HBM_AECOM-ISHTA Segmental Post-Tensioned Box Girder
Veterans Memorial Tollway (I-355)
Design Section Engineering Services
Illinois State Toll Highway AuthorityContact: Mr. Greg Stukel, PE
Project Contact (Prime)
AECOMContact: Matt Pregmon, PE, SE
March 2009 –October 2010
Moussa A. Issa, Ph.D. PE, SEProject Manager(708)236-0900
Key Team Members
Mahmoud A. Issa, Rating Engineer John Saraceno, Structural Engineer
EN, SE and SW Segmental Box Girder Ramps
The purpose of this analysis/rating study was to establish a procedure for the load rating of the EN, SE and SW segmental single box girder ramps. The rating was performed by the development of3-dimensional finite element models (longitudinal and transverse) and the use of EXCEL/MathCAD spreadsheets to calculate the inventory and operating ratings. The finite element models and spreadsheets will be used by ISTHA to rate the structure for permit trucks prior to issuance of permits. Rating calculations were performed according to the AASHTO LRFD Bridge Design Specifications, 4th Edition with 2008 and 2009 interims. The results of this study are presented in two parts:
1.Superstructure: Finite Element Analyses were performed using SAP2000. Three-dimensional models were generated to reflect the true geometry, stiffness and loads on the superstructure. Layout lines, i.e. reference lines, were utilized to define the horizontal and vertical alignment of the flyover bridge. An influence-based enveloping analysis was used to determine the effects of vehicular live loads for HL93 loading and this same enveloping analysis was then used to obtain force effects for all permit loads. Post-tension tendons accurately reflected the vertical and horizontal layout, tendon start and end locations, properties, loss parameters and jacking forces. SAP2000 results (moments, shears and stresses) were used as input to an EXCEL file to rate the subject box girders. Therating was performed at critical locations (longitudinal and transverse) and at each joint between box segments.
2.Substructure (Ramp EN -Piers 3, 4 and 6; Ramp SE –Piers 1 and 13): Reactions from the SAP2000 models were extracted and utilized for the purpose of rating and analysis of the piers. The ratings of Ramp EN Piers 4 and 6 were limited to the caps (at mid span for maximum positive moment and at face of pier columns for maximum shear). Ramp EN Pier 3, and Ramp SE Piers 1 and 13, ratings were performed at critical sections.
15 Feet to 50 Feet Cantilever Sign Structures
The scope of work for this task included complete design calculations and revised standard drawings for the cantilever overhead sign structures and their foundations according to the 2009 AASTHO Standard Specifications for Structural Supports for Highway Signs, Luminaries, and Traffic Signals, 5th Edition.
Phase II Roadway Resurfacing from I-55 to Army Trail Road, Phase I
HBM provided design and CADD support as required for the development of plans, quantities, and specifications. According to the Rating done in Project No. RR-05-9851 deficiencies in HL-93 Inventory and Operating Ratings (Ratings less than Unity) were noted. Areas with Operating ratings less than 1 were increased to values greater than 1.00 through rehabilitation utilizing Carbon Fiber Reinforced Polymer (CFRP).