(http://www.accessscience.com.ezproxy2.library.drexel.edu/) Hide Application of microbiology in geotechnical engineering Article by: Chu, Jian Department of Civil, Construction and Environmental Engineering, Iowa State University, Ames, Iowa. Ivanov, Volodymyr School of Civil and Environmental Engineering, Nanyang Technological University, Singapore. He, Jia School of Civil and Environmental Engineering, Nanyang Technological University, Singapore. Last updated: 2013 DOI: https://doiorg.ezproxy2.library.drexel.edu/10.1036/10978542.YB130098 (https://doiorg.ezproxy2.library.drexel.edu/10.1036/1097 8542.YB130098) Content Enhancing shear strength of sand or to make a strong ground Mitigation of soil liquefaction during earthquakes by using biogas Seepage and erosion control or construction of a water pond in a desert Outlook Links to Primary Literature Have you ever wondered how a highrise building can be constructed on soft ground? The answer is that the soft soil can be improved before the construction of the highrise building. In fact, bacteria, can be used to improve the engineering properties of soil. In this article, the application of this microbial approach to geotechnical engineering, a discipline that deals with soils and foundations, is discussed. There are a number of ways to strengthen soft or weak soil. One of the common ones is to use cement or chemicals to increase the loadbearing capacity or the socalled shear strength of the soil. The same process can be used to reduce the water conductivity of soil or the rate of water flow in soil. This is necessary when there is a need to prevent water from flowing in the ground, for example, to cut off the flow of contaminated groundwater. In this case, cement or chemicals are used as binders and mixed with soil to either increase the shear strength or reduce the water conductivity of the soil. However, the use of cement or chemicals for soil improvement is not sustainable in the long run, because cement and chemical production require a considerable amount of natural resource (for example, limestone) and energy. The production process also generates carbon dioxide, dust, and possibly other toxic substances and thus is not environmentally friendly. The use of cement or chemicals for soil improvement is also expensive and timeconsuming. There is an urgent need to develop new and sustainable construction materials that can reduce the need to use cement or chemicals for geotechnical applications. Using the latest microbial biotechnology, a new type of construction material, called biocement, has been developed as an alternative to cement or chemicals. Biocement is made by naturally occurring microorganisms at ambient temperature and thus requires much less energy to produce. It is sustainable, because microorganisms are abundant in nature and can be reproduced easily at low cost. The microorganisms that are suitable for making biocement are nonpathogenic and environmentally .