桥梁建设
橋樑建設
교량건설
BRIDGE CONSTRUCTION
2015年
4期
46-51
,共6页
郑开启%刘钊%张宇峰%秦顺全
鄭開啟%劉釗%張宇峰%秦順全
정개계%류쇠%장우봉%진순전
钢筋混凝土桥%梁式桥%斜裂缝%线性退化%分级评定%剪切刚度模型%刚度评估
鋼觔混凝土橋%樑式橋%斜裂縫%線性退化%分級評定%剪切剛度模型%剛度評估
강근혼응토교%량식교%사렬봉%선성퇴화%분급평정%전절강도모형%강도평고
reinforced concrete bridge%girder bridge%diagonal crack%linear degradation%as-sessment in grade%shear stiffness model%stiffness assessment
为研究腹板斜裂缝对混凝土梁桥剪切刚度退化的影响，提出一种基于桁架模型和实际斜裂缝状况的剪切刚度评估方法。根据变角桁架模型推导箍筋屈服时混凝土梁的极限剪切刚度，并通过剪切刚度退化因子极限值建立极限剪切刚度和弹性剪切刚度的定量关系；建立一般开裂程度下的剪切刚度线性退化模型，当斜裂缝开裂等级从1级升至5级时，开裂后剪切刚度由弹性剪切刚度线性降低至极限剪切刚度；提出斜裂缝开裂程度5级评定标准，建立实用的带斜裂缝混凝土梁桥剪切刚度评估方法。采用该方法对某斜向开裂预应力混凝土箱梁桥进行了斜裂缝分级评定与剪切刚度评估，结果表明，该方法能够较好地评价带斜裂缝桥梁的剪切刚度及下挠。
為研究腹闆斜裂縫對混凝土樑橋剪切剛度退化的影響，提齣一種基于桁架模型和實際斜裂縫狀況的剪切剛度評估方法。根據變角桁架模型推導箍觔屈服時混凝土樑的極限剪切剛度，併通過剪切剛度退化因子極限值建立極限剪切剛度和彈性剪切剛度的定量關繫；建立一般開裂程度下的剪切剛度線性退化模型，噹斜裂縫開裂等級從1級升至5級時，開裂後剪切剛度由彈性剪切剛度線性降低至極限剪切剛度；提齣斜裂縫開裂程度5級評定標準，建立實用的帶斜裂縫混凝土樑橋剪切剛度評估方法。採用該方法對某斜嚮開裂預應力混凝土箱樑橋進行瞭斜裂縫分級評定與剪切剛度評估，結果錶明，該方法能夠較好地評價帶斜裂縫橋樑的剪切剛度及下撓。
위연구복판사렬봉대혼응토량교전절강도퇴화적영향，제출일충기우항가모형화실제사렬봉상황적전절강도평고방법。근거변각항가모형추도고근굴복시혼응토량적겁한전절강도，병통과전절강도퇴화인자겁한치건립겁한전절강도화탄성전절강도적정량관계；건립일반개렬정도하적전절강도선성퇴화모형，당사렬봉개렬등급종1급승지5급시，개렬후전절강도유탄성전절강도선성강저지겁한전절강도；제출사렬봉개렬정도5급평정표준，건립실용적대사렬봉혼응토량교전절강도평고방법。채용해방법대모사향개렬예응력혼응토상량교진행료사렬봉분급평정여전절강도평고，결과표명，해방법능구교호지평개대사렬봉교량적전절강도급하뇨。
To study the impact of the web diagonal cracks on the shear stiffness degradation of concrete girder bridges ,a shear stiffness assessment method based on the truss model and actual diagonal crack situations was developed .From the variable angle truss model ,the ultimate shear stiffness of the concrete girder at the stirrup yielding was derived and according to the ultimate val‐ues of the shear stiffness degradation factors ,the quantitative relationship between the ultimate and elastic shear stiffness was established .The shear stiffness linear degradation model of general cracking degree was set up .When the cracking grade of a diagonal crack ascended from Grade 1 to Grade 5 ,the shear stiffness after cracking linearly descended from the elastic shear stiffness to the ultimate shear stiffness .The assessment criterion of 5 grades for the cracking degrees of the diago‐nal cracks was proposed .The practical shear stiffness assessment method for the concrete girder bridges with web diagonal cracks was worked out and the method was used to assess the web diag‐onal cracks of a prestressed concrete box girder bridge in grade and also the shear stiffness of the bridge .The results reveal that the method can well assess the shear stiffness and deflection of the concrete girder bridges with web diagonal cracks .
