Multilevel buffering limiting system

Abstract

The invention discloses a multi-level limiting system capable of realizing bridge structures under the action of near-fault pulse earthquakes. The system consists of an upper plate, a chute, a spring, a slider, a connecting rod, a middle cylinder and a lower plate. The initial slack is provided by the free length between the slider and the spring, and multi-level buffering is realized through eight chute systems in different orientations, so that the displacement of the bridge structure can be met by near-fault pulse earthquakes, and the structure is reduced by multi-level buffering internal force. And thanks to the springs, the system is self-resetting after an earthquake. This multi-level buffer limit system can be installed in long-span bridges, and is also suitable for medium- and small-span bridges (including oblique curved bridges); this system not only has good adaptability to near-fault pulse earthquakes, but also to far-field earthquakes efficient. The system does not affect the normal operation of the bridge structure, and only plays a role under strong earthquakes.

Description

technical field [0001] The invention belongs to the technical fields of civil engineering and earthquake engineering, and in particular relates to a multi-level buffering and limiting system suitable for bridge structures under the action of pulse earthquakes. Background technique [0002] When strong earthquakes occur, the structures near the faults are often severely damaged, which shows a strong pulse effect, such as the Northridge earthquake in the United States in 1994, the ChiChi earthquake in Taiwan, China in 1999, and the Wenchuan earthquake in China in 2008. Near-fault ground motions often contain long-period high-energy pulses, which can cause excessive instantaneous displacement and deformation of structures, thereby causing structural damage. Long-span bridges often have a longer natural vibration period, and near-fault earthquakes will significantly increase the displacement requirements of such bridges. Excessive displacement will lead to excessive displacemen...

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Problems solved by technology

Among them, the damper and shock-absorbing and isolating bearing have good energy dissipation effect, which can significantly reduce the demand of the structure under strong earthquake, but the viscous damper is sensitive to speed, and its adaptability under strong pulse is still debatable; while the steel Dampers often have limited displacement capacity, and it is difficult to adapt to the large displacement requirements of strong pulses; conventional limit devices can only provide a single stiffness limit, and often lead to excessive stress on the structure under strong pulses

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