Installation method of offshore water intake tank culvert

Abstract

The invention discloses an installation method of an offshore water intake tank culvert, which comprises the following steps: S1, construction preparation: determining a prefabrication site, a transportation route and engineering equipment for installation operation; s2, foundation trench leveling, foundation trench excavation, riprap foundation bed treatment, cushion block foundation bed leveling, cushion block installation and box culvert bottom foundation bed leveling are conducted; s3, box culvert shipment is conducted, specifically, a crane ship is berthed beside a box culvert prefabrication site for anchoring and positioning, and a transportation barge is berthed on one side and hoisted by the crane ship to be placed in the transportation barge; s4, box culverts are installed, two box culverts at a water intake are connected to a water intake head through a seawater pump room, each water intake box culvert is divided into three sections, and the box culverts are installed from the shore side to the sea side during installation; s5, mounting a water taking pipe, a chemical adding pipe and a chemical adding pipe groove box; s6, mold bag concrete, wherein the top face and the two sides of the box culvert connector are covered with a layer of C40 mold bag concrete with the thickness of 600 mm and the width of 2 m according to the design requirement; and S7, block stone backfilling is conducted. The problems that an offshore water taking tank culvert is tedious and complex in installation process and inconvenient to take water are solved.

Description

Technical Field

[0001] The present invention relates to a method for installing a sea water intake culvert. Background Art

[0002] A culvert refers to a culvert whose body is built with reinforced concrete box pipe sections. A culvert consists of one or more square or rectangular cross-sections. At present, seawater desalination and direct seawater utilization have become one of the important ways to solve the shortage of fresh water resources in densely populated coastal areas. The seawater at the intake of the box culvert type water intake is relatively deep, and the water intake is not affected by high and low tide levels, and it is suitable for rocky coasts or port and wharf areas where the siltation is not serious. The characteristics of this water intake method are that the culvert is located below the lowest sea water level and is not affected by the change of tide level. However, most of the current box culvert type water intake structures are not convenient to be fixed on the seabed. Before the box culvert type water intake structure is fixed on the bottom of the water, the construction team needs to drive the fixing pillars into the seabed one by one, and then fix the box culvert type water intake structure for seawater desalination on the pillars, resulting in a cumbersome and complex installation and fixing process of the culvert, which brings great inconvenience to the seawater intake operation.

[0003] Therefore, a method for installing a sea water intake culvert is provided. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for installing a sea water intake culvert to overcome the existing defects, and solve the problems of cumbersome and complex installation process of the sea water intake culvert and inconvenient water intake.

[0005] The technical solution to achieve the above purpose is as follows:

[0006] A method for installing a sea water intake culvert includes:

[0007] Step S1, construction preparation, determining the prefabrication site, transportation route and engineering equipment for installation operations;

[0008] Step S2, foundation trench leveling, including foundation trench excavation, rubble bed treatment, cushion bed leveling, cushion installation and culvert bottom bed leveling;

[0009] Step S3, loading the culvert onto the ship, the crane ship anchors and positions beside the culvert prefabrication site, the transport barge docks on one side, and the crane ship hoists and places it in the transport barge;

[0010] Step S4, culvert installation, there are two culverts at the water intake, which are connected from the seawater pump house to the water intake head. Each water intake culvert is divided into three sections, and it is installed from the shore side to the sea side during installation;

[0011] Step S5, installation of the water intake pipe, chemical dosing pipe and chemical dosing pipe trough box;

[0012] Step S6, concrete filled in flexible bags. According to the design requirements, a layer of C40 concrete filled in flexible bags with a thickness of 600 mm and a width of 2 m shall be covered on the top surface and both sides at the interface of the culvert box.

[0013] Step S7, backfilling with rubble. After the installation of the water intake culvert box and passing the acceptance, rubble shall be dumped on the top and both sides of the culvert box to protect the pipes.

[0014] Preferably, in the said Step S1, the construction preparation includes:

[0015] Prefabrication site. The precast culvert box shall be prefabricated under the steel bar shed and at the temporary dock inside the construction site.

[0016] Transportation route. After the precast culvert box is fabricated at the prefabrication site, it shall be hoisted by a 350t fixed jib crane from the prefabrication site and temporarily placed on a 2000t self-propelled transport barge, and then transported to the installation point.

[0017] Select engineering equipment for installation operations, including but not limited to a 350t fixed jib crane, a 2000t self-propelled transport barge, a 1000hp anchor boat, an excavator, a 50t crane boat, a stone material transport boat, diving equipment, a level and a total station.

[0018] Preferably, in the said Step S2, the foundation trench leveling includes:

[0019] Step S21, foundation trench excavation. Before the installation of the water intake culvert box, the existing cofferdam shall be blasted.

[0020] Step S22, treatment of the rubble bed. According to the geological report and design drawings, underwater dumping shall be carried out at the water intake head, and underwater dynamic compaction treatment shall be carried out on the dumped part.

[0021] Step S23, leveling of the cushion block foundation bed and installation of cushion blocks;

[0022] Step S24, leveling of the culvert box bottom foundation bed. After the leveling of the culvert box installation cushion blocks, the leveling of the culvert box bottom foundation bed shall be carried out.

[0023] Preferably, the said Step S22 includes:

[0024] Determine the scope of the foundation dumping treatment of the water intake head. The width of the foundation dumping scope of the water intake head is about 20 m, the length is about 12 m, the maximum dumping depth is about 10 m, and the slope is set at 1:2.

[0025] After the completion of the rubble bed dumping and passing the acceptance, the tamping barge enters the construction site and positions the ship according to the dumping marks.

[0026] Before tamping, the technical personnel shall give a technical disclosure to the construction personnel, explaining the tamping method, technical requirements, quality assurance measures, tamping scope, drop distance of the tamper and the uses of various marks.

