a. Casing size shall be adequate to permit proper construction of the carrier pipe to the required lines and grades. Carrier pipe used in bore casings shall be as specified herein.
b. All bore crossings shall be provided with casing spacers and end seals. Casing spacer configuration shall conform to the manufacturer's recommendations, but in no case shall less than 3 spacers per length of pipe be used.
c. In order to prevent over-belling of PVC or other flexible pipe while installing it through the casing, provide a method for restricting movement between the assembled bell and spigot conforming with the manufacturer's recommendations.
d. The design of the bore crossing shall include the following as a minimum:
1) Casing and carrier pipe materials and dimensions, including outside bell diameters of the carrier pipe.
2) Details for any part of the system which must be changed as a result of the boring operation (manhole, headwall, etc.).
3) Bore and receiving pit backfill material and compaction requirements.