| Author | Nguyen Anh Duc |
| Call Number | AIT Thesis no. GE-98-01 |
| Subject(s) | Subsidences (Earth movements)--Thailand--Bangkok
|
| Note | A thesis submitted in partial fulfillment of the requirement for the Degree of Master of
Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Intensive pumping of groundwater has caused more than 6, 160 Ian2 of land to
subside in the Bangkok area. Locally, groundwater level declined as much as 30m
between 1981 to 1998 and the maximum subsidence was about 88mm by 1984. The
subsidence occurred first in Central Bangkok and spread out to the East, to the South and
to the Southeast. The magnitude and rate of subsidence are directly related to the change
in groundwater level. Slight rebound of the land surface has been observed in some areas.
The average. rate of subsidence varied from an average of about 15-50 mm/year from
1978 to 1986, to about 10-35 mm/year from 1986 to 1997. During the 19-year period
from 1978 to 1997, the average volume loss due to subsidence was roughly approximated
as about 19% of the average groundwater discharge. Subsidence was due to compression
of aquifer system as well as compression of clay layers. Land subsidence in the Bangkok
area is mostly caused by compression of soil layers in upper 150 m zone (80-100% of
total land subsidence), where most of the groundwater is extracted. In the most subsiding
area, about 50 to 70% of the compression occurs in the zone below the first sand layer
(about 30m depth downward) and 50 to 30% of the compression occurs in the upper layer
(or Bangkok Clay). Outside the most subsiding area, Bangkok Clay contributes the major
part into the total land subsidence. The compression of Bangkok Stiff Clay is very small
compared to that of soft clay. The empirical prediction shows that in Central Bangkok the
subsidence is expected as 40 to more than 120 mm in the next 22 years from 1998 to
2020. |
| Year | 1999 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Noppadol Phienwej; |
| Examination Committee(s) | Bergado, Dennes T.;Otsu, Hiroyasu;Tian Ho Seah; |
| Scholarship Donor(s) | Swedish International Development Agency (SIDA); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |