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(1 天津大學(xué)建筑工程學(xué)院，天津 300072； 2 天津市土木工程結(jié)構(gòu)及新材料重點實驗室，天津 300072)

［摘要］采用可考慮塑性分布的梁柱單元模擬材料非線性，并建立了考慮初始變形的動力連續(xù)倒塌分析模型。通過對鋼框架結(jié)構(gòu)進(jìn)行詳細(xì)的連續(xù)倒塌分析，研究了底層柱失效時間對結(jié)構(gòu)響應(yīng)的影響和豎向荷載傳力路徑以及梁的受力機(jī)理，并對框架破壞后的連續(xù)倒塌狀況進(jìn)行了評估。結(jié)果表明，失效時間小于自振周期時，失效時間的長短對框架的動力響應(yīng)有顯著影響；局部破壞導(dǎo)致上部結(jié)構(gòu)形成新的豎向傳力路徑，上部不平衡的豎向荷載由失效柱相鄰的柱承擔(dān)；結(jié)構(gòu)在局部承重柱失效后上部梁中彎矩內(nèi)力發(fā)生重分布現(xiàn)象，失效柱上方的梁端彎矩作用方向發(fā)生改變，且彎矩值明顯增大。文中按我國規(guī)范設(shè)計的框架結(jié)構(gòu)在單根柱失效的情況下不會發(fā)生連續(xù)倒塌。

［關(guān)鍵詞］連續(xù)倒塌；動力分析；失效時間；彎矩重分布

Dynamic progressive collapse analysis of steel frame structure

Wang Tiecheng^1，2,Liu Chuanqing¹(1 School of Civil Engineering, Tianjin University, Tianjin 300072, China；2 Tianjin Key Laboratory of Civil Engineering Structure and New Materials, Tianjin 300072,China)

Abstract:Using the beam-column element considering the distributed plasticity to simulate the inelastic behavior, the model with initial deformation condition for dynamic progressive collapse analysis was constructed. Through the detailed analysis of a steel frame structure, the effect of failure time on structure dynamic response was investigated, the new vertical load path and the load-carrying mechanism of beams were analyzed, and eventually the resistance to progressive collapse of the frame was evaluated. It is shown that when the period of failure time is less than the structural nature period, the effect of failure time on structure dynamic response is obvious. A new vertical load path is created due to local damage, and the unbalanced vertical loads over local damage are supported by the columns in the vicinity of the removed column. After the column is failure, the redistribution of beam bending moment above the failure column is formed, the bending moment over the removed column reverses direction and the magnitude of bending moment increases significantly. The steel frame designed based on the codes in China has the resistance to progressive collapse when one column is removed.

Keywords:progressive collapse; dynamic analysis; failure time; redistribution of bending moment

作者簡介：王鐵成，教授，博士生導(dǎo)師，Email:wangtiecheng@eyou.com。

參考文獻(xiàn)

［1］ELLINGWOOD BR, SMILOWITZ R, DUSENBERRY DO. Best Practices for Reducing the Potential for Progressive Collapse in Buildings［S］ USA: National Institute of Standards and Technology, NISTIR 7396, 2007.

［2］GSA2003 Progressive Collapse Analysis and Design Guidelines for New Federal Office Buildings and Major Modernization Projects［S］ U S A: General Services Administration, 2003.

［3］DAVID N BILOW, MAHMOUD KAMARA U S. General service administration progressive collapse design guidelines applied to concrete moment-resisting frame buildings［C］//Structures 2004, ASCE. New York: 2004.

［4］MARJANISHVILI S M. Progressive analysis procedure for progressive collapse［J］. Journal of Performance of Constructed Facilities, 2006, 18(2): 79-85.

［5］LIU YUXIN. Progressive failure analysis of steel building structures under abnormal loads［D］. Canada: University of Waterloo, 2007.

［6］胡慶昌. 結(jié)構(gòu)的堅固性及鋼筋混凝土房屋防連續(xù)倒塌設(shè)計概念［J］. 建筑結(jié)構(gòu)，2008，38(1)：1-2,24.