高拉螺栓連結貼附式構架補強之面外行為研究

傳統校舍補強工法為擴柱、翼牆與剪力牆，其缺點為施工過程會影響既有建築物的運作功能，也會影響建築物之通風、採光及室內裝修，無法運用在具重要設備或需長時間停工之建築物，對於住宅、醫院或工廠等重要建物均難以實施補強工程，故本研究欲導入目前國內較少使用之補強工法，即為外加構架補強工法。外加構架補強工法會於屋前及屋後以樓板、植筋或螺栓連結既有結構物與外加RC構架，目的是將地震力由既有構架傳遞至外加構架來消散地震能量，同時也利用外加構架提升整體結構之耐震強度與韌性，其優點為工期短、噪音少與震動少，且施工過程並不會去影響到既有結構物內部，適用於多數住宅之補強工程。梁瀞方2021於《以高強度錨栓連接外加 RC 構架之補強工法》中驗證了外加構架於面內方向即沿騎樓方向之補強效果，測試結果證實，外加構架補強於新舊構架之梁構件接合方式，無論採用植筋接合或高強度錨栓接合，皆可有效提高既有構架的側向強度與變形能力；新舊構架之柱構件有無植筋接合，從面內測試的結果顯示，並無顯著差異。然而，鑒於對外加構架面外方向之疑慮，本研究設計一座未補強試體與三座補強試體於國家地震工程研究中心反力牆進行反覆載重試驗，用以比較面外方向之補強效果、施作柱介面植筋之必要性及外加構架柱箍筋種類對於植筋施工性之差異。本研究結果顯示貼附式構架補強於面外方向確實也能提升構架之耐震能力，並驗證補強構架柱與既有構架柱即使無介面植筋連結，仍然對面外方向有補強效果；若其介面有植筋連結，可提高補強效果，適用於在面外方向有高額補強需求的結構。若根據本研究建議之設計方式設計貼附式補強構架，且於新舊柱介面設計植筋連結，可讓新舊構架緊密連結，即使既有結構於地震力作用下發生破壞，或甚至發生挫屈喪失承載能力，結構物仍可透過介面的連結將重量及外力重新分配給外加構架來承接，而不導致整體結構發生崩塌。

關鍵字

外加構架補強；校舍補強；高強度錨栓；植筋；反覆載重試驗

並列摘要

The typical retrofit methods for school buildings include column jacketing, wing wall and shear wall, but the disadvantage of this is that the construction process will affect the operation of existing buildings, as well as the ventilation, lighting and interior decoration of buildings. Therefore, it is challenging to implement retrofit works for important buildings such as houses, hospitals or factories. This research proposes a technique seldom used in Taiwan: the external frame retrofit method. The external frame retrofit method will be carried out in front of and behind the house with floor slabs, post-installed rebars or bolts connecting the existing structure to the external reinforced concrete structure. The purpose is to dissipate the seismic energy by transferring the seismic force from the existing structure to the additional structure and enhancing the system's seismic strength and toughness of the overall structure by using the additional structure, with the advantages of short construction period and less noise and vibration.The construction process does not affect the interior of existing structures, which is suitable for most residential retrofit projects. Jing-Fang Liang, 2021, has vertified the retrofit effect of the external frame retrofit method in the in-plane direction, i.e., along the arcade direction. The test results confirmed that the beam member joining method of the new and old frames with the external frame could effectively improve the existing frame's lateral strength and deformation capacity ,whether using either post-installed rebar or high-strength anchor. Furthermore, there is no significant difference in the results of in-plane testing between the column members with and without post-installed rebar joints. However, given the concerns about the out-of-plane direction of the retrofit structure, this research designed one un- retrofited specimen and three retrofited specimens to conduct cyclic loading tests on the reaction wall of the National Center for Research on Earthquake Engineering (NCREE). The aims of the study are to compare the retrofit effect in the out-of-plane direction, the necessity of applying column interface post-installed rebars between the old and new frames, and the difference of constructability between the types of column hoop in the external columns. The results of this research show that the external frame retrofit method in the out-of-plane direction can also indeed improve the seismic capacity of the frame. It is also verified that the structure can still have retrofit effect in the out-of-plane direction even without interface connection by using post-installed rebars between external and existing frame columns. However, with interface connection by using post-installed rebars between external and existing frame columns, it can enhance further retrofit effect, which is suitable for structures with high retrofit demands in the out-of-plane direction. Due to the design approach recommended in this research, with the connection by using post-installed rebars between external and existing frame columns, the new and old structures can be closely connected; even if seismic forces excessively damage the existing structure, the structure can still redistribute its self-weight and external forces to the external frame through the interface connection without causing the overall structure to collapse.