assembling shall be only such as to bring the parts into position and not sufficient to enlarge the holes or distort the metal.
615.5.2 -Welded Connections: Surfaces and edges to be welded shall be smooth, uniform, clean and free of defects which would adversely affect the quality of the weld. Edge preparation shall be done in accordance with ANSI/AASHTO/AWS Bridge Welding Code D1.5.
615.5.3 -Preassembly of Field Connections: 615.5.3.1 -General: Field connections of main members of trusses, arches, continuous beams, plate girders, bents, towers and rigid frames shall be preassembles prior to erection to verify the geometry of the completed structure of un it and to verify or prepare field splices. Attaining accurate geometry is the responsibility of the Contractor and they shall propose and appropriate method of preassembly and submit the plan to the Engineer. The method and details of preassembly shall b e consistent with the erection procedure shown on the erection plans and camber diagrams prepared by the Contractor and submitted to the Engineer. Receipt of plans, drawings and calculations does not constitute review or approval or relieve the contractor of their responsibility to satisfactorily design the erection plan. As a minimum, the preassembly procedure shall consist of assembling three contiguous panels accurately adjusted for line and camber. Successive assemblies shall consist of at least on e section or panel of the previous assembly (repositioned if necessary and adequately pinned to assure accurate alignment) plus two or more sections or panels added at the advancing end. In the case of structures longer than 150 feet, each assembly shall be not less than 150 feet long regardless of the length of individual continuous panels or sections. At the option of the fabricator, sequence of assembly may start from any location in the structure and proceed in one or both directions so long as the pr eceding requirements are satisfied.
615.5.3.2 -Bolted Connections: For bolted connections, holes shall be prepared as outlined in Section 615.4.8. Where specified by the contract documents, major components shall be assembled with milled ends of compression members in full bearing and then shall have their subsized holes reamed to the specified size while the connections are assembled.
615.5.3.3 -Check Assembly -Numerically Controlled Drilling: When the Contractor elects to use numerically controlled dr illing, a check assembly shall be required for each major structural type, unless otherwise designated on the plans or in the special provisions, and shall consist of at least three contiguous shop sections or, in a truss, all members in at least three con tiguous panels but not less than the number of panels associated with three contiguous chord lengths (i.e., length between field splices). Check assemblies should be based on the proposed order of erection, joints in bearing, special complex points, and similar considerations. Special points could be the portals of skewed trusses, for example. More than one check assembly may be required by the Engineer. The check assemblies shall include the first sections of each major structural type to be fabricated and additional assemblies as required by the Engineer. Shop assemblies other than the check assemblies will not be required.
449 If the check assembly fails in some specific manner to demonstrate that the required accuracy is being obtained, further check a ssemblies may be required by the Engineer for which there shall be no additional cost to the Division.
615.5.3.4 -Field Welded Connections: For field welded connections the fit of members including the proper space between abutting surfaces shall be prepared and verified with the segment preassembled in accordance with Section 615.5.3.1.
615.5.3.5 -Assembly Verification: Each assembly, inc luding camber, alignment, accuracy of holes, and fit of milled or field welded joints, shall be approved by the Engineer before reaming or drilling is commenced or before an N/C drilled check assembly or field welded assembly is dismantled.
615.5.4 -Matc h Marking: Connecting parts preassembled in the shop to assure proper fit in the field shall be match -marked, and a diagram showing such marks shall be furnished to the Engineer.
615.5.5 -Connections Using Unfinished, Turned or Ribbed Bolts: 615.5.5.1 -General: When unfinished bolts are specified, the bolts shall be unfinished, turned, or ribbed bolts, conforming to the requirements of Grade A Bolts of the Specification for Low -Carbon Steel Externally and Internally Threaded Standard Fasteners , ASTM A307. Bolts shall have single self -locking nuts or double nuts unless otherwise shown on the plans or in the Special Provisions. Beveled washers shall be used where bearing faces have a slope of more than 1:20 with respect to a plane normal to the bolt axis. The requirements of this Section do not pertain to the use of high -strength bolts. Bolted connections using high -strength bolts shall conform to Section 615.5.6.
615.5.5.2 -Turned Bolts: The surface of the body of turned bolts shall meet th e ANSI roughness rating value of 125. Heads and nuts shall be hexagonal with standard dimensions for bolts of the nominal size specified or the next larger nominal size. Diameter of threads shall be equal to the body of the bolt or the nominal diameter o f the bolt specified. Holes for turned bolts shall be carefully reamed with bolts furnished to provide for a tight driving fit. Threads shall be entirely outside of the holes. A washer shall be provided under the nut.
615.5.5.3 -Ribbed Bolts: The body of ribbed bolts shall be of an approved form with continuous longitudinal ribs. The diameter of the body measured on a circle through the points of the ribs shall be 5/64 inch greater than the nominal diameter specified for the bolts. Ribbed bolts shall be furnished with round heads conforming to ANSI B 18.5 unless otherwise specified. Nuts shall be hexagonal, either recessed or with a washer of suitable thickness. Ribbed bolts shall make a driving fit with the holes. The hardness of the ribs shall be such that the ribs do not mash down enough to permit the bolts to turn in the holes during tightening. If for any reason the bolt twists before drawing tight, the hole shall be carefully reamed and an oversized bolt used as a replacement.