Deformation analysis and settlement prediction of Bangna-Bangpakong highway (section I) | |
| Author | Udomrerk Parnploy |
| Call Number | AIT Thesis no.GT-84-40 |
| Subject(s) | Settlement of structures Bangna-Bangpakong Highway |
| 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 |
| Abstract | The stress-path method gives the best prediction of the undrained movement if the result was added by primary consolidation settlement in weathered crust zone. At station 2+890 It. Frontage Road, the total settlement (30% from undrained movement and 70% from consolidation settlement) estimated by Skemption & Bjerrum ('u' parameter based on Lee 1983)'s and by Asaoka's method gave reasonable predicted values, as did stress-path method, although these estimation are believed to be on the conservatives side. Settlement characteristics of the Bangna-Bangpakong (section I) at sta. 2+899, for which COX(1981) had reported the settlement-time curve over 10 years (1968-1980), including subsidence, were analysed by different methods. The Asaoka's method with field CV value by La casse et al (1975) gave the best prediction. This portion has now been upgraded from 0.72 (MSL) to 2.9 (MSL). The magnitude and the rate of settlement of this reconstruction (preloaded) embankment were also predicted by skemption & Bjerrum's model and two dimensional consolidation theory developed by Lacasse(1975). At station 2+900 It. Main highway, the post construction settlement and rate of settlement are still high, although it had been preloaded from 1968 until the reconstruction time. The reason for this is thought to be due to the effect of deep well pumping in that area. Although deep well pumping cause most of the foundation soil to be in a normally consolidated state, it, however causes drainage pattern in multi-direction and hence increases rate of consolidation. The critical stresses and field pore pressure parameters are evaluated by the observation of excess pore pressure in the field (at station 2+940 Frontage Road). TAVENAS (1979)'s method and 3-D elasticity approach considering the concept of local yielding and critical stress has been following and reasonable good agreements with the measured values were found before critical height was constructed. Stability analysis of failure section (station 2+940; Frontage Road) with the shear strength from corrected Field Vane for total stress analysis and 0=33 ํ & c'/vm' = 0.05 at (01/3) max for effective stress analysis yielded a safety factor near to unity. The relationship of drained and undrained modulus (E'/Eu) varies from 0.25 to 0.5 for soft clay and was about 0.15 to 0.2 for very soft clay with yielding & undrained creep. The Eu/Sv (vane) value was about 253 for weathered clay and 131 for for soft clay. From the deformation analysis, Cv (field) of Frontage Road (795 cm2/day) by fitting Lacasse et al (1975)'s curve is approximately to be 82 times of Cv(lab.) In 1969, the Cv(field) value of Main Highway (1456 cm2/day) was about 25 times of Cv(lab.) |
| Year | 1985 |
| 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) | Balasubramaniam, A.S. |
| Examination Committee(s) | Sambhandharaksa, S. ;Chandra, Sarvesh |
| Scholarship Donor(s) | The Royal Netherlands Government |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1985 |