Seismic Response of Geosynthetic Reinforced Soil Retaining Structures Using FEM Program PLAXIS

• Main Authors: Jia-Cin Liu, 劉家欽
• Other Authors: Sao-Jeng Chao
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/44196798832185582733

碩士 === 國立宜蘭大學 === 土木工程學系碩士班 === 98 === Geosynthetic reinforced soil retaining structures (GRSRS) take over the role of the traditional retaining walls gradually and become the mainstream of the retaining structures because of the advantages of easy construction, being able to bear large differential settlement, seismic resistance ability, etc. A great number of GRSRS in Taiwan have been used to improve the slope stability. However, during the 921 Chi-Chi Earthquake, many buildings and structures, including a few GRSRS, have been destroyed. Therefore, the seismic response of the GRSRS turns out to be a significant research topic and needs more advanced study in detail. This research makes use of the PLAXIS finite element program to simulate the mechanical response of the GRSRS under both static condition and dynamic condition. Specifically speaking, the elastic deformations of the structures are analyzed under static condition first. Following that, the seismic responses of the structures are simulated comprehensively with considering earthquake acceleration records. The main purpose of this research is to predict the dynamic behavior of the GRSRS under earthquakes to understand the acceleration variations, the deformations, and the tensile force distribution of the reinforcement layers. This research simulates the seismic responses of subsurface soil layers, non-reinforced and reinforced soil retaining walls, and non-reinforced and reinforced soil embankment under the dynamic conditions. Furthermore, seismic data of Taiwan earthquakes happened in the recent years, such as 921 earthquake and 331 earthquake, are employed by taking them as the input data files for the seismic analysis of the 4 major projects of the GRSRS built in Ilan County, Taiwan. The numerical simulations focus on the acceleration variations and the predictions for the tensile forces of the reinforcements under various earthquake scales. This research observed that the tensile forces of the reinforcement layers under an earthquake bear greater values than those in static condition. On the process of analyzing the 4 major projects of the GRSRS built in Ilan County under the different scales of the earthquakes, it is found that the acceleration variations, the deformations, and the tensile force distribution of the reinforcement layers are not the same on a regular basis. As a result, it is recommended that the seismic numerical simulation needs to be carried out for each different project during the design analysis in order to guarantee the accuracy of the overall stability of the GRSRS.