Composite Geomembrane Construction Technology
Abstract: The dam type is a composite wholesale HDPE geomembrane anti-seepage core earth-rock dam. The construction quality of the anti-seepage project is directly related to the success or failure of the entire dam construction. Therefore, the construction technology control of the composite HDPE geomembrane factory price is particularly important.
Keywords: composite HDPE geomembrane for sale; welding; edge sealing; anti-seepage
The axis of the intercepting dam is located at a distance of about 1.65km from the upstream of the inlet and outlet of the lower reservoir. The dam type is a composite HDPE geomembrane manufacturers anti-seepage core earth-rock dam. The dam crest elevation is 1066m, the maximum dam height is 23.5m, and the dam crest length is 548m. The width is 8m, and the upstream and downstream dam slopes are 1:2.2. The dam body filling division is divided into the following steps: large stone slope protection, rockfill material, transition material, fine sand protective layer, composite high quality HDPE geomembrane, fine sand protective layer, transition material, rockfill material, and large stone slope protection.
The dam body anti-seepage is made of PE composite China HDPE liner manufacturers anti-seepage, the bottom of the China HDPE liner factory price and the surrounding area are anchored with the concrete of the dam foundation, and the top is anchored with the anti-wave wall of the sand bar. Each side of the low price China HDPE liner is protected by fine sand as a protective layer, with a width of 2.5 m, and the outer side of the fine sand is connected with the transition material.
2. The composite geomembrane construction method
2.1 Composite geomembrane overall construction procedure
The wholesale HDPE Liner made in China width selected for on-site construction is 6m, the length of each roll is 50m, and the weight of each roll is about 270kg. The high quality aquaculture geomembrane joints are connected by hot-melt welding. According to the characteristics of this project, in order to facilitate the low price aquaculture geomembrane welding and quality inspection, the aquaculture geomembrane factory price welding quality is ensured, and the wholesale aquaculture geomembrane is laid in the direction of the transverse parallel dam axis.
The main construction procedures are: construction preparation → composite purchase high quality HDPE liner and concrete pedestal connection construction → composite aquaculture geomembrane manufacturers field welding → upstream and downstream side fine sand protective layer backfilling and rolling →…→ composite high quality environmental geomembrane and wave wall connection.
2.2 Construction of composite wholesale environmental geomembrane and pedestal concrete
2.2.1 Construction procedure of composite environmental geomembrane for sale and pedestal concrete connection
Base concrete expansion joint cleaning → expansion joint filling HK elastic edge sealing agent → pedestal concrete table grinding → installation fixed stainless steel screw → concrete table surface cleaning → paste SR leveling layer and anti-seepage rubber strip → (adhesive rubber water stop) paste environmental geomembrane factory price → Fill SR plastic water stop material → Cover and paste EPDM SR anti-seepage cover sheet → Install pressure-angle angle steel → Apply HK elastic edge sealant seal.
2.2.2 Construction method
The filler in the concrete expansion joint of the pedestal is removed and cleaned with a duct. After passing the inspection, the HK elastic edge-sealing agent is filled and the surface of the expansion joint is closed. According to the design drawing position, the SR leveling line is ejected by the ink line, and the cement skin on the screed concrete of the leveling layer is polished by an angle grinder to expose the aggregate and sand of the concrete. According to the drawings, the stainless steel bolt holes are drilled with impact drills, the hole spacing is 1000mm, the hole diameter is 18mm, and the hole depth is 130mm. After the bolt hole is drilled, clear the hole with an air pump, fill the hole with RE500 anchoring agent and quickly insert the screw to be condensed.
After the stainless steel bolts are anchored, the screed concrete screed parts are cleaned and dried with clean water. After the concrete surface is dried, the brush width is 13cm, the SR primer is 2, and the brush should be evenly applied. When the SR primer starts to become viscous, the SR leveling filler plate is attached (the anti-stick on the side of the SR filler plate is torn off). The paper is gradually pasted from one end of the plate to the other along the length of the SR filler plate, taking care to discharge the air between the SR flexible filler plate and the adhesive face. Use the rubber hammer to strike the edge of the SR flexible packing plate to make it dense, and the joint part forms a slope-shaped transition to facilitate the SR sticking of the next piece. After the SR flexible packing is pasted, the tarpaulin is laid, the pressing strip of the board is set, and the sandbag is covered. Maintain pressure to ensure that the SR material adheres well to the concrete.
