The article introduces two different construction techniques for the sand rib soft body row of the southeast breakwater project of Jingtang Port District, Tangshan Port. It explains the advantages and disadvantages of the laying construction technology and the pulling construction technology respectively, and studies the sand rib soft body The working conditions adapted to the two construction techniques provide a reference for the future selection of construction techniques for sand rib software in different regions and under different sea conditions.
1. Project Overview
The southeast breakwater project of Jingtang Port District of Tangshan Port plans to build two breakwaters in the east and south, with a total length of 9,520m, divided into 2 tender sections , the project department undertook the construction of a section with a length of 4,760m, of which the east breakwater is 1,757m long and the south breakwater is 3,003m long. The breakwater adopts a fully bagged sand prism slope embankment structure. The top elevation of the wave wall of the east breakwater is +7.0m, and the top elevation of the wave wall of the south breakwater is +7.5m. The wave wall adopts a stepped stone-embedded concrete structure. The breakwater top elevation is +4.0m, the breakwater top width is 8m (the clear width of the road on the top of the breakwater is 5m), and the internal and external slopes are both 1:1.5. The outer slope is protected by 4t twisted king blocks. A 200~400kg riprap cushion is set under the face protection block. There are two stone cushions under the riprap cushion. There are bagged gravel reverse filter rows under the two stone cushions ( +0.0m or less) or bagged gravel + a layer of composite geotextile (+0.0m or more). This project requires the laying of 129,229m2 of sand rib soft body row. The base fabric is made of 380g/m2 composite woven fabric, that is, 230g/m2 anti-aging polypropylene woven fabric and 150g/m2 short fiber polyester non-woven fabric needle punched composite . The ballast sand ribs are all made of 150g/m2 anti-aging polypropylene woven cloth. The block application site is shown in Figure 1.
2. The original intention of using two construction techniques at the same time
The length of the southeast breakwater project in Jingtang Port District of Tangshan Port is 4,760m, and the construction mileage is long. In order to meet the construction period requirements, 3 must be installed The construction sections are being constructed at the same time, and one laying vessel that meets the requirements has entered the site. Only using the laying vessel for construction cannot meet the construction progress needs. After communicating with the supervisor and the owner, a typical construction of the sand rib soft row and tension technology was carried out. After confirming that the construction effect met the design and specification requirements, the tension construction was started [1].
3. Construction status of laying process and pulling process
1. Construction conditions of the paving process The construction process of the paving process is as follows: positioning of the paving ship → berthing of the sand transport ship, arranging the upper drum → review of the ship’s position → display of the paving layout, making the sand ship slurry → attaching positioning buoys, sand-piercing ribs → filling with sand Ribs, slide plates, and row body lowering → Repeat sand filling, lowering the row, and moving the ship → After the laying is completed, recover the row and pull the rope → Measure and inspect → Lay the next row body. (1) The sand rib soft body row is laid perpendicular to the axis of the embankment. Two figure-eight anchors are installed at the bow and stern of the laying ship. The hull is stationed parallel to the axis of the embankment. The ship is equipped with a GPS positioning system, and the hull graphics are aligned with the construction grid lines. Positioning (the positioning head position is 1.0m ahead of the design head position).
(2) The construction personnel unfold one end of the arrangement on the deck of the laying ship, connect the polypropylene ropes on the drum to the reinforced rings that have been set on the arrangement one by one, and start the roller to roll up the arrangement. , roll the arrangement flatly onto the roll and spread the other end of the arrangement to the edge of the arrangement ship's slide plate. (3) After the sand transport ship and the paving ship are tied together, the sand suction pump is lifted into the sand warehouse of the sand transport ship. Each sand suction pump is connected to a water suction pipe and a sand blowing pipe. Construction workers hold high-pressure water guns to make slurry. The first slurrying of each sand transport ship takes a long time and needs to be started 1 hour in advance [2]. (4) After the slurry making in the sand silo is completed, the sand pump is connected to the sand blowing pipe, and the construction workers begin to insert the sand ribs into the reinforced belt rings on the software arrangement. At the same time, the project department surveyors re-measure the position of the side of the laying ship, Calculate the row head position based on the extended length of the slide after it is lowered, and recheck the hull positioning to start filling the sand ribs. (5) When filling the sand ribs, a sand blowing pipe is connected to a sand rib for sand blowing and filling. At the same time, the construction workers press the sand ribs with their feet to help drain water and increase the fullness. Start by filling the sand ribs located on the skid and near the side of the boat.
(6) Before the paving boat lowers the arrangement, tie 3 buoys to the front end of the arrangement. Then the skateboard starts to lower and tilts to about 45°. The sand-filled ribs gradually slide down together with the arrangement under the action of their own weight. , until the unsand-filled part slides to the edge of the ship's side and stops, continue to fill the sand ribs and then lower the layout until the row body falls 1.0m to the bottom, and the layout ship moves back 1.5m. (7) The laying ship slowly moves away from the axis and fills the sand ribs. The distance of each movement is equal to the length of each row body lowering. During the lowering process, one buoy is tied to each end of the middle part of the row body. Three buoys are tied to the tail end of the body. (8) After the tail end of the row body touches the bottom, retract the polypropylene rope on the drum and move the boat to the next position where the row body is laid. 2. The construction situation of the pull-up process The construction process of the pull-up process is as follows: construction preparation → positioning of the sand blowing ship, berthing of the sand ship → spreading of the geotextile row → attaching detection buoy → filling the sand rib → sinking the row body to the designed position → Continue to fill the sand ribs → measure and inspect → proceed with laying the next row (or proceed with the construction of the next process).