[0027] Before construction, trial ramming shall be carried out first to determine the number of ramming passes and the settlement amount of the foundation bed. The number of ramming passes for single-point trial ramming is 6 times, and the settlement amount is 50 mm.

[0028] The foundation bed ramming is the overall ramming of the backfill area. According to the existing mechanical equipment situation, a 50t crawler crane is equipped to hang a rammer to carry out the foundation bed ramming construction. The rammer is a reinforced concrete rammer with a weight of 5.4t, a bottom area of 1.54㎡, a drop height of 3.5m, and a ramming impact energy of 189 kJ / ㎡.

[0029] Before ramming, the foundation bed shall be measured, and the local elevation difference shall not be greater than 30 cm. If it cannot meet the requirements, rough leveling shall be carried out by divers. After meeting the requirements, ramming shall be carried out. Among them, during the ramming process, the ramming scope and the number of ramming passes shall be strictly controlled, and the method of adjacent longitudinal and transverse pressing of half rams shall be adopted.

[0030] After the foundation bed ramming, ramming acceptance shall be carried out. In the construction scope, a 5m section shall be taken for re-ramming once, and the average settlement amount is required not to be greater than 30 mm.

[0031] After ramming, if the foundation bed top surface needs to be supplemented with dumped rubble, when the supplemented dumping area is greater than 1 / 3 of the caisson bottom area or the continuous area is greater than 30㎡ and the thickness is greater than 500 mm, supplementary ramming treatment shall be carried out.

[0032] During the ramming construction, the construction personnel shall make records, and the record content includes but is not limited to the ramming section, ram weight, number of ramming passes, drop height of the ram, overlapping situation, and hydro-meteorological conditions.

[0033] The said step S23 includes:

[0034] Block leveling construction. According to the requirements of the construction drawing, the foundation bed is backfilled with 400 mm thick two-piece stones and gravel for fine leveling, and then the culvert is placed. Among them, culvert connection pads are installed at the culvert joints, and the elevation of the pads is the same as that of the foundation bed.

[0035] The 50t crane ship is anchored and positioned in the foundation trench with the cooperation of the surveying personnel, and the processed leveling frame is placed at the set position.

[0036] The diver dives underwater and inserts the measuring rod of the leveling frame into the measuring conduit of the leveling frame.

[0037] Use a total station to measure the plane position of the leveling frame, and then use a level to measure the elevations of the four corners of the leveling frame. By adjusting the adjusting screws at the four corners of the leveling frame, the horizontal plane of the leveling frame is adjusted to the set elevation, and then bagged gravel is stacked around.

[0038] After the leveling frame is installed in place, remove the measuring rod, and the crane on the 50t crane ship grabs and dumps the two-piece stones on the two-piece stone and gravel transport ship parked beside the crane ship into the leveling frame.

[0039] During the dumping, the elevation of the rock surface is measured while dumping. After the two-piece stones are basically dumped in place, the diver dives underwater and places the No. 5 angle steel on the plane of the leveling frame. The plane condition of the two-piece stones is checked using this angle steel. If any two-piece stones higher than the plane are found, they are manually cleared to a lower place or out of the frame;

[0040] After the rough leveling of the two-piece stones, the diver notifies the water surface to hoist and dump crushed stones by crane. The dumping position and quantity are commanded by the diver underwater in real time. After the crushed stones are dumped on the foundation bed, the diver levels the crushed stone plane with an angle iron scraper;

[0041] After the foundation bed is leveled, inspection and acceptance are carried out. After passing the acceptance, the lifting ship hoists the cushion blocks onto the foundation bed. During the hoisting, the diver marks with the leveling frame underwater and places the cushion blocks at the set positions;

[0042] After the cushion blocks are installed in place, the elevation of the top surface of the cushion blocks is measured again. After passing the inspection, the diver fastens the buckle and installs the leveling frame to the next leveling position;

[0043] The said step S24 includes:

[0044] The guide beam I-beam is placed on both sides of the box culvert cushion block, making the top surface of the I-beam flush with the surface of the cushion block. The surface of the guide beam is adjusted to the designed elevation with adjusting lead screws in the middle of the guide beam;

[0045] After the two side guide beams are installed in place, bagged crushed stones are stacked in the middle and at both ends of the guide beam, and the 50t floating crane hoists and dumps two-piece stones onto the foundation bed;

[0046] During the dumping, the elevation of the rock surface is frequently measured manually. After the two-piece stones are dumped, the diver dives underwater and checks the rock surface condition with a scraper. If any two-piece stones higher than the surface are found, they are cleared to the low-lying areas, and the water surface is commanded to supplement the dumping in the areas where there is a shortage;

[0047] After the two-piece stones are leveled, the diver commands the water surface to dump crushed stones by crane, leveling while dumping until the leveling of this section is completed. After completing one section, continue to level other foundation beds according to the above process;

[0048] Immediately after the foundation bed leveling is completed, acceptance is carried out. The foundation bed after passing the acceptance needs to be protected.

[0049] Preferably, in the said step S3, the maximum weight of the hoisted box culvert is 304t, and a fixed boom lifting ship with a safe lifting load of 350t is selected for the installation operation; the transport barge is selected as a self-propelled deck barge with a load capacity of 2000t and positioning function; the box culverts are installed in the order of taking water box culverts, and 6 box culverts are placed on the barge at a time;

[0050] The ship loading operation process includes:

[0051] For the main lifting hook of Matsushita on the crane ship, hang the wire ropes on both sides of the main lifting hook, and connect the wire rope loops to the lifting points with shackles. Among them, two wire rope heads at the middle lifting point of the culvert box share one shackle.

[0052] After the wire ropes are connected to the lifting points of the culvert box, the crane ship hoists the wire ropes to a taut state, checks the condition of the wire ropes, and after confirming that there is no problem, hoists the culvert box off the quay surface.

[0053] The crane ship moves the ship by means of winching the anchor, hoists the hook after moving the culvert box above the barge, and places the culvert box on the deck of the barge.

[0054] After all the culvert boxes at the same position are loaded onto the ship, the crane ship weighs anchor with the assistance of the anchor boat and moves the crane ship to the installation site, and the transport ship also goes to the installation site together.

[0055] Among them, the culvert box is hoisted at 4 points, and steel core wire ropes with a diameter of 90 mm and a tensile strength of 1870 are selected. During hoisting, a lifting frame is used for hoisting. The culvert box selects steel bars as lifting rings, and steel plate limiters are welded outside the steel bars.

[0056] Preferably, in step S4, the installation of the culvert box includes:

[0057] Excavate a ground anchor in the land area as the mooring point of the crane ship, and cast three anchors at the rear of the crane ship.

[0058] After the crane ship is positioned, move the ship to the outside, and the transport barge docks on one side of the trench. First, insert the measuring rod into the measuring base and adjust it to be perpendicular to the top of the culvert box, and then install the guiding device on the embedded parts.

[0059] First, hook and lift, hoist the culvert box out of the barge and then move it to the installation position.

[0060] The crane ship slowly releases the hook, lowers the culvert box into the water and keeps the top of the culvert box in a state where it does not enter the sea level.

[0061] Connect the wire rope of the winch on the crane ship to the lifting lug on the sea side. Under the command of the surveyor, adjust the position of the culvert box and release the culvert box at a longitudinal distance of about 1 m.

[0062] When the culvert box is about 50 cm close to the bed, stop releasing. Two divers dive into the water at the same time, grope for the actual interface position on both sides of the culvert box, and at the same time command the crane ship to move, slowly approach the culvert box to the drop well until it is inserted into the guide reserved during the fabrication of the drop well.

[0063] The crane ship tightens the front cable rope to make the culvert box closely adhere to the connecting wall of the drop well. The surveying personnel measure the axis of the culvert box according to the measuring rod. After the axis meets the design requirements, the crane ship releases the hook and lowers the culvert box onto the bed.

[0064] The surveyors measure the axis and elevation of the culvert box again. After meeting the design requirements, the diver removes the steel wire rope underwater, and the crane ship lifts the sling out of the water surface. The outer measuring rod is not removed and serves as the guiding rod for installing the next section. Then, the guiding device is removed to complete the installation of this section of the culvert box.

[0065] When installing the second section, follow the above steps until all installations are completed.

[0066] Preferably, in step S5, the chemical dosing pipe is fabricated into a 6m-long pipe section on land according to the specified specifications of the design requirements, and the construction is carried out by flange connection.

[0067] Under the guidance of the diver, place the fabricated pipe section into the chemical dosing box groove, connect and tighten the flanges, and then connect the pipe clamp to the pre-buried connecting bolts to fix the pipeline on the culvert box wall.

[0068] The cover of the chemical dosing pipe groove box is installed on the barge, and the small crane ship, with the cooperation of the diver, hoists and covers it on the opening of the chemical dosing box groove.

[0069] Preferably, in step S6, the formwork bag concrete includes:

[0070] The fabricated formwork bag cloth is laid underwater by the diver at the joint of the culvert box. On the top surface, bagged crushed stones are pressed on the cloth surface, and on both sides, block stones are pressed on the foundation bed.

[0071] The concrete is transported to the side of the trench along the side shoreline by a ground pump truck, and then connected to the onshore pipe orifice by a pipe floating on the water surface with foam floats. The end of the floating pipe is a rubber hose. The diver inserts the end of the rubber hose into the injection port at the bottom layer of the formwork bag cloth, ties it firmly with iron wire, and starts injecting concrete into the bag.

[0072] When the concrete is injected to the height of the injection port, tie the injection port tightly with iron wire, move the pipeline to the upper injection port, and then inject concrete into the formwork bag cloth. After pouring to the top, tie the bag mouth tightly.

[0073] Move the pipeline to the other side for pouring, and finally pour the injection port in the middle of the top surface.

[0074] Preferably, in step S7, the requirements for throwing and filling block stones include: The stone materials are fresh and intact rocks without weathering cracks and can resist seawater corrosion. The wet compressive strength of the rocks is not less than 40MPa, the softening coefficient is not less than 0.85, and the single weight of the thrown block stones is 80 - 150kg.

[0075] Load the stones into the steel wire pockets at the stone yard, and the dock crane hoists the steel wire mesh pockets filled with block stones onto the transport ship and transports them to the construction site.

[0076] The rotary crane ship is positioned on top of the culvert box, the transport ship docks beside the crane ship, and the crane hoists the steel wire mesh pocket filled with stone materials underwater and overturns the stones onto the seabed.

[0077] During the process of throwing and filling, continuously measure the elevation of the rubble surface until a cross-section is completed, and then send divers underwater to trim and roughly level the rubble surface.

[0078] The beneficial effects of the present invention are as follows: Through construction preparation, determine the prefabrication site, transportation route, and engineering equipment for installation operations, foundation trench leveling, including foundation trench excavation, rubble bed treatment, cushion bed leveling, cushion installation, and foundation bed leveling at the bottom of the culvert box, loading the culvert box onto the ship, installing the culvert box, installing the water intake pipe, chemical dosing pipe, and chemical dosing pipe trough box, placing the formwork bag concrete, and backfilling with rubble; This method is convenient for construction, has high reliability, and low investment cost, solving the problems of cumbersome and complex installation processes for the water intake culvert box at sea and inconvenient water intake. Brief Description of the Drawings

[0079] Figure 1 is the flowchart of an installation method for a water intake culvert box at sea according to the present invention;

[0080] Figure 2 is the specific flowchart of foundation trench leveling in the present invention;

[0081] Figure 3 is the schematic diagram of the rammer in the present invention;

[0082] Figure 4 is the schematic diagram of the installation of the leveling frame in the present invention;

[0083] Figure 5 is the schematic diagram of the preparation and erection of the water intake culvert box in the present invention;

[0084] Figure 6 is the schematic diagram of the transportation and placement of the water intake culvert box by barge in the present invention;

[0085] Figure 7 is the schematic diagram of the hoisting of the water intake culvert box in the present invention;

[0086] Figure 8 is the design drawing of the lifting ring of the culvert box in the present invention;

[0087] Figure 9 is the schematic diagram of the installation sequence of the water intake culvert box in the present invention;

[0088] Figure 10 is the schematic diagram of the formwork bag concrete in the present invention;

[0089] Figure 11 is the schematic diagram after backfilling with rubble in the present invention;

[0090] Figure 12 is the schematic diagram of the water intake culvert box in the present invention. Detailed Embodiment

[0091] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0092] The present invention will be further described below in conjunction with the accompanying drawings.

