Amtrak Bridge over the Thames River
Construction of a new railroad bridge lift span was halted when a caisson experienced unexpected settlement. MRCE, in collaboration with Amtrak and the bridge construction team, diagnosed the cause and crafted a unique deep grouting program to place more than 1 million gallons of microfine cement grout to successfully stop the movement. The MRCE design used deep tube-a-manchette pipes to control grout placement, and real-time computer monitoring to control grout injection. Confirmation borings demonstrated successful permeation of the microfine cement grout and compressive strengths from 500 to 1500 psi. This inventive approach stabilized the existing foundation, extending its life and supporting the new lift bridge.