ABSTRACT
The MICP mechanism most often discussed in the literature is ureolytic hydrolysis. The schematic process of Microbially Induced Calcite Precipitation (MICP) can be described by Equation 1 and 2. In general, bacterial cell method is used for calcium carbonate precipitation. The widely used bacterium is Sporosarccina pasteurii, which dissociates urea into ammonium and carbonate ions because of its metabolic activity. Several interesting research works have been conducted on the Microbially Induced Calcite Precipitation (MICP) based on the bacterial cell methods (Whiffin et al. 2007; DeJong et al. 2010; De Jong et al. 2013; Anderson et al. 2014). However, bacterial growth in soil or sand is a complicated process due to the growth and the transport of bacteria are only possible in special environments. For many traditional geotechnical laboratories, it’s kind of hard to culture these bacteria; even these bacteria are very common in soil or sand mass. It also has some
1 INTRODUCTION
1.1 Background
There are many earthen archaeological sites along the Silk Road in China. And the wind erosion issue is the main damage type. There are many various techniques to improve the ability of anti-wind erosion of soils in practice, such as chemical reinforcement, chemical grouting, cement and dynamic compaction. Currently, chemical treatment is widely used to improve the ability of anti-wind erosion of soils. Chemical treatments maybe also increase the toxicity of the soil. For the conservation of historical and cultural heritages, it’s becoming more and more difficult to choose suitable reinforcement material to improve the physical and mechanical properties of soils due to the sustainability and eco-environmental considerations. According to the requirements of the State Administration of Culture Heritage of China, it’s not recommended to use materials, which are irreversible to reinforce the culture heritage sites.