[0093] As shown in Table 1, if 4 sections of the water intake box culvert are installed underwater for the project, with a single-section weight of 231t, and 2 sections of the water intake head are installed, with a single-section weight of 299t, then according to the component weight and lifting distance, a 350t fixed derrick crane ship is arranged to arrive at the site for waterborne lifting operations, and a grab dredger is used for reef clearing and leveling of the foundation bed. The water intake box culvert is transported using a 2000t self-propelled transport barge.

[0094]

[0095] Table 1

[0096] As Figures 1-12 shown, a method for installing a water intake box culvert at sea includes:

[0097] Step S1, construction preparation, determining the prefabrication site, transportation route, and engineering equipment for the installation operation.

[0098] In the embodiment, the construction preparation includes:

[0099] Prefabrication site, prefabricating the box culvert under the steel shed inside the construction site and at the temporary wharf;

[0100] Transportation route, after the prefabricated box culvert is made at the prefabrication site, it is lifted from the prefabrication site by a 350t fixed derrick crane ship and temporarily placed on a 2000t self-propelled transport barge, and then transported to the installation point;

[0101] Selecting the engineering equipment for the installation operation includes, but is not limited to, a 350t fixed derrick crane ship, a 2000t self-propelled transport barge, a 1000hp anchor handling tug, an excavator, a 50t crane ship, a stone material transport ship, diving equipment, a level, and a total station, as shown in Table 2.

[0102]

[0103]

[0104] Table 2

[0105] Step S2, leveling the foundation trench, including foundation trench excavation, rubble bedding treatment, leveling of the cushion bedding, installation of cushions, and leveling of the foundation bed at the bottom of the culvert box.

[0106] As Figure 2 shown, leveling the foundation trench includes:

[0107] Step S21, foundation trench excavation. Before installing the water intake culvert box, the existing cofferdam is blasted. For the blasting construction plan and safety precautions, refer to the "Blasting Construction Plan".

[0108] Step S22, rubble bedding treatment. According to the geological report and design drawings, underwater filling is carried out at the water intake head, and underwater dynamic compaction treatment is carried out on the filled part.

[0109] In the embodiment, step S22 includes:

[0110] Determine the scope of underwater filling treatment for the foundation of the water intake head. The width of the underwater filling range of the foundation of the water intake head is about 20m, the length is about 12m, and the maximum filling depth is about 10m (subject to the actual terrain), and the slope is set at 1:2;

[0111] After the rubble bedding is completed and passes the acceptance, the tamping barge enters the construction site and is positioned according to the rubble filling marks.

[0112] Before tamping, the technical personnel give a technical briefing to the construction personnel, explaining the tamping method, technical requirements, quality assurance measures, tamping scope, drop height of the rammer, and the uses of various marks.

[0113] Before construction, trial tamping is carried out first to determine the number of tamping passes and settlement of the foundation bed. The number of tamping passes for single-point trial tamping is 6 times, and the settlement is 50mm.

[0114] The foundation bed tamping is the overall tamping of the filled area. According to the existing mechanical equipment, a 50t crawler crane is equipped to hang and hoist the rammer for foundation bed tamping construction. The rammer is a reinforced concrete rammer. As Figure 3 shown, the weight of the rammer is 5.4t, the bottom area is 1.54㎡, the drop height is 3.5m, and the tamping impact energy is 189kJ / ㎡;

[0115] Before tamping, the foundation bed is measured, and the local height difference is not more than 30cm. If it cannot meet the requirement, rough leveling should be carried out by divers. After meeting the requirement, tamping is carried out. Among them, during the tamping process, strictly control the tamping scope and number of tamping passes, and adopt the method of adjacent longitudinal and transverse pressing with half ramming; to strictly control the impact energy of the rammer, make obvious marks on the steel wire rope; strictly control the correct position of the rammer, make marks on the anchor cable to control the forward distance of the moving barge; make an arc-shaped guide frame similar to the tamping track of the rammer and fix it on the bow of the barge, and make marks on the guide frame to control the correct position of each rammer;

[0116] After the foundation bed is tamped, a tamping acceptance test shall be carried out. In a 5m section within the construction area, re-tamp once (the tamp hammers are arranged tangentially without overlapping half a tamp), and the average settlement shall not be greater than 30mm.

[0117] After tamping, if riprap needs to be filled on the top surface of the foundation bed, when the filled area is greater than 1 / 3 of the caisson bottom area or the continuous area is greater than 30㎡ and the thickness is greater than 500mm, re-tamping treatment shall be carried out.

[0118] During the tamping construction, the construction personnel shall make records, and the record content shall include but not be limited to the tamping section, hammer weight, tamping times, drop height of the hammer, overlapping situation and hydro-meteorological conditions.

[0119] Step S23: Level the cushion foundation bed and install the cushion blocks.

[0120] In the embodiment, step S23 includes:

[0121] For the cushion leveling construction, according to the requirements of the construction drawing, the foundation bed is filled with 400mm thick two-piece stones and gravel for fine leveling, and then the culvert is placed. Among them, culvert connection pads are installed at the joints of the culverts, and the elevation of the pads is the same as that of the foundation bed.

[0122] With the cooperation of surveyors, anchor and position a 50t crane ship in the foundation trench, and place the processed leveling frame at the set position.

[0123] The diver dives underwater and inserts the measuring rod of the leveling frame into the measuring conduit of the leveling frame.

[0124] Measure the plane position of the leveling frame with a total station, and then measure the elevations of the four corners of the leveling frame with a level. By adjusting the adjusting screw rods at the four corners of the leveling frame, adjust the transverse plane of the leveling frame to the set elevation, and then stack bagged gravel around to ensure the stability of the frame, as Figure 4 shown;

[0125] After the leveling frame is installed in place, remove the measuring rod, and use the crane on the 50t crane ship to grab and throw the two-piece stones on the two-piece stone and gravel transport ship parked beside the crane ship into the leveling frame.

[0126] During the throwing and filling, measure the stone surface elevation while throwing. When the two-piece stones are basically thrown and filled in place, the diver dives underwater, places a 5-angle steel on the plane of the leveling frame, and uses the angle steel to check the plane condition of the two-piece stones. If any two-piece stones higher than the plane are found, clean them manually to a lower place or out of the frame.

[0127] After the rough leveling of the two-piece stones, the diver notifies the water surface to use the crane to throw and fill gravel. The throwing position and quantity are commanded by the diver underwater in real time. After the gravel is thrown and filled on the foundation bed, the diver uses an angle iron scraping ruler to level the gravel plane.

[0128] After the bed leveling is completed, it shall be inspected and accepted according to the standard 4.4.7.3 in the "Quality Inspection Standard for Waterway Engineering" (JTS257-2008). After passing the acceptance, the lifting vessel shall lift and place the cushion blocks onto the bed. During the lifting and placing, the diver shall, underwater and with the leveling frame as a mark, place the cushion blocks at the set positions;

[0129] After the cushion blocks are installed in place, measure the elevation of the top surface of the cushion blocks again. After passing the inspection, the diver shall fasten the connection and install the leveling frame at the next leveling position.

[0130] In the embodiment, the technical requirements for the leveling of the cushion block bed: The thickness of the cushion block bed for the water intake culvert is 20 cm, and the plane size is 5×2×0.2 m; According to the requirements of 8.4.1 in the "Code for Design and Construction of Gravity Wharves" (JTS167-2-2009), the requirement for widening each side of the bed leveling by 50 cm, so the width of the leveling of the cushion block bed is 6.2×3 m, and the leveling standard is extremely fine leveling.

[0131] Step S24, leveling the bed at the bottom of the culvert. After leveling the cushion blocks for the installation of the culvert, level the bed at the bottom of the culvert. The width at the bottom of the culvert for water intake is 5 m, and it shall be leveled with a 0.5 m widening on each side according to the specification requirements. Use 20a I-beams as the leveling guide beams, and take the erection schematic diagram of the water intake culvert, as Figure 5 shown.

[0132] In the embodiment, step S24 includes:

[0133] Place the guide beam I-beams on both sides of the cushion blocks of the culvert, making the top surface of the I-beams flush with the surface of the cushion blocks, and adjust the surface of the guide beam to the design elevation with adjusting screws inside the guide beam;

[0134] After the guide beams on both sides are installed in place, stack bagged crushed stones in the middle and at both ends of the guide beams, and use a 50t floating crane to throw two-piece stones onto the bed;

[0135] During the throwing, the diver shall frequently measure the elevation of the stone surface manually. After the two-piece stones are thrown, the diver shall dive underwater and use a scraping ruler to check the situation of the stone surface. If any protruding two-piece stones are found, they shall be cleared to the low-lying areas, and the water surface shall be directed to supplement the throwing in the places where there is a shortage;

[0136] After the two-piece stones are leveled, the diver shall direct the water surface to throw and fill crushed stones with a crane, leveling while throwing until the leveling of this section is completed. After completing one section, continue to level other beds according to the above process;

[0137] Immediately conduct an acceptance inspection after the bed leveling is completed. The bed that has passed the acceptance inspection needs to be protected.

[0138] Step S3, loading the culvert onto the ship. The lifting vessel anchors and positions beside the prefabrication site of the culvert, and the transport barge docks on one side. The lifting vessel lifts and places it into the transport barge.

[0139] In the embodiment, the maximum weight of the hoisted box culvert is 304t, and a fixed-arm crane with a safe lifting load of 350t is selected for installation; a self-propelled deck barge with a load of 2000t and a positioning function is selected as the transport barge; the box culvert is installed in the order of the water intake box culvert, and 6 box culverts are placed on the barge at a time. The water intake box culvert barge is transported according to the schematic diagram, as shown in the figure. Figure 6 As shown;

[0140] The loading operation process includes:

[0141] The crane ship loosens the main hook, hangs the wire rope on both sides of the main hook, and connects the rope buckle of the wire rope to the lifting point with a shackle. The two wire buckle heads of the lifting point in the middle of the box culvert share one shackle.

[0142] After the wire rope is connected to the lifting point of the box culvert, the crane vessel will lift the wire rope to a taut state, check the condition of the wire rope, and lift the box culvert away from the dock after confirming that it is correct;

[0143] The crane ship moves the ship by winching the anchor. After the box culvert is moved above the barge, the crane ship releases the hook and places the box culvert on the deck of the barge.

[0144] After all the box culverts at the same location are loaded on board, the crane ship weighs anchor with the assistance of the anchor boat and moves the crane ship to the installation site, and the transport ship also goes to the installation site together;

[0145] Among them, the box culvert uses 4-point lifting, and uses a steel core wire rope with a diameter of 90mm and a tensile strength of 1870. The hanger is used for lifting. The box culvert uses steel bars as lifting rings, and welds steel plate limit plates on the outside of the steel bars. The schematic diagram of the water box culvert lifting is as follows: Figure 7 As shown in the figure, the design drawing of box culvert lifting ring is as follows: Figure 8 shown.

