| Author | Shahrizaila, Zaidi Bin |
| Call Number | AIT Thesis no.GT-91-06 |
| Subject(s) | Vertical drains
|
| 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. GT-91-06 |
| Abstract | Soil improvement techniques using prefabricated vertica l band drains are currently very much in u se. Conso lidation of the soil in especially soft c l ay soi l is accelerated through the us e of prefabricated drains which enable a faster rate of horizontal flow of water through the s oil . A wid e range of prefabricated drains are avai l able in the market , each h aving their respective properties. Thi s s tudy is aimed t o evaluate the performance of vertical band drains us ing three different laboratory mode l tests, namely; The Small Scale , Medium Scale and Large Scale Mode l s. Using Bangkok soils , each mode l wa s u sed to mea s ure settlement again st time with and without the installation of vertical drain. At the same time the related factors affecting the rate of consolidation were also observed s u ch as deformation, s iltation and smear. Results obtained were analysed ·to derive t h e coefficients of consoli - d at ion, fi lte r criteria and t h e s mear zone effect which were then compared to values obtained from earlier researchers. The p erformance of prefabricated band drains i s influen ced by t h e magnitude of the lateral pressure, the rigidity and the geometrica l stru cture of the core ma t er i a l. The stiffness of the filter jacket i s important for better bridging s upport against high l ateral pressure, thereby, maintaining its disc h arge capacities. In the case of Ch a nd the prediction of the final settlement, t h e values obta ined from the l aboratory test were fair l y cons istent with those using the method of ASAOKA (1 978 ) . The laboratory test results also confirmed earlier work done by HANSBO (1978) a nd BERGADO et al (1 991) where the s mear zone effect , is in the order of 1 to 2. The ratio of horizonta l permeability in the undisturbed zon e to that in the s meared zone was about 1.3 to 3. For the filter criteria, the ratio of o90;d85 was establis hed to be l ess than 3, whilst for o50 ;d50 it was l ess than 24, whereby, "On" corresponding to "n" percent size for filter materia l and "d" corresponding to particle di ameter as determine d by sieve a nalys i s for soil. |
| Year | 1991 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GT-91-06 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical and Transportation Engineering (GT) |
| Chairperson(s) | Bergado, D.T.; |
| Examination Committee(s) | Seah, T.H.;Balasubramaniam, A.S.;Honjo, Y.; |
| Scholarship Donor(s) | The Government of Switzerland.; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology |