复合受扭型钢混凝土柱受力性能及设计方法研究.pdf

分类号密级UDC _博士学位论文复合受扭型钢混凝土柱受力性能 及设计方法研究学科专业 结构工程 复合受扭型钢混凝土柱受力性能及设计方法研究摘要随着高层、大跨和重载结构的日益增多，型钢混凝土结构的应用日益 广泛。工程应用中，型钢混凝土柱不可避免承受复合扭矩的作用，但是，目前我国组合结构设计规范中缺乏复合扭矩作用下型钢混凝土柱的承载力 计算方法，理论研究也相对滞后于工程应用。因此，亟需对其复合受扭问 题进行深入和系统的研究。本文以压弯剪复合受扭型钢混凝土柱为研究对象，通过40个型钢混凝 土柱低周反复加载试验，结合数值模拟和理论分析等研究手段，揭示复合 受扭型钢混凝土柱的破坏机理，分析各参数变化对其抗震性能的影响规律,提出在该复杂受力状态下有效提高抗扭性能和抗震性能的构造措施，并建 立理论分析模型和恢复力模型，提出其承载力计算公式。所取得的主要研 究成果如下：(1)采用自主研发的加载装置对20根不同配钢形式型钢混凝土柱在压 弯剪扭复合受力作用下进行了拟静力往复加载试验，观察了型钢混凝土柱 在压弯剪往复扭矩荷载作用下的破坏过程、破坏形态，获取了加载全过程 中型钢和钢筋的应变状态及相应的变化规律，研究分析了滞回曲线、骨架 曲线、刚度退化、延性系数、层间位移角、耗能系数以及强度衰减等力学 性能，揭示了复合受扭作用下型钢混凝土柱的抗震性能以及破坏机理。试 验结果表明：复合受扭作用下，型钢混凝柱的荷载-位移滞回曲线饱满，扭 矩-扭转角滞回曲线捏拢特征明显；随着扭弯比的增大，抗弯承载力降低，位移延性变差，截面扭矩的存在对试件的抗震性能具有不利作用。(2)对比分析了不同配钢形式型钢混凝土在复合扭矩作用下的抗震性 能，分析结果表明，在压弯剪复合受扭作用下，实腹型钢混凝土柱的抗扭 I承载力较空腹型钢混凝土差，但抗剪承载力较空腹型钢混凝土大，且变形 延性性能更好。综合各项抗震指标，复合受扭实腹型钢混凝土柱的抗震性 能比空腹型钢混凝土柱更加优越。(3)对20根增强抗扭构造措施型钢混凝土柱在压弯剪复合受扭作用下 进行拟静力荷载试验，研究了截面尺寸、型钢含钢率、纵筋配筋率、体积 配箍(腹杆)率、混凝土保护层厚度以及焊接抗扭(剪)栓钉等增强抗扭 措施，对型钢混凝土柱在压弯剪扭复杂受力状态下的破坏模式及滞回性能 的影响规律，分别从承载力、刚度、延性性能、耗能能力和层间位移角等 方面，分析了可有效提高型钢混凝土柱抗扭性能的影响因素，研究结果表 明：增大截面尺寸、增加型钢含钢率、提高体积配箍率以及焊接栓钉可有 效提高复合受扭型钢混凝土柱的抗震性能。(4)基于扭转效应并考虑粘结滑移的影响，建立了压弯剪复合受扭实腹 型钢混凝土柱的数值模型，验证了模型的可行性，拓展并分析了扭弯比和 轴压比两个重要影响参数的影响规律，计算结果表明：复合扭矩作用下，扭弯比小于0.5时，扭矩对抗剪承载力影响不大，当扭弯大于0.5时，扭矩 对抗剪承载力具有明显的削弱作用，且扭矩越大，承载力越低；轴压比小 于0.6时，承载力随着轴压比的增大而增大，轴压比大于0.6后，承载力随 着轴压比的增大而减小；根据数值计算结果，提出了型钢混凝土柱的抗扭 及抗剪计算方法。(5)研究分析了压弯剪扭复合受力作用下扭弯比、轴压比、剪跨比、截面配钢、截面尺寸等重要参数对型钢混凝土柱抗剪承载力的影响，揭示 了扭矩对不同破坏形态的抗剪机理，经理论推导，考虑扭转效应的削弱作 用，提出了型钢混凝土柱的抗剪承载力计算公式，并提出了有利于工程设 计应用的实用计算方法。结果表明：复合扭矩作用下型钢混凝土柱的实用 计算方法与试验实测结果的平均误差小于2%,具有较高的计算精度。(6)通过揭示压扭、压弯剪扭复合受力型钢混凝土柱的抗扭机理，基 II于变角空间桁架理论模型，采用叠加理论、统一计算理论、半经验半理论 模型，然后归纳拟合了国内外具有代表性复合受扭试验的实测数据，得到 复合受扭作用下剪力对抗扭承载力的削弱影响系数，提出了型钢混凝土柱 在压弯剪扭作用下的抗扭承载力的计算，然后根据试验结果，考虑型钢与 混凝土的相互作用及栓钉的影响，提出了实用抗扭承载力计算公式。结果 表明，所提实用计算式与试验结果误差在5%以内，吻合度较好，且具有一 定的安全储备。(7)通过对本文研究的40根压弯剪扭复合受力状态下型钢混凝土柱的 抗震性能试验结果进行分析，提取试验所获得的2滞回特性和T-6滞回特 性参数，提出了以屈服点、峰值点和破坏点为特征点的三折线模型，基于 试验参数、数值计算及承载力计算理论给出了特征点的确定方法；通过对 屈服荷载、峰值荷载、卸载刚度及再加载刚度等力学指标的退化研究，建 立了压弯剪复合受扭作用下的尸-4恢复力模型及T-e恢复力模型。结合试验 结果，对本文建立的恢复力模型的有效性进行了验证。结果表明，所建立 的恢复力模型与实测结果吻合良好，具有较高的精确度。本论文获得了国家自然科学基金项目(51268004),广西城乡建设与工 程安全首批“八桂学者”专项经费，广西高等学校高水平创新团队及卓越 学者计划资助项目，广西优秀在读博士研究出国研修项目和广西优秀博士 学位论文培育项目(YCBZ2014007)的资助关键词：型钢混凝土实腹空腹复合受扭压弯剪扭抗震性能构造措施 焊接栓钉抗剪承载力抗扭承载力恢复力模型illMECHANICAL PROPERTIES AND DESIGN METHODS OF STEEL CONCRETE COLUMNS UNDER COMBINEDTORSIONABSTRACTWi t h t he i ncreasi ng of hi gh-ri se,l arge span and heavy l oad st ru ct u re,t he appl i cat i on of st eel concret e st ru ct u re i s becomi ng more and more ext ensi ve.Engi neeri ng appl i cat i ons,t he st eel rei nforced concret e col u mn u nder t he effect of compou nd t orqu e i nevi t abl e.At present ou r cou nt ry combi nat i on st ru ct u re desi gn codes i n t he l ack of t he beari ng capaci t y of composi t e st eel rei nforced concret e col u mns u nder t he act i on of t orqu e cal cu l at i on met hod,t heoret i cal research i s rel at i vel y l aggi ng behi nd t he engi neeri ng appl i cat i on.Therefore,i t i s u rgent t o carry ou t i n-dept h and syst emat i c research on t he compl ex t orsi on probl em.Based on bendi ng shear composi t e t wi st ed st eel rei nforced concret e col u mns as t he research object,t hrou gh 40 st eel rei nforced concret e col u mn su bject ed t o l ow-cycl i c l oadi ng t est,combi ned wi t h t he research met hods su ch as nu meri cal si mu l at i on and t heoret i cal anal ysi s,reveal t he compou nd t orsi on fai l u re mechani sm of st eel rei nforced concret e col u mn,anal ysi s t he i nfl u ence l aw of paramet er change on t he sei smi c performance,pu t forward u nder t he compl ex st ress st at e effect i vel y i mprove t orsi on propert i es and t he sei smi c performance of st ru ct u ral measu res,and est abl i sh a t heoret i cal anal ysi s model and t he rest ori ng force model,i t s beari ng capaci t y cal cu l at i on formu l a i s pu t fbrward.The mai n research resu l t s are as fol l ows:(1)Throu gh a sel fdevel oped l oadi ng set u ps,qu asi st at i c cycl i c pat t ern l oadi ng t est s were performed on 20 S RC speci mens wi t h di fferent st eel form su bject ed t o compressi on,bendi ng,sheari ng and t orsi on.The fai l u re process and pat t erns of t he S RC col u mn su bject ed t o compressi on-bendi ng-shear IVreci procat i ng t orsi on were observed and t he hyst eret i c l oops of t orsi on-t wi st angl e and l oad-di spl acement were obt ai ned.The st at e of st rai n and correspondi ng vari abi l i t y i n st eel and rei nforci ng bar were acqu i red du ri ng t he t est.Respect i vel y,di spl acement du ct i l i t y,st ory dri ft,energy di ssi pat i on,st rengt h and st i ffness degradat i on of speci mens as t he sei smi c performance val u e were anal yzed.The hyst eresi s charact eri st i cs and t orsi on resi st ance mechani sm of S RC col u ni n u nder combi ned t orsi on were reveal ed i ni t i al l y.The experi ment al resu l t s show t hat t he l oad-di spl acement hyst eresi s cu rve i s fu l l and t he t orqu e-t orsi on Angl e hyst eresi s cu rve i s obvi ou s.Wi t h t he i ncrease of t he t orsi on rat i o,t he fl exu ral capaci t y i s redu ced and t he di spl acement du ct i l i t y becomes worse,whi ch i ndi cat es t hat t he exi st ence of sect i on t orqu es has an adverse effect on t he sei smi c performance of t he speci mens.