1 Underwater geotextile fabric laying construction technology
1.1 Laying program
The foundation should be leveled before laying on the beach, and the debris on the beach such as weeds and fishnets should be removed. Geotextile laying starts When the geotextile fabric starts to be laid, the operating vessel enters the lying position according to the positioning method and then throws The four anchors at the four corners of the ship should be fixed in a figure-of-eight shape. After that, the rolled geotextile roller is fixed on the geotextile laying ship. Then put the geotextile roller into the water slowly, and the starting end of the geotextile is fixed with a small anchor. The beginning of the geotextile is fixed with a small anchor, and the vessel is slowly moved by four hinged anchors on the working vessel. slowly move, drag the drum to lay the geotextile, and throw the ship-loaded gravel as it is laid. The rock will be thrown as it is laid. The same procedure is followed for the next geotextile.
1.2 Construction process and technical points
Construction process: geotextile fabric processing → geotextile fabric transport inspection testing → geotextile roll setting → paving ship loading → paving ship anchoring and positioning →Drum lowering, geotextile laying→Riprap suppression→this geotextile laying is completed.
(1) Measurement control network setting and measurement and sampling. Establish the base station, draw the geotextile release map and import the shipboard navigation chart to form the construction navigation chart. Determine the position of geotextile edge on the drum, adjust the ship so that the ship navigation chart shows two red coordinates for the geotextile edge coordinates, and check the accuracy of the ship coordinates with a mobile station, no error before the cloth can be rolled
(2) Coating surface cleaning. Use two ships towing long wire rope to the construction range of the coated surface to sweep the sea work, towing wire rope to ensure that the wire rope close to the coated surface, back and forth once, two ships are equipped with positioning systems to ensure that the clean-up range is not less than the design laying area.
(3) Geotextile processing, transportation, testing, and cloth rolling. geotextile processing and storage firstly, geotextile is sewn and spliced on land, single-width 6m geotextile is spliced into width 23m geotextile and cut according to the designed processing length. After the geotextile is tested and qualified, the work of rolling the cloth is carried out.
(4) Stone loading and transportation. After the geotextile is rolled, the laying vessel leans on the loading dock to load stone materials, and after the vessel is loaded, it drives itself to the construction area and anchors at the laying position planned for implementation.
(5) Vessel positioning. Use the positioning device international more advanced GPS real-time differential positioning system.
(6) Geotextile laying. After the geotextile fabric is opened normally underwater, the underwater paving is carried out by controlling the stranded anchor machine according to the set location of the paving area, and four anchor machines must be moved simultaneously, two tensioned and two relaxed, such as not at the same time or go off must be adjusted in time. In the paving process each time move around the distance, backhoe excavator throwing gravel will pave the geotextile pressure so that it can not float up. When paving to the end, appropriately increase the amount of gravel throwing, relax the roller sling, move the paving boat out of the paving area, lift the paving roller, the whole paving process is completed, and then move the paving boat for the next piece of cloth paving.
(7) Gravel throwing and filling. Gravel throwing construction, the main work of loading → transport → positioning → throwing, construction content and requirements and laying the same, construction focus on the control of gravel bedding thickness. Geotextile lap, not repeatedly throwing gravel, in the adjacent block of geotextile is not laid, the distance reserved for the time being not throwing fill, to avoid the completion of gravel throwing, two pieces of geotextile lap quality is not good. Good. After the geotextile laying is completed, lift the roller and put away the positioning anchor. The laying of a single geotextile is completed.
(8) Laying quality and gravel bedding layer quality inspection. The quality inspection of geotextile laying mainly includes steel Pipe probe and underwater feel two kinds. On-water probing is carried out during the construction process. The probing tool is a steel pipe of 4cm in diameter and 3mm in thickness. The length of the steel pipe is more than 2.5~3m meters, and when the water depth is too deep, a 3cm diameter steel pipe is used to prevent the steel pipe from being used. A 3cm diameter steel pipe is used to prevent the steel pipe from over-sinking and causing people to fall into the water. In the process of geotextile laying, the method of probing is to take a trafficking boat At the edge of the geotextile with steel pipe down to the coating surface, through the steel The feeling of the tube touching the bottom to judge whether the geotextile is laid in place, The geotextile has elasticity at the bottom and can not be inserted downward, and there is no elasticity and can continue to be inserted. There is no elasticity and no geotextile if it can continue to be inserted. Gravel bedding layer Check the use of underwater divers feels.