# Seismic Effectiveness of Multiple Seismic Measures on a Continuous Gider Bridge
## 1 Introduction  
In recent years, many bridges have become damaged, even by bounding and unseating, due to the failure of bearings and the bounding between adjacent structures during earthquakes. These incidents cause significant economic losses and many casualties [1; 2; 3; 4; 5; 6]. Therefore, it is essential to explore new seismic measures to prevent the bounding, unseating, and collapse of bridges in earthquake-prone countries. The researchers used experiments [7; 8] and numerical simulation techniques to study different seismic measures, such as concrete shear keys [9; 10; 11], steel bar restrainers [12; 13], cable restrainers [7; 14], viscoelastic dampers, and innovative devices [15; 16]. Numerical simulation techniques (including quasi-static [17; 18; 19], the seismic design method [20; 21; 22], and dynamic simulation [23; 24; 25; 26]) are widely used for anti-seismic research on the prevention of rounding and unseating because of their advantages that they consume few resources and acquire a large amount of physical information. [PERSON] et al. [17] investigated four bridges retrofitted with seismic measures during the 1989 Loma Prieta earthquake. They found that measures are effective to reduce the displacement of the bridge and are generally capable of reducing the intensity of impact between two adjacent decks. [PERSON] et al. (2018, 2019) carried out a series of full-scale tests of a simply-supported bridge to evaluate the force-displacement behavior of the cable restrainers. They found that the inadequate performance of restrainers during large earthquakes remained elastic. [PERSON] et al. (2018) proposed a displacement-based seismic design method for cable restrainers in a three-span simply supported highway bridge; the behavior of cable restrainers was modeled using a tension-only elastic element with a gap/slack. The results show that the restrainers could remain functional and limit the relative displacement within a design value during earthquakes. [PERSON] et al. (2018) studied a multidirectional cable restrainer on the seismic fragility of a curved bridge, and their results indicate that multidirectional cable restrainers can remarkably decrease the failure probability of a bridge subjected to a strong earthquake, and that a pier with fixed bearings will experience severe axial forces. Some researchers compared the seismic performance of seismic measures in limiting the relative displacements of the bridge; the studies indicated that all the devices could control the bearing deformation to a safe limit if they were designed correctly ([PERSON] and [PERSON], 2018; [PERSON] and [PERSON], 2018). Another mitigation measure for the bounding of adjacent structures would be the prevention of impact incidents by providing sufficient gaps. However, the size of expansion joints has to be limited for smooth traffic flow, making the adjacent structures susceptible to earthquake-induced poundings ([PERSON] and [PERSON], 2018). The incorporation of layers of soft material on the expansion joints to act as shock absorbers has been suggested; previous studies have assessed the effectiveness of this impact mitigation measure on the response of bridges and buildings ([PERSON] et al., 2018). Researchers have studied the single factor of seismic measures and the effectiveness of seismic measures for preventing bridge grounding and collapse in an earthquake. However, the combination of multiple seismic measures is seldom considered, and the seismic effects of a single seismic measure and multiple seismic measures are rarely compared ([PERSON] et al., 2018). [PERSON] and [PERSON] (2018) revealed that a rubber bumper, along with restrainers at the bridge joint, was not only effective in reducing joint acceleration and relative joint displacements but also reduced the response of the bridge pier to some extent. [PERSON] et al.