The municipal drainage pipe is indispensable for urban construction. The PE pipe is used on the road drainage with vehicle load. It has the characteristics of abrasion resistance, smooth drainage, durability and low price. Most of them use reinforced concrete pipe to cooperate as one of the drainage pipes. .
1 PE pipe construction process
Construction process: measurement → stakeout → trench excavation → basic treatment → connection, lower pipe, school pipe → pipe groove backfill → inspection well masonry, returning → acceptance. PE pipe construction in addition to implementation according to construction specifications, PE pipe itself, should pay attention to the following points:
(1) The PE tube has serious thermal expansion and contraction, so the PE tube should be constructed and used in an environment where the temperature difference does not change much.
(2) When the buried depth of the PE pipe is lower than the bottom surface of the foundation of the structure, the pipe shall not be located within the range of the foundation diffusion angle under the foundation of the structure.
(3) In areas where the groundwater level is higher than the bottom elevation of the trench, the groundwater level is reduced to 0.3 m to 0.5 m below the nearest point of the trough.
(4) When the pipe trench is excavated, the excavation depth shall be strictly controlled, and the undisturbed soil at the bottom of the basement shall not be disturbed. If over-excavation and disturbance occur, the natural grade sand and gravel with a particle size of 0.1 m to 0.5 m shall be replaced and leveled.
(5) The PE pipeline foundation adopts the gravel foundation instead of the concrete foundation, and the thickness is 0.05 m to 20 m, depending on the geological conditions.
(6) Pipe laying process, the lower pipe is carried out by hand or crane. When the crane is under the pipe, the non-metallic rope buckle is used to tie the ends of the pipe to 1/4 of the pipe mouth.
(7) The backfilling requirements are stricter in the backfilling. Some backfilling materials use a certain size of medium (coarse) sand (locally called asbestos sand). The hard corners of the gravel (soil) are easy to damage the PE pipe and the backfilling is not easy to be dense. Asbestos sand It has an automatic compacting function at the optimum water content, and a compact tamping machine can meet the compactness requirements.
(8) Backfilling at the top of the pipe 0.7 m or more, using mechanical backfilling. Backfilling below the top of the pipe must be backfilled from both sides of the pipe at the same time, and compacted. Otherwise, the PE pipe will be unevenly pressed, resulting in deformation and displacement of the PE pipe. Other backfills are performed according to specifications.
(9) The pipeline is connected to the inspection well. In the original construction plan, the nozzle was retracted into the inner wall of the inspection well by 0.3 m to 0.5 m, and it was painted with a mortar to form a "horn". The surrounding area was filled with mortar and compacted. After that, the brick was built, but the closed water test could not meet the requirements. The following problems exist in the inspection: 1 The thermal expansion and contraction of the PE pipe will check the well cracking, resulting in leakage of the inspection well. 2 The inspection well was not cracked, but the sealing at the joint between the pipeline and the inspection well did not meet the requirements, resulting in seepage and water leakage.
In view of the above two problems, the following solutions are proposed: 1 The PE pipe is deepened, so that the PE pipe is in an environment where the relative temperature does not change much, and the PE pipe is immediately backfilled after being laid, and completed in a short time. The construction length is controlled within a certain range. After the 2PE pipe is laid, the inspection well is built. 3 For the second problem, the connection method is re-applied, and the joint between the inspection well and the PE pipe is sealed by hot-melt fiber, replacing the original mortar packing seal.
2 Advantages and characteristics of the collecting tube
(1) Compared with reinforced concrete, the water delivery capacity is improved by hydraulic calculation.
(2) Good corrosion resistance, the main raw material of FRP is composed of polymer unsaturated polyester resin and mineral fiber glass fiber, which is effective against corrosion of acid, alkali, salt and other media and untreated domestic sewage. With industrial wastewater and a large number of chemical liquids, FRP can be used for a long time in the range of -40 ° C ~ 80 ° C.
(3) The pressure bearing capacity is enhanced. The reason is two aspects: First, during the compounding process, the primer will be immersed in the micropores of the concrete to reinforce it. Second, the FRP lining itself has a high load carrying capacity.
(4) Compared with the glass steel pipe, the composite pipe is 25 yuan/m larger than the reinforced concrete pipe, which is about 1/2 lower than the cost of the FRP pipe with the same pipe diameter on the market. It can be seen that the economic benefits are very obvious and are of great significance to the construction of the drainage pipe project.
(5) There is a possibility of leakage in the concrete drainage pipe, so it will pollute the soil and groundwater, and the composite pipe will not leak and have no secondary pollution. The main road for the drainage pipe works will be transported to the sewage treatment plant. Pipelines have good social benefits for protecting the environment.
3 Construction process of composite pipe
(1) According to the design drawings, measure the center line of the drainage pipe, measure the height of the design pipe bottom, and excavate the trench. The surveyor commands and controls the center line of the groove and the elevation of the bottom of the ditch. After the design of the bottom of the ditch, the concrete belt is poured. base.
(2) The glass mesh is reinforced with the reinforced concrete pipe according to the strength of the pipe base concrete up to 60%. The process of on-site pipe is the same as the normal drain pipe. The end of the pipe is completed, and the bottom line is reached through the center line of the inspection pipe. After the design requirements, start the pipe interface.
(3) Pipe interface. Need equipment, blower, electric hair dryer, emergency light or 220 V transformer l2 V transformer, install a blower before 1:3 in each well section to ensure smooth ventilation inside the pipe, then fill the pipe joint with fiber soaked resin glue, fill After 100 mm on both sides of the inner slit of the pipe, the joint glass fiber reinforced plastic is 200 mm wide. The resin mixture is applied to fully infiltrate the glass fiber reinforced material. The glass fiber is laid and heated by an electric hair dryer. The above process is repeated until the requirements are met.
(4) Masonry inspection wells. Inspection wells in accordance with the requirements of GB50268-97, according to the design requirements 100# concrete foundation 75# red brick, 75# mortar masonry, 1:25 cement mortar surface 20 mm thick, to meet the requirements of the surface, when the surface is dry, start to apply resin Mix the mixture, evenly, then lay the glass fiber, apply the resin mixture, must soak the glass fiber, heat and dry with an electric hair dryer, repeat the above process until the required thickness is reached.
(5) Closed water test. Check the pipeline interface before the closed water test, and the appearance of the inspection well is qualified; the pipeline is not backfilled and there is no water in the trench; all reserved holes are blocked in advance and must not seep. When the design head upstream of the test section does not exceed the inner wall of the pipe top, the test head shall be calculated by adding 2 m to the inner wall of the upstream pipe top of the test section.
The backfilling is started after the closed water test is passed, and the backfilling is carried out according to the design requirements.
4 Construction precautions
(1) Choose a construction in the rainy season.
(2) When the temperature is high, the resin is easily cured.
(3) Try to be as large as possible from the original drain pipe to avoid seepage through the construction trench.
storage system,2 Function In One Cabinet,tool storage system
Jiangsu Xicang Intelligent Technology Co., Ltd. , https://www.xciwarehousing.com