Land Subsidence in Joshimath, Uttarakhand Based on the Field Observations
摘要
The recent damage of buildings and large cracks in the Joshimath hills due to land subsidence encouraged the need for geotechnical investigation and monitoring of the slopes. Due to the lack of availability of flat ground, buildings are often constructed on the hill. The movement of the hill slope under gravitational load, may be accelerated by the building loads. Further, other factors associated with land subsidence may aggravate shallow slope failures or landslides. Therefore, the factors associated with land subsidence are discussed from the field observation and the localized ground deformation in terms of cracks presented in this paper. Based on field observations, the site Joshimath is made of mostly sand and gravel/boulder mixtures. The size of the boulders is too large, but the distribution is random. The cavities in between the gravels may also contribute to the slope movement. The heavy rain, snowfall and poor drainage condition may be the reason for the formation of such cavities. The most vulnerable area within the Joshimath is identified based on damage of the buildings as well as visible cracks in the ground. Further, the possible factors associated with land subsidence are discussed. This study also suggests the research gap in the field of land subsidence.