The contractor shall excavate all rock encountered in the trenches and areas occupied by structures as directed by the Engineer and dispose of all such rock in accordance with the requirements under Article IV, Excavation and Backfill.
A.
In removing rock, special care shall be taken to excavate
it as closely as possible to the required shape and with no projection
into the neat outside line of such trenches. The surfaces of all rock
foundations shall be sufficiently rough to bond well with masonry.
Before any masonry is built on or against a rock surface, the latter
shall be scrupulously free from all dirt, gravel, boulders, ice, snow
or other objectionable substances, including loose fragments of rock.
The space between the springing line of the pipe and the surface of
the rock shall be filled with crushed stone or gravel.
B.
Unless otherwise directed by the Engineer, rock shall
be fully taken out at least 25 feet in advance of pipe laying and
to a point six inches below the invert of the pipe and to a width
sufficient to enable good working room for the size of the pipe to
be laid therein. Rock shall also be excavated so as to provide a minimum
clearance of six inches from the outside face of all pipes and structures.
(Reserved)
