Shear, tensile, and flexural strength characteristics of stiffened cement-admixed clay in laboratory | |
| Author | Jare Chiaolian |
| Call Number | AIT Thesis no.GE-08-11 |
| Subject(s) | Clay--Thailand--Bangkok Shear stength of soils--Testing Concrete piling--Testing |
| Note | A thesis submitted in partial fulfillment of requirements for the degree of Master of Engineering in Geotechnical and Geoen vironmental Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. GE-08-11 |
| Abstract | The stiffened cement-admixed clay defined as the cement-admixed clay reinforced with concrete core pile is a new type of soft ground improvement. This technique is utilized in order to increase bearing capacity and stiffness of cement-admixed clay. This study presents the results of the experimental investigations in the laboratory on cement-admixed clay and stiffened cement-admixed clay for stiffened deep cement mixing pile (SDCM pile). Two factors, namely: cement content (Aw) and area ratio of concrete core pile over SDCM pile, Acore/ASDCM, were systematically varied and considered their effects on SDCM pile. Furthermore, 20 finite element simulation was performed to back-analyze the results by comparing with the laboratory test results. From the unconfined compression test and direct shear test of cement-admixed clay with remolding water content at its liquid limit for optimum strength, the optimum cement content by weight was found to be 15%. Based upon the results of flexural strength test, the empirical relationships were obtained for the flexural strength, Ot = 0.16qu and the splitting tensile strength, Ot = 0.23qu as well as the relation of flexural strength and tensile strength of cement-admixed clay, Of = 0.73 Ot. The results of shear strength test on SDCM pile shows that ratio of area between concrete core pile and SDCM pile, Acore/ASDCM, significantly affected on the unconfined compressive strength, qu, development of stiffened cement-admixed clay. The results also indicated that the influence of cement content is meaningful on qu of DCM pile but it had lower effects than the area ratio, Acore/ASDCM. Moreover, the numerical analysis using PLAXIS 2-D confirmed the corresponding results observed from the laboratory tests. The laboratory investigations of the interface shear strength between concrete core and cement-admixed clay showed that the strength reduction factor, Rinter, calculated from the ratio of the interface shear strength and cohesion of cement-admixed clay obtained from the direct shear tests varied from 0.38 to 0.50 for cement contents of 10% to 20%. Similarly, the observed result obtained from pullout interface tests varied from 0.39 to 0.51 |
| Year | 2009 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GE-08-11 |
| 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) | Dennes T. Bergado; |
| Examination Committee(s) | Noppadol Phienwej;Pham Huy Giao; |
| Scholarship Donor(s) | Thailand (HM King); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2009 |