A jet grout stabilized excavation beneath an existing building

A new single basement was constructed as part of a building refurbishment project in Singapore. The excavation was carried out within the tight confines of the existing building. The sides and bottom of the excavation were stabilized by jet grout columns installed using the triple-tube technique. The excavation was carried out without shoring. The installation of the jet grouting works and subsequent excavation was monitored by geotechnical instruments. This paper presents the monitoring data obtained and discusses the influence of the jet grouting and construction activities on the surrounding ground and structures.