土木建筑与环境工程
土木建築與環境工程
토목건축여배경공정
Journal of Chongqing Jianzhu University
2015年
4期
45-50
,共6页
许红胜%王晟%颜东煌%林鸣
許紅勝%王晟%顏東煌%林鳴
허홍성%왕성%안동황%림명
桥梁工程%桥梁状态%增量分析%混凝土斜拉桥%收缩徐变%应力松弛%恒载性超载
橋樑工程%橋樑狀態%增量分析%混凝土斜拉橋%收縮徐變%應力鬆弛%恆載性超載
교량공정%교량상태%증량분석%혼응토사랍교%수축서변%응력송이%항재성초재
bridge engineering%bridge condition%incremental load method%concrete stay cable bridge%creep& shrinkage%stress relaxation%overload of dead
为准确掌握混凝土斜拉桥换索施工前的索力和主梁受力状态,建立的换索施工前的初态分析模型,需要对其运营期间混凝土收缩徐变、预应力索应力松弛、恒载性超载等因素产生的影响进行评估。而混凝土弹性模量、徐变、收缩及预应力筋松弛等因素具有与时间历程和应力历史紧密关联的材料非线性特征,采用有限元增量分析是合理的选择。为此,在时间历程划分的基础上,推导了考虑材料徐变、松弛、收缩影响的弹塑性有限元求解方程,建立了时间增量步内单元计入徐变、收缩、松弛影响的数值函数表达式,给出了斜拉索损伤刚度修正的具体措施和恒载性超载影响计入的分析方法,建立的初态模型分析技术进一步改善了混凝土斜拉桥运营期的桥梁状态评估方法。
為準確掌握混凝土斜拉橋換索施工前的索力和主樑受力狀態,建立的換索施工前的初態分析模型,需要對其運營期間混凝土收縮徐變、預應力索應力鬆弛、恆載性超載等因素產生的影響進行評估。而混凝土彈性模量、徐變、收縮及預應力觔鬆弛等因素具有與時間歷程和應力歷史緊密關聯的材料非線性特徵,採用有限元增量分析是閤理的選擇。為此,在時間歷程劃分的基礎上,推導瞭攷慮材料徐變、鬆弛、收縮影響的彈塑性有限元求解方程,建立瞭時間增量步內單元計入徐變、收縮、鬆弛影響的數值函數錶達式,給齣瞭斜拉索損傷剛度脩正的具體措施和恆載性超載影響計入的分析方法,建立的初態模型分析技術進一步改善瞭混凝土斜拉橋運營期的橋樑狀態評估方法。
위준학장악혼응토사랍교환색시공전적색력화주량수력상태,건립적환색시공전적초태분석모형,수요대기운영기간혼응토수축서변、예응력색응력송이、항재성초재등인소산생적영향진행평고。이혼응토탄성모량、서변、수축급예응력근송이등인소구유여시간역정화응력역사긴밀관련적재료비선성특정,채용유한원증량분석시합리적선택。위차,재시간역정화분적기출상,추도료고필재료서변、송이、수축영향적탄소성유한원구해방정,건립료시간증량보내단원계입서변、수축、송이영향적수치함수표체식,급출료사랍색손상강도수정적구체조시화항재성초재영향계입적분석방법,건립적초태모형분석기술진일보개선료혼응토사랍교운영기적교량상태평고방법。
In order to understand the cables forces and girder forces state of concrete cable-stayed bridge before the cable replacement construction,and to establish the analysis model of the bridge,the influence factors such as concrete creep & shrinkage,stress relaxation of prestressing tendons,element damage, overload of dead need to be evaluated .Creep,relaxation and shrinkage are closely associated with the material nonlinearity which dependent on time and stress history so it’s reasonable to adopt the finite element analysis technology based on elastic-plastic incremental load method.Based on the specified time intervals,the incremental elastic-plastic finite element equilibrium equation is deduced which includes the effect of creep,relaxation and shrinkage.For the time increment step,numeric expressions of creep, shrinkage and stress relaxation are established for beam element.Methods are proposed to analyze the influence of stay-cables damage and overload of dead.The methods will improve the structure state analysis techniques for the concrete cable-stayed bridge in service period.