To study the damage of bridge pile foundations caused by scouring, two damage mechanisms of scouring are proposed in this paper. Considering the vehicle-bridge coupled vibration in terms of two aspects of the scouring depth and erosion depth, the vertical and transversal dynamic characteristics and dynamic responses of the bridge are studied under different cases for the most sensitive vehicle speed. The dynamic characteristics include the 1st and 2nd vibration modes of the vertical and transversal directions of the bridge. The dynamic responses include the vertical and transversal dynamic load allowances and acceleration of the bridge. The souring depth is more sensitive than the erosion depth, and the 2^nd vertical mode is most substantially influenced by scouring and erosion. Because of the small value of the natural frequency of the vertical vibration modes, the transversal vibration modes may be more convenient to obtain. The study of the dynamic responses shows that the scouring depth can be represented by the dynamic load allowance in the middle of the span’s section and the erosion depth can be characterized by the dynamic load allowance at the quarter location of the span’s section.

中文翻译：

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基于车桥耦合振动的冲刷影响大跨度悬索桥动力性能研究

为了研究冲刷对桥梁桩基的破坏，提出了两种冲刷破坏机理。考虑到冲刷深度和冲刷深度两个方面的车桥耦合振动，研究了在最敏感车速的不同情况下，桥梁的垂直和横向动力特性以及动力响应。动态特性包括桥梁垂直和横向的第一和第二振动模式。动态响应包括垂直和横向动态载荷容差以及桥梁的加速度。酸蚀深度比侵蚀深度更敏感，^第二垂直模式受冲刷和腐蚀的影响最大。由于垂直振动模式的固有频率的值较小，因此横向振动模式可能更方便获得。对动力响应的研究表明，冲刷深度可以用跨度截面中间的动载荷余量来表示，冲蚀深度可以用跨度截面的四分之一位置的动载荷余量来表征。