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

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

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

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

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

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

(F) To pro­vide pro­tec­tion of util­i­ty con­duc­tor or car­ri­er from super­im­posed loads and/or “dig-in” damage.

(G) 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 Under-ground util­i­ty cross­ings with­out encase­ment, when per­mit­ted, will gen­er­al­ly pre­clude future main­te­nance or repair with­in the area between the ditch lines or toes of slopes.