secondary arch

rear arch

1. An inner arch of an opening which is smaller in size than the external arch of the opening and may be different in shape.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
C[pounds sterling]Most recently we successfully completed a complex 2,000-tonne Secondary Arch structure, a major component of the 845-meter-long Sheikh Zayed crossing connecting Abu Dhabi Island with the mainland,C[yen] he pointed out.
This assembly would support a secondary arch structure made of steel tubing that holds the polyester shells.
The main entrance is located on Al-Suyufiya Street, a central portal richly decorated with the forms of stalactites flanked by two secondary arches.