Cook County, Chicago, Illinois, FAU Route No. 3730
ChicagoDepartment of Transportation
Project Contact (Prime)
H.W. Lochner, Inc.Rick Cholewa, P.E., S.E.Senior Project Manager(312) 994-9714
Key Team Members
Moussa A. Issa, Project Manager Mahmoud A. Issa, Project Engineer Joseph Glennon, was the Project Manager while he was with LOCHNER John Saraceno, Structural Staff Engineer
Description of Project
The HBM scope of improvements included the Phase II analysis; design; structural final plans; special provisions, quantity calculations, specifications, and Quality Assurance / Quality Control (QA/QC) for the south and north abutments, wingwalls, cofferdams, south and north Conspan precast arches. The HBM team’s responsibilities included preparation of TS&L plans; cost estimates; plan development outlines; structure reports; analysis; design; structural final plans; special provisions and quantities.
Main Span Bridge (Tied Arch Bridge):
Existing bridge superstructure was removed and replaced with new structure. Existing substructure was strengthened and reused for the approach spans. New reinforced concrete abutments on steel piles were built in canalto support the main span. The length of the proposed bridge is 156’-8” back to back of abutments with no skew. The proposed superstructure is a simply supported tied arch bridge with 10” deep structural deck slab. The bridge seismic performance category (SPC) is A. The horizontal alignment is straight.
South and North Conspan Pedestrian Tunnels:
The portion of the existing abutments interfering with the Conspan prestressed foundation mat were removed. Concrete Counterweights remained in their pits. The existing and remaining portions of abutments were extended to cover the area between the wingwalls. The Conspan prestressed foundation mat was dowelled and supported on the top of the remaining abutments and their extensions.
All wingwalls were designed as Cantilever Retaining Wall with footing supported on Steel H-Piles.
A temporary cofferdam system was installed at both North and South Abutments. The cofferdam height was designed according to Estimated Water Surface Elevation (EWSE) which was used to evaluate the need for underwater structure excavation protection.