To explore the influence of spatially varying ground motion on the dynamic behavior of a train passing through a three-tower cable-stayed bridge, a 3D train–track–bridge coupled model is established for accurately simulating the train–bridge interaction under earthquake excitation, which is made up of a vehicle model built by multi-body dynamics, a track–bridge finite element model, and a 3D rolling wheel–rail contact model. A conditional simulation method, which takes into consideration the wave passage effect, incoherence effect, and site-response effect, is adopted to simulate the spatially varying ground motion under different soil conditions. The multi-time-step method previously proposed by the authors is also adopted to improve computational efficiency. The dynamic responses of the train running on a three-tower cable-stayed bridge are calculated with differing earthquake excitations and train speeds. The results indicate that (1) the earthquake excitation significantly increases the responses of the train–bridge system, but at a design speed, all the running safety indices meet the code requirements; (2) the incoherence and site-response effects should also be considered in the seismic analysis for long-span bridges though there is no fixed pattern for determining their influences; (3) different train speeds that vary the vibration characteristics of the train–bridge system affect the vibration frequencies of the car body and bridge.

Running safety assessment of a train traversing a three-tower cable-stayed bridge under spatially varying ground motion

In this paper, the dynamic response analysis of long-span continuous bridge under earthquake and train load was simultaneously performed. In order to clearly reveal the mechanism of vibration coupl...

Dynamic Response Analysis of Long-Span Continuous Bridge Considering the Effect of Train Speeds and Earthquakes

Structures on coral reefs are often subjected to the earthquakes. However, few researches have been reported about the seismic response of coral sand site. Shaking table tests of structures support...

Shaking Table Tests on Seismic Responses of Pile-soil-superstructure in Coral Sand

Monorail bridges play an important role in urban transportation networks, and their proper seismic performance is an issue of great concern in earthquake-prone countries. Seismic isolation...

Seismic Retrofit of Monorail Bridges Considering Soil–Pile–Bridge–Train Interaction

This paper is conducted on evaluating the seismic responses of long bridges under the effect of the soil-structure interaction (SSI) and spatially varying earthquake ground motions (SVEGM). The commonly used spring-dashpot method for analysis of the pile-supported structures under the effect of (SSI) improves to a more capable model. Also, a comprehensive investigation of the dynamic response of a long bridge subjected to spatially varying earthquake ground motions (SVEGM) is performed based on a proposed analytical model which includes the effect of (SSI). The modeling methodology is discussed in detail. To emphasize the importance of the SVEGM and SSI, bridge responses are also determined for the uniform ground motion and fixed base cases. This study proposing a compatible analytical model concerns the relative importance of the SSI and SVEGM and shows that these effects cannot be neglected in seismic analysis and design of long bridges.

A New Approach in Equivalent Spring-Dashpot Method for Seismic Soil-Structure Interaction Analysis of Long Bridges Including Non-uniform Excitations

Evaluation of long bridges dynamic responses under the effect of spatially varying earthquake ground motion

A new approach to soil-pile-structure modeling of long-span bridges subjected to spatially varying earthquake ground motion

In this paper, a comprehensive investigation of the dynamic response of a long-bridge subjected to spatially varying earthquake ground motions (SVEGM) is performed based on a proposed analytical model which includes the effect of soil-structure interaction (SSI). The spatial variability of ground motions is simulated by the powerful record generator, SIMQKE II. Modeling of the SSI in the system is simplified by replacing the pile foundations and soil with sets of independent equivalent linear springs and dashpots along the pile groups. One of the most fundamental objectives of this study is to examine how well the proposed model simulates the dynamic response of a bridge system. For this purpose, the baseline data required for the evaluation process is derived from analyzing a 3D numerical model of the bridge system which is validated in this paper. To emphasize the importance of the SVEGM and SSI, bridge responses are also determined for the uniform ground motion and fixed base cases. This study proposing a compatible analytical model concerns the relative importance of the SSI and SVEGM and shows that these effects cannot be neglected in the seismic analysis of long-bridges.

Shima Sadat Hoseini

Papers

Evaluation of long bridges dynamic responses under the effect of spatially varying earthquake ground motion

A New Approach in Equivalent Spring-Dashpot Method for Seismic Soil-Structure Interaction Analysis of Long Bridges Including Non-uniform Excitations

A new approach to soil-pile-structure modeling of long-span bridges subjected to spatially varying earthquake ground motion

The effect of foundation soil behavior on seismic response of long bridges