Engineering properties of greywacke rockfill and their effect on the dynamic stability analysis of the Chiew Larn Dam | |
| Author | Wijewardena, L. S. S. |
| Call Number | AIT Thesis no. GT-90-28 |
| Subject(s) | Graywacke Chiew Larn Dam |
| 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-90-28 |
| Abstract | With the aim of studying the engineering behavior of crushed rockfill, a series of laboratory testing was conducted using crushed greywacke rockfill, a form of sandstone used in the construction of Chiew Larn Dam in southern Thailand. Isotropically consolidated, drained triaxial tests were done on rockfill samples using the large scale triaxial testing apparatus. Samples were subjected to a range of confining pressures applicable to the dams of moderate heights. In order to study the scaling effects, the gradings of samples were made parallel to the field grading curve. Test results thus obtained revealed that the Mohr-Coulomb failure envelope of rockfill ls markedly curved. A formula is also proposed to evaluate the confining pressure dependent shear strength of greywacke rockfill. The shear strength computed using an empirical formula was a lso found to compare satisfactorily with the test results. The stresses at failure of greywakce rockfill was found to fit very well with the non linear failure criteria for rockfill. Based on this observation, two failure criteria are proposed for greywackey rockfill. In the analytical phase, a homogeneous rockfill slope was analyzed for safety to investigate the validity of using a horizontal inertia force to represent earthquake loading. Using the experimentally determined parameters, dynamic stability of Chiew Larn Dam, a zoned rockfill dam constructed using greywakce rockfill, was studied. A pseudo-static analysis using a horizontal inertia force, and a parametric permanent displacement analysis using the modified modulus approach were performed. The pseudo-static analysis revealed that the critical acceleration at limit equilibrium is much higher than the probable values predicted by the seismologists for the area concerned. The permanent deformation analysis showed that even with a 50% deterioration of the modulus of construction materials due to an earthquake, the maximum vertical and horizontal displacements were 2.796 m and 1.01 5 m, respectively. |
| Year | 1991 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GT-90-28 |
| 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) | Indraratna, Buddhima |
| Examination Committee(s) | Balasubramaniam, A.S. ;Honjo, Yusuke |
| Scholarship Donor(s) | Government of Switzerland ; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1991 |