819TUNNEL LINING MATERIALS

819.01DESCRIPTION. This section covers materials requirements for steel plates and

fittings to be used for lining tunnels. Refe r to the Contract for sectional properties.

.01 Steel Plates. Use base metal for steel plates that conforms to the chemical

requirements of ASTM A 1011. Ensure that the flat plate, before cold forming, conforms to the following minimum mechanical properties: Tensile Strength 42,000 psi Yield Strength 28,000 psi Elongation, 2 inches 30%

Ensure that nominal plate dimensions provide the sectional properties shown in the current edition of the AASHTO Standard Specifications for Highway Bridges. For thickness tolerances, conform to Table 6 of AASHTO M 167. Provide steel liner plates of additional thickness or protect by coatings or other means when specified in the Contract for resistance to abrasion or corrosion.

.02 Bolts and Nuts. Do not use any bolts and nuts with lapped seams that are

less than 5/8 inch in diameter. Provide bolts conforming to ASTM A 449 for plate thicknesses equal to or greater than 0.209 inch and A 307 for plate thickness less than 0.209 inch. Provide nuts conforming to ASTM A 307, Grade A. Only use bolts and nuts with 4-flanged plates of no less than 1/2 inch in diameter for plate thicknesses to and including 0.179 inch and no less than 5/8 inch in diameter for plates of greater thickness.

SECTION 820 TIMBER POLES

820.01REQUIREMENTS. Provide poles of Southern Pine conforming to ANSI

Specification 05.1. Provide poles of the length and ANSI size classification specified in the Contract. The Department will not allow sweep exceeding one inch in 10 feet or double sweep. Treated timber poles shall meet all the general requirements of this subsection and shall be treated with pentachlorophenol (oil borne) or CCA (water borne) preservative as noted in AASHTO M133 in accordance with requirements of the current AWPA standards. Treat poles with pentachlorophenol conforming to AWPA P35 according to AWPA U1 or CCA conforming to AWPA P23 according to AWPA U1. Ensure that net retention is no less than 0.75 pounds per cubic foot on the outer 1/2-inch and no less than 0.45 pounds per cubic foot in the 1/2 to one-inch zone with average retentions of no less than 0.80 and 0.50 pounds per cubic foot, respectively. Follow the guidelines for the care of preservative treated wood products as set in AWPA M4.

820.02ACCEPTANCE. The Department will inspect, test and accept poles according

to Subsection 818.01.