Undrained shear strength characteristics of soft Bangkok clay by recompression triaxial tests | |
| Author | Ahamad, Mohiuddin |
| Call Number | AIT Thesis no.GE-96-08 |
| Subject(s) | Shear strength of soils--Testing Clay--Thailand--Bangkok--Testing |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. GE-96-08 |
| Abstract | The thesis presented here in contains the result of a study on undrained shear strength characteristics of Bangkok soft clay by Recompression Triaxial Test. The study was canied out on the undisturbed samples collected from the site of Bangkok -Chonburi Highway (Contract section 2-Nl and 2-N2). This study includes determination of undrained shear strength through performing 31 K0 consolidated Triaxial tests and comparison of those with the results obtained from unconfined tests, tested under different stress and drainage boundary conditions. The results of Unconfined tests were obtained from Highways Department of Thailand. • The findings of the study are as follows: • The coefficiant of earth pressure at rest K0 was found in the range between 0.70±0.02. This value of Ko as evaluated through the principle of no lateral strain during the consolidation is higher than the values estimated through emperical equation. • Undrained shear strength obtained by Recompression Triaxial test are higher than the values obtained from Unconfined tests. The increase in undrained strength due to K0 consolidation is approximated by the relation of S11 (CKoUC) = 1.4 S11 (UC) for normally consolidated clay. • Undrained strength as evaluated from CK0UC were also compared with Field Vane test results after necessry correction. In that case, the undrained strength from CK0UC tests were found 1.12 times higher than the Field Vane results. However, the values obtained from Recompression Triaxial and Field Vane tests were found in close proximity and the results are compareable. • Undrained Stress Strain modulus was estimated from Stress strain relation for both CKoUC and Unconfined test. The modulus estimated at 50% of the failure stress for both the tests were found in good agreement. However, the modulus evaluated through CK0UC stress strain curves were a little bit higher as compared with the results from Unconfined tests. • The undrained Shear strength and pore pressure were normalized with the effective vertical consolidation pressure and were plotted against the axial strain. However, no unique relation was found. The reason mainly attributed to the light overconsolidation effects, presence of weathered crust and non-homogenity of the soil specimen. The sample disturbance during sampling, handling and testing could also be one of the good reason for the non-compliance of the normalization concept. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; vno. GE-96-08 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Balasubramaniam, A. S. ;Tian Ho Seah (Co-Chairperson); |
| Examination Committee(s) | Shibuya, S.; |
| Scholarship Donor(s) | Asian Institute of Technology Partial; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology |