontal members should not be located in the same span or at the same time. The horizontal distance between two adjacent joints in different spans or at different times should not be less than 500mm. The distance from the center of each joint to the nearest main node should not be less than 1 / 3 of the longitudinal spacing.

[0043] The overlap length should not be less than 1m, and three swivel fasteners should be installed at equal intervals for fixing; the distance from the edge of the fastener cover plate at the end of the main horizontal bar to the end of the main horizontal bar should not be less than 100mm.

[0044] ④ Small horizontal bar

[0045] At each intersection of an upright and a main horizontal bar (main node), a small horizontal bar must be installed and fastened to the main horizontal bar using a right-angle coupler. The axis of this bar should deviate from the main node by no more than 15cm. The spacing between the small horizontal bars is the same as the longitudinal spacing of the uprights. In addition, according to the needs of the scaffolding erection at the working level, one small horizontal bar should be installed at equal intervals between two uprights, with a maximum spacing of no more than 75cm.

[0046] The distance between the small horizontal bars and the edge of the outer row of large horizontal bars should be no less than 10cm, and the distance between the small horizontal bars and the edge of the inner row of large horizontal bars should be 20cm. The small horizontal bars of the upper and lower layers are staggered at the uprights, and the adjacent small horizontal bars of the same layer are arranged facing each other at the uprights.

[0047] ⑤ Scissor bracing

[0048] The double-row ground platform scaffolding adopts scissor bracing, which is erected simultaneously with the columns and longitudinal and transverse horizontal bars. The continuous scissor bracing is arranged along the height of the scaffolding, and all of them use single-pole continuous scissor bracing.

[0049] One set of scissor bracing is installed every 6 steps and 4 spans, with the angle between the diagonal brace and the ground between 45° and 60°. The scissor bracing is continuously arranged along the height of the frame. One diagonal brace is fastened to the upright, and the other is fastened to the end of the extended horizontal bar. Both ends are fixed with swivel couplers, and 2 to 4 additional fastening points are added in the middle. All fixing points are no more than 15cm away from the main node.

[0050] The scissor bracing members are connected by overlapping, with an overlap length of ≥100cm, and are fixed with no less than 2 swivel couplers. The distance from the edge of the end coupler cover plate to the end of the member is ≥10cm.

[0051] ⑥ Scaffold boards

[0052] The first layer of scaffolding is made of hardwood planks, 50mm thick, 250-350mm wide, and 3.0m long. A horizontal safety net is installed below the working layer.

[0053] The working platform scaffold boards are made of steel mesh protective boards. Scaffold boards are installed at both the top and bottom of the working platform, along with safety nets and protective waist bars.

[0054] The scaffold planks are set on three horizontal bars and secured at both ends with 2-3 turns of 1.2mm diameter galvanized steel wire hoops, 15cm from each end. When the length of the scaffold plank is less than 2m, two small horizontal bars can be used, and the ends of the plank should be reliably fixed to them to prevent tipping.

[0055] Scaffold boards should be laid flat, fully, and securely. Two small horizontal bars should be installed at the joints, with each bar no more than 15cm from the joint. The distance between the scaffold board and the wall should not exceed 15cm to avoid gaps or protrusions.

[0056] 5) Safety measures and precautions

[0057] ① The tightness of the fasteners should be between 40 and 50 N·m, and not exceed 65 N·m. The tensile bearing capacity of the butt joint fasteners is 3 kN. When installing butt joint fasteners, the opening should face inward to prevent rain from entering. When installing right-angle fasteners, the opening should not face downward to ensure safety.

[0058] ② The end of each member extends at least 100mm beyond the edge of the fastener cover plate.

[0059] ③ Steel pipes with severe rust, flattening, or cracks must not be used, and fasteners with brittleness, deformation, or stripped threads are prohibited.

[0060] ④ It is strictly forbidden to mix steel pipes with an outer diameter of 48mm and 51mm.

[0061] ⑤ Steel pipes and fasteners must be sampled on-site and sent for testing. They can only be used after passing the test.

