| Author | Supavat Kongpanickul |
| Call Number | AIT Thesis no.GE-18-08 |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in
Geotechnical and Earth Resource Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The general engineering behavior of fine-grained soil in track design that overlays on the soft soil have been interested and many researchers have done the experimental, analytical and modeling analyses. The one of the most important conclusion is the soft soil under cyclic loading exhibits the lower shear strength than its shear strength under static loading condition. Currently, the mega project called “Bangkok-Nakhon Ratchasima High Speed Rail Way Project” are constructing from Bang Sue station, Bangkok to Nakhon Ratchasima. Some of the sections in this project located in the Ayutthaya province southward to Bangkok which commonly consists of the soft soil called Bangkok soft clay at the shallow depth. In this study, the reduction of shear strength of Bangkok clay under cyclic loading was investigated as well as the plastic settlement behavior of soft soil and its prediction. The experimental work was carried out the laboratory investigation by using cyclic triaxial tests with the loading frequency of 2 Hz and 4 Hz which respected to the current design of the high-speed railway in Thailand. The saturated normally-consolidated and lightly over-consolidated clays were used to investigate the behavior of soft Bangkok clay under cyclic loading. The effect of load frequency, deviator stress level, and stress history of soil were investigated in this study. The results of this study show that for the dynamic compression test, the shear strength of soil could reduce up to 20% of the shear strength obtained from monotonic compression test. Therefore, the progressive shear strength under the cyclic loading can be lower than its monotonic strength for soil samples with the same confining pressure and consolidation pressure. The plastic settlement behavior of Bangkok soft clay is power functional of soil type and number of applied loading. Li & Selig (1996) utilized fitting parameters a, b, and m in their power model to predict cumulative plastic strain. The average values of parameters a, b, and m obtained from the testing conducted for the Bangkok soft clay are 1.9, 0.12, and 2.46, respectively. |
| Year | 2019 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Kuo-Chieh Chao; |
| Examination Committee(s) | Pham Huy GiaoTian Ho Seah; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2019 |