Title: High Performance Concrete to Plug the Flooding of the Chicago Tunnels

Author(s): J. Moreno and G. Detwiler

Publication: Symposium Paper

Volume: 140

Issue:

Appears on pages(s): 215-226

Keywords: caissons; cracking (fracturing); failure; flood control; heat of hydration; high performance concretes; mix proportioning; performance; piles; strength; temperature; thermocouples; tremie concrete; tunnels; underwater construction; Materials Research

DOI: 10.14359/3911

Date: 9/1/1993

Abstract:
On April 13, 1992, the engineer of the Merchandise Mart, one of Chicago's downtown buildings, reported flooding of the building basement. A few hours later flooding was found to be related to an eddy observed at the Chicago River. The flooding was occurring through a system of service tunnels built at the beginning of the century and abandoned in the late 1940s. The failure of the tunnel was caused by wood pilings installed at the end of 1991 to protect the bridge abutment in the Chicago River. The flooding of these tunnels affected more than 100 downtown Chicago businesses, which had to be evacuated for several weeks. The repair of the tunnel was conducted in two stages using high-performance concrete (HPC). First, an interim plug was placed using a high-performance, underwater concrete. The severe environment caused by the current in the tunnel required concrete to be highly fluid, have anti-washout properties, set quickly, and gain strength rapidly Second, a permanent plug was placed using HPC concrete designed to reduce heat of hydration and minimize potential for thermal cracking. Actual temperature of the permanent plug was monitored by thermocouples and compared to a computer-generated model. The use of this system to predict performance of special concretes allowed the concrete supplier to start a new generation of high-performance concretes.