constructed in the approach trench and may be eithe r timber or steel rail or concrete guides on a cradle. Since the pipe guides will support the pipe as it enters the jacking face, the pipe guides shall be accurately set to line and grade, and excavation for the guides shall be made to grade to avoid occu rrence of settlement. Guides shall be spaced, as required. Reaction of the jack to the pipe shall be transmitted by either a jacking frame or jacking beams constructed of timber or steel. Jacking frames and beams shall be so placed as to exert equal pre ssure on each side of the pipe. For pipes thirty -six (36) inches in diameter or smaller, a steel jacking ring may be used in lieu of the jacking frame. The pressure from the jacking frame or beams may be transmitted to a jacking collar or head on the pip e itself. Jacking collars or heads for concrete pipe shall be constructed to prevent damage to the pipe ends. Jacking collars and jacking frames shall be constructed to allow passage of men and material. Joints of concrete pipe shall be cushioned and pr otected from infiltration of fine materials occurring during the jacking operation by insertion of a plywood or OSB of ½” -¾” thickness cushioning material into each pipe joint. After the pipe is in position, the joints shall be pointed from the inside wit h mortar joint compound. The use of a jacking shield is permitted. To prevent the pipe from "freezing" and becoming incapable of movement, jacking operations should, if possible, be carried out on a 24 -hour basis. Alignment and grade of the pipe guidess hall be checked at least once each shift. To aid in the prevention of "freezing," the pipe shall be lubricated in a manner and with a material meeting the approval of the Engineer. Excavation for the bore shall be to grade at the bottom and approximately one (1) inch greater than the diameter of the pipe at the top and sides. As excavation proceeds, the jacking shall proceed until the effective limit of the jacking is reached, at which time additional blocking shall be added. This process shall be conti nued until there is room for an additional pipe section. For long runs of pipe, the use of intermediate jacking stations will be allowed as approved by the Engineer. Pipe cover shall be a minimum of one diameter or three ( 3) feet from top of pipe to bottom of the subgrade of ballast when jacking under a highway. After the pipe has been jacked into place, the annular area between the pipe wall and the remaining soil sh all be pressure grouted to remove any chance of settling. The backfill shall be tightly compacted around both ends of the culvert to prevent erosion. Any departure from the above specifications necessitated due to site conditions shall be approved in wri ting by the Engineer. Areas resulting from caving or excavation outside the above limits shall be backfilled with grout, or by a method which will fill the voids. Joints shall be completed as specified for the type of pipe being installed .
604.12INSPECTION AND ACCEPTANCE :
In addition to the inspection performed by the Division during the initial installation of pipe culverts, a post installation inspection will be conducted before final acceptance. No sooner than 30 days following installation, the Engineer will visually i nspect all culverts. Pipes larger than forty -two ( 42) inches in diameter will be manually inspected by inspectors on the project for excessive deflection of flexible pipe, excessive cracking in rigid pipe, and joint issues for all pipes. Inspectors will note and document any defects with locations in their daily work reports. Any excessive cracks, differential movement, spalls, exposed reinforcement, delamination, slabbing, dents, buckling, holes, damaged coating, obstructions, improperly engaged joints, improper gasket placement, excessive joint gaps, misaligned joints, excessive deflection, or undue horizontal or vertical misalignment will be cause for repair or replacement at no cost to the