[0062] ⑥ The foundation of the platform scaffolding must be hardened to meet the load-bearing requirements, ensuring no water accumulation or subsidence. The concrete of the foundation must reach more than 75% of the design strength before construction can begin.

[0063] ⑦ When starting to erect the poles, a bracing should be installed every 6 spans until the wall ties are installed stably, and then it can be removed as needed.

[0064] ⑧ The platform scaffolding should be promptly connected to the structure or temporarily supported to ensure safety during the erection process. Before the end of each workday, it is essential to ensure that the scaffolding is stable.

[0065] ⑨ Platform scaffolding must be erected in accordance with the construction schedule, and the height of each erection shall not exceed two steps above the adjacent wall ties.

[0066] ⑩ During the erection process, the safety officer and scaffolding foreman should conduct inspections, acceptance checks, and obtain approvals. Inspections should be conducted every two steps, and a certificate of conformity should be posted once the design and construction requirements are met.

[0067] According to the "Safety Technical Specification for Coupler-Type Steel Pipe Platform Scaffolding" (JGJ 130-2011).

[0068] S2. Install spiral ground stakes

[0069] Overall process flow: site leveling and compaction → surveying and marking of pile positions → equipment positioning and leveling → test pile construction (parameter determination) → formal rotary pile driving into the soil → dynamic monitoring of the process → pile calibration → pile head treatment → finished product protection → zoned acceptance.

[0070] 1) Secondary leveling and layered compaction of the site

[0071] The entire field was meticulously leveled, with elevation differences controlled within ±3cm;

[0072] Special attention should be paid to the backfill areas: use a small compactor to compact the soil in layers, with a compaction thickness of 20cm / layer, and repeat the compaction 2-3 times. Check the density of the backfill surface layer to prevent local loose voids; the original loam areas can be simply leveled to avoid excessive compaction that may damage the original soil structure.

[0073] After compaction, allow the site to stand for 2 hours to ensure stability and prevent localized settlement.

[0074] 2) Surveying and setting out, and marking pile positions

[0075] Based on the design axis and pile location drawings, a total station was used to accurately lay out the center points of all pile locations.

[0076] Each pile location is marked with a wooden stake and a white lime cross. The pile location layout deviation is ≤5mm. After the layout is completed, it is checked by two people and a layout record is made.

[0077] According to the construction zone number, mark the pile position number one by one to avoid missing or incorrect piles;

[0078] Record the geological conditions of each pile location, distinguish between pile locations in native soil and those in backfill soil, mark them properly, and carry out differentiated construction.

[0079] 3) Positioning and precise leveling of the piling machine

[0080] The piling machine is driven to the center of the designated pile position, and the position is slowly adjusted so that the center of the drill rod is completely aligned with the center point of the pile position mark;

[0081] Adjust the hydraulic outriggers of the pile driver and use a level to calibrate the machine body to ensure that the longitudinal and lateral horizontal deviations of the machine body are ≤0.5°, so as to prevent the machine body from tilting and causing the pile body to deviate.

[0082] Hang vertical control lines, calibrate the verticality of the drill rod, with an initial verticality deviation of ≤0.5%, and fix and lock the equipment to prevent machine position deviation during construction.

[0083] After the piles are in place, the technicians will check the pile positions, levelness, and verticality. Construction can only begin after the piles have passed inspection.

[0084] 4) Test pile construction

[0085] Because the site contains both loam and backfill soil layers, 3-5 test piles of each layer were selected before construction to determine the construction parameters.

[0086] Native soil: Medium swirl speed, standard torque application;

[0087] Backfill: Use low speed and low torque, and gradually rotate the soil multiple times to avoid soil disturbance and pile tilting caused by rapid rotation;

[0088] Test piles record the soil penetration resistance, pile rotation speed, verticality changes, and settlement, determine the formal construction standard parameters, and retain images and data records throughout the process.

[0089] 5) Formal rotary pile driving construction

[0090] The total length of the piles in this project is 2m. The entire process involves pure rotary compaction into the soil, without impact or excavation, and is carried out in stages at a uniform speed.

