Case study of landscape lake construction project

　　With the increasing attention paid to the living environment, more and more residential communities, parks, and ecotourism areas have planned large-scale landscape artificial lakes. However, due to the influence of climate and geology, the lake water will gradually drain and even dry up. This requires frequent replenishment of the lake water to maintain water level. The cost of supplementing the artificial lake is expensive. In order to reduce the maintenance cost of the artificial lake, we need to carry out waterproof and anti-seepage treatment on the artificial lake.

　　In recent years, the awareness of garden landscapes has gradually strengthened, and high requirements have been put forward for the utilization of landscapes. Traditional anti-seepage methods such as using cement concrete, stone stacking, and waterproof coatings for the lake bottom are no longer applicable. The emergence of HDPE anti-seepage film has solved this problem. HDPE anti-seepage film has a short construction cycle, simple construction, convenient maintenance, low investment cost, good anti-seepage effect, and meets the design requirements of garden landscapes.

　　1. Construction of geotextile

　　(1) When supporting the installation of the lower geotextile; The overlap should be maintained at least 30cm.

　　(2) When supporting the installation of upper geotextile; The overlap should be maintained at least 10cm; And use a sewing machine to sew tightly.

　　2. Preparation before construction of HDPE anti-seepage film:

　　(1) Check the removal of debris in the site and clean it according to the design requirements. This is the key to the anti-seepage effect. Remove debris such as sharp stones and tree roots, and do not allow local unevenness on the foundation surface. The cleaned foundation surface should be compacted tightly with a hammer or plate to make it dense and flat. Clean up the debris to prevent the geotextile from being punctured by debris. To prevent leakage due to uneven density during the use of artificial lakes in the future.

　　(2) Laying workers should wear soft soled shoes to avoid damaging the geomembrane.

　　3. Laying of anti-seepage membrane:

　　(1) Laying HDPE anti-seepage film is a crucial process in the entire anti-seepage system. Before laying the film, conduct an open-package inspection of the appearance quality of the HDPE anti-seepage film, record and repair any mechanical damage, production trauma, holes, folds, and other defects that have been discovered.

　　(2) Before cutting the HDPE anti-seepage film, its relevant dimensions are measured, and then cut according to the actual situation. During the laying of the film, the overlapping width of the joint between the film and the film is not less than 100mm, so that the joint arrangement direction is parallel to the slope toe line, that is, along the slope direction.

　　(3) When laying HDPE anti-seepage film, efforts should be made to minimize welding seams and save raw materials as much as possible under the premise of quality. It is also easy to achieve quality. Usually, in areas with deformed corners, the joint length should be minimized as much as possible. Unless otherwise required, within a range of 1.5 meters from the top slope or stress concentration area on slopes with a slope greater than 1:6. welding seams should be avoided as much as possible.

　　(4) During the laying of HDPE anti-seepage film, artificial wrinkles should be avoided. When the temperature is low, it should be tightened and flattened as much as possible.

　　(5) After the completion of HDPE anti-seepage film laying, it is necessary to minimize walking and moving tools on the film surface. Any objects that can cause harm to the HDPE anti-seepage film should not be placed or carried on the film to avoid accidental damage to the film.

　　4. Welding of HDPE anti-seepage film:

　　(1) The welding of HDPE anti-seepage film uses a wedge welding machine and adopts dual track hot melt welding. For areas that cannot be welded by a wedge welding machine, an extrusion hot melt welding machine should be used, accompanied by welding rods of the same quality as the raw materials, to form a single weld seam for overlay welding.

　　(2) The welding process of a hot wedge welding machine is divided into: adjusting pressure, setting temperature, setting speed, inspecting weld overlap, installing film into the machine, and starting the motor.

　　(3) There should be no oil or dust at the joints, and the overlap surface of the HDPE anti-seepage film should be free of debris such as sediment, condensation, moisture, etc. When there are debris, it should be cleaned before welding.

　　(4) At the beginning of welding every day, it is usually necessary to test weld a 0.9mm weld on site first × A 0.3mm sample with a lap width of no less than 10cm shall be subjected to peel and shear tests on site. Once the sample is qualified, normal welding can be carried out using the adjusted speed, pressure, and temperature at that time. During the welding process of the hot wedge welding machine, attention should be paid to the operation of the welding machine, and the speed and temperature should be adjusted according to the actual situation on site.

　　(5) The welding seam should be neat, beautiful, and free from slipping or jumping.

　　(6) When the length of the anti-seepage film is not enough, it is necessary to splice it in the long direction. The transverse weld seam should be welded first, and then the longitudinal weld seam. The transverse weld seam should be T-shaped with a distance of more than 50cm and should not cross.

　　(7) When welding the film, it is not allowed to press out or fold. When laying the HDPE anti-seepage film, the expansion and contraction deformation caused by temperature changes should be reserved according to the local temperature change amplitude and the performance requirements of the HDPE anti-seepage film.

　　(8) Welding cannot be carried out during rainy periods or when there is moisture, dew, or heavy sand at the joints (except when protective measures are taken).

　　(9) When the temperature is lower than 5 ℃, construction should not be carried out according to the specifications. If construction is carried out, the welding machine should be preheated before welding.

　　(10) When welding the anti-seepage membrane, whether using local power or generator power, it is necessary to maintain voltage stability and use a voltage regulator.