§ 721S.8. Field Erection

A.

General

1.

Field erection shall be in accordance with the approved shop drawings. Such approval shall not relieve the Contractor of responsibility for the safety or adequacy of methods or equipment, or from carrying out the work in full as indicated. No work shall be done without the approval of the Engineer or designated representative.

2.

Field erection plans for beam units will not be required unless indicated.

3.

Spot welding for the purpose of eliminating field erection bolts or for holding steel parts together while bolting will not be permitted.

4.

The Contractor shall provide falsework and all tools, machinery, and appliances (including drift pins and fit-up bolts) necessary for the expeditious handling of field erection work. Drift pins sufficient to fill at least ¼ of the field holes for main connections shall be provided.

5.

When railroad or roadway traffic must be maintained beneath girders or beams already placed, traffic shall be protected against falling objects during the erection of diaphragms and other structural members, during the placing of cast-in-place concrete, and during the erection and dismantling of forms thereof. The protection shall consist of safety nets of 1 inch (25 mm) mesh maximum or a flooring with openings not larger than 1 inch (25 mm).

B.

Storing, Handling, and Assembling Materials

1.

All material shall be handled in a manner that prevents damage.

2.

Stored material shall be placed on skids above the ground and kept clean and properly drained. Girders and beams shall be placed upright and shored. Long members, such as columns, shall be supported on skids placed closely enough to prevent excessive deflection.

3.

The parts shall be match-marked and assembled accurately as indicated on the approved erection drawings.

4.

Hammering which will injure or distort the members is not allowed.

5.

All bearing and faying surfaces of structural steel in bolted connections shall be cleaned before the connection members are assembled. When ASTM A588 (A588M) steel is used these, surfaces shall receive a Class B blast cleaning conforming to Item No. 722S, "Paint and Painting", prior to assembly of the connection members. The areas of the outside ply under washers, nuts, or bolt heads shall be cleaned prior to installation of the bolts.

6.

Unless erected by the cantilever method, truss spans shall be erected on blocking located so as to provide proper camber. The blocking shall be left in place until the tension chord splices are fully connected and all other truss connections pinned and bolted. Main connections shall have ½ of the holes filled with bolts and erection pins (½ bolts and ½ pins) before swinging the span. Splices and connections carrying traffic during erection shall have ¾ of the holes so filled.

7.

Fit-up bolts shall be of the same nominal diameter as the connection bolts. Erection pins shall be 1/32 inch (1 mm) larger diameter.

8.

There shall be no temporary welds for transportation, erection, or other purposes on main members, except at approved locations more than 1/6 the depth of the web from the flanges of beams and girders, unless otherwise approved by the Engineer or designated representative.

C.

Falsework

1.

Falsework shall be properly designed for the loads to be supported and shall be substantially constructed and properly maintained. The Contractor shall prepare and submit to the Engineer falsework plans, including calculations.

2.

The falsework plans shall include all details of members, connections, equipment, etc., so that a structural check can be made of them.

3.

Approval of the falsework plans does not relieve the Contractor of responsibility/liability for the falsework during field erection.

D.

Welding and Nondestructive Testing

Welding and nondestructive testing shall conform to Item No. 723S, "Structural Welding".

E.

Ancillary Items

All ancillary items such as castings, bearing plates, etc. shall be in accordance with the drawings or as specified elsewhere.

F.

Errors in Shop Work

1.

Any errors in shop work which prevent the proper assembling and fit-up of parats by the moderate use of drift pins or a moderate amount of reaming and slight chipping or cutting shall be reported immediately to the Engineer or designated representative, along with the proposed method(s) of correction.

2.

Corrections of minor misfits and a reasonable amount of reaming will be considered a legitimate part of the work.

3.

Corrections shall be made in the presence of the Engineer or designated representative, unless otherwise directed. Such work is to be done at the entire expense of the Contractor.