Identification of Expansive Soils as Weathering Product of Volcanic Materials in Jatinangor Area, West Java, Indonesia Riyan Rizki Fauzi, R. Irvan Sophian, Dicky Muslim, Hendarmawan, and Iyan Haryanto Abstract Jatinangor had been decided as a new location of several campuses such as Unpad, ITB, IKOPIN, and IPDN. This has the implication of development of many infrastructures to support the educational activities. To avoid the occurrence of problematic soils such as a infrastructural damage and landslide phenomena, it is necessary to identify the expansive soils as the basement of buildings and any infrastructures. The research method includes geological mapping, petrographic analysis, engineering geologic mapping, undisturbed soil sampling, mineralogical analysis and physical properties analysis. The result of this study shows that the study area is divided into four soil units due to the USCS (Unified Soil Classification System) and shows low—very high swelling potential, activity ranges from 0.34 to 1.36 and composed kaolinite, chlorite, and montmorillonite clay minerals. Keywords Clay minerals Á Expansive soils Á Swelling Á Volcanic Á Weathering 1 Introduction Jatinangor is one of the districts in Sumedang Regency, West Java Province, Indonesia. This area was decided to be a new location of several campuses such as Unpad (Universitas Padjadjaran), ITB (Institut Teknologi Ban- dung), IKOPIN (Institut Koperasi Indonesia), and IPDN (Institut Pemerintahan Dalam Negeri). This has meant increasing the numbers of population due to the relocation of students, of ficers, lecturers, etc. So far, more than 500,000 students and 98,000 local people reside this area. It also implied the development of many infrastructures to support the educational activities targeted to be completed in 2025 (Anonymous 2013). Thus, the rate of urban growth is equivalent to the rate of infrastructure and land use growth in this region. Jatinangor is a region which is dominantly made up of Quaternary volcanic deposits (Frini 2016). Soils as weathering product of volcanic deposits are often the result of the expandable clay minerals such as montmorillonite, illite, and chlorite (Nicols 2009). It is also caused the problematic soils especially the highly water sensitive ones (expansive soils). A great infrastructure damage arose from the expandable soil characteristics. This included damage of foundation structure buildings and serious cracking of some infrastructures. Moreover, expansive soils may also induce the landslide phenomenon which often killed many lives and damaged the infrastructure. Referring to the above enlight- enment, it is very essential to identify the expansive soils in Jatinangor area. The results of this study were expected to be a reference in accordance of planning and development of the future. R. R. Fauzi (&) Á R. I. Sophian Á D. Muslim Laboratory of Engineering Geology, Universitas Padjadjaran, Bandung, Indonesia e-mail: riyan12003@mail.unpad.ac.id Hendarmawan Laboratory of Hydrogeology and Environmental Geology, Universitas Padjadjaran, Bandung, Indonesia e-mail: hendarmawan@unpad.ac.id I. Haryanto Laboratory of Geodinamic, Universitas Padjadjaran, Bandung, Indonesia e-mail: iyanharyanto4141@gmail.com © Springer International Publishing AG 2018 A. Kallel et al. (eds.), Recent Advances in Environmental Science from the Euro-Mediterranean and Surrounding Regions, Advances in Science, Technology & Innovation, https://doi.org/10.1007/978-3-319-70548-4_530 1829