Installation of Geotechnical Instruments for Finite Element Analysis of an Old ​​​Reservoir: A Case Study of Klong Tha-ngiew Reservior, Trang

Abstract

This paper presents the stability analysis of Tha-ngiw Reservoir, located in Trang. It began by investigating the data obtained from the geotechnical instruments installed, including piezometers, observation wells, and standard rain gauges. Then, it was used to analyse its behaviour using the finite element method via Plaxis. The model was created by referring to the drawings and the actual dimensions in the field at current conditions. After that, the water level was varied between the lowest and highest. The results showed that the reservoir is still intact when the water level was the highest. When the water level was the lowest because of rapid decrease of water level,settlements and deformations occur at the front of the reservoir. These were quite useful for that they can be employed in order to prevent the damage of old reservoirs. In addition, the results could be used in the design of a new reservoir so that the rapid change of water level would not trigger the damage.