Construction of Chicago's Initial System of Subways
V. E. Gunlock
Appears on pages(s):
The construction of subways in Chicago by tunneling methods has been a moot question for many years. Proof that this can be accomplished now exists. These subways have been constructed bv tunnelina methods thrbug h Chicago’s underlying ‘stratum of soft blue clay. The paper describes the two methods used in the subway tunnel construction, mentions some of the special problems encountered, describes methods of placing the concrete, and explains-the control exercised to insure sound concrete in the finished structure.