Shape factors and pore pressure equalization of piezometers | |
| Author | Jerasak Premchitt |
| Call Number | AIT Thesis no. 908 |
| Subject(s) | Soil permeability Piezometer |
| Note | A Thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok , Thailand. |
| Publisher | Asian Institute of Technology |
| Abstract | This research was concerned with the factors which govern the response of field piezometer systems, in as far as they have not been completely explained hitherto. The investigation was divided into two sections, namely: (1) Determination of accurate shape factors for a range of field piezometers. (2) Study of the equalization process in soil-piezometer systems. Shape factors were determined using a liquid electric analogue and a finite difference technique. The effects of boundary conditions and boundary proximity were first determined before \'infinite\' shape factors were established. The results of these measurements agreed well with some of the reliable results from past investigations, and the values obtained during the investigation described herein are thought to be the most accurate ever published. In order to study the process of pore pressure equalization, a computerized finite difference model was established to represent the consolidation process within a soil mass subjected to a stress increment. It was found that this gave exactly the same numerical results as the closed-form theoretical solution of GIBSON (1963) which predicts the response characteristics of piezometer systems in compressible soils. In order to verify the theoretical results experimentally, two spherical piezometers were tested in a large cylindrical clay specimen subjected to isotropic stress increments. The experimental results supported the theoretical conclusions absolutely. This work led to the establishment of an "equalization chart" for the interpretation of the response characteristics of soil-piezometer systems. Preliminary field tests showed that this provides a means for measuring the in-situ coefficients of permeability and consolidation of soils, but that further development is needed to perfect the method. |
| Year | 1975 |
| Type | Thesis |
| School | Student Research Before 1980 |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Thesis (Year <=1979) |
| Chairperson(s) | Brand, E.W. |
| Examination Committee(s) | Exell, Robert H.B. ;Brand, J. M. ; Brenner, R.P. ;Balasubramaniam, A.S. |
| Scholarship Donor(s) | Shell International Co., |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1975 |