[0091] Initial stage of spiral pile insertion (0-500mm): Slowly screw in at a low speed, controlling the rotation speed at 10-15r / min. Manually observe the pile position and verticality in real time, and make timely fine adjustments to the machine position to correct the initial deviation. This stage is the key stage for pile quality.

[0092] During the middle stage of helical pile driving into the soil (500 / 1500mm): In the loam area, the rotation speed can be appropriately increased to 15 / 20r / min to maintain a uniform speed; in the backfill area, maintain a low speed to avoid soil compression and loosening, voids, and to keep the pile vertical and stable.

[0093] Later stage of helical pile driving into the soil (1500~2000mm): Reduce the rotation speed again and slowly spin to the designed depth. The pile body is fully driven into the soil and the pile bottom is in place. Strictly control the total driving depth to 2000mm. Over-driving and under-driving are strictly prohibited.

[0094] Throughout the construction process, keep the drill rod vertical. Forcibly applying pressure or deflecting the drill rod is strictly prohibited. When encountering slightly hard soil clods or impurities, slow down to pass through. If encountering large-area obstacles, stop the machine immediately for inspection. Rough construction is prohibited.

[0095] 6) Dynamic testing and calibration of piles

[0096] The pile driving process is monitored in real time, and parameters are checked every 50cm depth.

[0097] Pile position deviation: The center displacement deviation after pile completion is ≤10mm;

[0098] Pile verticality: Deviation ≤1% throughout (maximum deviation ≤20mm for 2m piles);

[0099] Pile top elevation: Strictly conforms to the design elevation, with uniform elevation throughout the site, and deviation controlled within ±5mm;

[0100] The settlement of the backfill piles should be monitored closely. If slight settlement occurs, the piles should be fine-tuned and recalibrated in a timely manner.

[0101] 7) Pile driver relocation and pile head treatment

[0102] After the single pile construction is completed and the parameters are verified to be qualified, unlock the hydraulic outriggers of the pile driver and move it smoothly to the next pile position. Dragging or colliding with the completed pile is prohibited.

[0103] Clean the soil and debris off the top of the pile, and check that the pipe opening at the top of the pile is free from deformation and cracks, and that the galvanized layer is undamaged.

[0104] Fine-tune and correct the piles with elevation deviations to ensure that the pile tops are flat and have a uniform elevation;

[0105] No need to cut or weld the pile body, maintaining the integrity of the 2m standard pile length.

[0106] 8) Finished Product Protection

[0107] After the piles are completed, warning signs should be set up, and it is strictly forbidden to run over them with machinery, step on them, or collide with them.

[0108] After the piles are installed in the backfilled area, the soil should be left to stand for 4 hours to allow it to solidify naturally and reduce subsequent settlement.

[0109] The galvanized anti-corrosion layer of the pile body is protected throughout the entire process to avoid scratches, bumps and damage.

[0110] S3, Laying the air rib air membrane

[0111] Large-span air ribs typically utilize high-strength, high-toughness fiber-reinforced composite materials to ensure sufficient compressive and deformation resistance. Each air rib must be inspected for appearance defects such as breakage, scratches, and aging. For air-supported membrane structures, membrane materials with excellent airtightness, strong weather resistance, and high tensile strength should be selected. The dimensions and thickness of the membrane material must be precisely checked to ensure they meet design standards, and the membrane surface must be free of any flaws.

[0112] Prepare the materials needed for splicing the air ribs and filling the membrane, such as blowers, electrical control cabinets, tie rods, heat sealing welding materials, air pipes (main pipes and branch pipes), stainless steel carabiners, etc. Ensure that the materials are compatible with the main material and have excellent tensile strength, waterproof, airtight, and electrical properties.

[0113] It is equipped with various connectors for connecting air ribs to supporting structures and fixing devices, such as metal carabiners, high-strength webbing, nuts, washers, plugs, air hoses, and pressure sensors. Depending on the characteristics of the excavation pit environment, the connectors are made of stainless steel or specially treated corrosion-resistant alloy materials to prevent corrosion from weakening the connection strength.

