台灣既有典型加強磚造中小學校舍常見高型磚牆，此類磚牆由於採光通風或留設出入口之需求而形成於開口部旁，雖然多為三邊圍束或雙側開口而形成兩邊圍束，且高寬比多大於1，仍可提供相當程度的側向強度，但其強度評估與分析方式卻少有研究。因此本文以側推試驗探討加強磚造高型磚牆之耐震行為，並以試驗結果與既有分析模型比對驗證。
本文以4座加強磚造高型磚牆試體進行側向加載試驗，為探討軸力大小及邊界束制條件之影響，其中2座為無邊界柱之試體且分別加載不同大小軸壓力，另2座則為加載相同軸壓力之單側邊界柱試體及兩片磚牆夾中央柱試體。
試驗結果顯示兩座無邊界柱之高型磚牆中，加載軸力較大者，其極限強度較大，且強度與軸力約呈線性關係，軸力與側力之比值約等於試體之高寬比。邊界柱會影響試體之破壞模式及側向強度，無邊界柱試體發生撓曲破壞，發生剛體旋轉行為且韌性較佳，以拱機制抵抗側力。有邊界柱試體發生剪力破壞，韌性及側向變位皆較小，試驗中，柱表面皆可見均勻分布之水平拉力裂縫，顯示柱的作用類似拉力構件，而磚牆的作用相當於壓桿，與柱一起以壓拉桿機制抵抗側力。雖然單側邊界柱試體及兩片磚牆夾中央柱試體皆發生剪力破壞，但兩者在破壞前之行為並不相同，前者牆體未發揮韌性，且磚牆達剪力破壞時，邊界柱尚未破壞，使其並未一次喪失所有側向承載力；後者在試驗初期，呈現若干撓曲與韌性行為，而中央邊界柱與磚牆同時達到剪力破壞，使其達到極限強度後隨即喪失側向承載力。
試驗結果與既有評估公式比對顯示，FEMA 356對無側邊圍束磚牆之剛度公式高估試驗結果，但在判斷破壞模式及評估理論極限強度方面很準確。具有邊界柱試體之極限強度可用陳奕信分析模型，採不分配軸壓力至牆體之計算方式評估，以保守估計磚牆之極限強度，亦可以FEMA 356對有邊界柱磚牆之剪力強度公式評估，但其結果更保守，且破壞模式與試驗觀測結果不同。

This study aims at the seismic behaviour of the slender confined masonry (CM) panels restrained either at two or three sides, which were very common in the low-rise school buildings in Taiwan, because of the requirement of openings. However, there are very few analysis and evaluation models for their capacity under earthquake load. In this paper, therefore, experiments were performed to study the behaviours of slender CM panels under lateral loading and the results were used to verify the existing analytical models.
Four specimens were tested, and two parameters of the vertical force as well as the conditions of the boundary restraint, were considered in this paper. The first two specimens were identical piers without tie columns at both sides but with varying vertical compression forces. The third and fourth specimens were with the same vertical force with the second, but differed in the boundary condition. One tie column had been built in the side and in the middle of the third and the forth specimen, respectively.
Testing results showed that the strengths of the pier specimens increased with the vertical force. Moreover, the ratio of the lateral force to the vertical force was a constant and it consisted with the slenderness ratio of the specimen. The conditions of boundary restraint affected the strengths as well as the failure modes of the specimens. The pier specimens exhibited rocking behaviours and flexural failure modes, resisting the lateral force by the arch mechanism during the test. The specimens with tie columns were found to show shear failure modes, resulting in a higher strength but less ductility. Moreover, the horizontal tension cracks were found in the columns, revealing that the column and the panel acted as the tensile and the compressing elements, respectively, forming a strut-and-tie system to resist the lateral force during the test. It showed difference behaviour between the third and the fourth specimen before collapse. For the third specimen, the side restraining column stayed undamaged while the shear failure occurred at the panel, leading to the system remained lateral-force resistant. For the fourth one, the flexural and ductile behaviour revealed at the beginning of the test. As the test went on, the system collapsed right after reaching the ultimate strength, for the shear failure simultaneously occurred at the column and the panel.
Comparing the testing results and the prestandard for the masonry piers in FEMA 356, it showed that the analytical stiffness overestimates the testing ones. However, the failure mode and the estimated strength could be determined accurately. For the strength of specimens with tie columns, it could be estimated by the Chen analytical model without considering the vertical compression for the conservative evaluation. If the FEMA 356 model is used, it showed the even more conservative results and the failure modes were also different from the test.

1.Drysdale, R. G., Hamid, A. A., and Baker, L. R., Masonry Structures: Behavior and Design, Prentice-Hall. Inc., Englewood Cliffs, 1994.

2.黃國彰，『有邊界柱樑之磚牆耐震試驗與等值牆版分析』，碩士論文，國立成功大學建築研究所，台南，1995。

3.林正偉，『有邊界柱樑之磚牆耐震試驗與等值桁架分析』，碩士論文，國立成功大學建築研究所，台南，1995。

4.張文德，『磚牆及含磚牆RC構架之耐震試驗分析與應用』，博士論文，國立成功大學建築研究所，台南，1997。

5.Federal Emergency Management Agency (FEMA), Prestandard and Commentary for the Seismic Rehabilitation of Buildings (FEMA 356), FEMA, USA, 2000.

6.陳奕信，『含磚牆RC建築結構之耐震診斷』，博士論文，國立成功大學建築研究所，台南，2003。

7.ElGawady, M. A., Lestuzzi, P., and Baboux, M., “In-Plane Seismic Response of URM Walls Upgraded with FRP,” Journal of Composites for Construction, ASCE, vol. 9, pp. 524-535, 2005.

8.ElGawady, M.A., Lestuzzi, P., and Baboux, M., “Shear Strength of URM Walls retrofitted Using FRP,” Engineering Structures, vol. 28, no. 12, pp. 1658-1670, 2006.

9.Abrams, D., Smith, T., and Lynch, J., “ Effectiveness of Rehabilitation on Seismic Behavior of Masonry Piers,” Journal of Structural Engineering, ASCE, vol. 133, no. 1, pp. 32-43, 2007.

10.薛凱元，『RC構架內填高型磚牆面內受力行為』，碩士論文，國立成功大學建築研究所，台南，2008。

11.Kuang, J. S. and Wong, H. F., “Improving Ductility of Non-seismically Designed RC Columns,” Proceedings of the Institution of Civil Engineers: Structures and Buildings, vol. 158, pp. 13-20, 2005.

12.莊宗樺，『RC構架內填磚牆面外振動台試驗分析』，碩士論文，國立成功大學建築研究所，台南，2007。

13.ACI Committee 318, Building Code Requirements for Structural Concrete (ACI 318-08) and Commentary (ACI 318R-08), American Concrete Institute, Farmington Hill, 2008.

14.ASTM, “Standard Test Method for Compressive Strength of Masonry Prisms,” Masonry Test Methods and Specifications for the Building Industry, ASTM-C1314-07, Philadelphia, 2007.