Use of Jet Grouting in Retrofitting of a RMG Factory Building in Chittagong, Bangladesh

In April 2013, a deadly collapse of a ready-made garment (RMG) building occurred in Bangladesh which caused instant death of 1,134 and injury to more than 2500 people. RMG in Bangladesh faces challenges to ensure workplace safety for the millions of garment workers. The recent structural assessment of the existing 3,500 RMG factory buildings identified that approximately 700 factories needed to be urgently retrofitted. In this paper, the methodology to retrofit a 4-storied RMG building in Chittagong was described in detail. The existing foundation of the building was inadequate, jet grouting together with bored piles were used to improve the foundation condition. The paper also describes the design, construction and performance of the jet grouting process. Soil modeling, settlement of the mat foundation under super structural loads and static pile load test for JGC (jet grouted column) is discussed. The choice of jet grouting as a soil and foundation improvement solution and its advantages are pointed out. In application of jet grouting, type of treatment, application procedure and operational parameters are also discussed.