(2)Cont rast anal ysi s of t he st eel rei nforced concret e wi t h di fferent st eel form i n a composi t e t orqu e u nder t he act i on of sei smi c performance,t he anal ysi s resu l t s show t hat t he bendi ng u nder t orsi onal shear compou nd,sol i d web st eel rei nforced concret e col u mn t orsi on beari ng capaci t y of a sol i d web st eel rei nforced concret e i s poor,bu t t he shear beari ng capaci t y of t he hol l ow st eel rei nforced concret e hi gh,deformat i on and du ct i l i t y performance bet t er.The sei smi c performance of composi t e rei nforced concret e col u mn i s su peri or t o t hat of empt y st omach.(3)Qu asi st at i c cycl i c pat t ern l oadi ng t est s were performed on 20 S RC speci mens wi t h di fferent enhancement t orsi on-resi st ant const ru ct i onal measu re u nder compress-fl exu re-shear-t orsi on combi ned cycl i c act i on.The enhancement t orsi on-resi st ant const ru ct i onal measu re su ch as cross-sect i on,st eel rat i o,l ongi t u di nal rei nforcement rat i o,st i rru p rei nforcement rat i o(web member),t hi ckness of concret e cover,and wel di ng t orsi on(shear)bol t s were i nvest i gat ed for t he effect of fai l u re mode and hyst eret i c behavi or on S RC Col u mns u nder combi ned compressi on-bendi ng-shear-t orsi on.Respect i vel y from t he beari ng capaci t y,st i ffness,du ct i l i t y,energy di ssi pat i on capaci t y performance and vi nt erl ayer di spl acement Angl e and so on,whi ch can effect i vel y i mprove t he st eel rei nforced concret e col u mn are anal yzed t he i nfl u ence fact ors of t orsi on performance,t he resu l t s show t hat i ncreasi ng t he cross sect i on si ze,i ncrease st eel st eel cont ent,i ncrease t he vol u me,st i rru p rat i o and wel di ng st u d can effect i vel y i mprove composi t e by t wi st i ng t he sei smi c performance of st eel rei nforced concret e col u mn.