钢管混凝土空间组合桁架连续梁桥地震响应影响分析  

Seismic response analysis for the CFST and space composite trussed continuous bridge

作　　者：王海良[1,2] 王世广[1] 刘中宪[1,2] 黄磊[1] 

机构地区：[1]天津城建大学土木工程学院,天津300384 [2]天津市土木建筑结构防护与加固重点实验室,天津300384

出　　处：《世界地震工程》2017年第2期199-210,共12页World Earthquake Engineering

基　　金：国家自然基金项目(51678390);天津市自然科学基金重点项目(12JCZDJC28900);天津市科技兴海项目(KJXH2012-19)

摘　　要：为揭示河谷场地"钢管混凝土空间组合桁架连续梁桥"地震响应规律,以京昆高速公路"干海子特大桥"为工程背景,建立其三维有限元动力计算模型;采用有限元与间接边界积分方程耦合法(FEM-IBIEM耦合法)进行场地反应计算,并通过多点激励(改进LMM法)方式进行地震动输入,研究行波效应、局部场地效应对其地震响应影响,并和一致激励进行比较,结果表明:该类桥梁低墩较高墩对地震动更敏感,且在墩高突变区域最为明显;较一致激励和高墩和对应梁跨,行波效应增大其墩底轴力、跨中下弦杆和斜腹杆轴力,但减小其它量测值;低墩和对应梁跨,行波效应减小其墩底弯矩、墩顶位移和跨中位移;较一致激励和行波效应,局部场地效应显著增大了大多桥墩和梁跨的位移和内力,且对墩高突变处低墩、梁跨的放大作用最为明显,因此对于河谷场地中"钢管混凝土空间组合桁架连续梁桥"抗震设计,特别是墩高突变区的低墩和梁跨,必须重点考虑局部场地效应的影响。In order to reveal the earthquake response characteristics of ＇ CFST and space composite trussed continu- ous beam＇ in the valley site, incorporating with the ＇ Ganhaizi Bridge＇ of Beijing Kunming Expressway, the FEM model of whole bridge is established and the site effect is calculated by using the finite element-indirect boundary integral equation coupled method. The multi-point ground motion excitation is considered by improved LMM for studying on the traveling wave effect and the local site effect, compared with the uniform excitation. The results in- dicate that for the seismic motion the low piers is more sensitive than the high piers , especially at the height-muta- ted region; For the high piers and beams with the support, compared with the uniform excitation, traveling wave effect increases the axial force at bottom of pier, the axial force of lower chord and of oblique abdominal rod in mid- span but reduces the other measurements. For the low piers and beams with the support, compared with the uniform excitation, traveling wave effect reduces the moments at bottom of pier, the displacement at top of pier and the dis- placement in mid-span; Compared with the uniform excitation and traveling wave effect, local site effects signifi- cantly increase the internal force and displacement of most piers and girders, especially the low piers and beams with the support at the height-mutated place. So the anti-seismic design of ＇ CFST and space composite trussed continuous beam＇ , especially the low piers and beams with the support at the height-mutated region, should focus on consider the local site effect.

关 键 词：钢管混凝土空间组合桁架连续梁桥 改进LMM法 FEM-IBIEM耦合法 河谷场地效应 行波效应 

分 类 号：TU4[建筑科学—土工工程]