摘 要

随着我国交通建设的推进，修建通过深水水库和跨海跨江的深水桥梁已是越来越普遍的情况，而我国处于两大地震带，所以有些深水桥梁就无法避免这些地震区域。地震也会给桥梁带来巨大影响，处于深水中的桥墩会由于墩水耦合效应，对结构的动力特性产生影响，从而对桥梁的地震响应产生影响，这种情况会对深水桥梁的抗震设计带来困难，基于这一点本文选取了深水矩形桥墩做了一下研究：

（1）了解国内外研究墩-水耦合效应的现状，总结目前常用到的分析方法，发现各个方法可能再某一方面会有不足之处，提出了本文中所研究的题目为地震作用下深水矩形桥墩水动力模型与数值模拟方法研究。

（2）利用ADINA建立有限元模型，介绍模型建立过程，对比不同水深下的动力特性，发现水深增加墩的自振频率减小，周期增大，所以水对墩的动力特性影响不容忽略。

（3）计算模型的附加质量，建立墩水耦合模型的等效模型，分析等效模型与墩-水耦合模型的动力特性有什么区别，得出等效模型与原模型的频率是基本一致的。

（4）分析研究水下桥墩动水附加质量。在考虑桥墩材料的弹性模量分别在局部和整体发生变化时，对桥墩动水附加质量有什么影响，通过计算分析发现不论是改变局部模量还是改变整体模量墩的动水附加质量不会发生变化。

关键词：深水矩形实心桥墩；流固耦合；动力特性；等效模型；附加质量；

Abstract

With the advancement of traffic construction in our country, it is becoming more and more common to build deep-water bridges through deep-water reservoirs and cross-sea crossing rivers, and China is in two major seismic zones, so some deep-water bridges can not avoid these earthquake areas. The earthquake will also have a great impact on the bridge. The pier in the deep water will have an influence on the dynamic characteristics of the structure due to the coupling effect of the pier and water, which will affect the seismic response of the bridge. This will affect the seismic design of the deep water bridge To this point, this paper selected a deep-water rectangular piers made a look at the study:

(1) to understand the status of domestic and foreign research pier-water coupling effect, summed up the commonly used analytical methods, found that each method may be a certain aspect of the shortcomings, proposed in this paper studied under the earthquake Study on Hydrodynamic Model and Numerical Simulation of Rectangular Piers.

(2) Using ADINA to establish the finite element model, the model establishment process is introduced. Compared with the dynamic characteristics under different water depth, the natural frequency of the pier is reduced and the period is increasing. Therefore, the influence of water on the dynamic characteristics of the pier can not be neglected.

(3) Calculate the additional quality of the model, establish the equivalent model of the coupling model of the pier and water, and analyze the difference between the equivalent model and the dynamic characteristics of the coupled model. The equivalent model is basically consistent with the frequency of the original model The

(4) Analysis of underwater piers moving water additional quality. Considering the elastic modulus of the pier material in the local and the overall change, the impact of the hydraulic flow of the bridge has any effect, through the calculation and analysis found that whether to change the local modulus or change the overall modulus of the dynamic pressure of the pier will not Change.

Key words: deep water rectangular solid piers; fluid-solid coupling; dynamic characteristics; equivalent model; additional quality;

目录

第1章 绪论 ........................................................................................................... 1

1.1研究背景 ............................................................................................................... 1

1.2 研究现状 .............................................................................................................. 2

1.3研究目的 ...............................................................................................................3

1.4研究内容 ............................................................................................................... 4

1.5技术路线图 ......................................................................................................5

第二章 墩-水流固耦合数值模型 .............................................................................. 6

2.1 概述 ..................................................................................................................... 7

2.2势流体理论 ..........................................................................................................8

2.2.1势流体单元介绍 ........................................................................................... 9

2.2.2势流体单元的基本方程 .................................................................................. 10

2.2.3流固耦合动力方程 ........................................................................................11

2.2.4 动力特性求解方程 ..................................................................................... 12

2.2.5边界条件 ................................................................................................... 13

2.3模型的建立 .......................................................................................................... 14

2.3.1模型介绍及相关参数 ................................................................................... 15

2.3.2模型建立的步骤 ......................................................................................... 16

第三章 水下桥墩结构模态参数特征 ......................................................................17

3.1概述 .................................................................................................................... 18

3.2 60米桥墩的模态参数特征 .................................................................................19

3.3 90米桥墩的模态参数特征 .................................................................................20

第四章 水下桥墩结构等效模型 ..............................................................................21

4.1概述 .................................................................................................................... 22

4.2 60米桥墩的等效模型建立 ...............................................................................23

4.3 90米桥墩的等效模型建立 ................................................................................24