抗沖切鋼筋對板柱中節(jié)點抗震性能的影響

唐明 易偉建 吳越凡 劉力維

摘要：為研究抗沖切鋼筋和暗梁對板柱節(jié)點抗震性能的影響，進行了5個低周往復荷載作用下的板柱節(jié)點試驗，其中，1個試件無抗沖切鋼筋，另外4個試件分別配置螺旋箍筋、四肢箍筋、八肢箍筋和栓釘。對各試件的裂縫發(fā)展特征、破壞形態(tài)、滯回性能、不平衡彎矩承載力和延性性能等進行了分析。試驗結(jié)果表明：配置抗沖切鋼筋試件的不平衡彎矩承載力和延性性能較無抗沖切鋼筋試件分別提高13%～48%和68%～198%;合理設計暗梁能明顯提高試件的整體抗震性能，配置四肢箍筋的試件能滿足中國規(guī)范的抗震性能需求，且較采用八肢箍筋的試件更經(jīng)濟。總結(jié)和分析已有試驗數(shù)據(jù)發(fā)現(xiàn)，中國規(guī)范對于配置抗沖切鋼筋板柱節(jié)點的計算結(jié)果與試驗結(jié)果整體較吻合，但離散度偏高。

關鍵詞：板柱節(jié)點;抗震性能;沖切破壞;栓釘;箍筋

中圖分類號：TU375.2 文獻標志碼：A 文章編號：20966717（2020）03005410

Abstract：

To study the effect of shear reinforcement and installation of concealed beam on seismic behavior of slabcolumn connections， five slabcolumn connections were tested under lowcycle reversed load. The control specimen had no shear reinforcement， while the other four specimens were equipped with spiral stirrups， fourleg stirrups， eightleg stirrups and studs， respectively. Crack development characteristics， failure modes， hysteretic behaviour， unbalanced moment capacity and ductility of each specimen were analyzed. The results show that compared with the specimen without shear reinforcement， unbalanced moment capacity and ductility of specimens with shear reinforcement are increased by 13%～48% and 68%～198%， respectively. The general seismic performance of specimens is significantly improved by properly designing the concealed beam. The specimen with fourleg stirrups can meet the requirement of seismic performance in Chinese code and is more economical than the that with eightleg stirrups. By summarizing and analyzing existing test data， it is found that for slabcolumn connections with shear reinforcement， the calculated results with Chinese code are in good agreement with test results， but the dispersion of calculated results is relatively high.

Keywords：slabcolumn connection; seismic performance; punching failure; studs; stirrups

鋼筋混凝土平板結(jié)構體系具有施工方便、降低結(jié)構層高和傳力路徑直接等優(yōu)點。然而，對處于中震地區(qū)的平板結(jié)構，其在使用過程中可能產(chǎn)生較大的內(nèi)力和變形，因此，抗沖切鋼筋常被運用于板柱節(jié)點的設計，以提高其承載能力和變形能力等抗震性能。目前，開展試驗研究采用的抗沖切鋼筋類型主要有兩類：箍筋[16]和栓釘[415]。學者們研究了抗沖切鋼筋的直徑、間距、數(shù)量、布置方式和類型等因素對板柱節(jié)點抗震性能的影響。Hawkins等[1]完成了5個板柱節(jié)點試驗，結(jié)果表明，合理設計箍筋能有效提高節(jié)點的延性、耗能能力和殘余承載力，避免節(jié)點發(fā)生脆性破壞。……