[0114] Strictly inspect the dimensional accuracy and surface quality of the connectors. There should be no deformation or cracks. The threaded parts should be smooth and burr-free to facilitate installation and tightening.

[0115] 1) Preliminary preparations

[0116] ① Site Planning: Select a spacious, flat, and suitable area on the top platform of the foundation pit as the air rib deployment site. Thoroughly clean the site, ensuring there are no sharp objects to prevent damage to the air ribs during deployment. It is recommended to use cotton felt, non-woven fabric, tarpaulin, etc., to protect the entire platform.

[0117] ② Inflation preparation: Lay cotton felt at the bottom of the air rib column base to prevent the bottom of the column base from being scratched by sharp objects.

[0118] 2) Deploy auxiliary airbags

[0119] Deploy the inflatable auxiliary airbags (φ18*40 meters) in the middle of the air rib field and lay them out for later use.

[0120] Based on the air-supported membrane plan, calculate the appropriate placement of the airbags and then place them at the bottom according to the designated locations.

[0121] 3) Single air rib laying

[0122] ① Removal of Air Rib Packaging: Carefully remove the outer packaging of the air ribs, taking care to protect the surface of the air ribs during the removal process to avoid damage. At the same time, carefully check the air ribs for any damage caused during transportation, and record and deal with any problems in a timely manner.

[0123] ② Starting end fixing: Securely fix one end of the air rib to the pre-set starting fixing point (or the fixing pull point on the moving platform). The fixing point must be firm and reliable, and able to withstand the tensile and lateral forces during the air rib deployment process. A fixing device (two 1.5T straps and a 3.25T shackle) with a special pull ring structure can be used for fixing.

[0124] ③ Slowly unfold and lay the air ribs: Arrange multiple construction workers to be evenly distributed on both sides of the air ribs, and slowly and steadily unfold the air ribs according to their unfolding direction. During the unfolding process, be sure to maintain the straightness of the air ribs and avoid twisting and folding. At the same time, arrange for a dedicated person to closely observe the surface of the air ribs. If any damage, scratches or other problems are found, the unfolding should be stopped immediately and the problem should be dealt with.

[0125] ④ Air rib fixing: After the air rib is fully extended, use connecting straps and carabiners to connect the top and bottom tension points of the air rib in sequence according to the numbers. The carabiner screws must be tightened (after unfolding and connecting, be sure to check repeatedly to prevent incorrect connection points and to prevent the air rib from rotating 360° and getting knotted. If this happens, you can only deflate and readjust).

[0126] 4) Interrib connection

[0127] ① Connection Verification: Before connecting multiple air ribs, verify the buckle numbers at the connection points. Begin by connecting the white (bottom) pull rings, checking each one afterward to ensure accuracy. Then connect the gray (top) pull rings, again checking each one to ensure accuracy. The surfaces of the connected air ribs should be clean, and the M8 stainless steel carabiners used for the pull rings should be securely tightened to ensure a high-quality connection.

[0128] ② Connecting with connectors: For air ribs that use metal carabiners, webbing, or other connectors, install the connectors at the air rib connection points, and tighten the bolts or webbing as specified to ensure a tight connection without any looseness.

[0129] 5) Outer membrane application

[0130] ① Membrane Material Deployment and Positioning: Use a crane to lift the membrane material to the deployment position of the air ribs on the platform, and slowly lower it so that the membrane material covers the air rib structure. Hoist the outer membrane to the position marked on the design drawings, and then deploy the membrane material after it is in place.

[0131] ② Connection of membrane material and air ribs: Specialized membrane material connectors, such as stainless steel carabiners, are used to connect the membrane material and air ribs. During the connection process, the tension of the membrane material must be strictly controlled to avoid slackness or excessive stretching. Following the design requirements, the connection should begin from one end of the membrane material and proceed gradually towards the other, ensuring a secure, well-fixed, and accurately positioned connection.

