Grouting to Protect Structures and Utilities During Nearby Construction Activities-Video

Video Transcription

Video Summary

The speaker reviews grouting methods used for underpinning, ground improvement, and construction protection, drawing on four case histories. In Vermont, inconsistent permeation grouting led to an alternative system of grout columns and shotcrete to stabilize a building during excavation, with limited movement. In New York City, jet grouting near piled buildings caused grout to spread beneath basement slabs, producing significant heave; work was stopped and replaced with micropiles. Another Manhattan project suffered substantial settlement when underpinning and grouting were inadequately planned and executed. On Pittsburgh’s North Shore Connector, jet and compensation grouting successfully protected utilities and buildings during tunneling.<br /><br />The key lessons are to plan grouting early, match methods to soil conditions and local expertise, and provide contractors with enough information for sound design and costing. Jet grouting requires particular care to control pressure and grout escape. A suitable monitoring program is essential throughout the work.

Keywords

grouting methods

underpinning

jet grouting

ground improvement

construction protection

monitoring program