横系梁道数对现浇超高墩连续刚构桥抗震性能影响研究

Study on the Influence of the Number of Transverse Beams on the Seismic Performance of Cast-in-Place Super High Pier Continuous Rigid Frame Bridge

摘要: 为研究不同类型横桥向地震作用下横系梁道数对双幅带系梁现浇超高墩连续刚构桥抗震性能的影响，本文基于OpenSees软件建立了CRFB-SP-RC非线性纤维模型，探究了非长周期地震动、长周期非脉冲型地震动和近断层脉冲型地震动作用下横系梁数量变化对超高墩连续刚构桥抗震性能的影响。结果表明，不同类型横桥向地震动激励下，横系梁道数对CRFB-SP-RC横桥向地震响应影响规律如下：墩顶峰值位移：${\text{Ld}}_{\text{NLP}}<{\text{Ld}}_{\text{NPLP}}<{\text{Ld}}_{\text{NFPT}\left({\text{T}}_{\text{P}}\approx {\text{T}}_{\text{1}}\right)}$ ，墩底峰值弯矩：${\text{M}}_{\text{NLP}}<{\text{M}}_{\text{NPLP}}<{\text{M}}_{\text{NFPT}\left({\text{T}}_{\text{P}}\approx {\text{T}}_{\text{1}}\right)}$ ；同一类型地震动横桥向激励下，CRFB-SP-RC的横桥向墩顶峰值位移、墩底弯矩以及墩底截面耗能均随横系梁道数的增加而降低。

Abstract: In order to study the influence of the number of tie beams on the seismic performance of cast-in-place continuous rigid frame bridge with super-high piers under different types of transverse earthquakes, this paper established a CRFB-SP-RC nonlinear fiber model based on OpenSees software, and explored the influence of the number of tie beams on the seismic performance of super-high pier continuous rigid frame bridge under non-long-period ground motion, long-period non-pulse ground motion and near-fault pulse ground motion. The results show that the influence of the number of transverse beams on the seismic response of CRFB-SP-RC transverse bridge under different types of transverse bridge ground motion excitation is as follows: The peak displacement of the pier top: ${\text{Ld}}_{\text{NLP}}<{\text{Ld}}_{\text{NPLP}}<{\text{Ld}}_{\text{NFPT}\left({\text{T}}_{\text{P}}\approx {\text{T}}_{\text{1}}\right)}$ , the peak bending moment at the base of the pier: ${\text{M}}_{\text{NLP}}<{\text{M}}_{\text{NPLP}}<{\text{M}}_{\text{NFPT}\left({\text{T}}_{\text{P}}\approx {\text{T}}_{\text{1}}\right)}$ . Under the transverse bridge excitation of the same type of ground motion, the peak displacement of the pier top, the bending moment of the pier bottom and the energy dissipation of the pier bottom section of CRFB-SP-RC decrease with the increase of the number of transverse beams.