·Pipe laying■Slotted construction process, according to the construction site environment, deep groove, the water level, soil, construction equipment and seasonal factors such as the comprehensive selection.■Trench bottom 1 for width, trench depth, underground water level, soil conditions and easy to operate, the provisions of the space of the trench width of the table can be used to refer to the construction unit.■Underground water level is higher than that of the trench bottom elevation and construction must take effective measures to underground water level dropped to groove bottom below 0.3 to 0.5 M.■Trench excavation, should strictly control the base height, base and overbreak shall not be disturbed. The base is above 0.2 to 0.3 meters above the level of the original soil to...