[0132] ③ Membrane splicing (if necessary): For large-area outer membranes, splicing may be required. Before splicing, verify the accuracy of the numbers at the splicing points. Use stainless steel carabiners to connect the membrane materials together. Strictly control the sequence position during splicing; after splicing, visually inspect the splicing areas.

[0133] ④ Membrane edge treatment: After the outer membrane is laid, the edges of the membrane are treated with guy ropes. Sufficient length is left for fixing after membrane filling. This prevents detachment and wind damage.

[0134] S4, Arching and Shaping

[0135] Use webbing (75mm wide, 3.6mm thick) to pass through the top of the air ribs one by one, fix one end and leave the other end pre-lengthened for later use. Use it to assist in the inflation of the auxiliary airbags and air ribs. After the air ribs are inflated and shaped, use a tensioner to tighten and shape the webbing to enhance the wind resistance of the air ribs after they arch and shape them.

[0136] 1) Preparations before inflation

[0137] ① Air rib and air membrane inspection: Conduct a comprehensive inspection of the installed air rib and air membrane, including whether the connections of the air ribs are secure and the seals are good, whether the outer membrane is damaged or scratched, and whether the electrical equipment cables are installed correctly. Rectify any problems found promptly to ensure the air rib and air membrane is ready for inflation.

[0138] ② Inflation Equipment Commissioning: Commission and test the inflation equipment, including the air pump, pressure gauge, pressure control system, and power distribution cabinet. Check the equipment's operating status to ensure it functions properly and that the inflation pressure and flow rate meet design requirements. During commissioning, calibrate the equipment parameters to ensure accurate and reliable measurement data.

[0139] ③ Safety Inspection: Inspect the safety protection facilities at the construction site, such as safety nets, guardrails, and warning signs, to ensure they are intact. Check that construction personnel are wearing their safety protective equipment to ensure a safe construction process. Simultaneously, develop an emergency plan for the inflation process, clearly defining emergency response measures and personnel responsibilities.

[0140] ④ Surrounding Environment Inspection: Inspect the surrounding environment of the foundation pit to ensure there are no obstacles or hazards that could affect the inflation operation. Communicate and coordinate with surrounding construction units to avoid overlapping operations during inflation and ensure the smooth progress of the inflation operation. Protect surrounding buildings and fences using flexible protective materials such as cotton felt and membranes.

[0141] 2) Inflation and arching, and fixing

[0142] ① Slow Inflation: Start the air pump to inflate the auxiliary airbag. Once the airbag reaches a height of approximately 12 meters, slowly inflate the air rib membrane. During inflation, closely observe the expansion of the air rib membrane and strictly control the inflation speed to avoid excessive local pressure and damage caused by rapid inflation. The inflation of the auxiliary airbag and each air rib should be coordinated to ensure that the auxiliary airbag effectively supports the middle of the air rib, preventing kinks, and that the expansion of each part of the air rib is roughly uniform. Simultaneously, use a pressure gauge to monitor the inflation pressure in real time, ensuring that the inflation pressure gradually increases according to design requirements.

[0143] ② Pressure Regulation and Stabilization: When the inflation pressure approaches the design pressure (3200 Pa), adjust the output pressure of the air pump more slowly to gradually stabilize the air pressure inside the air rib membrane at the design pressure value (3200-3800 Pa). After the air pressure stabilizes, keep the air pump running for a period of time and observe whether the air pressure inside the air rib membrane drops. If the air pressure drops, promptly check the sealing of the air rib membrane, find the leak, and repair it.

[0144] ③ Fixing and Adjustment: After the air ribs have arched to the designed height, the shape of the arch is finely adjusted to fully meet the design requirements. The surface of the air rib membrane is inspected. If there are wrinkles, looseness, or other phenomena, appropriate adjustments are made to make the surface of the air rib membrane flat and taut. As needed, temporary supports or fixing devices are used to fix the arched state of the air ribs to prevent deformation during subsequent construction.

[0145] After the air-supported membrane structure is fully inflated and stabilized, the connections between the air-supported membrane structure and the supporting structure and fixing devices are tightened and adjusted again. Ensure the connections are secure and that the position and orientation of the air-supported membrane structure meet design requirements.

