Probabilistic Seismic Evaluation and Experimental Tests of Multi-Direction Damping System on a Super-Long Column-Pylon Cable-Stayed Bridge

ABSTRACT

In view of the insufficiency of bidirectional seismic control of long-span cable-stayed bridges as well as the limitations of existing schemes, a multi-direction damping system (MDDS) was proposed and investigated in this manuscript, which can provide seismic resistance bidirectionally. The new damping system owned a unique middle connecting structure, which overcomes the disadvantages that axial instability caused of excessive long rod and the demand of large installing space of traditional dampers. Both the performance stability and constitutive relationship of MDDS were verified by engineering tests, and the equivalent design method was then proposed and proved to be applicable. A detailed finite element numerical model of a super-long (main span over 800 m) column-type pylon cable-stayed bridge which equipped with MDDS in practice was established, the fragility curves of critical components were obtained by non-linear time history analysis, which exhibited the high efficiency of MDDS seismic performance in both transversal and longitudinal directions. Through extracting the median fragility value of 35 sections of the pylon under four damping cases, i.e. setting dampers transversely (TDS), longitudinally (LDS), bidirectionally (BDS), and MDDS, it can be concluded that MDDS performed far better on seismic resistance than LDS and TDS, and made the similar contribution with BDS. On account of half number of damper setting and the reduction in installing space demand, MDDS becomes the optimal choice in practical application for its economic efficiency and superiority. Furthermore, the optimal horizontal installing angle of MDDS was derived through six angle cases which was based on the system-level fragility curves comparison.

KEYWORDS:

• Multi-direction damping system
• super-long cable-stayed bridge
• performance test
• seismic fragility analysis
• transversal seismic control

Highlights

1. A new multi-direction damping system (MDDS) is proposed and investigated on a super-long cable-stayed bridge based on the support of engineering tests.

2. The novel design of MDDS overcomes the defects that traditional damping schemes have, and an equivalent design method is put forward and verified.

3. Seismic fragility analysis on component and system levels is carried out to exhibit the superiority of MDDS on its seismic performance.

4. As an authorized invention patent, the MDDS has been applied in practical engineering which is a super-long cable-stayed bridge with main span over 800 m.

Acknowledgements

This work is funded by the National Natural Science Foundation of China (52178135) and the Anhui Provincial Natural Science Foundation (2208085ME151). The supports are gratefully acknowledged.

Disclosure Statement

No potential conflict of interest was reported by the authors.