| Author | Chong, Kui-choi |
| Call Number | AIT Thesis no. GT-86-11 |
| Subject(s) | Soil consolidation test--Thailand--Bangkok
|
| Note | A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | This investigation has centered on the performance of screw plate
test (SPLT) to determine undrained and drained deformability and
consolidation characteristics of the soft Bangkok clay in AIT campus. A
series of stress path triaxial consolidation tests were carried out on
good quality samples using loading conditions simulating the in-situ
screw plate tests. Undrained modulus, drained modulus and coefficient of
consolidation obtained in the laboratory tests were compared to the
results obtained from screw plate tests. Ultimate bearing capacity of
the soil from screw plate test derived from the load-deformation
relationship has been investigated and computed using different methods,
namely, Terzaghi ' s method, double tangent method, hyperbolic method and
peak value of the load-deformat ion curve. It was found that the
hyperbolic method is more appropriate for computing ultimate bearing
capacity of the soil. Two alternative approaches are proposed to derive
undrained and drained moduli of t he soil, namely, hyperbolic method and
from the time-deformation relationship measured during the screw p l ate
test. The deformation modulus obtained from hyperbolic were large and
scattered, and the modulus obtained from time-deformation records were
decreased with the increase of applied load.
Asaoka ' s graphical method was used to compute the coefficient of
consolidation from the screw plate test in the field as well as stress
path triaxial consolidation in laboratory, and the Cv values from SPLT
and stress path triaxial consolidation tests were also compared to
standard oedometer tests. The ratio of Cv(SPLT) /Cv (tri) ranges from 20
to 80 in 0 . C. range and ranges from 2 to 40 in N. C. range. These
values agree well with the Cv(field)/Cv(lab) ratio obtained by past
investigations . The pressure-settlement-time relationship of settlement
rate control screw plate test were evaluated. Based on these data, the
deformation-time relationship were predicted and compared to the
measured value at each stress levels. Similarly, the time -pressure deformation relationship from stress path triaxial consolidation tests
were evaluated and compared to the measured axial deformation during the
test . It was found that for both SPLT and stress path triaxial
consolidation tests, the logarithm of time, log t, decreased almost
linearly with t he logarithm of stress level, log p ' . The agreement
between predicted and measured values was satisfactory only of the stress
level less than 0.8 . A predicted settlement of AIT test embankment by
elastic method based on soil parameters obtained from SPLT has been
done, and the settlements agree well with measured values. |
| Year | 1987 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Geotechnical and Transportation Engineering (GT) |
| Chairperson(s) | Bergado, Dennes T. |
| Examination Committee(s) | Towhata, Ikuo ;Chandra, Sarvesh
|
| Scholarship Donor(s) | The Lee Foundation of Singapore |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1987 |