(1) The tow boat is positioned after the row hull with sand ribs has been lifted to the tow boat, and the tow boat group (2 boats) is positioned outside both ends of the row body laying position, in line with the The horizontal clear distance between the ends of the row body is 15m. After positioning the tugboat, four ground anchors are thrown outside the four corners of the row body to hold the four corners of the row body and accurately locate the position of the row body [3].
(2) Arrangement of offshore exhibition paving The water paving paving body is constructed using two sand blowing boats parallel to the embankment axis to pull and position the paving body. The positioning boats are positioned on both sides of the designed row body position. First, tie the two corners of the bag body with white brown ropes. Live on one of the boats, and then connect the other two corners to the other ship through ropes. Slowly tighten the rope through the windlass on the ship while pulling the rows apart until the rows are unfolded on the water. For detection After the sand is filled, the sand rib software row is positioned, and buoys are attached to the four corner points of the row body.
(3) Filling sand ribs In order to avoid displacement of the row body, the filling cuffs are filled at the same time to make the row body settle to the designed position. Each cuff is connected to a sand filling pipe and tied with a buoy. Construction The personnel take a boat to the cuff and insert the sand filling tube into the cuff. Each sand rib is equipped with 2 cuffs, 1 drainage cuff and 1 sand filling cuff. The cuffs are tied with two closing techniques: one on top and one on the back. Drainage cuffs and sand filling cuffs are arranged at intervals on each sand rib. The sand ribs are denser at both ends of the arrangement, and one sand rib is added on each side of the arrangement. Figure 2 shows the floor plan of the sand-filled cuff. After all the sand ribs of the sand rib software row have been filled, the row body sinks smoothly into the water, and the pulling boat retracts the sand blowing dragon and moves to the next row body position. 3. Comparison between paving and pulling technology (1) Construction efficiency Paving technology: Sand rib soft row paving technology construction, 2 rows can be constructed in each flat tide period, 3 flat tide construction per day, the number of rows that can be constructed per day*** Total 6, approximately 5,880m2. Counter-pulling technology: sand rib soft body row laying technology construction, one row can be constructed in each low tide period, three flat tide constructions per day, and a total of three rows can be constructed per day, which is approximately 2,940m2. The construction time of a single row body of the paving process is short, and the construction efficiency of the paving process is twice as high as that of the double-drawing process.
(2) Construction positioning and paving technology: The sand rib software row paving is positioned using professional Haidar measuring instruments. The row body positioning is controlled by the coincidence of the sand rib software row head edge displayed in the instrument and the edge line of the paving ship skateboard. The position and movement of the ship during the laying process are controlled according to the relative size of the ship shape diagram and the grid lines. Counter-pull technology: The positioning of the sand rib soft row-to-pull construction on the water is measured by surveyors using GPS measurement equipment by boat. The surveyors review the 4-corner coordinates of the row body on site. Ground anchors are used to control the row body during the sinking process. 4 corners to ensure the accurate position of the 4 corners of the row body [4-5]. The double-drawing process has obvious advantages in construction positioning. The accurate position of the row body is ensured through 4-corner positioning. However, the acceptance of the 4 corners requires surveyors to measure one by one, which takes a long time. The laying process can only re-measure the edge line of the row head during construction to ensure the accurate positioning of the row head. The tail of the row may not be laid to the designed position due to wrinkles in the row body during construction, so the length of the row body needs to be appropriately increased during processing.
IV. Sand rib soft row arrangement and application of pull-out technology in the southeast breakwater project of Jingtang Port District, Tangshan Port
In the southeast breakwater project of Jingtang Port District, Tangshan Port undertaken by the project department The size of the sand rib software row is divided into 3 types, namely 25m×35m, 28m×35m, and 35m×35m. Since the row length and width are both small, and the flat tide period of Jingtang Port is long, both pulling and laying techniques can be constructed. The main construction steps of the double-pull process are the water expansion of the drainage body and the intubation of the cuffs. The construction time of this step is about 1h20min, while the sand rib filling time is about 25min. The main construction steps of the paving process are lowering the row body and filling the sand ribs. The construction time of this step is about 40 minutes, and the time of rolling up the row body is about 20 minutes (the first row can be constructed in advance and does not take up the low tide time at sea) .
V. Conclusion
In summary, through the analysis and research of the laying process and the pulling process, the article provides a reference basis for the selection of construction technology in engineering construction and improves the efficiency of engineering construction. The efficiency ensures the quality of project construction, is of great significance to the construction of breakwater projects, and is worthy of promotion and application.
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