Biocementation of sand filled geotextile tubes

• Main Author: Yong, Hoi Zett
• Other Authors: Chu Jian
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Civil engineering
• Online Access: http://hdl.handle.net/10356/77366
• Institution: Nanyang Technological University

Due to climate changes, construction of coastline structures such as dikes and breakwaters have become more and more important. There is an urgent need to develop methods to build coastal structures in a cheaper and more sustainable way. The use of geotextile tubes is one of the most important development in coastal engineering in recent years. Nonetheless, the strength and durability of geotextile tubes that filled with sand or clay slurry still need to be improved. In this project, some model tests were carried out to investigate the feasibility to apply biocementation through a Microbially Induced Calcite Precipitation (MICP) process to strengthen the sand inside geotextile tube. For comparison, model tests using sand treated with cement was also carried out. The confinement effect by soil when geotextile tubes are buried underground was also studied in this project. This study reveals that biocementation can be used to improve the properties of sandy materials such as its compressive strength and permeability. The calcite crystals that produced from the reaction of bacteria and cementitious solution are able to bind the aggregates and reduce the pores and thus reduce its water conductivity. The biocement treated sands also has a higher compressive strength compared with these treated sands using than Ordinary Portland cement treated.