Effects of high water content on the undrained shear strength of Bangkok clay treated with cement using CIU triaxial test | |
| Author | Ning, Zhang Gao |
| Call Number | AIT Thesis no.GE-02-10 |
| Subject(s) | Shear strength of soils Soil consolidation test |
| 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-02-10 |
| Abstract | In this study, a total of 33 CIU triaxial tests have been conducted to investigate the undrained strength behavior of the base clay and cement treated Bangkok soft clay at higher water content. The remolding water content (w*) varies from 100%, 130%, to 160%, and the water content to cement content ratio (cw/Aw) ranged from 5 to 20. The cement content (Aw), vary from 5% to 22%. The results demonstrated that cement treatment modify the soft Bangkok clay from normally consolidated to overconsolidated state. The degree of overconsolidation is influenced by the cement content, the preconsolidation pressures and the water content. Generally, the higher cement content, the lower preconsolidation pressure and the lower water content (near the LL); the higher the degree of overconsolidation and the more brittle behavior. On the other hand, the lower cement content, the higher preconsolidation pressure and the higher water content (more than LL); the lower the degree of overconsolidation and more ductile behavior. At higher cement content (Aw2::10%), the preconsoliadtion pressures from 50 to 200kPa have no effect on the stress-strain characteristic of cement treated clay because the mean yield stress is much more higher than the preconsolidation pressures. At the same cw/ Aw ratio, the strength of the treated soil is not the same. Moreover, the water content has bigger effect than cement content on the undrained strength of cement treated clay, especially for cement content equal to or greater than 10%. For any ratio cw/Aw such that the cement content, Aw2::10%, the strength behavior is governed by the mixing water content; the closer the mixing water content to liquid limit, the higher the strength developed for certain ratio cw/Aw. For any ratio cw/Aw, such that the cement content Aw<10%, the strength behavior is governed by the cement content; and the higher the Aw, the higher the strength developed for certain value of cw/Aw. Furthermore, there is an optimum clay water content, which is found close to the Liquid Limit of the base clay, that the treated soft Bangkok clay can get the highest strength at particular cement content. For remolding water content varying from 100%, 130% and 160%, the corresponding minimum optimum cement content are 10%, 15% and 20%, respectively, for cement treated clay. The failure criterion of samples with cement content of Aw2:: 10% is bulging failure and eventually the samples split associated with shear failure. In contrast, the failure criterion of the samples with cement content of Aw<10% is the shear failure with distinct failure plane. Finally, an empirical strength development equation is proposed for the Bangkok treated clay with cement content (Aw2::10%). |
| Year | 2003 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GE-02-10 |
| 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) | Bergado, D.T.; |
| Examination Committee(s) | Takemura, Jiro;Glawe, Ulrich ; |
| Scholarship Donor(s) | AIT Partial Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2003 |