Reservoir seepage geomembrane prevention construction plan

Reservoir seepage prevention construction plan

Artificial paste anti-seepage construction scheme

Pond anti-seepage construction plan

Please make appropriate adjustments according to the construction site. The following schemes are for reference:

1. Pre-construction requirements

1 .1The anti-seepage construction of the reservoir is the core of the whole project. Therefore, the anti-seepage construction must be completed with the close cooperation of the civil works.

1.2 The materials used in the project must meet the requirements.

1.3 Welding machines and welding rods are commonly used for materials construction equipment, and in special cases, extrusion welding torches, pressure gauges, and E-type locks are required.

2. Requirements for controlling the laying site of the civil foundation level:

2.1 Flatness: ±2cm/m2, flat and straight.

2.2. Compaction degree: 95%, geomembrane can be laid on it after rolling.

2.3. Longitudinal and transverse slopes: The longitudinal and transverse slopes should be above 2%.

2.4 Cleanliness: There shall be no sharp-edged debris such as tree roots, rubble, stones, and concrete particles within a vertical depth of 2.50cm.

3.Requirements for several anchoring joints

3.1 Anchoring ditch: The excavation size of the anchoring ditch is 30-50cm. The anchoring ditch is to fix the HDPE geomembrane and the protective layer geotextile. After the HDPE geomembrane and the protective layer geotextile are laid, immediately press the concrete plate.

4.Laying construction climate requirements:

4.1 The temperature is 5-40℃. Considering the thermal expansion and contraction of the geomembrane, according to experience, the laying of the geomembrane should be tighter when it is cold; it should be relaxed when it is hot; high temperature.

4.2 Wind and rainy days: construction should be stopped when the wind force exceeds level 4 or rainy days; when the wind is small, sand bags should be used to press the geomembrane to facilitate construction.

5. HDPE geomembrane construction and installation

5.1 HDPE geomembrane construction and installation process

5.2 Cutting and Shipping:

According to the measurement records of the laying base, cut out large bundles of geomembrane, record the numbers, and transport them to the laying site according to the numbers. Note that the geomembrane should not be dragged or pulled during transportation to avoid being stabbed by sharp objects.

5.3 Construction and installation of HDPE geomembrane

5.3.1 It should extend from the bottom to the high position, do not pull too tight, and leave a margin of 1.50% for local sinking and stretching. Sometimes taking into account the actual situation of the project, the slope is laid from top to bottom.

5.3.2 The longitudinal joints of two adjacent sheets should not be on a horizontal line, and should be staggered by more than 1M.

5.3.3 The longitudinal joint should be more than 1.50M away from the dam foot and the bent foot, and should be set on the plane.

5.3.4 Slope first and then the bottom of the field.

5.3.5 When laying the side slope, the film spreading direction should be basically parallel to the max slope line.

5.3.6 Slope laying control: Before the anti-seepage geomembrane is laid on the slope, first check and measure the laying area, and transport the anti-seepage membrane matching the size in the warehouse to the first-stage anchoring ditch platform according to the measured size. When laying, according to the actual conditions of the site, a convenient way of "pushing" from top to bottom is adopted. It should be cut reasonably in the fan-shaped area so that the upper and lower ends are firmly anchored.

5.3.7 Control of laying at the bottom of the field: Before laying the anti-seepage geomembrane, check and measure the laying area, and transport the anti-seepage membrane with the matching size in the warehouse to the corresponding position according to the measured size: when laying, use artificial According to a certain direction, "push shop".

5.3.8 Alignment and alignment: The laying of HDPE geomembrane, whether it is a side slope or a field bottom, should be smooth and straight to avoid wrinkles and ripples, so as to align and align the two geomembranes. The lap width is generally about 10cm according to the design requirements.

5.3.9 Control of lamination: use a sand bag to press the aligned and aligned HDPE anti-seepage film in time to prevent it from being pulled by the wind.

5.3.10 Control of laying in the anchoring ditch: On the top of the anchoring ditch, a margin anti-seepage membrane shall be reserved according to the design requirements to cope with the sinking and stretching.

5.3.11 Longitudinal joints: the upslope section is up, the downslope section is down, and there is enough overlap length ≥ 15 cm

5.3.12 The film spreading direction should be basically parallel to the maximum gradient line.

6. Welding precautions for HDPE geomembrane.

6.1 The joints of HDPE geomembrane shall not have oil stains and dust, and the overlapping surface of HDPE geomembrane shall not contain debris such as sand and sand. When there are debris, it must be cleaned before welding.

6.2 At the beginning of welding every day, a 0.9mm×0.3mm sample must be tested on site first, and the lap width should not be less than 10cm, and the peeling and shearing test should be carried out on site with a tensile machine. After the sample is qualified, it can be adjusted at that time. Good speed, pressure, and temperature are just welding. The date, time and ambient temperature should be marked on the sample. During the welding process of the hot wedge welding machine, attention should be paid to the operation of the welding machine at any time, and the speed and temperature should be fine-tuned according to the actual situation on site.

6.3 HDPE geomembrane welds are required to be neat and beautiful, without slip welding and jumping.

6.4 When the length of HDPE geomembrane is not enough, it needs to be spliced in the long direction. The horizontal weld should be welded first, and then the longitudinal seam should be welded. The distance between the horizontal welds is more than 50cm and should be T-shaped, and should not cross.

6.5 The adjacent HDPE geomembrane welds should be staggered and overlapped as much as possible. The joints formed between the membrane blocks should be T-shaped, and cross-shaped should be minimized. The intersection of the longitudinal mold and the weld should be strengthened by an extrusion welder.

6.6 When welding the film, it is not allowed to press out the dead break. When laying the HDPE geomembrane, according to the local temperature change range and the performance requirements of the HDPE geomembrane, reserve the expansion and contraction amount caused by the temperature change.

6.7 When the temperature of the welding machine indicated by the temperature control of the portable welding machine is lower than 200 °C, it should be wiped off with a clean cloth or cotton yarn before welding. If necessary, it should be re-polished.

6.8 When the joints of HDPE geomembrane are affected by condensation, moisture, sediment, etc., welding should be carried out after treatment.

6.9 Welding cannot be carried out during rain or when there is moisture, dew, or heavy sand in the joints, unless protective measures are taken.