Rev. 7-1-95
PROOF TESTING OF ROCK
206-B-120
The Standard Specifications are revised as follows:
SECTION 206, AFTER LINE 173, INSERT AS FOLLOWS:
If rock is encountered at the bottom of the footing, such rock shall be proof tested. Exploratory holes of 50 mm (2 in.) diameter shall be drilled into the foundation base. Holes shall be drilled into sound rock to a depth of 1.5 m (5 ft) or as directed. Three holes shall be drilled into each foundation base. Observations shall be made at each hole as follows:
1. Speed of drilling
2. Drill pressure
3. Dropping or clogging of drill bit
4. Loss of drill water, if used
5. Probing of the sides of the holes with a right angled chisel point. The chisel shall be formed from a rod of 10 mm or 13 mm (3/8 or 1/2 in.) diameter.
6. Continuity of bearing material
A licensed professional engineer shall perform and supervise the proof testing work. The Contractor shall submit the name of such professional engineer for approval prior to performing such work.
A report for each hole shall be prepared and submitted for review and approval.
SECTION 206, AFTER LINE 318, INSERT AS FOLLOWS:
The cost of furnishing all materials and labor associated with proof testing of rock shall be included in the costs of other pay items.