Section 530.510  Encasement

a)         Encasement of underground utility crossings where required is intended to serve one or more of the following purposes:

1)         To allow replacement of utility without future disruption of roadway structure.

2)         To allow installation of additional facilities without future disruption of roadway structure.

3)         To vent or drain leaks of volatile gases or liquids that might occur under the roadway structure.

4)         To serve as bridge or carrier through unstable soil structure.

5)         To prevent cavitation under pavement structure from leaks of pressurized liquids.

6)         To allow ease of insertion and coating protection of utility conductor or carrier.

7)         To provide protection of utility conductor or carrier from superimposed loads or "dig-in" damage.

b)         Casing pipe shall be designed to withstand the load of the highway and any other superimposed loads.  The casing shall be continuous either by one-piece fabrication or by welding or jointed installation approved by the Department as defined in Section 530.30.

c)         Underground utility crossings without encasement will generally preclude future maintenance or repair in the area between ditch lines or toes of slopes.