Jacking Tilted Building by Automatic Multiple Grouting

A tilted eight-story reinforced concrete building with one-story basement on a thick soft clay deposit is leveled with a special two-stage grouting program. The first grouting stage conducted by injecting mild setting grout through sleeved pipe is used to stabilize soft soil zone in depth. As soon as the foundation soil is hard enough to act as a reaction block, the second stage of grouting is conducted in which quick setting grout is injected right under mat foundation to jack and level the building. The grouting duration at each grouting tube and grouting order of each cycle monitored by a central processing computer is scheduled each day based on the elevation surveying results. The elevated volume of mat foundation due to grouting and resettled volume from excessive pore water pressure dissipations are estimated from the elevation surveying results. This can be used to evaluate the grouting efficiency and verify the building being successfully and permanently leveled.