Out-of-plane Behavior and Evaluation of Masonry Historic Buildings

• Main Authors: Fu-KaiHu, 胡復凱
• Other Authors: Ja-Shian Chang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/33158030261532071619

碩士 === 國立成功大學 === 建築學系碩博士班 === 99 === Past earthquakes in Taiwan have shown the collapse of masonry historic buildings to be associated with out-of-plane damage of the masonry walls. The main purpose of this study is to study the out-of-plane behavior of masonry walls through experiments. The effect of pilasters, openings and different loading conditions on the strength and damage mode of masonry walls will be analyzed. Based on the experimental results, a method for assessing the horizontal load resistance of masonry walls will be developed. Eight specimens are constructed for testing and analysis. The dimensions of the eight specimens are identical (383cm×133cm×11cm), each with an opening measuring 49cm×78cm. The experiments take the span, type and position of openings and loading modes as parameters. During each test, the load-deformation relationships, ultimate loads and damage modes will be recorded and analyzed. According to the experiment: 1.The out-of-plane damage behaviors of walls without pilasters are as follows: minor cracking at the middle of the top part of the wall, after which the wall reaches ultimate loading, signaled by further cracking of the top part into an A-shape split. Horizontal cracks develop at the bottom of the wall. 2.For specimens with a single pilaster, the load capacity is increased by 5%, whereas in the case of specimens with double pilasters, the pilasters serve to help increase the load capacity by 26%. 3.Specimens with window openings show a reduction of wall strengths ranging from 49%~35%. The damage behavior is vastly different from that of walls without openings. The width of the masonry wall between adjacent openings is the main factor influencing the wall strength. 4.An uniformly distributed load is applied to walls with single and double pilasters. Results indicate an increase in the ultimate load capacity of specimens by 41-43% relative to specimens with double concentrated load. Using the Yield Line Theory for Slabs and experimental results, a method for assessing the out-of-plane endurance of masonry walls is constructed. The subject of assessment, namely the masonry historic buildings, is restricted by the following constraints- the ratio of distance between the pilasters to the total wall length must lie within 0.33~1, and the ratio of the total length of the opening to the total wall length must be between 0 and 1. Furthermore, results from an assessment of the Er-Shui Railway Station Garage D reveal the lateral endurance of walls in both directions to be higher than the out-of-plane force imposed upon them in the event of the September 21 Chi-Chi earthquake. This finding explains the very little damage caused to the garage by the Chi-Chi earthquake.