超音波法應用於臺灣傳統大木構件非破壞檢測適用性之研究

THE STUDY ON THE APPLICABILITY OF NON-DESTRUCTIVE TESTING ON THE WOODEN STRUCTURAL COMPONENTS OF TRADITIONAL HISTORIC BUILDINGS IN TAIWAN BY USING ULTRASONIC TESTING

古蹟修復的過程中，大木構件損壞程度的判斷是否準確不僅影響古蹟結構安全，也往往成為保存爭議的焦點。近年來國內已應用超音波法進行傳統建築大木構件之非破壞檢測，然此法受限於儀器的特性與受檢測構件性質的影響，如僅以波速高低來判別大木構件之損壞，仍無法滿足實際評估所需。本文即以超音波法針對不同的新舊料，透過各種檢測方式來釐清其問題所在。研究之結果顯示，超音波縱向量測可有限度地適用於大木構件新料的擇用，然難以應用於落架或未落架大木構件舊料損壞之研判；超音波徑向量測，則可能因不同的量測方式及構件表面之彩畫、補土、批麻捉灰而影響量測結果，如僅以波速評估舊料的損壞程度，將不足以呈顯實際情形。現階段以超音波法應用於大木構件舊料的非破壞檢測，不論是徑向量測或縱向量測仍有無法克服的議題，尚難以達到準確評估的目的。

On conservation of historic buildings, the damage judgment of wooden structural components not only influences the safety of the structure of listed historic buildings but also leads to an argument point of conservation. Recently, non-destructive testing of ultrasonic method has been used apply on investigating wooden structural components, but this method is restricted by the characteristics of ultrasonic device and the properties of wooden components. It can not satisfactorily meet the demand of evaluation on wooden structural components by only using ultrasonic velocity. The aim of this study is therefore to find out the problems by using various testing of ultrasonic method on different wooden components new or used. The result shows that ultrasonic method is only suitable for new wooden structural components parallel to grain. Unfortunately, if only adopting the velocity parameters, ultrasonic methods, both parallel and radial to grain, could not achieve a precise evaluation on wooden structural components used, because of many issues still not being overcome.