[0146] Step S4, box culvert installation. There are two box culverts in the water intake, which are connected from the seawater pump room to the water intake head. Each water intake box culvert is divided into three sections. When installing, it is installed from the shore side to the sea side. The installation sequence is as follows: Figure 9 shown.

[0147] In the embodiment, the box culvert installation includes:

[0148] A ground bull was dug on land to serve as a mooring point for the crane ship, and three anchors were dropped at the rear of the crane ship;

[0149] After the crane ship is positioned, move the ship to the outside, and the transport barge is docked on one side of the trench. First, insert the measuring rod into the measuring base and adjust it to be vertical to the top of the box culvert, and then install the guide device on the embedded parts;

[0150] First, lift the box culvert out of the barge by hook lifting and move it to the location where it needs to be installed;

[0151] The crane ship slowly releases the hook, lowering the culvert into the water and keeping the top of the culvert above the sea level;

[0152] Connect the winch wire rope on the crane ship to the lifting lug on the sea side. Under the command of the surveyor, adjust the position of the culvert and release it at intervals of about 1 m longitudinally;

[0153] When the culvert is about 50 cm close to the foundation bed, stop releasing. Two divers dive underwater simultaneously, feel for the actual interface positions on both sides of the culvert, and at the same time command the crane ship to move, slowly approaching the culvert to the drop well until it is inserted into the guide reserved during the fabrication of the drop well;

[0154] The crane ship tightens the front cable, pressing the culvert tightly against the connecting wall of the drop well. The surveyors measure the axis of the culvert using a measuring rod. After the axis meets the design requirements, the crane ship releases the hook, lowering the culvert onto the foundation bed;

[0155] The surveyors measure the axis and elevation of the culvert again. After meeting the design requirements, the divers remove the wire rope underwater. The crane ship lifts the sling out of the water. The outer measuring rod is not removed and serves as the guiding rod for installing the next section. The guiding device is removed, completing the installation of this section of the culvert;

[0156] When installing the second section, follow the above steps until all installations are completed.

[0157] Step S5, installation of the dosing pipe for the water intake pipe and the dosing pipe trough box.

[0158] In the embodiment, the dosing pipe is fabricated into 6 - m - long pipe sections on land according to the specified specifications and constructed using flange connection;

[0159] Under the guidance of the divers, place the fabricated pipe sections into the dosing box trough, connect and tighten the flanges, and then connect the pipe clamps to the embedded connecting bolts to fix the pipeline on the culvert wall;

[0160] The cover of the dosing pipe trough box is installed on the barge and hoisted by a small crane ship with the cooperation of divers to cover the opening of the dosing box trough.

[0161] Step S6, placing shotcrete - filled fabric forms. As required by the design, a layer of C40 shotcrete - filled fabric forms with a thickness of 600 mm and a width of 2 m is to be covered on the top surface and both sides at the interface of the culvert.

[0162] In the embodiment, the shotcrete - filled fabric forms include:

[0163] The fabricated shotcrete - filled fabric forms are laid underwater by divers at the joint of the culvert. On the top surface, crushed stones in bags are pressed on the fabric, and on both sides, boulders are pressed on the foundation bed;

[0164] The concrete is transported to the side of the trench along the side shoreline by a ground pump truck, and then connected to the onshore pipe orifice with a pipe floating on the water surface by foam floating clips. The end of the floating pipe is a rubber hose. Divers insert the end of the rubber hose into the injection orifice at the bottom layer of the formwork fabric, tie it firmly with wire, and start injecting concrete into the bag;

[0165] When the concrete is injected to the height of the injection orifice, tie the injection orifice tightly with wire, move the pipe to the upper injection orifice, and then inject concrete into the formwork fabric. After pouring to the top, tie the bag mouth tightly;

[0166] Move the pipe to the other side for pouring, and finally pour the injection orifice in the middle of the top surface, as Figure 10 shown.

[0167] Step S7, backfill with riprap. After the installation and acceptance of the water tank culvert, riprap for protecting the pipe needs to be dumped on the top and both sides of the culvert, as Figure 11 shown.

[0168] In the embodiment, the requirements for dumping riprap include: the stones are fresh and intact, without weathering and cracking, and can resist seawater corrosion. The wet compressive strength of the rock is not less than 40 MPa, the softening coefficient is not less than 0.85, and the single weight of the dumped riprap is 80 - 150 kg;

[0169] Load the stones into the steel wire pockets at the stone yard, and the quay crane lifts the steel wire mesh pockets filled with stones onto the transport ship and transports them to the construction site;

[0170] Position the rotary crane ship on top of the culvert. The transport ship docks beside the crane ship, and use the crane to lift the steel wire mesh pocket filled with stones underwater and dump the stones onto the seabed;

[0171] During the dumping process, continuously measure the elevation of the riprap surface until a section is dumped. Then, divers dive underwater to trim and roughly level the riprap surface.

[0172] Working principle:

[0173] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for installing an offshore water intake culvert, characterized in that: include: Step S1, construction preparation, determining the prefabrication site, transportation route and engineering equipment for installation; Step S2, foundation trench leveling, including foundation trench excavation, riprap foundation bed treatment, pad block foundation bed leveling, pad block installation, and box culvert bottom foundation bed leveling; Step S3, the box culvert is loaded on the ship. The crane ship is anchored beside the box culvert prefabrication site, and the transport barge is anchored on one side. The crane ship lifts the box culvert and places it on the transport barge. Step S4, box culvert installation. There are two box culverts at the water intake, which are connected from the seawater pump room to the water intake head. Each water intake box culvert is divided into three sections and is installed from the shore side to the sea side; Step S5, installing the water intake pipe, the dosing pipe and the dosing pipe tank box; Step S6, mold bag concrete, the design requires that a layer of C40 mold bag concrete with a thickness of 600mm and a width of 2m be covered on the top surface and both sides of the box culvert interface; Step S7, rock backfilling: after the water intake box culvert is installed and accepted, rock backfilling is required on the top and both sides of the box culvert to protect the pipe.