(4)Based on t he t orsi onal effect and t he i nfl u ence of bond sl i p,a nu meri cal model for compress-bendi ng-shear-t orsi on combi ned act i on was est abl i shed,whi ch were veri fi ed t o be feasi bl e.Throu gh t he model,t he i mport ant paramet ers of t orsi on-bendi ng rat i o and axi al compressi on rat i o were ext ended t o i n est abl i shed t he dat abase of t he performance i ndi cat ors u nder composi t e t orsi on.The cal cu l at i on resu l t s show t hat t he composi t e u nder t he act i on of t orqu e,t wi st ed t han l ess t han 0.5,t he i mpact i s not bi g,t he sheari ng t orqu e agai nst when t wi st ed i s great er t han 0.5,has obvi ou s effect,t he sheari ng t orqu e confront at i on and t he great er t he t orqu e,t he l ower beari ng capaci t y;When t he axi al compressi on rat i o i s l ess t han 0.6,t he beari ng capaci t y i ncreases wi t h t he i ncrease of axi al compressi on rat i o.When t he axi al compressi on rat i o i s great er t han 0.6,t he beari ng capaci t y decreases wi t h t he i ncrease of axi al compressi on rat i o.Accordi ng t o t he resu l t s of nu meri cal cal cu l at i on,t he t orsi on and shear cal cu l at i on met hods of t he concret e col u mns are present ed.(5)The i nHu ence of t he i mport ant paramet ers of t he st eel i n S RC col u mn su ch as t orsi on-bendi ng rat i o,axi al compressi on rat i o,shear-span rat i o,sect i on st eel rat i o and sect i on si ze were st u di ed and anal ysi s on t he beari ng capaci t y of S RC col u mns.The i nfl u ence l aw of t he hori zont al beari ng capaci t y were reveal ed.Consi deri ng t he t orsi on effect i s proposed t hrou gh t heoret i cal deri vat i on formu l a of shear beari ng capaci t y of st eel rei nforced concret e col u mn,and pu t s forward t he pract i cal cal cu l at i on met hod i s hel pfu l for engi neeri ng desi gn appl i cat i ons.The resu l t s show t hat t he pract i cal cal cu l at i on met hod and t he average error of t he experi ment al resu l t s are l ess t han 2%,whi ch has hi ghaccu racy.Research anal yses t he force u nder t he act i on of bendi ng shear and composi t e t wi st ed rat i o,axi al compressi on rat i o,shear span rat i o,sect i on st eel,sect i on si ze and ot her i mport ant paramet ers t o affect t he shear st rengt h of st eel rei nforced concret e col u mn,reveal s t he shear mechani sm of t he t orqu e fbr di fferent fai l u re pat t ern,and consi deri ng t he t orsi on effect i s proposed t hrou gh t heoret i cal deri vat i on formu l a of shear beari ng capaci t y of st eel rei nforced concret e col u mn,and pu t s forward t he pract i cal cal cu l at i on met hod i s hel pfu l fbr engi neeri ng desi gn appl i cat i ons.