been removed, refill the holes and level the area toprevent the accumulation of water.STRIPPINGStripping consists of removing and disposing ofobjectionable topsoil and sod. It may either follow orbe done with clearing and grubbing. Actualearthmoving begins with stripping; surface soil androcks are removed from the area to be excavated.Deeply embedded rocks and large boulders may haveto be blasted before they can be removed.The material removed by stripping is called spoil.Unless otherwise directed, you should dump spoilalong the area to be excavated within range of theearthmoving equipment. If the spoil will not be put touse, such as turfing or finishing the shoulder of a roador runway, it should be wasted along the edges of theproject, as shown in figure 15-64. Take care not todisturb necessary drainage.Equipment, commonly used in stripping, consistsof a dozer, a scraper, and a grader. As mentionedearlier, the dozer is the most often used whenremoving trees. Dozers can handle all short-haulexcavations (up to 300 feet). For long-haulexcavations (over 300 feet), scrapers should be used.A scraper may be used also on fine soils for shallowstripping. A grader is used mainly for shaping andfinishing a stripped surface. It is adaptable also forditching, for sidecasting, and for sloping banks.DRAINAGEDrainageis the construction of facilities neededto allow excess surface and subsurface water to flowfrom the construction site. Properly designed andconstructed drainage systems are one of the mostimportant parts of a construction project. Withoutproper drainage, rainwater and water running off thesurrounding ground could turn the area into a lake. Itis also necessary to drain off surface water that wouldsoak down and wet the subgrade.The elements, determining drainage needs for aroad or project site, are the amount of annual rainfallin the area and the routes or areas that can be used tocollect or channel excess surface and subsurfacewater, such as lakes, ponds, streams, or voids (i.e.,gullies).The type of soil is critical to the design andconstruction of a road. It is poor judgment to constructa road over or through clay, sand, or other undesirablematerial if it cannot be properly compacted. It is bestto bypass this type of material.If a road surface is to endure continued use foryears, it must have firm support from the subgrade. Allorganic materials, such as living or decayedvegetation, should be removed from the area of thesubgrade unless the road is for emergencies or istemporary (detour or military road). In designing andbuilding a road, consider the type of drainage, the typeof soil, and the amount of clearing or grubbingnecessary.To facilitate drainage, excavate diversion ditchesto conduct all surface water into natural channels oroutfall ditches. Outfall ditches are constructed todrain low or boggy spots. At the point or the end ofthe system when the accumulated runoff dischargesinto the disposal point, the runoff is technically knownas discharge. The discharge point in the system iscalled the outfall. This preliminary work is done at thesame time the area is cleared and grubbed.The finished drainage system usually consists ofground slopes, ditches, culverts, gutters, storm drains,and underground water drains. Open channels shouldFigure15-64.-Stripping.15-40
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