2. The installation method of an offshore water intake box culvert according to claim 1, characterized in that: In the step S1, construction preparation includes: Prefabrication site: prefabricate box culverts under the steel shed inside the construction site and at the temporary wharf; Transportation route: After the prefabricated box culvert is completed at the prefabrication site, it is lifted from the prefabrication site by a 350t fixed-beam crane ship, temporarily placed on a 2000t self-propelled transport barge, and then transported to the installation site; The engineering equipment selected for the installation work includes but is not limited to a 350t fixed gantry crane, a 2000t self-propelled transport barge, a 1000hp anchor throwing boat, an excavator, a 50t crane, a stone transport vessel, diving equipment, a level and a total station.

3. The method for installing an offshore water intake culvert according to claim 1, characterized in that: In the step S2, the base trench is leveled, including: Step S21, excavation of the foundation trench, blasting of the existing cofferdam before installation of the water intake box culvert; Step S22, riprap bed treatment, according to the geological report and design drawings, take water head for underwater dumping and perform underwater strong compaction treatment on the dumping part; Step S23, leveling the cushion block base and installing the cushion blocks; Step S24, leveling the bottom bed of the box culvert. After the box culvert installation pads are leveled, the bottom bed of the box culvert is leveled.

4. The method for installing an offshore water intake culvert according to claim 3, characterized in that: The step S22 comprises: Determine the scope of the water intake head foundation dumping treatment. The width of the water intake head foundation dumping range is about 20m, the length is about 12m, the maximum dumping depth is about 10m, and the slope is 1:2; After the bed riprap is completed and passed the acceptance, the ramming ship enters the construction site and positions itself according to the riprap marks; Before tamping, the technical staff shall give technical instructions to the construction personnel, explaining the tamping method, technical requirements, quality assurance measures, tamping range, the drop distance of the tamping hammer and the purpose of various signs; Before construction, a test tamping is carried out to determine the number of times the base bed is compacted and the amount of settlement. The number of times of single-point test tamping is 6 times, and the amount of settlement is 50mm; The subgrade tamping is the overall tamping of the dumping area. According to the existing mechanical equipment, a 50t crawler crane is equipped to hang a tamping weight to carry out subgrade tamping. The tamping hammer is a reinforced concrete tamping hammer with a weight of 5.4t, a bottom area of ​​1.54㎡, a drop distance of 3.5m, and a tamping impact energy of 189kJ / ㎡. Before compaction, the subgrade should be measured, and the local height difference should not exceed 30cm. If it cannot meet the requirements, it should be roughly leveled by diving. After meeting the requirements, compaction can be carried out. In the compaction process, the compaction range and the number of compaction times should be strictly controlled, and the method of half-compacting in the longitudinal and transverse directions should be adopted; After the base bed is compacted, a compaction test should be conducted. A 5m section should be selected within the construction range for repeated compaction. The average settlement should not exceed 30mm. After compaction, if additional stones are needed on the top surface of the subgrade, additional compaction shall be carried out when the additional area is larger than 1 / 3 of the caisson bottom area or the continuous area is larger than 30㎡ and the thickness is larger than 500mm; During the tamping construction, the construction workers shall keep records, including but not limited to the tamping section, hammer weight, number of tamping passes, hammer drop height, overlap conditions and hydrological and meteorological conditions; The step S23 comprises: Pad leveling construction: according to the requirements of the construction drawings, the subgrade is backfilled with 400mm thick two-piece stone and crushed stone for fine leveling before placing the box culvert. The box culvert connection pad is installed at the culvert joint, and the elevation of the pad is level with the subgrade; With the cooperation of surveyors, the 50t crane ship was anchored in the foundation trench and the processed leveling frame was placed in the set position; The diver dives underwater and inserts the measuring rod of the leveling frame into the measuring guide tube of the leveling frame; Use a total station to measure the plane position of the leveling frame, and then use a level to measure the elevation of the four corners of the leveling frame. By adjusting the adjustment screws at the four corners of the leveling frame, adjust the horizontal surface of the leveling frame to the set elevation, and then stack the bagged gravel around it; After the leveling frame is installed in place, the measuring rod is removed, and the crane on the 50t crane ship grabs and throws two pieces of stone from the crane ship and the crushed stone transport ship parked beside the crane ship into the leveling frame; When dumping and filling, measure the elevation of the stone surface while dumping. When the two pieces of stone are basically in place, the diver dives underwater and puts No. 5 angle steel on the plane of the leveling frame to check the plane of the two pieces of stone. If two pieces of stone are found to be higher than the plane, they are manually cleaned to a lower place or cleared out of the frame. When the two pieces of stone are roughly leveled, the diver notifies the surface to use a crane to throw the crushed stone. The location and quantity of the throwing are directed by the diver in real time underwater. After the crushed stone is thrown onto the base bed, the diver uses an angle iron scraper to scrape the surface of the crushed stone flat. After the base bed is leveled, it is inspected and accepted. After passing the acceptance, the pads are hoisted onto the base bed by the crane ship. When hoisting, the divers place the pads to the set position underwater according to the leveling frame as a mark; After the pad is installed in place, the top surface elevation of the pad is measured again. If it is qualified, the diver will fasten it and install the leveling frame to the next leveling position; The step S24 comprises: The I-beam guide beam is placed on both sides of the box culvert pad, so that the top surface of the I-beam is flush with the pad surface, and the guide beam surface is adjusted to the design elevation using an adjusting screw in the guide beam; After the guide beams on both sides are installed in place, bagged crushed stones are piled in the middle and both ends of the guide beams, and two pieces of stones are thrown onto the base bed by a 50t floating crane; During the filling process, the elevation of the stone surface is measured manually. After the two pieces of stone are thrown, the diver dives underwater and uses a scraper to check the stone surface. If two pieces of stone are found to be higher, they are cleared to the low-lying areas. If there are too many missing pieces, the diver directs the water to throw more stones. After the two pieces of stone are leveled, the diver directs the surface to use a crane to throw gravel, leveling while throwing until the section is leveled. After completing one section, continue to level the other foundation beds according to the above process; After the base bed is leveled, it should be inspected and accepted immediately, and the base bed that passes the inspection needs to be protected.

