Removal of disturbed zone around prefabricated vertical drain (PVD) using thermal method | |
| Author | Nyo Mar Than |
| Call Number | AIT Thesis no.GE-05-05 |
| Subject(s) | Vertical drains Soil mechanics |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ;no. GE-05-05 |
| Abstract | This study was directed to investigate the development of the consolidation rate in the disturbed zone around PVD due to heat. Laboratory testing programs were conducted on undisturbed and reconstituted sample in both small and large consolidometer with heater and thermal controller. Two types of heaters used in this study. The heater drain made of copper tube is used for all tests except large consolidometer and flexible wire heater is used for large consolidometer. The tests were performed under temperatures of 90°C with thermal-mechanical paths for all tests and thermal paths for large consolidometer. Specimens demonstrated volume contraction upon heat and without heat. This. contraction is dependent on temperature magnitude. When the specimen is heated, the magnitude of settlements is higher and rate of consolidation is faster. In the results, the settlement is not so high but the benefit is to accelerate the rate of consolidation. Due to the low value of thermal conductivity of soft Bangkok clay, the temperature profile shows steep reduction of temperature transmission within limited zone around the heat source. Shear strengths increase with increasing temperatures and decreasing of water contents. The preconsolidation pressure of specimen increased with increasing temperature after heating and cooling cycle because the induced contractions reduce the void ratios and water contents of the specimens. After treatment using PVD combined without heat and with heat for undisturbed specimens the Ch values obtained were to 3.45m²/yr and 3.83m²/yr, respectively, from 3.2m²/yr before treatment. The Kh/Ks ratios were 3 for the specimen without heat and 2 for the specimen with heat. Similarly, in reconstituted specimens without heat and with heat, the Ch values were obtained 2.1m²/yr and 2.5m²/yr with Kh/Ks ratios of 1.75 and 1.5, respectively. |
| Year | 2005 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GE-05-05 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Bergado, Dennes T.; |
| Examination Committee(s) | Noppadol Phien-wej;Pham Huy Giao ; |
| Scholarship Donor(s) | Royal Thai Government Fellowship ; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2005 |