基底摇摆隔震在双肢薄壁高墩刚构桥中的应用

The Application of Controlled Rocking Isolation in the Continuous Rigid Frame Bridge with Double Limb Thin-Wall High Piers

研究基底摇摆隔震在高墩大跨连续刚构桥中的应用,包括减隔震装置的原理、力学模型、参数确定以及在有限元中的实现。利用耐震时程法分析基底摇摆隔震的优缺点,为工程应用提供参考。结果表明:采用基底摇摆隔震的高墩刚构桥在同一地震作用下桥墩最大转角、弯矩都比未采用隔震时小,隔震效果明显;地震强度较低时,采用摇摆隔震后的桥梁端支座位移与未采用隔震时相差很小,中跨跨中弯矩也相差很小;地震强度较高时,采用摇摆隔震后的梁端支座位移、中跨跨中弯矩都比未采用隔震时大,尤其是中跨跨中弯矩相差甚大,因此对于高烈度地带超高刚构桥地震采用摇摆隔震有待深入研究。

Based on a long-span continuous rigid frame bridge with double limb thin-wall high piers,seismic reducing of the controlled rocking isolation is analyzed by the endurance time method（ ETM）. The research includes the design principle of controlled rocking isolation,mechanical model,parameter calculation and how to implement in finite element software. The results show that piers＇ rotation and maximum bending moment of the rigid bridge with controlled rocking isolation in earthquake is less than that with no isolation. The vibration isolation effect in lower intensity earthquake is very significant. in weaker intensity earthquake, the displacement of end supports and mid- span moment of the rigid bridge with controlled rocking isolation has much the same value from the bridge with no isolation. However,the result is opposite in stronger intensity earthquake. for long-span continuous rigid-frame bridges in high intensity seismic zone using controlled rocking isolation needs further research.