高烈度强震区典型公路简支梁合理减隔震体系分析

Analysis of Reasonable Seismic Isolation System for Typical Highway Simple-supported Beam in High Intensity Strong Seismic Region

摘要:

为研究高烈度强震区高速公路简支梁桥合理减隔震体系，以8度地震区某高速公路典型40 m简支T梁为工程背景，提出了多种减隔震方案，研究了各方案的本构模型，运用非线性时程分析法，对比分析了8度和9度地震下各种减震体系对桥梁关键构件的减震效果。研究表明：E2地震作用下，采用双球面减隔震支座措施时，不能有效控制支座位移，存在落梁的风险；而采用高阻尼橡胶支座可显著降低桥墩、桩基内力，有效控制梁端位移，该方案适用于高烈度地震区高速公路简支梁抗震，研究成果可为近断层高速公路简支梁桥的抗震设防提供技术支撑。

Abstract:

In order to study the reasonable seismic isolation system of expressway simple-supported beam bridge in high intensity strong seismic regions, taking a typical 40-m simple-supported T-type beam of expressway in 8-degree seismic region as the engineering background, a variety of seismic isolation schemes are proposed. The constitutive model of each scheme is studied. By using the nonlinear time-history analysis, the damping effects of various seismic isolation systems on the key components of bridge under the 8-degree and 9-degree earthquakes are compared and analyzed. The study results show that the measure of the double spherical aseismic bearing cannot effectively control the bearing displacement and there is a risk of beam falling under E2 earthquake. But the use of high damping rubber bearing can significantly reduce the internal forces of the pier and pile foundation, and effectively control the displacement of the beam end. This scheme is suitable for the simple-supported beams of expressway in high intensity seismic region. The study results can provide the technical support for seismic fortification of simple-supported beam bridges near fault expressways.