Evaluation of Land Subsidence Based on Distributed Monitoring and SEM Analysis
A better understanding on the relationship between macro compression behavior and microstructure of soil is essential in order to evaluate the trend of land subsidence. In this paper, distributed fiber optic sensing (DFOS) technology was applied in a borehole located in Guangming Village, Wuxi, China, to obtain the deformation of soil layers after the prohibition of deep groundwater withdrawal in this area. DFOS provided detailed information on the movement of soil layer within any depth range. The microstructure of undisturbed soil samples from the borehole was analyzed using SEM images. With the application of Particle/Pore and Crack Analysis System (PCAS), the micro porosity of samples were characterized by two statistical parameters called area probability distribution index and fractal dimension. Area probability distribution index described the distributions of micro-porosities and fractal dimension described the shape of pores in nature regardless of complexity. Good correlations between the deformation of soil layers and the two parameters about the microstructure characteristics were illustrated.
KeywordsLand subsidence DFOS SEM Compressibility
Financial support from National Natural Science Foundation of China (No. 41372265, 41230636, 41502274), Natural Science Foundation of Jiangsu Province (No. BK20150389), China Postdoctoral Science Foundation (No. 2015M580414), Open foundation of State Key Laboratory of Geohazard Prevention and Geoenvironmental Protection, Chengdu University of Technology (SKLGP2016K010) was greatly appreciated.
- Hu, J.P.: A study on the land subsidence effect after prohibiting extraction of groundwater in Suzhou- Wuxi-Changzhou area. Ph.D. thesis, Nanjing University (2011)Google Scholar
- Tan, Z., Kong, L., Guo, A., Wan, Z.: Research on effect of compaction on pore size distribution of laterite soil. Rock Soil Mech. 31, 1427–1430 (2010). (in Chinese)Google Scholar