Final Design Requirements.docx

BRIDGE DESIGN REQUIREMENTS:

PREFABRICATED BY-PASS BRIDGE

PROVIDE 60’ LONG BY 16’ ROADWAY STEEL MODULAR BRIDGE.

DESIGN LOADS

LIVE LOAD: HL93 (LRFD)

DESIGN SPECIFICATIONS

DESIGN BRIDGE SUPERSTRUCTURE IN ACCORDANCE WITH THE CURRENT EDITION OF AASHTO LRFD BRIDGE DESIGN SPECIFICATIONS AND THE ABOVE-STATED DESIGN LOADS.

PROVIDE CALCULATIONS, INCLUDING A LOAD RATING FOR THE PROPOSED SUPERSTRUCTURE, ONLY. LOAD RATE STRUCTURE IN ACCORDANCE WITH THE “MANUAL FOR BRIDGE EVALUATION,” CURRENT EDITION WITH INTERIMS, USING LRFR METHODOLOGY (CH. 6A). RATE FOR THE FOLLOWING VEHICLES AND CONFIGURATIONS USING THE DESIGNATED LOAD MODIFICATION FACTORS: HL-93 (VEHICLE + LANE OR TANDEM AXLES + LANE); TYPE 3, TYPE 3S2, AND TYPE 3-3; SPECIAL HAUL VEHICLES SU4 THROUGH SU7; EMERGENCY VEHICLE CONFIGURATIONS EV2 ANDEV3; AND OREGON SPECIAL PERMIT LOADS, OR STP-3, 4A, 4B. RATE THE HL-93 FOR INVENTORY AND OPERATING, AND RATE ALL OTHER VEHICLES FOR THE SAFE OPERATING CAPACITY, INCLUDING IMPACT.

SUBMIT DESIGN CALCULATIONS AND SHOP DRAWINGS TO THE ENGINEER FOR APPROVAL AT LEAST 3 WEEKS PRIOR TO FABRICATION.

FURNISH GALVANIZED STEEL SHEET PILE BULKHEAD.

PRECAST CONCRETE SILL

PROVIDE PRECAST CONCRETE SILL AS BEARING SURFACE USING STATED BEARING CAPACITY. PRECAST CONCRETE TO BE MANUFACTURED BY PCI OR NPCA CERTIFIED PLANT, OR FABRICATOR WITH AN EQUIVALENT QUALITY CONTROL PROCESS. SUBMIT SHOP DRAWINGS AND CALCULATIONS FOR APPROVAL AT LEAST 3 WEEKS PRIOR TO FABRICATION.

PRELIMINARY SOIL INVESTIGATION

THE SUBSURFACE INVESTIGATION WAS CONDUCTED AUGUST 9-10, 2009. THE GEOTECH REPORT INDICATES A SOIL BEARING CAPACITY OF 5.1 TSF USING A SAFETY FACTOR OF 3.

HARDWARE AND STRUCTURAL STEEL

FURNISH ALL STEEL SHAPES, PLATES, AND BARS IN CONFORMANCE WITH AASHTO M270 GRADE 36 (ASTM A36), AND ALL BOLTS AND NUTS IN CONFORMANCE WITH ASTM A307 EXCEPT AS NOTED.

ELASTOMERIC BEARING PADS

DESIGN AND FURNISH PLAIN ELASTOMERIC BEARING PADS 1" THICK, 60 DUROMETER, LOW TEMPERATURE, ZONE D, IN CONFORMANCE WITH AASHTO M251.

BRIDGE RAIL SYSTEM

FURNISH A BARRIER SYSTEM ON THE BRIDGE, DOUBLE THICK 12 GA. WEATHERING W-BEAM TYPICAL WITH REFLECTOR TABS (2-SIDED CRYSTAL) AT ALTERNATE POSTS. MOUNT RAIL POSTS WITH TOP HEIGHT 18” ABOVE RUNNING SURFACE.

DESIGN BARRIER SYSTEM TO TEST LEVEL 1 (TL-1) 13.5K STATIC LOAD (AASHTO LRFD BRIDGE DESIGN SPECIFICATIONS, 7th EDITION WITH INTERIMS, TABLE A13.2-1). THE RAIL SYSTEM IS OWNER DESIGNATED, IS NOT REQUIRED TO MEET GEOMETRIC REQUIREMENTS OF LRFD, AND IS NOT REQUIRED TO BE CRASH-TESTED, THOUGH IT SHOULD BE A CONFIGURATION THAT RE-DIRECTS TRAFFIC IF IMPACTED.

DIMENSIONS

ALL LONGITUDINAL DIMENSIONS FOR THE STRUCTURE ARE MEASURED HORIZONTALLY AND INCLUDE NO CORRECTION FOR GRADE. REINFORCING STEEL SPLICE LENGTHS SHALL BE IN ACCORDANCE WITH ACI 315 AND AASHTO SPECIFICATIONS.

DECKING

PROVIDE STEEL CORRUGATED DECKING. NO ADDITIONAL WEARING SURFACE REQUIRED.