桥梁建设
橋樑建設
교량건설
BRIDGE CONSTRUCTION
2010年
1期
25-28
,共4页
拱桥%钢管混凝土结构%行波效应%自振特性%地震反应分析%有限元法
拱橋%鋼管混凝土結構%行波效應%自振特性%地震反應分析%有限元法
공교%강관혼응토결구%행파효응%자진특성%지진반응분석%유한원법
arch bridge%concrete-filled steel tube structure%traveling wave effect%natural vibration characteristic%seismic response analysis%finite element method
基于多点激励的运动方程,在考虑行波效应的前提下,应用有限元软件ABAQUS,对某下承式钢管混凝土拱桥(倾斜拱肋、倾斜吊杆)建立全桥模型,进行自振特性及地震反应分析.由2~4阶振型表明,桥面梁系刚度大于拱肋刚度;由6阶以后振型表明,桥面外刚度大于面内刚度,在低频区主要是面内振动为主.由地震反应分析结果表明:行波效应使钢管混凝土拱桥结构内力有不同程度的增大,拱脚轴力比弯矩增幅更大,增幅与加速度峰值无正比关系,当超过临界波速后拱脚弯矩增幅开始反弹.临界波速与结构动力特性、地震波频谱特征等因素有关.另外,行波效应对拱桥控制截面位移影响比较复杂.
基于多點激勵的運動方程,在攷慮行波效應的前提下,應用有限元軟件ABAQUS,對某下承式鋼管混凝土拱橋(傾斜拱肋、傾斜弔桿)建立全橋模型,進行自振特性及地震反應分析.由2~4階振型錶明,橋麵樑繫剛度大于拱肋剛度;由6階以後振型錶明,橋麵外剛度大于麵內剛度,在低頻區主要是麵內振動為主.由地震反應分析結果錶明:行波效應使鋼管混凝土拱橋結構內力有不同程度的增大,拱腳軸力比彎矩增幅更大,增幅與加速度峰值無正比關繫,噹超過臨界波速後拱腳彎矩增幅開始反彈.臨界波速與結構動力特性、地震波頻譜特徵等因素有關.另外,行波效應對拱橋控製截麵位移影響比較複雜.
기우다점격려적운동방정,재고필행파효응적전제하,응용유한원연건ABAQUS,대모하승식강관혼응토공교(경사공륵、경사조간)건립전교모형,진행자진특성급지진반응분석.유2~4계진형표명,교면량계강도대우공륵강도;유6계이후진형표명,교면외강도대우면내강도,재저빈구주요시면내진동위주.유지진반응분석결과표명:행파효응사강관혼응토공교결구내력유불동정도적증대,공각축력비만구증폭경대,증폭여가속도봉치무정비관계,당초과림계파속후공각만구증폭개시반탄.림계파속여결구동력특성、지진파빈보특정등인소유관.령외,행파효응대공교공제절면위이영향비교복잡.
On the basis of the motion equations of multi-support excitation and under the prerequisite that the traveling wave effect iS taken into account,the finite element software ABAQUS is used to establish the model of the whole bridge of a concrete-filled steel tube (CFST) through arch bridge with inclined arch ribs and inclined hangers and the relevant natural vibration characteristics and seismic response are analyzed.The 2nd to the 4th modes show that the rigidity of the bridge deck is greater than that of the arch ribs.The modes after the 6th mode show that the out-of-plane rigidity of the deck is greater than the in-plane rigidity and in the lowfrequency area,the in-plane vibration is dominant.The analysis of the seismic response demonstrates that it is the traveling effect that causes the increase of the structural internal force of the CFST bridge in different degrees,the increasing amplitude of axial force of the arch spring is even greater than that of the bending moment,the amplitude has no direct proportion relation with the peak acceleration.When exceeding the critical wave speed,the amplitude of the arch spring starts to rebound.The critical wave speed is related to the factors of the structural dynamic behavior and seismic wave frequency spectrum and moreover the influences of the traveling wave effect on the displacement of the controlled sections of the arch bridge are complicated.