西南交通大学学报
西南交通大學學報
서남교통대학학보
JOURNAL OF SOUTHWEST JIAOTONG UNIVERSITY
2014年
5期
747-753
,共7页
郑史雄%张金%贾宏宇%张克跃%康锐
鄭史雄%張金%賈宏宇%張剋躍%康銳
정사웅%장금%가굉우%장극약%강예
大跨度斜拉桥%多维多点激励%随机响应%地震动作用
大跨度斜拉橋%多維多點激勵%隨機響應%地震動作用
대과도사랍교%다유다점격려%수궤향응%지진동작용
large-span cable-stayed bridges%multi-dimensional and multi-support seismic excitation%random response%ground motion action
为研究大跨度斜拉桥地震激励下的平稳随机响应规律,以某大跨度斜拉桥为例,用ANSYS软件建立了三维有限元分析模型.考虑地震动的多维性、行波效应、部分相干效应及局部场地效应对主梁及主塔位移和内力随机响应的影响,用该模型分析了大跨度斜拉桥在多维多点地震激励下的响应.研究结果表明:相对于一致激励,大跨度斜拉桥在多维多点激励下的结构响应显著增大,主梁的纵向位移增大了约2.3倍,①号塔顶的纵向位移和塔底横向弯矩分别增大了约2.2和2.3倍;仅考虑一致地震激励不能保证大跨度斜拉桥的结构安全;考虑行波效应时斜拉桥的地震响应减小,相干效应较小可忽略,软场地条件下结构的地震响应更大.
為研究大跨度斜拉橋地震激勵下的平穩隨機響應規律,以某大跨度斜拉橋為例,用ANSYS軟件建立瞭三維有限元分析模型.攷慮地震動的多維性、行波效應、部分相榦效應及跼部場地效應對主樑及主塔位移和內力隨機響應的影響,用該模型分析瞭大跨度斜拉橋在多維多點地震激勵下的響應.研究結果錶明:相對于一緻激勵,大跨度斜拉橋在多維多點激勵下的結構響應顯著增大,主樑的縱嚮位移增大瞭約2.3倍,①號塔頂的縱嚮位移和塔底橫嚮彎矩分彆增大瞭約2.2和2.3倍;僅攷慮一緻地震激勵不能保證大跨度斜拉橋的結構安全;攷慮行波效應時斜拉橋的地震響應減小,相榦效應較小可忽略,軟場地條件下結構的地震響應更大.
위연구대과도사랍교지진격려하적평은수궤향응규률,이모대과도사랍교위례,용ANSYS연건건립료삼유유한원분석모형.고필지진동적다유성、행파효응、부분상간효응급국부장지효응대주량급주탑위이화내력수궤향응적영향,용해모형분석료대과도사랍교재다유다점지진격려하적향응.연구결과표명:상대우일치격려,대과도사랍교재다유다점격려하적결구향응현저증대,주량적종향위이증대료약2.3배,①호탑정적종향위이화탑저횡향만구분별증대료약2.2화2.3배;부고필일치지진격려불능보증대과도사랍교적결구안전;고필행파효응시사랍교적지진향응감소,상간효응교소가홀략,연장지조건하결구적지진향응경대.
In order to investigate the stationary random response of large-span cable-stayed bridge under seismic excitations,a large-span cable-stayed bridge was employed for numerical simulation, and a three-dimensional finite element model in ANSYS software was used to study the response of large-span cable-stayed bridge subjected to multi-dimensional and multi-support seismic excitations (MDMSSE). The spatial variations of earthquake action including traveling wave effect (TWE ), coherent effect (CE),and local site effect (LSE)were taken into account to analyze their effect on displacement and internal force responses of the main beam and the main tower. Results show that the structural seismic response increased remarkably under MDMSSE in comparison with uniform excitation:the main beam longitudinal displacement increased about 2 . 3 times;the top longitudinal displacement and bottom traverse moment of main tower ① increased about 2. 2 and 2. 3 times, respectively. Therefore,only considering uniform excitation is unsafe to a large-span cable-stayed bridge. In addition,the structural response will reduce when considering TWE and CE influence,and hence can be ignored. A soft site has a great influence on structural seismic response.