Hanover, Maryland (PRWEB) February 13, 2014
Geotechnical construction contractor Hayward Baker (HB) is the recipient of the Keystone Award from the Associated General Contractors of St. Louis (AGC). The award was presented to HB in the “Specialty Contractor/Subcontractor Project Under $1 Million” category for performing micropile and compaction grouting work on the St. Louis Central Library, a 100-year-old historic structure located in downtown St. Louis, MO.
The award was presented to senior engineer Jeffrey R. Hill, PE, and area manager Gregory A. Terri, PE, of Hayward Baker's St. Louis area office at AGC's 2013 Construction Awards Gala held on November 14, 2013 in downtown St. Louis.
The Keystone Award honors the achievements of St. Louis-area construction firms and their employees in building the facilities that support and enhance the quality of life in Greater St. Louis. Keystone Award recipients display excellence in providing solutions to unique obstacles and challenges specific to their projects. The selection panel for the award consists of leaders in the St. Louis construction and engineering industry. Winners are selected based on the complexity and uniqueness of construction, their solutions to these challenges, the innovative use of manpower and technology, safety, project communications, workforce diversity, the quality of construction, schedule and budget adherence as well as the carbon footprint of the project’s life.
Challenges faced by the St. Louis Central Library
Current fire code requirements mandated renovations to the historic St. Louis Library structure, as did the planned shift from a traditional library to an interactive media center. Due to the historic features of the library, special considerations were required to ensure that activities and vibrations from construction did not disturb the structure.
Prior to construction, asbestos was found, delaying the project start by four months. Despite this, the finish date could not change as the owner planned to re-open the library on the building’s centennial anniversary.
Other challenges that contributed to the project’s difficulty included the unknown geometry and conditions of the existing foundations.
Scope of Work
HB’s innovative use of micropiles and compaction grouting supported new structural loads and prevented damage to the existing building throughout the renovation.
Current fire codes required the demolition of the existing wrought iron book stacks and flooring system. Removal of these structures made way for construction of a state-of-the-art multimedia and community gathering space. High-capacity micropiles were constructed after the demolition of the stacks to support this new space – essentially creating a new building within the existing historic shell.
Settlement of one of the library’s trademarks, the east perimeter stone balustrade, also required attention. Compaction grouting gently lifted and stabilized the balustrade without the need to excavate or connect to the foundation of the balustrade. This technique reduced the risk of further damage to the structure.
The existing grillage foundations were not always defined – and the proposed elevator tower foundations needed to connect seamlessly to them – resulting in a variety of earth retention systems used to safely support the excavation beneath the library for the construction of mechanical suites and new elevators.
A pit of +/-6 feet was required below the planned elevator’s bottom floor that would undermine the grillage foundation, which would result in movement of the existing load bearing walls. Hayward Baker designed a system to underpin the grillage foundation and take the full vertical load of the masonry wall. Shotcrete and soil nails were then utilized to prevent the fill soils from caving into the elevator pit excavation.
Commenting on the project, Jeffrey Hill said, “It was a privilege to work on such a unique and historic structure, and to be part of a transformation of a state-of-the-art media center and gathering place for the citizens of St. Louis.”
For more information on the St. Louis Central Library project in Downtown St. Louis and the ground improvement capabilities and services provided by Hayward Baker, contact Jeffrey Hill at 314-802-2920 or jrhill(at)haywardbaker(dot)com.
About Hayward Baker Inc.
Hayward Baker http://www.haywardbaker.com is North America’s leader in geotechnical construction. Ranked by Engineering News-Record magazine as the #1 Excavation/Foundation Contractor, Hayward Baker is the industry leader in applying ground modification technologies to site improvement and remedial work, with a 60-year record of experience.
A wide range of technologies are employed in providing foundation support and rehabilitation services, as well as settlement control, structural support, site improvement, soil and slope stabilization, underpinning, excavation shoring, earth retention, seismic/liquefaction mitigation, and ground water control. Every service provided by Hayward Baker is designed to be the most effective, cost-efficient solution, based on a proven track record of performance in the field.
Hayward Baker services are provided through a network of more than 20 company-owned offices and equipment yards across the continent, with recent expansion activities adding new offices in Salt Lake City and Toronto.
Hayward Baker Inc. is part of the Keller Group of companies, a multinational organization providing geotechnical construction services throughout the world. Web site address: http://www.keller.co.uk.