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Exhibit A- Supplement 1 <br /> Task 00300 Reports <br /> Geotechnical Investigation <br /> Update Soil Geotechnical Report(SGR)for LRFD <br /> Original scope of work included review of the SGR report prepared in Phase I and update with the latest IDOT <br /> Geotechnical Manual. The report needed to be updated for the Seismic parameters and the driven H-pile <br /> lengths to conform to the latest guidelines. This original scope included using the previously prepared Soil <br /> Geotechnical Reports (SGR) for the proposed structures prepared with the Phase I design as the basis for <br /> the update. It was assumed that the Seismic Zone 1 basis in the Phase I report would not change when <br /> updating to the new LRFD requirements. During the update process additional work was required for <br /> Seismic Zone 2 analysis and settlement issues for RR concern with the alignment shifted closer to the IC <br /> RR. Additional clay consolidation calculation were requested by structural designers based on the new soil <br /> boring data. An additional text section to the SGR on temporary soil retention systems was added at the <br /> request of structural designers.The timing of the soil boring field work due to weather and preparation of <br /> the TS&Ls for submittal to the Bridge office to keep the project on schedule did not coincide. Some extra <br /> effort was used to prepare a Draft SGR for submittal with the TS&Ls in early February and the Draft SGR <br /> was later finalized when the soil borings and lab work were complete. Also, an analysis of the soldier pile <br /> cut wall on the south end of BCR was added to the report. Additional hours are presented for SGR work. <br /> Drainage Memorandum <br /> During preparation of the Drainage Memorandum it was determined that the existing storm sewer system <br /> along East Harrison east leg is undersized. This section of storm sewer was not within the current project <br /> limits. It was determined that an update to this section of storm sewer would be beneficial to the project and <br /> to include this work in the project. WHKS has been assigned the drainage design and memorandum work <br /> and will add this section of storm sewer. Additional cost by WHKS are presented for Drainage Design work <br /> under the Drainage Modeling,Analysis and Study-Proposed. <br /> Task 00400 Phase II Design-Plans Special Provisions and Estimates <br /> Roadway Design(only item 5,6,and 14 from original scope shown here for additional scope discussion) <br /> 5. Establish final roadway geometry at"tie-in"points at ends of project.Additional 340 feet length of <br /> roadway and tie in work was added to southern limit on Brush College Road. <br /> 6. Revise Phase I profiles to match beginning and ending points of the project.Additional 340 feet <br /> length of roadway and tie in work was added to southern limit on Brush College Road. <br /> 14. Additional reconstruction is required on East Harrison east leg for the added storm sewer <br /> improvements. Additional plan preparation and quantity work is necessary for removal and <br /> proposed roadway repair work. <br /> Additional work is required for the ADM dirt pile that did not exist in Phase I. Coordination with WHKS on <br /> options that may require barrier walls to stay inside of approved ROW. Coordination with IDOT will be <br /> required to extend limits to remove the existing dirt pile possibly with a temporary easement with ADM to <br /> eliminate the need for the barrier walls. <br /> Additional hours are presented for Phase II Roadway Design work. <br /> Structural Design <br /> The overpass structure will be designed in accordance with the latest AASHTO LRFD Bridge Design <br /> Specifications,the Illinois Department of Transportation(IDOT)Bridge Manual,and the Norfolk Southern <br /> Public Projects Manual. <br /> Additional Scope 08-21-20 ExA SI-3 <br />