Effects on seismic strengthening of coupling beams with or without bolt connections in beam span

Abstract

Reinforced concrete coupling beam is an important member of a major lateral load-resisting structure-coupled shear wall or core wall.Under seismic actions,local failure of coupling beams may lead to a more serious global failure of the whole lateral load resisting system of the building.Along with the development of economy and society,it is necessary and important to strengthen coupling beams that are substandard under seismic actions due to the lack of safety margin and new service in old RC buildings.This paper presents an experimental study into the effects on seismic strengthening of coupling beams with or without bolt connections in beam span.The study shows that the strengthened coupling beam without bolt connections in beam span subjected to cyclic loads has better energy dissipation,larger strength,less stiffness degradation.

鋼筋混凝土連梁是抗側向力剪力墻或核心筒結構中的一個重要構件。在地震作用下,局部連梁的失效可引起抗側力結構的整體失效。隨著經濟、社會的發展,由于安全性或新的用途要求,需對老舊建筑中的連梁進行加固處理。通過對在連梁抗震加固中梁跨內采用有、無螺栓連接連梁的試驗,對加固后連梁的抗震結構性能的影響進行研究。研究表明:梁跨內無螺栓連接加固的連梁在循環荷載下,具有更好的耗能性能、強度增加更大、較小的剛度退化、延性性能增強且延性系數不降低。實際連梁加固中推薦在梁跨內無螺栓連接,且用其他方法克服鋼板屈曲問題。