Modern Times: Restoration of 860-880 Lake Shore Drive
The building and garage structure consists of a concrete-encased steel frame and reinforced concrete floor slabs. Glass lobbies from both buildings are set back from the perimeter columns. Having endured more than half a century of harsh Chicago weather, the buildings developed water leakage and severe deterioration that necessitated significant restoration.
Krueck & Sexton Architects retained WJE to provide investigation, technical consulting, and structural engineering design services. WJE investigated the plaza paver system, garage structure, tower facades, lobby storefront walls, interior lobby finishes, and roofing systems. The investigation included visual examination and documentation of distress conditions and as-built details; limited field testing; and laboratory testing.
Inspection of the plaza systems revealed widespread cracking, large areas of ponding water, significant upward displacement, bowing of the lobby storefront walls, and visible corrosion at the base of most building columns. WJE recommended that the existing travertine paving, setting bed, and waterproofing system be completely replaced with a new waterproofing and paving system.
The plaza needed to properly shed water to the perimeter and drain without compromising the original design. Options for the new paving and waterproofing system were severely limited by the shallowness of the original design. Some design approaches were eliminated because of the architectural significance of the site. WJE presented several alternative concepts for the paving system and discussed the longevity and structural performance of each.
The plaza's poor drainage had caused deterioration of the lobby storefront, especially at its base. The bottom structural member was removed and replaced, but most of the storefront's vintage stainless steel cladding was salvaged and reinstalled. To meet the plaza's redesign requirements, the storefront's base detail was revised to accommodate the plaza but closely approximate the original design detail. Throughout the design process, WJE provided conceptual details and peer review of the technical details prepared by the design architect for the plaza and storefront. During construction, WJE assisted with on-site observations for quality control of the plaza paving installation.
For concrete repairs at the plaza structural deck, WJE recommended chipping and removal of delaminated concrete; sandblast cleaning of exposed concrete, structural steel, and reinforcing bars; coating of exposed steel beams and reinforcement with steel cover plates; and restoration of original concrete cross-sections using cast-in-place concrete. WJE served as structural engineer of record for the project and provided site observation and submittal review during the construction phase.
WJE also investigated the towers' steel cladding. The best value, given the owner's budget, proved to be overcoating the steel elements with a compatible paint system, with complete recoating of the facade deferred to coincide with future sealant replacement. WJE also recommended the replacement of existing roofing membrane systems.
WJE's involvement was invaluable to the success of this project. The repairs were recently completed, giving new life to these landmark buildings.
Wiss, Janney, Elstner Associates, Inc. (WJE), is an interdisciplinary firm of architects, structural engineers, and materials scientists that specializes in the investigation, analysis, testing, and design of repairs for historic and contemporary structures. WJE focuses on delivering practical, innovative, and technically sound solutions across all areas of construction technology. Since the firm's founding more than fifty years ago, WJE specialists bring the collective experience gained from conducting more than seventy-five thousand investigations worldwide to every construction challenge. WJE combines state-of-the-art laboratory and testing facilities, nationwide offices, and knowledge sharing systems to provide solutions for the built world. For more information, please visit wje.com.
Return to News Index