On the Influence of the Soil and Groundwater to the Subsidence of Houses in Van Quan, Hanoi

The area of Van Quan, Hanoi before 2004 was the rice field. Nearby, Ha Dinh water plant has  well-drilled underground water for residential activities. Van Quan's new urban area after being formed has detected many subsidences. The objective of this study is to assess the main causes of the subsidence of the houses, based on groundwater and soil. This paper applied the regression method to study the effect of soil and groundwater on the residential constructions in Van Quan urban area, Hanoi. Subsidence monitoring was carried out for 4 consecutive years, from 2005 to 2009, including over 500 subsidence monitoring points with high-precision Ni007 and INVAR gauges. A groundwater observation well is 30 meters deep at the site of the settlement. The results show a small effect of groundwater on subsidence. The characteristics of the young sediment area and the soil consolidation process are the main causes leading to serious subsidence in residential constructions in Van Quan urban area. This paper provides a different perspective on the impact of groundwater on the subsidence of residential structures within approximately 100 ha.