Experimental and Numerical Study on Modal Dynamic Response of Water-Surrounded Slender Bridge Pier with Pile Foundation

Yulin Deng,Lueqin Xu,Qingkang Guo

doi:10.1155/2017/4769637

Yulin Deng, Lueqin Xu + Show 1 more

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https://doi.org/10.1155/2017/4769637

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Abstract

This paper presents an experimental program performed to study the effect of fluid-structure interaction on the modal dynamic response of water-surrounded slender bridge pier with pile foundation. A reduced scale slender bridge pier specimen is built and tested through forced vibration method. The vibration periods of the first four lateral modes, including the first two modes along x-axis and the first two modes along y-axis, are measured based on the specimen submerged by 16 levels of water and designated with 4 levels of tip mass. Three-dimensional (3D) finite-element models are established for the tested water-pier system and analyzed under various combined cases of water level and tip mass. Percentage increases of vibration periods with respect to dry vibration periods (i.e., vibration periods of the specimen without water) are determined as a function of water level and tip mass to evaluate the effect of fluid-structure interaction. The numerical results are successfully validated against the recorded test data. Based on the validated models, the modal hydrodynamic pressures are calculated to characterize the 3D distribution of hydrodynamic loads on the pier systems. The research provides a better illumination into the effect of fluid-structure interaction on the modal dynamic response of deepwater bridges.

Highlights

Bridges with high and slender piers have widely been found in deepwater areas like estuaries, straits, reservoirs, and so on
In order to discuss the effect of fluid-structure interaction on the modal dynamic response of the specimen, percentage increases of vibration periods are applied to show the tendency of the specimen vibration period in different test cases where the water levels varied from 0 to 1.8 m and the tip masses altered from 0 to 31.7 kg (i.e., 0, 12.1, 23.4, and 31.7 kg), respectively
This paper presented an experimental program performed to investigate the effect of fluid-structure interaction on the modal dynamic response of water-surrounded slender bridge pier with pile foundation

Summary

Introduction

Bridges with high and slender piers have widely been found in deepwater areas like estuaries, straits, reservoirs, and so on. The piers, such as those of Miaoziping Bridge [1, 2], Sutong Bridge [3, 4], and China East Sea Bridge [5], are composed of a group of piles connected by a large pile cap and a high reinforced concrete column (or bent) which is submerged partially in water. The dynamics of such bridge piers require special considerations which do not arise for piers elevating on land. The research efforts have confirmed that fluid-structure interaction might cause considerable change to the dynamic characteristics of the deepwater structures, producing additional hydrodynamic loads [6,7,8,9]

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