臺灣傳統疊斗式木構造之木柱節點結構行為研究

Structural Behavior of Taiwanese Traditional DiehDou Timber Beam-Column Connection

傳統疊斗式木構架的構件種類多且接合形式多元，其中點金柱與通材的接合性能對整體結構之耐震行為影響最為顯著。為了解柱通接合處通材之貫入深度對接合抗彎矩強度的影響以及在接合處常使用的插角對接合性能的貢獻，本研究以數座足尺寸的柱通接合試體，利用反覆靜態加載的方式測試其耐震性能。試體為長度2.4公尺、直徑30公分的柱，與通材以貫入深度為柱寬一半以及完全貫穿等兩種形式接合，其中貫入深度為柱寬一半之接頭設置插角以模擬真實構架之組構方式，柱子試體施加20千牛頓之軸向載重以模擬屋頂載重的影響。結果顯示柱與通材接合形式、座頭斗以及插角的存在均會影響整體的抗彎矩性能。完全貫穿的柱通接合試體的抗彎強度可達貫入深度一半的試體的兩倍，插角構件在通材受負彎矩時，提供如同角撐的作用，使接頭抗彎強度得到明顯提升。

The structural performance of the Taiwanese Dieh-Dou Jia-Dong timber frame is studied so as to understand the behaviour of the column, beam and Dou region in the global frame. Two main parameters are studied, the penetration depth of the beam member into the column mortise (half- and full-penetrating beam joint) and the absence and presence of a brace-like member, Cha-Jiao. Cyclic horizontal loading test with constant 20 kN vertical force was applied to the China fir specimens. Results shown that moment-resistance of the‘full-penetrating beam’test is around four times greater than the half-penetrating beam case due to its longer moment arm, subsequently causing partial embedment around the upper and lower region of the beam and column mortise edges simultaneously. Due to its bracing effect, the Cha-Jiao member is most effective when under compression (pullin), where a maximum moment resistance of around 2 kN.m was observed during the 1/15 rad test. However, its influence became minimal when subjected to loading in the opposite direction, as it tends to be pulled out from the column mortise during tension. This study suggests that the Cha-Jiao member should be taken into consideration during structural evaluation in future.