Studying the seismic effects of valley site has critical guiding significance for site selection and aseismic design. Based on the analysis of centrifuge shaking table tests

the ground motion response pattern of the trapezoidal valley was studied. The results showed that there was a certain amplification effect of ground motion in the bedrock valley site. The amplification effect varied with the change of terrain

but the amplification effect was not significant. Different site locations had a small influence on the response spectrum. In the bedrock-overburden model

an obvious increase of the ground motion magnification was observed at the bedrock surface. Different magnifications were found under different input ground motions. The amplification effect of the ground motion was particularly evident on different sites when the frequency band was in the range of 0.5?2.5 s. In this frequency band

the frequency range of ground motion amplification was increased significantly

which was different from the pure bedrock sites. In the case of the pure bedrock sites

although the shape of the response spectrum was somewhat different for individual sites

the plateau value and characteristic period of the response spectrum were similar. Due to the terrain effect of the valley site

the amplification factors of the peak surface acceleration of the valley site changed with the change of the terrain. The higher the terrace levels of the valley

the greater its magnification

and the amplification of valley bottom was the smallest. With the increase of the input ground motion intensity

the higher the terrace levels

the higher the plateau value

and the greater the characteristic period of the response spectrum.