Pay attention to retain the protective layer paper on the upper part of the SR when laying, to prevent the adhesion of the ash to the environmental geomembrane manufacturers. The laid SR leveling layer should be covered with tarpaulin, plastic cloth, etc. in the upper part to prevent the sand dam from sticking to the SR leveling layer.
After the SR leveling layer is firmly bonded, the composite wholesale LDPE geomembrane is unfolded along the SR laying direction, and the geotextile at the lower edge of the composite LDPE geomembrane for sale is torn and folded back, and the high quality LDPE geomembrane bonding surface is cleaned (removing the supporting fibers, wiping dust, Water, etc., make it clean and dry). At the same time, uncover the SR upper protective paper, apply 2 times of SR primer on the SR, and paste the 3mm thick, 5cm wide anti-seepage strip (the material face up) when the SR primer starts to become sticky, and then brush 2 times. SR primer (13cm wide), when the SR primer begins to become sticky, the LDPE geomembrane manufacturers is adhered (the rubber is sealed at the rubber stop), and the strip is pressed tightly to cover the presser. When pasting the LDPE geomembrane factory price, push the paste from one side to the other side. The SR protective layer and the protective paper should not be uncovered in advance, which affects the quality of the paste. When attaching the SR leveling layer and the textured geomembrane for sale, keep the bonding parts clean and dry. The high quality textured geomembrane transverse joint is double-slot hot-melt welded.
After the wholesale textured geomembrane firmly adheres, the textured geomembrane factory price is turned to the other side, and the SR filler is filled on the backside, and the width is 10 cm, so that the geotextile and the low cost textured geomembrane in the coverage area of the ternary vinyl rubber cover sheet are on the same level, and then the folding is reversed. The geotextile adheres to the concrete base with superglue, and the width of the paste is not less than 20cm. After the paste is completed, the composite wholesale HDPE geomembrane is turned back to the original position. When turning the HDPE geomembrane factory price, the force should be controlled, and the HDPE geomembrane for sale of the pasted part should not be pulled.
Then wipe the floating ash on the HDPE geomembrane manufacturers with clean cotton yarn, and apply the width of 34cmSR primer 2 times. When the SR primer starts to become sticky, paste the EPDM cover sheet and compact it. Install the angle steel and press the angle steel with the expansion bolt nut. Finally, apply an HK edge sealer to the edge of the EPDM cover sheet.
2.2.3 Composite high quality HDPE geomembrane and concrete connection of the left and right bank slope base
The connection and fixing method of the composite China HDPE liner manufacturers and the sloping base of the left and right bank are the same as the concrete pedestal of the horizontal section of the dam foundation. However, since the sill between the two banks and the dam axis have a certain angle, the China HDPE liner factory price should be tested before the low price China HDPE liner is pasted. And the wholesale HDPE Liner made in China cuts the excess along the fixed edge. When cutting the purchase high quality HDPE liner, it should be repeatedly tested and contrasted to determine the cutting edge line, to ensure that the high quality aquaculture geomembrane and the riverbed section geotextile edge line are parallel, and there is no wrinkle when lap joint.
2.3 Composite low price aquaculture geomembrane connection construction
The composite aquaculture geomembrane factory price connection adopts hot-melt welding and seaming, and the lower and upper layers of the non-woven fabric are stitched and the middle layer wholesale aquaculture geomembrane is hot-melt welded. The non-woven fabric was hand-sealed with a non-woven machine and double-threaded with a nylon thread. The overlap width was 10 cm. The aquaculture geomembrane manufacturers and the membrane are connected by double-slot hot-melt welding, and the welding tool adopts double-slot hot-melt welding machine; the local welding is not possible or the hole and the defect are repaired by a hot air welding torch.
2.3.1 Climatic conditions for composite high quality environmental geomembrane construction
The composite wholesale environmental geomembrane connecting the concrete of the foundation is filled with the dam body, and the composite environmental geomembrane for sale can be connected when the exposed section is 1.0~2.0m. The specific environmental geomembrane factory price welding construction period is determined according to the construction progress and weather forecast. In principle, environmental geomembrane manufacturers construction is carried out in fine weather at 5 °C, and the wind force is less than 5 when construction. When the sand bar is filled until the wholesale LDPE geomembrane is to be welded, and the weather is not allowed, the step method can be used to fill the construction, and the LDPE geomembrane for sale construction site is reserved. When the weather meets the high quality LDPE geomembrane construction, the LDPE geomembrane manufacturers construction is carried out.
2.3.2 Composite LDPE geomembrane factory price paving
(1) Before the composite textured geomembrane for sale is paved, draw a paving map, mark the weld and number according to the length of the axis and the length of the coil.
(2) The composite high quality textured geomembrane paving and welding sequence are carried out, and a piece of welding is spread. The composite wholesale textured geomembrane laying construction is paved along the axis of the dam. The length of each roll is 50m. The paving is artificially paved. The composite textured geomembrane factory price is unfolded from the left bank to the right bank and from the right bank to the left bank along the axis of the dam, and then the composite low cost textured geomembrane is artificially Roll up in the width direction, place and take the weight fixing measures (with sandbags).
2.3.3 When the composite wholesale HDPE geomembrane is paved, the joint between the two HDPE geomembrane factory price and the joint of the upper composite HDPE geomembrane for sale should be staggered to form a “T” joint, and no “ten” joint should be made. Appropriate relaxation should be carried out when laying composite HDPE geomembrane manufacturers, and avoiding artificial hard folds and damage. Two rolls of composite high quality HDPE geomembrane overlap 10cm. At the corner where the composite China HDPE liner manufacturers is connected to the pedestal, the composite China HDPE liner factory price should be properly cut to ensure that the composite low price China HDPE liner is properly connected to the periphery and parallel to the edge of the upper composite wholesale HDPE Liner made in China.
2.3.4 The appearance of the film should be checked at any time for defects such as breakage, pitting, and perforation. It is found that defects or damages such as perforations on the film surface should be repaired with fresh base metal in time, and each side of the patch should be 10-20 cm beyond the damaged part.
2.3.5 Detail enhancement treatment: the yin and yang angles at the corner of the base should be strengthened. The male corners are cut at the bottom and welded with a purchase high quality HDPE liner with a radius of not less than 0.5m; the bottom of the female corner will be cut open. The two parts are welded together and then reinforced with another high quality aquaculture geomembrane with a radius of not less than 0.5 m.
2.4 Geomembrane welding
2.4.1 Welding parameters, according to the previous on-site welding process test, when the temperature is in the range of 23 °C ~ 33 °C, the low price aquaculture geomembrane welding parameters should adopt the welding speed of II gear (0.8m/min), the welding temperature is 270±15°C; the speed of III speed 1m/min, welding temperature 300±15°C, IV file 1.2m/min, 330±15°C. On this basis, during the field welding operation, the actual welding temperature and welding speed are fine-tuned according to the site environment.
2.4.2 Horizontal seam welding. The horizontal seam welding adopts double-slot hot-melt welding. The construction method is as follows: 1 Laying 3cm thick and 30cm wide wooden board at 50cm on the side of the composite aquaculture geomembrane factory price, as a welding platform for the welding machine. The edge of the constructed composite wholesale aquaculture geomembrane is unfolded, the geotextile is peeled off, and the welded surface is cleaned and placed on the wooden board. The aquaculture geomembrane manufacturers to be welded and lengthened is overlapped thereon, and the overlap width is greater than 10 cm. When welding after rain, the tarpaulin material should be laid on the surface of the fine sand to separate the evaporated water vapor in the fine sand and then lay the wooden board. 2 Straighten the welding power supply and cable, and place it on the other side. And connect the power to test the condition of the welding equipment. 3 Check the geotextile edge peeling condition of the high quality environmental geomembrane edge and the cleanliness and dryness of the welding surface, and clean and dry the welding surface. The weld lap joint surface must not have dirt, sand, water (including dew) and other impurities that affect the welding quality. presence. The surface of the film surface is welded to the film surface in the range of about 200mm. Wipe off dust and dirt with a damp cloth. Wipe dry with clean gauze to keep this part clean and dry. The wholesale environmental geomembrane should be aligned in parallel. 4Measure the ambient temperature, adjust the welding equipment to heat the equipment to the welding temperature, take a small piece of film of 300mm × 600mm for test welding for test welding, visually check whether the weld quality is abnormal, and carry out the hand peeling test to determine the welding temperature (The final soldering temperature is within the approved temperature range). When the temperature and wind speed of the site change greatly, the parameters should be adjusted in time to redo the test to ensure that the welder performance, site conditions and product quality of the construction meet the requirements of the specification. Generally, not less than 2 times per day, once in each Before the official operation, once in the middle shift, the experimental welding was carried out under the same surface and environmental conditions as the productive welding. After the on-site peeling test is passed, the formal welding is performed with the adjusted working state. Only through experimental stripping welding, productive welding can be carried out. When welding, the machine head should be aligned correctly, and the welding should not be welded. No welding, leakage welding, jump welding or over-welding is allowed. 5 After starting the machine, carefully observe the temperature rise displayed by the indicator meter, so that the equipment is fully preheated. During the welding, the welder should pay close attention to the condition of the weld and adjust the welding speed in time to ensure the welding quality and keep it in the welding. If the weld is straight and tidy, countermeasures should be taken against the uneven part of the film as early as possible to avoid affecting the smooth operation of the welder. When a special fault occurs, stop it in time to avoid scalding the film. 6 During the welding process, a special person should be set up to keep the environmental geomembrane for sale stable and prevent the environmental geomembrane factory price from shifting due to the wind blowing. Two special personnel are set in front of the weld to check the cleanliness between the seams and the weld overlap width. The rear of the welder is 2 to 3 people alternately follow the weld to be responsible for the stability of the environmental geomembrane manufacturers. After the weld temperature drops to normal temperature, it can be evacuated.
2.4.3 Vertical seam welding. Vertical seam welding is mainly for the welding of each composite wholesale LDPE geomembrane joint, and the vertical seam welding length is 6m for each welding. The vertical seam welding adopts double-slot hot-melt welding, and the welding method is the same in horizontal seam welding. However, in the welding process, 3 to 5 people should be arranged on both sides, and the LDPE geomembrane for sale on both sides of the high quality LDPE geomembrane weld be expanded and fixed to ensure the weld seam. Flattening, the welded LDPE geomembrane manufacturers can be rolled up in the width direction until the weld is at normal temperature. After the transverse welding is completed, a square 300 mm × 300 mm patch is welded at the “T” joint to strengthen the joint.
2.4.4 Repair welding. Repair welding uses hot-melt welding, mainly using extrusion welding. For the defects such as pinholes, holes, punctures, serious damage to the membrane surface, sampling place, “T” intersection, wrinkles and other various factors found during the construction of LDPE geomembrane factory price, the patching method is adopted. To fix it. Repair the textured geomembrane for sale with the same material, heat the repaired part with a hot air gun, weld from the side of the solder joint to the opposite side, and squeeze while welding to make the repair material and the original material as a whole. Workers should wear insulated gloves when extrusion welding. For different parts, different patches are used for patching and welding, as follows: 1 for pinholes, holes, etc., and the side of the patch should be 10 to 20 cm beyond the damaged part. 2 When the high quality textured geomembrane overlap occurs in the wrinkles, the wrinkles should be removed, and the wrinkles cannot eliminate the wrinkles. If the wrinkle elimination is greater than 10cm, a circular or elliptical patch should be used. The patch size should be 15cm beyond the perimeter of the incision. 3 At the “T” joint, add a square 300mm × 300mm patch with a chamfered corner. The right angle of the patch should be rounded, and the patch margin defect should be no less than 10~20cm.
After each weld is welded, the weld shall be visually inspected: lap width, weld width and cavity width between the two welds. The weld shall be smooth and beautiful, straight and smooth, and the weld profile shall be clear. State, no burns, bubbles, virtual welding leaks. The defects found in the wholesale textured geomembrane welding construction and quality inspection process are marked with the paint pen, and the records are repaired one by one according to the defect type.
2.4.5 Welding quality inspection. After the textured geomembrane factory price is welded on-site, the weld is sampled for tensile inspection. At the same time, the welding quality of the joint is inspected by the inflation method, and the quality of the repair defect is checked by the vacuum negative pressure method. On-site sampling and quality inspection standards and frequency.
2.5 Composite geomembrane joint construction
After the low cost textured geomembrane welding is completed, the welding quality is checked and all the holes and defects are processed. After the inspection by the supervision engineer, the geotextile is stitched. When the geotextile is seamed, the HDPE geomembrane for sale is first opened and leveled, and the tightness of the surrounding is kept consistent. The geotextiles of the composite HDPE geomembrane manufacturers on both sides are erected and tightened and then folded together by a portable sewing machine, and the suture is double-threaded with a nylon thread.
3. Composite high quality HDPE geomembrane construction quality inspection
The quality inspection of composite wholesale HDPE geomembrane construction mainly refers to the quality inspection of the weld seam. The on-site welding quality test takes the breaking test as the main control index, and the joint welding strength breaking value is not less than 85% of the base material strength. The test is carried out by a third party. Because the construction site does not have tensile test conditions, the quality of the weld on the construction site is checked by visual inspection, inflation inspection, vacuum negative pressure inspection, and sampling tensile test.