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（中國(guó)礦業(yè)大學(xué)建筑工程學(xué)院，徐州  221008）
［摘要］荷載比率、軸向支撐剛度對(duì)約束鋼梁的性能影響很大，各國(guó)學(xué)者對(duì)其研究主要還集中在升溫階段。對(duì)約束鋼梁進(jìn)行了升降溫全過(guò)程的承載性能試驗(yàn)，給出了鋼梁跨中撓度、軸向支撐應(yīng)變和柱底水平推力在整個(gè)升-降溫過(guò)程中的變化情況。試驗(yàn)結(jié)果表明：鋼梁跨中撓度和軸向支撐應(yīng)變都有不同程度的恢復(fù)。潑水冷卻過(guò)程中也會(huì)引起結(jié)構(gòu)或構(gòu)件的破壞。無(wú)支撐或弱支撐情況下，失穩(wěn)類(lèi)別為梁端局部失穩(wěn)；強(qiáng)支撐情況下，失穩(wěn)類(lèi)別為梁的整體失穩(wěn)。同時(shí)冷卻階段鋼材的強(qiáng)度得到恢復(fù)，這對(duì)梁的承載能力是有利的；但由于梁的收縮，梁內(nèi)將產(chǎn)生收縮拉力，加之柱對(duì)梁端轉(zhuǎn)動(dòng)的約束引起的附加彎矩，這些對(duì)梁兩端的節(jié)點(diǎn)是很不利的。基于此，最后從框架節(jié)點(diǎn)和鋼框架整體兩個(gè)方面提出了相應(yīng)的鋼框架抗火概念設(shè)計(jì)建議。
［關(guān)鍵詞］約束鋼梁；升-降溫全過(guò)程；支撐剛度；失穩(wěn)類(lèi)別；抗火概念設(shè)計(jì)；試驗(yàn)研究
Experimental investigation of behavior of steel beams with axial restraint in cooling phase at elevated temperature
Sun Dongming, Xia Junwu, Long Moushi(School of Architecture and Civil Engineering, China University of Mining and Technology, Xuzhou 221008, China)
Abstract:Load ratio and stiffness of axial restraint have a great influence on the behavior of steel beams with axial restraint. Scholars home and abroad mainly concentrated on it in heating phase. So the whole-process experiment from heating to cooling phase was conducted, the development of mid-span deflection, strain of axial bracing and horizontal force at column base were presented in the whole-process. It shows that mid-span deflection and strain of axial bracing have different degrees of reversal. Breakage of members or structure occurred in splashing cooling phase. Beam with weak axial bracing results in local buckling at beam end, strong overall instability. Due to the strength reversal, it is advantage to loading capacity of beam. On the contrary, it may be disadvantage to the joints owing to shrinkage tension resulting from temperature decreasing. Based on these phenomena, advice in conducting anti-fire conceptual design is put forward on both joints and steel frame.
Keywords:steel beam with axial restraint; the whole-process in heating and cooling phase; stiffness of axial bracing; buckling mode; anti-fire conceptual design; experimental investigation
作者簡(jiǎn)介：孫冬明(1980-)，男，江蘇靖江人，博士，一級(jí)注冊(cè)結(jié)構(gòu)工程師，主要研究鋼結(jié)構(gòu)防火，采動(dòng)區(qū)建筑保護(hù)。
參考文獻(xiàn)
［1］LIU T C H,  FAHAD M K,  DAVIES J M. Experimental investigation of behavior of axially restrained steel beams in fire［J］. Journal of Constructional Steel Research, 2002,58: 1221-1230.
［2］YIN Y Z,  WANG Y C. A numerical study of large deflection behavior of restrained steel beams at elevated temperatures［J］. Journal of Constructional Steel Research, 2004,60: 1029-1047.
［3］殷穎智,王永昌. 火災(zāi)下鋼梁懸索效應(yīng)分析研究［J］. 建筑鋼結(jié)構(gòu)進(jìn)展, 2004,6(3):1-8,15.
［4］YU H X,  LIEW J Y R. Moment curvature method for fire safety design of steel beams［J］. Steel and Composite Structures,2004,4(3): 227-246.
［5］YU H X,  LIEW J Y R. Considering catenary action in designing end-restrained steel beams in fire［J］. Advances in Structural Engineering, 2005,8(3): 309-324.
［6］周宏宇. 鋼混凝土組合梁抗火性能理論與試驗(yàn)研究［D］. 上海：同濟(jì)大學(xué)，2004.
［7］王銀志, 李國(guó)強(qiáng). 火災(zāi)中考慮整體性的鋼梁破壞形態(tài)研究［J］. 結(jié)構(gòu)工程師, 2005,21(3):25-29,18.
［8］王銀志, 李國(guó)強(qiáng). 火災(zāi)中約束鋼梁破壞過(guò)程分析［J］. 鋼結(jié)構(gòu), 2005,20(81):79-81,67.
［9］李國(guó)強(qiáng),丁軍. 耐火鋼梁的抗火性能參數(shù)分析與抗火設(shè)計(jì)［J］. 鋼結(jié)構(gòu)防護(hù), 2003,18(67):52-55.
［10］李國(guó)強(qiáng),丁軍,張韌. 耐火鋼梁抗火計(jì)算與設(shè)計(jì)的實(shí)用方法［J］. 工業(yè)建筑, 2005,35(7):80-82.
［11］李國(guó)強(qiáng), 杜詠, 王銀志，等. 杭州國(guó)際會(huì)議中心鋼結(jié)構(gòu)工程進(jìn)行了抗火性能評(píng)估與設(shè)計(jì)［J］. 建筑鋼結(jié)構(gòu)進(jìn)展, 2006,8(1):14-22.
［12］孫玉萍,虎彥政,王萬(wàn)禎. 端板連接的半剛性對(duì)門(mén)式剛架結(jié)構(gòu)性能的影響［J］. 建筑科學(xué),2006,22(3):15-20.