HBM-IL171

Description of Work

HBM Engineering Group, LLC prepared bridge type, size and location plans (TS&L), structural geotechnical report (SGR), Phase II contract plans, specifications, and cost estimates,(PS&E), estimated time of construction, permitting and engineering support services for the bridge replacement and approach roadway reconstruction of IL Rte. 171 (Archer Avenue) bridge over Long Run Creek in Will and Cook Counties.

Descriptionof Bridge

The existing 2-span bridge (26’-10 ½”) with back to back of abutment length of 58’ and width of 47’ was constructed with pre-stressed concrete box beams (SN 099-0080). The existing bridge will be replaced with a new 3-span bridge with back to back of abutment length of 246’-3 ¾” and width of 83’-2”. The new bridge will be constructed with cast-in-place concrete deck on precast pre-stressed concrete beams supported on steel H-pile integral abutments and piers structures. (SN 099-0537) The new structure design was based on 2012 AASHTO LRFD Bridge Design Specification, 6th Addition for HL-93 lane loading, IDOTABD Memorandum 12.3, and the most current additions of IDOT’s Bridge and Hydraulics Manuals. The design provided for cofferdam type 2 for construction of pier 1, earth retention system and temporary sheet pile for staged construction of the bridge and roadway.

Description of Scope of Work

HBM designed or supervised the preparation of reconstruction plan specification and estimates for 2,144.55’ of roadway at a new profile approximately 6’ higher than the existing roadway profile at some locations. Existingtopographic survey was verified and updated, horizontal and vertical controlwas established. Plans were prepared for typical sections, alignment and ties, detail pavement jointing and ADA sidewalk elevations, pavement markings, erosion control, landscaping, utility and drainage, and cross sections. Drainage design included analysis and design for storm sewers, ditches and compensatory storage. Geopak was utilized for roadway design and cross section preparation.

HBM provided for Traffic Control and Protection plans for staged construction. A multi-stage traffic control plan utilizing temporary sheet pile walls and temporary pavement was used to maintain IL Rte. 171 thru traffic throughout the construction period. A detour route was provided for alternative access to IL Rte 171 for local 135th Street traffic. Coordination with IDOT detour committee was provided.

The HBM design team prepared Traffic Signal plans for reconstruction of one existing intersection and one new intersection. Traffic signal interconnect plans were provided to link three signalized intersections.The project included permanent and temporary impacts to wetlands and WOUS. The HBM team prepared permits and environmental documentation including Storm Water Pollution Prevention Plan, Application for Section 404 Permit Authorization and Illinois Department of Natural Resource documentation. The construction estimate of cost was 7.8 million dollars.