TABLE OF CONTENTS A great deal of construction activity involves the installation or rerouting of underground utilities (sanitary and storm sewers, domestic water lines and fire mains, electrical and telecommunications services, and natural gas lines). The nature and variety of these installations vary substantially from site to site, but the basic materials of construction generally do not.
Underground site utility work consists of the installation of conduits of various sizes and materials of construction to carry these utilities; the basic piping materials are either reinforced concrete pipe, thermoplastics, cast iron or ductile iron, lightweight aluminum or steel and corrugated metal pipe.
Installation of these types of pipes have several things in common:
Excavation and pipe laying Depending upon the type of soil and the width and depth of excavation, either open cut will be used or a trench cut (utilizing sheet piling) or a trench box (to avoid collapse of the walls of the excavate).
Bedding material Depending upon the type of pipe being installed and the nature of the subsoil, off-site bedding materials might be required, not only to place under the pipe, but for initial backfill
Compaction of the soil above the pipe will also depend on the depth of the excavate, the soil conditions, and the percentage compaction required.
To discuss the backfill procedures for underground pipes, it is necessary to understand pipe zone terminology.
Foundation Might not...
