Seminar - Viet Nguyen- Land subsidence due to groundwater extraction and its effects on pile foundations

Wednesday, November 22, 2000, 3 - 4 pm
Civil Engineering Lecture Room 3

Abstract

Groundwater is the only source of water to supply to Hanoi City. It began to be exploited by the French in the beginning of this century with a small scale and gradually increased. Until the 1980's, in order to meet the demand of the booming economic development the groundwater extraction has been increased significantly. Consequently, the water levels within the aquifers have reduced to about 20m. In the first of the 1980's the water head initially was 2-5m below the ground surface, but by 1993 it had declined to 15-20m and in 1995-1996 is dropped to 25-30m. As the result, the subsidence of ground surface which reached about 10-30 cm from 1988 to 1993 caused damaging houses, schools and factories in the surrounding water extraction wells areas. This study will concentrates on the calculation of land subsidence due to ground water extraction and that will be compared with the case study data in the Hanoi area and giving the further prediction of land subsidence due to ground water extraction in Hanoi. In addition the effect of ground subsidence on buildings and foundations, especially the behaviour of pile foundation in the adjacent to the pumping wells, will be considered.