Pouring concrete inspection wells: During the trenching process of the pipeline, the size of the excavation should be controlled in place, and the work injustice should be reserved around the well, and then the relevant surveyors will establish the center position so that the wooden piles can be determined. Concrete inspection wells can be constructed only when the final elevation measurement is correct. Since there are steel bars in the concrete inspection wells, some standard atlases should be made with reference to the inspection wells during construction. In particular, the connection between the elevation of pipes with different diameters and the elevation of the bottom of the well is very prone to errors, so special attention should be paid. Then stabilize the pipe and straighten the pipeline interface to ensure that the elevation is correct, and then construct the inspection well. If the water level is too high, use the method of mercury pumping for precipitation to ensure that the trench is dry during construction, otherwise there will be water when the trench is excavated. Backfilling of pipelines: Backfilling is carried out after the closed water is qualified. First, drain the accumulated water in the tank, and use an excavator to excavate the soil to the edge of the trench in the land section. In the landless section, excavate and transport 1km of earthwork to the edge of the trench to level the soil, plough repeatedly, and backfill with an excavator. simultaneously. When the backfill reaches a certain height, it is compacted by a two-way vibration compactor.
Application in pipeline repair: With the continuation of the use time, it is inevitable that the underground pipeline will corrode, and the corrosion of the pipeline will cause leakage, which will cause a series of problems such as environmental pollution and the loss of the transport medium in the pipeline. repair. Commonly used methods are soft lining method, spraying method, lining method and so on. ①The soft lining method, also known as the curing method, is to lining a layer of thermosetting material on the inner wall of the existing old pipe, and curing it by heating (using hot air, ultraviolet rays or hot water, etc.) to form a thin lining pipe and the old pipe. The tube fits tightly, and there is almost no loss in the flow cross-section of the tube, but the flow performance is greatly improved. ②It is mainly used for anti-corrosion treatment of pipelines by spraying method, and structural lining can also be formed for use in old pipes. During construction, the spray head rotating at high speed under the traction of the winch will evenly spray epoxy resin or cement slurry on the inner wall of the old pipe while retreating. ③The inner lining method, also known as the intubation method, is to insert a plastic pipe of equal or smaller diameter than the original pipe into the original pipe, and the annular gap is grouted between the old and new pipes to be consolidated, and the pipe forms a kind of pipe-in-pipe. Therefore, the mechanical properties of metal materials and the anti-corrosion properties of plastic pipes are combined into one, and the working performance of pipes is improved.
