A Preliminary Analysis on the Seismic Response of Taichung Gravel Formation

• Main Authors: Chih-Ning Hsu, 許植甯
• Other Authors: Shang-Yuh Lin
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/6nu5qy

碩士 === 朝陽科技大學 === 營建工程系碩士班 === 93 === Abstract With the reference to the geological conditions in Taichung areas, its topography was classified as the alluvial gravel formation and main gravel deposit was over 100 m in thickness. Due to the main characteristics of alluvial basin in which weak soil to be deposit easily, it is also apt to easily cause the focus of the refract wave and the formulation and enlarge of the surface wave. When 921 earthquakes, the east-west largest acceleration of the earth''s surface of the Wu-Feng elemental school is up to 0.774g, but there is only 0.367g in the east-west largest acceleration of the earth''s surface of the National Chung-Shing University. The decay phenomenon in gravel is greater than enlarge phenomenon, thus the decay phenomenon becomes important identity when the gravel formation be shaked by earthquake. it has already been a very important thing. This research purpose is to set up a analysis procedure which uses in the seismic response analysis of gravel formation of Taichung; Utilizing the theory of one-dimensional wave transmission (SHAKE 91) and two-dimensional finite difference method (FLAC 4.0 ) to do seismic response analysis, discussing both difference and suitability from these two kinds of numerical software；It’s needed to find out the mainly influence and the secondary influence from discussing the different depth of the base rock、 the different dynamic parameters and static parameters of gravel deposit. In the reference of the practice response design of gravel formation is able to bear seismic in Taichung. This research result shows: (1) FLAC 4.0 software can present the energy absorbing of gravel formation than SHAKE 91 software, and FLAC 4.0 software is more suitable to apply at the seismic response analysis of gravel formation in Taichung. (2) Gravel formation is a formation of hard and short seismic period, and FLAC 4.0 which gets predominant period (0.33 seconds) is more close to the seismic station which gets records (0.47 seconds). (3) When shear modulus values are higher, the result of seismic response analysis is smaller; When damping values are higher, the result of seismic response analysis is smaller. And damping values are more influence than Shear modulus values in the results of seismic response analysis. (4)Li (2001) cyclic simple shear tests get shear modulus and damping curve which get results more close to the records of seismic station. (5)In the static parameters, it is the most influential that is soil cohesiveness c. And there are different soil parameters in the different field location；Therefore, it can''t use soil parameters value of the large range area. (6) The dynamic parameters are greater influence than the static parameters in the seismic response analysis. (7)The analysis procedure which uses in the gravel formation of different field location, its result is also good.