(6)By reveal i ng t he bendi ng shear composi t e by t wi st i ng t he t wi st i ng mechani sm of st eel rei nforced concret e col u mn,based on t he vari abl e Angl e space t ru ss t heory model,u si ng su perposi t i on t heory,u ni fi ed compu t at i on t heory,experi ence and t heory model,and fi t t i ng of t he domest i c and forei gn represent at i ve compou nd t orsi on t est dat a,get t he composi t e st ress u nder t he act i on of shear force agai nst a weakeni ng t he i nfl u ence coeffi ci ent of t he beari ng capaci t y of t orsi on i s pu t forward of st eel rei nforced concret e col u mns u nder t he act i on of bendi ng shear and t orsi on beari ng capaci t y cal cu l at i on,and t hen accordi ng t o t he t est resu l t s,consi deri ng t he i nt eract i on of st eel and concret e and t he i nfl u ence of t he st u d,pract i cal t orsi on beari ng capaci t y cal cu l at i on formu l a are pu t forward.The resu l t s show t hat t he error of t he pract i cal cal cu l at i on formu l a and t he t est resu l t i s wi t hi n 5%,t he anast omosi ng degree i s good,and has cert ai n safet y reserve.(7)From t he t est resu l t s of 40 st eel rei nforced concret e col u mns u nder compress-bendi ng-shear-t orsi on,t he P-A hyst eresi s and T-0 hyst eresi s were ext ract ed.Accordi ng t o t he resu l t,t he t ri l i near skel et on cu rve model of t he st eel rei nforced concret e col u mns was present ed,charact eri zed by t he yi el d poi nt,t he peak poi nt and fai l u re poi nt.Aft er i nvest i gat i ng t he degradat i on l aw of t he maxi mu m,t he u nl oadi ng st i ffness and t he rel oadi ng st i ffi i ess,t he P-A rest ori ng force model and T-0 rest ori ng force model of st eel rei nforced concret e col u mns VIIu nder compress-bendi ng-shear-t orsi on were est abl i shed.The val i di t y of t he proposed rest ori ng force model was veri fi ed t he val i di t y compared t o t he t est resu l t s.The resu l t s show t hat t he reconst ru ct ed model i s i n good agreement wi t h t he measu red resu l t s and has hi gh preci si on.Thi s paper was awarded by t he Nat i onal Nat u ral S ci ence Fou ndat i on of Chi na(No：51268004),t he fi rst Bagu i S chol ar S peci al fu nds of Gu angxi Urban and Ru ral Const ru ct i on and Engi neeri ng S afet y,t he hi gh l evel i nnovat i ve t eams and ou t st andi ng schol ars fu nded project s i n Gu angxi hi gher edu cat i on i nst i t u t i ons,Gu angxi Excel l ent Doct or Abroad t rai ni ng project and Innovat i on Project of Gu angxi Gradu at e Edu cat i on(No：YCBZ2014007).Key