## 1 Introduction  
The Circum-Pacific belt, also known as the Ring of Fire, has recently been active, so earthquakes of varying intensity are frequently occurring in various regions around the world. Earthquakes such as the 2001 Indian Gujarat earthquake, the 2005 Pakistan earthquake, the 2008 Sichuan earthquake, and the 2011 East Japan earthquake have caused 200,000 casualties and caused enormous loss of life and property [1, 2, 3]. In addition, the increased frequency of strong earthquakes raises questions about whether existing infrastructure is sufficiently safe from strong earthquakes.  
Infrastructure such as bridges, dams, and nuclear power plants requires a lot of time and money to plan, design, and construct. In addition, such infrastructure plays an important role in a nation's economy, including transportation of goods, electricity production, and preparedness for droughs and floods. If such infrastructure is damaged by earthquakes, it can have a huge impact on the national economy, beyond the structures simply not functioning properly. Therefore, ensuring the earthquake resistance of such infrastructure should be considered extremely important.  
The seismic capacity of infrastructure should be evaluated comprehensively, considering not only their strength and deformability, but also the soil-structure interaction (SSI), which is the mutual interaction between soil (ground) and a structure built on it [4]. This is because seismic waves generated from bedrock increase in peak acceleration and change in natural frequency depending on the properties of the soil. The earthquake that occurredin Mexico City in 1985 is a representative example [5]. Therefore, recent studies related to the seismic response of structures are necessarily conducted in consideration of the soil's essential properties [6; 7; 8; 9; 10; 11; 12].  
The seismic wave travels through the bedrock with a time difference due to the shear wave velocity of the bedrock, which causes a difference in the characteristics of the seismic load that accelerates the ground on which the foundation of the structure is placed. In particular, the wave passage effect cannot be ignored when the bedrock is extremely deep or is not sufficiently hard [13; 14; 15; 16; 17]. Therefore, the wave passage effect of earthquakes is an important consideration in the seismic design of a variety of long infrastructure such as bridges, pipelines, and tunnels [18].  
The purpose of this study was to investigate the seismic response of a bridge with multiple supports under seismic loads, considering both the soil properties of the area where the bridge was constructed and the wave passage effect. To this end, the seismic load acting on the bedrock was prepared to meet the design criterion presented in the standard of the U.S. NRC. In order to reflect the soil properties of the area where the piers are installed in the initial seismic load generated in this way, a ground response analysis was performed using DEEPSOIL--a site response analysis program. Furthermore, the wave passage effect was reflected by considering the shear wave velocity of the bedrock for each support. Prior studies on the seismic response of bridges during earthquakes have been conducted by applying each parameter individually [19; 20; 21; 22; 23], but studies that consider both the amplification and the wave passage effect of seismic waves due to the soil characteristics are insufficient. Therefore, in this study, the seismic response of the bridge during earthquakes was investigated by considering both soil properties in the area where the bridge is located and the wave passage effect of the seismic wave at each support. Figure 1 shows an overall flowchart of the analysis performed in this study.