基于振动台试验的两跨连续斜交梁桥地震响应研究

Seismic response research of a two-span continuous skew girder bridge by the shaking table test

以福建省公路桥梁为工程背景,设计制作一个系列共9个1/5缩尺两跨连续混凝土斜交梁桥试验模型.选取斜度、配箍率和轴压比等设计参数,利用正交试验分析方法,进行振动台试验.试验中对两跨连续斜交梁桥进行单向和双向地震动输入下结构的地震反应分析,研究斜交梁桥地震响应及震害特点.试验结果表明:不同场地类别的地震动及同一场地类别但不同的地震动作用下,结构的加速度响应、位移响应差别均较大;仅考虑单因素变化时,斜度越小、轴压比越小或长细比越大,结构的加速度和位移响应越大.从试验可知,在斜交桥设计中,合理选择几何参数和力学参数对桥梁动力性能有很大的影响.

Taking a skewed girder bridge of Fujian for engineering background, designing a total of nine with I/5 scale models of two - span continuous skewed girder bridge for the shaking table experi- ment. The shaking table experiment was using orthogonal test analysis method, which based parame- ters such as skew angle, shear span ratio, reinforcement ratio and axial compression ratio. The seismic response rules and destroy characteristic of two span continuous skew girder bridge with a single direc- tion and two way dimensional seismic wave input was studied. Results of shaking table test showed that the structural acceleration response and displacement response were different under different types of ground motion and the same site category but with different seismic action. When the single factor was considered, the smaller the skew angle and the smaller axial compression ratio or the greater the slen- derness ratio, the larger the acceleration and the displacement response of the structure. From the experimental results, the reasonable choice of geometrical parameters and mechanical parameters has great influence on the dynamic performance of the bridge in the skew bridge design.