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J • STRUCTURAL STEEL Structural steel shall be new, clean stock conforming to ASTM A-36, unless otherwise noted. Welded courecfions shall conform to the requirements of the latest version of the SAWS "Stmchual Welding Code." Hotted connections for strucnual steel shall be fastened using corrosion resisturt (galvanized or other), high-strength bolts, nuts, urd washers conforming to ASTM A-325. CONCRETE REINFORCING BARS Reinforcement for concrete shall be deformed bars conforming to ASTM A-615, Grade 60 (except for stirtups which shall be Grade 40), urd have deformations in eccordurce with ASTM A-308. 3~ CONCRETE All concrete shall employ a mu designed for a minimum 28-day strength of 4,000 psi, unless otherwise noted. Testing shall be performed by Contractor (slump, air conrMr temperature, end strength) for each 50 cubic yards placed, or portion thereof placed in my one day. Four cylinders shall be prepared for atrrngth testing. Concrete mixing, placement, sad curing shall conform m the most current applicable rAC[ specifications. Concrete shall not be placed in ambient temperatures below 40°F. FIBERCRETE Fibercrete shall employ a mix designed for a m7airtn,m 28-0ay s[rengt6 of 4,000 psi. Testing shall be performed by Contractor (strength) for each 50 cubic yards placed, or portion thereof pLrced in ury one day. Cylinders or cores may be used for strength testing of fiberorete. Fibers maybe steel or plastic and the amount of fibers used shall not be less than 100 pounds per cubic yard of fibercrete. Fiberorete mixing, placement, and curing shall conform to the most current applicable ACI specifications. Fibercrete shall not be placed in ambient temperatures below 40°F, or when the temperature of the 5bercrete application surface is below 50°F. SURVEY CONTROL AND DIMENSIONAL TOLERANCES Survey control monuments will be provided by Owner on Ore surface. The monuments will provide a lineof--sight baseline on the N/S end HRV axis of each slope, with at least three points on each line b provide a check against possible disturburce. The monuments will have benchmarks to provide elevation control. Contractor will protect the monuments against damage, obstroction, and distutburce throughout Ore performance of the contract Once established, the lineof--sight reference points will be used for setting out Contractors baseline at the portal of each slope. Subsequent resetting will only be performed by using the line-of--sight reference points. Ind'vec[ setting out by angular measruemrnt will not be acceptable Contractor shall provide aLeer or urOwner-approved equivalrnt system for establishing urd maintaining excavation neat lines and alignmrnt as required to complete coasturction within Ote specified tolerances. • I Vertical alignment will be tl inch per 1,000 ft along grsde. Horizontal alignment will be f I inch per 1,000 ft along the slope centerline 'ASTM-American Society for Testing Materials where steel sets are used Where steel sets ere not used, sad the nbs and back are rock or shotcrete, neat line clearance from the centerline TAWS-American Welding Society will be maintained as specified in the drawings. Horizontal or vertical deviation over the entire slope length will be not more than 2 inches. 'ACI--American Concrete Lrslitute BLASTING AND OVERBREAK Contractor shall obtain all necessary permits for storage and use of explosives, and shall obtain MSHA, state, end federal approval es required for the planned method of constmction urd the type of equipment purposed for use. Explosives shall be stored, hurdled, urd used is accordance with the best practice in conformurce with federal, state, urd local laws urd regulations. Contractor shall excavate the slopes to neat line and grade. All wderpfound excavation shall be performed in a maurer that will m+n~mi~P overbreak. No rocks or protrosions will be permitted within the neat line as shown on the drawings. Aay deviations from the lines, grades, sad mlerurces shown oa the drawings or required by the specificaioas shall be corrected by the Contractor at no additional cost m Owner. In the event of overbreak, the Contractor shall instatl rock support stmctures such as steel sets, wood blocking, rockbelts, roof trusses, wire mesh, urd fibercrete, as deemed necessary by Owner for the proper urd safe support of the excavation All such additional support structures required due to Contractors negligence shall be et Contractor's expense, except when caused by adverse geologic conditions as agreed upon by Owner. ROCKBOLTS, PLATES, AND NUTS Rackbelts shall be fabricated fiom Grade 60 deformed bar conforming to ASTM Afi15. Rockbolts shall be of the length urd diameter indicated on the drawings. All rockbolts shall be fully grouted with polyester resin; mixing and setting times shall be appropriate for the type of equipment used to install rockbolts. Acceptable rockbolt types are sturdard rebar, I)ywidag, or tensioned rebaz. Minimum yield strength of the rockbolt installation shall be 11,000 pounds. Rockbolt nuts shall be of sufficient strength to withstand loads greater than the yield strength of the roof bolt Steel-bearing plates shall be used on all rock-bolts. Bearing plates shall be the embossed dome type, a minimum size of birch x 6inc6 x '/.-inch thick, sad fabricated from m.aim„m 30,000-pound yield strength steel. Hole diameter shall be sized according m the bolt murufaclare~s recommendations for the rockbolt employed. Washers shall be thoroughly hardened to a hardness of 34 m 45, as measured on the Rockwell C scale. Washers shall conform to the shape of the bearing plate urd be of sufficiwt strength to withstood loads greater thur the yield strength of the rockbelt. 8~ WIRE MESH Wire mesh employed shall be either 4-inch x 4-loch x 10 gage or birch x Mach x 8 gage welded wire fabric. Wrre mesh shell be tightened m the rock surface, in between the primary tockbolt support, using 24-inch (minimum length) split-set stabilizers or other means prior to application of fibercrete, where applicable.