Biogrouting for prevention of seepage due to excavation (JTC Sponsored Project)
Lim, Yinn Wey
Date of Issue2016
School of Civil and Environmental Engineering
There are a lot of sand treatment methods where properties of sand are enhanced. This study uses biocementation method to treat the sand in order to decrease the seepage effect and permeability of water. The common problem found in sheet piling is the seepage effect during the excavation. Biocementation method is used to minimise the seepage effect in sheet piling method. Biocementation involves Microbial-Induced Calcium Carbonate Precipitation (MICP) reaction where calcium carbonate is precipitated and used to fill up the sand pores so that the water permeability and seepage effect could be reduced. This method is also environment friendly as no heavy metals are involved but microorganism, Urease-producing Bacteria (UPB) is used in MICP reaction to increase the rate of hydrolysis of urea. The seepage effect of the sheet pile model had been reduced up to 96.1% by biocementation method. The average water permeability of samples also reduces up to 88.1%. Biocementation reduced the permeability of samples regardless of normal UPB or centrifuged UPB is used in the treatment. The strength of sand is also enhanced by biocementation.
Final Year Project (FYP)
Nanyang Technological University