Strength Improvement of Bangkok soft clay backfilled in a lake with vacuum PVD technique | |
| Author | Piyavat Ngernbumrung |
| Call Number | AIT Thesis no.GE-18-13 |
| Subject(s) | Vacuum technology Soil mechanics--Thailand--Bangkok Clay--Thailand--Bangkok |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Geotechnical and Earth Resources Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | This study presents the studies about the increasing of the undrained shear strength resulted from the vacuum consolidation method and some prediction by applied theoretical and empirical equation proposed by Ladd and Foot (1974), Mesri (2011), and Stamatopoulos and Koitioz (1985). Data used in this study come from the ground improvement site, which uses the vacuum consolidation method to reclaim the pond. For the undrained shear strength (Su) after improvement, it was found that the improvement of the soil properties was achieved throughout the PVD length. Comparisons between Su before and after improvement are at depth 3.00-6.00 Su increased 300%, and at depth 6.00-10.00 Su increased 190% and at a depth of 10.00- 18.00 Su increased 170%. Moreover, the correlation between original water content and increasing of Su was founded, for soil with the original water content in range of 30-60% undrained shear strength increases 90%, wn in range of 60-80% Su increases 250%, and soil that has water content about 80-112% Su increases 320%. For the prediction part, by using SHANSEP concept with Su measured by unconfined compression test (UC) and maximum past pressure measured by odeometer test. S and m parameters that fit with Su (UC) are 0.41 and 1.12. Mesri 2011 proposed the equation to predict the increasing of Su after subjected to VCM. Form the study, Su from Mesri equation match well with Su(UC) in the shallow depth and deeper depth, but at the middle depth, Su (Mesri) were under-predicted. From the theoretical equation proposed by Stamatopoulos and Koitioz (1985). Su predicted from this equation was under-predicted about 0.7 to 8.2 times compared with Su(UC). In this study also including CPTu investigation. By using equation proposed by Baligh et al. 1980 to estimate Su from CPT data. From the study, the cone factor of 26.22 was match very well with Su (UC). |
| 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) | Chao, Kuo-Chieh; |
| Examination Committee(s) | Pham Huy Giao;Suttisak Soralump; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2019 |