[0146] During the fixing process, it is essential to ensure that the fixing device is secure and reliable, capable of withstanding the weight of the air rib and external forces.

[0147] ④ Final Inspection and Acceptance: Conduct a comprehensive final inspection of the inflated air-ribbed membrane structure, including its appearance, dimensions, connections, sealing performance, and the operational status of electrical equipment. The inspection results should meet design requirements and relevant standards and specifications. Organize relevant personnel to conduct acceptance testing; only after passing acceptance can subsequent construction or commissioning proceed.

[0148] S5. Ancillary (supporting) facilities

[0149] 1) Cable route planning: Based on the location and functional requirements of the electrical equipment, carefully plan the cable laying path on the air ribs. Select the shortest and safest path possible to avoid friction and compression between the cable and the air ribs. Clearly mark the cable laying route on the air ribs for easy construction.

[0150] 2) Cable Laying: Lay the cables along the pre-marked path, taking care to avoid twisting or knotting them during the process. For different types of cables, such as power cables and control cables, lay them separately to prevent mutual interference. After laying, organize the cables to ensure they are neat and orderly.

[0151] 3) Blower Installation: Place the blowers in their designated positions. Currently, four high-pressure blowers are placed at the four positions on the air rib column bases and connected to the main inflation pipe (made of membrane material). Six medium-pressure blowers are placed at the positions of the inflation pipes extending from the auxiliary airbags. The middle section of the main inflation pipe (made of membrane material) has external connection holes for the auxiliary inflation medium-pressure blowers. Use inflatable PVC tubing (2-inch or 4-inch) to connect to the main inflation pipe (made of membrane material) and the airbag extension inflation pipe. Install quick connectors (2-inch or 4-inch), G1 / 4 plugs, and pressure relief valves on the corresponding flanges of the main inflation pipe (made of membrane material) and the air rib column bases. Use inflatable PVC tubing to connect the main inflation pipe (made of membrane material) to the air rib inflation port. Install check valves and quick connectors on the blowers (pay attention to the arrow direction when installing the check valve; reverse installation is strictly prohibited).

[0152] 4) Installation of pressure relief valve and pressure sensor: Each air rib is equipped with 2 air inlet pipes, 2 pressure relief valves and pressure sensors, which can accurately monitor the pressure of each pipe. The pressure relief valve is a mechanical pressure relief valve, which will automatically release pressure when a certain pressure is reached to ensure the pressure stability of the air rib.

[0153] 5) PLC Control System Installation: Each project is equipped with a PLC cabinet control system to monitor the air fin pressure and parameters in real time, set the safe pressure range, and automatically control the booster fan. During normal operation, the pressure is set to 2200-3200 Pa. When the pressure is below 2200 Pa, the PLC will automatically turn on the booster fan to supplement the pressure; when the pressure is above 3200 Pa, the PLC will automatically turn off the booster fan to ensure the pressure safety of the air fin. The following is a schematic diagram of the monitoring screen.

[0154] 6) Cable Connection and Testing: Connect the cable to the electrical equipment, ensuring the connection method strictly complies with electrical installation specifications. After connection, perform insulation and continuity tests on the cable to ensure good electrical performance and the absence of short circuits, open circuits, or other problems. After passing the tests, protect the cable connection points to prevent moisture and corrosion.

[0155] S6. Debugging and Maintenance

[0156] 1) Functional testing

[0157] The various functions of the air-ribbed membrane system were tested, including the support function of the air ribs, the sealing performance of the membrane, the operation of the inflation and deflation system, and the working status of the electrical equipment. During the testing process, different operating conditions were simulated to comprehensively check the system's performance under various circumstances.

[0158] Test the emergency functions of the air rib air-supported membrane system, such as emergency exhaust function and backup power switching function, to ensure that the system can work normally in case of emergencies and protect personnel safety and project safety.

[0159] 2) Performance optimization

[0160] Based on the functional test results, the performance of the air rib air-film system was optimized. If the supporting stiffness of the air ribs was found to be insufficient, the inflation pressure could be increased appropriately or the structural parameters of the air ribs could be adjusted. If the sealing performance of the air film was poor, the sealing parts could be resealed or the sealing material could be replaced. If the electrical equipment was unstable, the cable connections and equipment parameters could be checked and adjusted accordingly.

[0161] During performance optimization, it's crucial to closely monitor the system's operational status to avoid causing additional problems due to excessive adjustments. Simultaneously, maintain thorough test records and conduct comparative analysis of performance data before and after optimization to determine the optimal optimization approach.

[0162] Unless otherwise specified, the preferred and optional technical means disclosed in this invention can be arbitrarily combined to form several different specific embodiments when one preferred or optional technical means is a further limitation of another technical means.

Claims

1. A large-span, cross-river air-ribbed membrane structure, composed of several arched air ribs connected sequentially, forming an arch shape, characterized in that... The air-supported membrane structure spans the river horizontally, with its two ends connected to the foundations on both sides of the river.

2. The large-span trans-river air-supported membrane structure as described in claim 1, characterized in that... The total span of the arched air rib air membrane shall not be less than 60 meters.

3. The large-span trans-river air-supported membrane structure as described in claim 1, characterized in that... Spiral ground stakes are installed on the foundations on both sides of the river channel. The top of the spiral ground stakes is equipped with air rib connectors. Both ends of the arched air ribs are equipped with several ground stake connectors. The ground stake connectors at each end of the air ribs are connected to the corresponding air rib pull rings on the corresponding ground stakes through connecting straps, thereby realizing the connection of the arched air ribs on the foundations on both sides of the river channel.

4. The large-span trans-river air-supported membrane structure as described in claim 1, characterized in that... The outer side of the arched air rib air membrane is covered with a membrane material, which is connected to the arched air ribs that make up the arched air rib air membrane through connectors, thereby connecting the membrane material to the arched air rib air membrane.

5. The large-span trans-river air-supported membrane structure as described in claim 1, characterized in that... Both sides of the arched air rib are provided with connectors for connecting with adjacent arched air ribs. The corresponding connectors on adjacent arched air ribs are connected by connecting strips, thereby realizing the connection between the arched air ribs.

6. The construction method of the large-span cross-river air-supported membrane structure as described in any one of claims 1-5, characterized in that... A platform scaffold is erected in the riverbed / foundation pit. The top scaffold boards of the platform scaffold are connected to the foundations on both sides of the riverbed to form a working surface for laying the air ribs before inflation. The air ribs are laid and inflated based on this working surface.

7. The construction method of the large-span cross-river air-supported membrane structure as described in claim 6, characterized in that... Before laying each air rib flat on the working surface, first lay the auxiliary airbag in the middle of the working surface in the transverse direction so that each air rib can press on the auxiliary airbag after being laid flat. When inflating and arching, first inflate the auxiliary airbag. After the auxiliary airbag inflates to a certain height, then inflate each air rib and the auxiliary airbag in coordination. Alternatively, inflate the auxiliary airbag and each air rib simultaneously at the beginning so that the auxiliary airbag is under the middle of the air rib to avoid dead bending of the air rib. After the auxiliary airbag is inflated, the air rib may or may not reach the target state. If the air rib reaches the target state, stop inflating the air rib. If the air rib does not reach the target state, continue inflating the air rib until the air rib reaches the target state. The auxiliary airbag is a cylindrical airbag and is set longitudinally.

8. The construction method of the large-span cross-river air-supported membrane structure as described in claim 7, characterized in that... The number of auxiliary airbags can be one or multiple airbags arranged side by side.

9. The construction method of the large-span cross-river air-supported membrane structure as described in claim 7, characterized in that... The number of auxiliary airbags is one or three in a row. The diameter of the auxiliary airbag located in the center of the lateral direction is 40%-80% of the design height of the air rib membrane.

10. River channel construction site protection, characterized in that... It is composed of a large-span cross-river air rib air membrane as described in any one of claims 1-5, and may or may not be provided with a liftable soundproof soft curtain at any of its ports.

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