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1 D. Jacking Pits - Excavated areas from which jacking and receiving operations are accomplished. 1) Jacking Pit Excavation - Pit excavation shall be no closer than four (4) feet from the roadway or shoulder pavement edge, or two feet from back of curb, whichever is applicable. When deemed necessary for safety, the Maintenance Engineer may require a greater distance than four (4) feet from the edge of pavement 1 when shoulder pavement is not present. Pits on limited access facilities shall be no closer to the pavement edge than the toe of the front slope. The pit dimensions shall be large enough to provide a safe, adequate working area with slopes no steeper than 1 in hard pan, clay or hard Sand -clays 1 1 in stable cohesive soils 2 : 1 in loose unstable soils Slopes shall extend from proposed casing invert elevation to existing ground level. Slopes are not required in solid rock. In lieu of constructing slopes as above, the pit walls may be shored, sheeted, braced or otherwise supported by means of 1 sufficient strength to protect the employees and inspectors working within them. 1 07/03 I' 2) Pit Floor Stabilization - Where necessary to ensure a solid, stable base for boring machinery, some means of stabilizing the pit floor must be provided. Stabilizing may vary depending upon job site condition, from timber supports under tracks, addition of clean sand or gravel to pit floor, or in some cases the construction of concrete slabs on the pit floor. Al stabilizing materials other than sand, gravel and like materials must be removed upon completion of the project. E. Equipment Set Up 1) Aligning and leveling of auger tracks - To properly control line and grade during the crossing operation, it is imperative that the jacking unit tracks be rigidly set to the predetermined level and 16200 -10 03- 1438.A