5. The method for installing an offshore water intake culvert according to claim 1, characterized in that: In step S3, the maximum weight of the hoisted box culvert is 304t, and a fixed-arm crane with a safe lifting load of 350t is selected for installation; a self-propelled deck barge with a load of 2000t and a positioning function is selected as the transport barge; the box culvert is installed in the order of the water intake box culvert, and 6 box culverts are placed on the barge at a time; The loading operation process includes: The crane ship loosens the main hook, hangs the wire rope on both sides of the main hook, and connects the rope buckle of the wire rope to the lifting point with a shackle. The two wire buckle heads of the lifting point in the middle of the box culvert share one shackle. After the wire rope is connected to the lifting point of the box culvert, the crane vessel will lift the wire rope to a taut state, check the condition of the wire rope, and lift the box culvert away from the dock after confirming that it is correct; The crane ship moves the ship by winching the anchor. After the box culvert is moved above the barge, the crane ship releases the hook and places the box culvert on the deck of the barge. After all the box culverts at the same location are loaded on board, the crane ship weighs anchor with the assistance of the anchor boat and moves the crane ship to the installation site, and the transport ship also goes to the installation site together; Among them, the box culvert uses 4-point lifting, and uses a steel core wire rope with a diameter of 90mm and a tensile strength of 1870. The hanger is used for lifting. The box culvert uses steel bars as lifting rings, and steel plate limit plates are welded on the outside of the steel bars.

6. The method for installing an offshore water intake culvert according to claim 1, characterized in that: In step S4, the box culvert installation includes: A ground bull was dug on land to serve as a mooring point for the crane ship, and three anchors were dropped at the rear of the crane ship; After the crane ship is positioned, move the ship to the outside, and the transport barge is docked on one side of the trench. First, insert the measuring rod into the measuring base and adjust it to be vertical to the top of the box culvert, and then install the guide device on the embedded parts; First, lift the box culvert out of the barge by hook lifting and move it to the location where it needs to be installed; The crane ship slowly releases the hook, lowers the box culvert into the water and keeps the top of the box culvert below the sea level; Use the winch wire rope on the crane ship to connect with the lifting lug on the sea side. Under the command of the surveyor, adjust the position of the box culvert according to the longitudinal distance of about 1m and release the box culvert. When the box culvert is about 50cm close to the bed, the loosening stops. Two divers dive underwater at the same time to feel the actual interface position on both sides of the box culvert. At the same time, they direct the crane boat to move and slowly move the box culvert closer to the drop well until it is inserted into the guide reserved when the drop well is made. The crane ship tightens the front cable to make the box culvert close to the wall connecting the drop well. The surveyor measures the axis of the box culvert using the measuring rod. When the axis meets the design requirements, the crane ship loosens the hook and puts the box culvert onto the foundation bed. The surveyors measured the axis and elevation of the box culvert again. When the design requirements were met, the divers removed the wire rope underwater, and the crane lifted the sling out of the water. The measuring rod at the outer end was not removed and was used as a guide rod for installing the next section. The guide device was removed to complete the installation of this section of the box culvert. When installing the second section, follow the above steps until the entire installation is completed.

7. The method for installing an offshore water intake culvert according to claim 1, characterized in that: In step S5, the dosing pipe is processed and manufactured into a 6m long pipe section on land according to the design requirements, and the construction is carried out in a flange connection manner; Under the guidance of the diver, place the prepared pipe section into the dosing box slot, connect and tighten the flange, and then connect the pipe clamp with the pre-buried connecting bolts to fix the pipeline on the box culvert wall; The cover of the dosing pipe slot box is installed on the barge and is lifted by a small crane boat with the cooperation of divers and covered on the slot of the dosing box.

8. The method for installing an offshore water intake culvert according to claim 1, characterized in that: In step S6, the bagging of concrete comprises: Divers spread the processed mold bag cloth underwater at the joint of the box culvert, press the top surface with bagged gravel on the cloth surface, and press the two sides with blocks of stone on the base bed; Concrete is transported to the side of the trench along the side shoreline by a ground pump truck, and then connected to the pipe on land by a pipe floated by a foam float on the water. The end of the floating pipe is connected to a rubber hose. The diver inserts the end of the rubber hose into the injection port of the bottom layer of the mold bag cloth, ties it with wire, and starts to inject concrete into the bag; When the concrete is poured to the height of the injection port, tie the injection port tightly with wire, move the pipe to the upper injection port, and then pour concrete into the mold bag cloth, and tie the bag tightly after pouring to the top; Move the pipe to the other side for pouring, and finally pour the sprue in the middle of the top surface.

9. The method for installing an offshore water intake culvert according to claim 1, characterized in that: In step S7, the requirements for the stone dumping include: the stone material is fresh, complete, weathered and crack-free, and resistant to seawater corrosion, the wet compressive strength of the rock is not less than 40 MPa, the softening coefficient is not less than 0.85, and the weight of a single stone dumping block is 80-150 kg; The stones are loaded into wire mesh bags at the quarry, and the dock crane lifts the wire mesh bags containing the stones onto the transport ship and transports them to the construction site; The rotating crane ship is positioned on the top of the box culvert, and the transport ship is docked beside the crane ship. The wire mesh bag filled with stones is lowered into the water by a crane and the stones are dumped onto the seabed. During the filling process, the elevation of the stone surface is continuously measured until a section is filled. Divers then dive underwater to level the slope and rough-level the stone surface.

Images