words:steel reinforcement concrete,solid-web,fasting,combined torsion,compress-bending-shear-torsion,seismic behavior shear capacity,torsional capacity,restoring force modelVIII目录第一章绪论-11.1 研究背景和意义.11.2 国内外抗扭研究现状及不足.41.2.1 钢筋混凝土抗扭研究现状.41.2.2 钢-混凝土组合结构抗扭研究现状.41.2.3 钢管混凝土结构抗扭研究现状.51.2.3 型钢混凝土抗扭研究现状.51.2.4 型钢混凝土柱抗扭性能研究的不足.91.3 论文研究目标和总体思路.101.3.1 研究目标.101.3.2 总体研究思路.111.4 主要创新点.12第蝴型弯剪复合峭抗震性能13m研究-132.1 概述.132.2 试验目的.132.3 试验概况.1423.1试 件设计.142.3.2 试件的制作及材料性能.162.3.3 加载装置及加载制度.182.3.4 量测内容.212.4 试验现象及破坏形态.212.4.1 压弯剪试件.222.4.2 压扭试件.232.4.3 压弯剪扭试件.242.4.4 破坏特征分析.272.4.5 塑性较破坏区长度.292.5 试验结果及分析.312.5.1 滞回曲线.312.5.2 骨架曲线.332.5.3 特征点参数.342.5.4 强度退化.362.5.5 刚度退化.372.5.6 耗能能力.382.5.7 延性系数.412.5.8 层间位移角.：.422.5.9 承载力相关关系.422.6 影响因素分析.432.6.1 扭弯比的影响.43IX2.6.2 轴压比的影响.452.6.3 剪跨比的影响.482.7 小结.49第三章空腹型钢混凝土柱压弯剪复合受扭抗震性能试验研究-513.1 概述.513.2 试验目的.523.3 试验概况.523.3.1 试件设计.533.3.2 试件的制作及材料性能.543.3.3 加载装置及加载制度.553.3.4 量测内容及测点布置.563.4 试验现象及破坏形态.573.4.1 压弯剪试件.573.4.2 压扭试件.583.4.3 压弯剪扭试件.593.4.4 破坏特征分析.623.5 试验结果及分析.643.5.1 滞回曲线.643.5.2 骨架曲线.663.5.3 强度退化.683.5.4 刚度退化.693.5.5 耗能能力.703.5.6 延性系数.723.5.7 层间位移转角.723.6 承载力相关关系.733.7 影响因素分析.733.7.1 扭弯比的影响.733.7.2 轴压比的影响.763.7.3 剪跨比的影响.783.8 小结.80第四章不同配钢型钢混凝土柱压弯剪复合受扭作用下抗震性能对比研究-824.1 概述.824.2 研究对象选取.824.3 试件破坏过程及破坏形态对比.834.4 滞回曲线对比.864.5 骨架曲线对比.874.6 承载力对比.884.7 刚度退化对比.894.8 耗能能力对比.89X4.9 延性性能和层间位移角对比.904.9.1 延性系数对比.904.9.2 层间位移角对比.914.10 小结.91第无8增强措施压弯剪复合受扭型钢混凝土柱抗震性能研究-935.1 概述.935.2 试验目的.935.3 增强措施实腹型钢混凝土柱.935.3.1 试验概况.935.3.2 试验现象及破坏形态.975.3.3 滞回曲线和骨架曲线.995.3.4 特征点参数.1045.3.5 刚度退化.1065.3.6 耗能能力.1085.3.7 延性性能.1085.3.8 层间位移角.1105.4 增强措施空腹式型钢混凝土柱.1105.4.1 试验概况.1105.4.2 试件破坏特征.1125.4.3 滞回曲线及骨架曲线.1135.4.4 特征点参数.1155.4.5 刚度退化.1165.4.6 耗能能力.1185.4.7 延性性能.1195.4.8 层间位移角.1205.5 焊接栓钉实腹型钢混凝土柱.1205.5.1 试验概况.1205.5.2 破坏现象与破坏形态.122553滞回曲线和骨架曲线.1235.5.4 特征点参数.1255.5.5 刚度退化.1275.5.6 耗能能力.1275.5.7 延性性能.1295.5.8 层间位移角.1305.5.9 影响因素分析.1305.6 小结.131考-1336.1 概述.1336.2 数值模型的建立.1336.2.1 混凝土材料本构.1336.2.2 钢材的本构关系.137XI6.2.3 单元类型选取.1376.2.4 材料间的相互作用.1376.2.5 边界条件及加载方式.137626非线性方程的求解.1386.3 数值模拟计算结果验证与分析.1386.3.1 等效应力分布云图对比.1386.3.2 试验滞回曲线与数值模拟滞回曲线对比.140633试验与计算峰值荷载值对比.1416.4 参数拓展分析.1436.4.1 扭弯比的影响.1436.4.2 轴压比的影响.1476.5 小结.151第七章基于扭转效应型钢混凝土柱抗剪承载力计算理论研究-1537.1 概述.1537.2 压弯剪扭实腹型钢混凝土试验.1537.2.1 试验概况.1537.2.2 试件破坏形态.153723影响抗剪承载力的主要因素.1537.3 复合受扭作用实腹型钢混凝土柱抗剪机理分析.1567.3.1 扭剪粘结破坏的抗剪机理.1567.3.2 弯扭破坏的抗剪机理.1577.3.3 扭弯破坏抗剪机理.1587.4 复合扭矩作用实腹型钢混凝土柱抗剪承载力计算方法研究.1607.4.1 扭剪粘结破坏抗剪承载力计算.1607.4.2 弯扭破坏、扭弯破坏的抗剪承载力.1647.5 压弯剪扭空腹型钢混凝土试验研究.1687.5.1 试验概况.1687.5.2 试件破坏形态.1687.5.3 影响抗剪承载力的主要因素.16