Xây dựng mạng lưới bao gồm các bước sau: chuẩn bị trang web 1, khai quật 2, 3 tách nước rãnh, đặt ống 4, nối 5, san lấp mặt bằng 6, kiểm tra 7 & khử trùng. Sau khi trang web đã được chuẩn bị, tất cả các bước khác được tiến hành đồng thời tại các phần khác nhau của các tuyến đường ống, kết thúc của nó, các đường ống được kiểm tra, một vài ống dẫn hơn nữa, san lấp diễn ra, và cùng một lúc ở phần trên các đường ống nối, . . | CHAPTER 5 Network Construction Network construction comprises the following steps 1 site preparation 2 excavation 3 trench dewatering 4 pipe laying 5 jointing 6 backfilling 7 testing disinfection. After the site has been prepared all the other steps are conducted simultaneously at various sections of the pipe route at its end the pipes are tested a few pipes further the backfilling takes place and at the same time at the preceding section the pipes are jointed etc. This coordinated method of working is important in order to shorten the total duration of the construction reducing both the cost and disturbance. The laying of a few sections of steel pipe is shown in Figure . Pipes can also be laid above ground or in tunnels which then require adapted laying techniques such as the use of casings anchorages and supports etc. Some typical principles and solutions are briefly presented in this chapter. Figure . Laying of steel pipe. 2006 Taylor Francis Group London UK Network Construction 207 SITE PREPARATION Pipes can be laid only when the route is completely clear. Site preparation in urban areas can be a complex task where cooperation with other utilities is very important. Works on water electricity gas road or other infrastructure are often carried out simultaneously. Before the work can commence mutual agreement should be obtained about the working area so that other daily activities are not significantly affected during the construction. Proper signalling footpaths and crossings for pedestrians signs and warnings a restricted access to the equipment in operation etc. must be provided during the entire period of work. Pipes will be tested prior to leaving the factory and should also be tested after reaching the site in order to check for possible damage resulting from transportation. Further damage to the pipe is possible during the process of unloading stacking and or stringing along the laying route. The dropping of pipes pipes striking each other .
