考虑桩土相互作用下双塔悬索桥抗震性能研究

Study on Seismic Performance of Two-pylon Suspension Bridge Considering Pile-Soil Interaction

摘要:

以河南省某双塔自锚式悬索桥为依托，系统研究了此类桥梁的抗震性能。所研究桥梁全长 985.5 m，主桥采用82 m+145 m+82 m 跨径布置，中轴线与河道水流方向呈70°夹角。对桥梁动力特性及抗震性能进行分析的结果表明：在低抗震烈度地区，双塔自锚式悬索桥经合理选择结构体系和支座类型后，主缆及吊索在 E2 地震作用下可保持弹性工作状态，塔、墩、桩结构能满足弹塑性验算要求；研究时应重点关注桥梁动力特性，包括自振周期、频率及关键振型特征，除塔柱、墩柱、桩基等关键截面需重点验算外，还应特别重视短吊杆的动力响应及其受力性能。

Abstract:

Relying on a two-pylon self-anchored suspension bridge in Henan Province, the seismic performance of the bridge is systematically studied. The total length of the bridge is 985.5 m, the main bridge is arranged with the spans of 82 m+145 m+82 m, and its central axis forms a 70° angle with the river flow direction. Through the analysis on the dynamic characteristics and seismic performance of the bridge, the results show that in areas with low-seismic intensity, after reasonable selection of the structural system and bearing type for the two-pylon self-anchored suspension bridge, its main cables and slings can maintain an elastic working state under the action of E2 earthquake, and the pylon, pier and pile structure can meet the requirements of elastoplastic checking calculation. In the research, the special attention should be paid to the dynamic characteristics of the bridge, including natural vibration period, frequency and key vibration-type features. In addition to the key sections such as pylon columns, pier columns and pile foundations that need focus on checking calculation, the special emphasis should be also placed on the dynamic response and the stress performances of short suspenders.