潼河桥（64+108+108+64）连续梁桥抗震设计研究(硕士)(论文24000字)
Tong Bridge (64+108+108+64) on seismic design of continuous girder bridge
摘 要
地壳岩石在地球内力的作用下，发生错位或断裂，从而导致的震动，这种效果就叫做地震。地震在发生破坏时，兼具能量大、范围广和难以预测等特点，在地震几十秒的持续作用时间内，能够造成巨大的生命及财产损失，与其他自然灾害相比，其突发性和破坏性的特点尤为突出。汶川地震中部分连续桥梁受损破坏，使桥梁工程的抗震设计获得了重视。
提托潼河桥，基于模态分析、瞬态动力法研究了依托工程-潼桥在三种不同的地震波作用下的动力响应。获得结论如下：
(1) 针对矮墩高度以及是否考虑桩土效应，建立了4种不同工况，对潼河桥三维模型进行了模态分析。结果表明：1）矮墩高度减小后，结构整体刚度增加，桥梁自振频率随之变大，并且桥的振型也随之改变。即：矮墩高度变化后，桥梁的动力特性随之改变；2）是否考虑桩土效应对结构自振频率有影响，若不考虑，结构的各阶自振频率略有升高。
(2) 基于瞬态动力法研究了依托工程-潼桥在三种不同的地震波作用下的动力响应。结果表明：1）E波与T波作用下主梁的位移及内力较为接近，但明显大于人工波；最大竖向位移出现于主梁跨中截面以及靠近矮墩边跨梁跨中截面处。最小竖向位移出现于边跨根部，只占跨中位移的6%左右；2）同一种地震波作用下，结构各截面纵向位移十分接近，且最大值均出现在高墩边跨梁根部截面处；3）最大剪力值均出现在主梁跨中截面，弯矩最大位置均在墩边跨根部；4）不同地震波作用下，墩顶和墩中的纵向位移、剪力和弯矩均有不同，E波、T波作用下结构响应较大，人工波作用下响应较小。
关键词：预应力混凝土梁桥；地震；模态；一致激励
Abstract
Earthquakes are vibrations caused by dislocation or rupture of the earth's crust under the influence of the earth's internal forces. The earthquake destructive energy and damage characteristics of a wide range and it is difficult to predict, the earthquake often lasts only tens of seconds, but may cause huge loss of life and property, the sudden and devastating natural disasters can not be compared to other. In the Wenchuan earthquake, some continuous bridges were damaged and damaged, which made the seismic design of bridge engineering pay more attention to.
Tito Tong Bridge, modal analysis, transient dynamic method based on the project - Tong Bridge in three kinds of seismic waves under different responses based on the. Conclusions are as follows:
(1) for the short pier height and considering the effect of pile and soil, established 4 different conditions, the three-dimensional model of the Tong Bridge modal analysis is carried out. The results show that: 1) after the height of the pier decreases, the overall stiffness of the structure increases, the natural frequency of the bridge becomes larger, and the vibration mode of the bridge changes accordingly. That is to say, when the height of the short pier is changed, the dynamic characteristics of the bridge will change; 2) whether the pile-soil effect should be considered in response to the natural frequencies of the structure; if not considered, the natural frequencies of the structures are slightly increased.
(2) transient dynamic method based on the study of the power in the three kinds of seismic waves under different response based on the project - Tong bridge. The results show that: 1) the displacement and internal force of the main beam under the action of E wave and T wave are close, but obviously larger than the artificial wave; the maximum vertical displacement occurs at the midspan section of the main girder and near the cross section of the cross section of the short pier side. The minimum vertical displacement in side span root, only about 6% of the midspan displacement; 2) effects of the same kinds of seismic waves, the longitudinal displacement of structure of each section is very close, and the maximum value appeared in the high pier side span beam root section; 3) the maximum shear force values in the mid span section the maximum bending moment, position of the root of the pier side span; 4) under different seismic waves, longitudinal displacement, shear force and bending moment of pier and pier in different E and T wave under the action of structure response is larger, less artificial wave response.
Key words: prestressed concrete beam bridge; earthquake; mode; uniform excitation
目 录
第一章 绪 论 - 1 -
1.1 引言 - 1 -
1.2 桥梁抗震分析国内外研究现状 - 3 -
1.2.1 拟静力法 - 4 -
1.2.2 反应谱法 - 4 -
1.2.3 时程分析法 - 6 -
1.3 本文主要研究内容 - 6 -
第二章 潼河桥空间有限元分析 - 8 -
2.1 引言 - 8 -
2.2 潼河桥结构概述 - 8 -
2.2.1 工程概况 - 8 -
2.2.2 主梁 - 9 -
2.2.3 墩柱 - 9 -
2.2.4 地质构造 - 11 -
2.3 潼河桥有限元模拟方案 - 13 -
2.3.1 模拟思路 - 13 -
2.3.2 ANSYS在桥梁工程中的应用 - 14 -
2.3.3 结构单元的选用 - 14 -
2.3.4 桩土共同作用 - 15 -
2.3.5 4种工况的有限元模型 - 16 -
2.4 材料参数 - 21 -
2.4.1 材料特性 - 21 -
2.4.2 荷载取值 - 22 -
2.5 本章小结 - 22 -
第三章 模态分析 - 23 -
3.1 引言 - 23 -
3.2 模态分析的基本原理 - 23 -
3.3 ANSYS的模态分析 - 26 -
3.4 模态分析结果 - 26 -
3.5 本章小结 - 32 -
第四章 连续梁桥瞬态时程分析 - 33 -
4.1 引言 - 33 -
4.2 阻尼与ANSYS阻尼 - 33 -
4.2.1 阻尼及ANSYS阻尼类型 - 33 -
4.2.2 阻尼模型 - 36 -
4.3 基本运动方程及其求解 - 37 -
4.3.1 Newmark法 - 37 -
4.3.2 HHT法 - 39 -
4.3.3 ANSYS瞬态动力分析关键技术 - 40 -
4.4 地震波的选择与输入 - 44 -
4.5 ANSYS的动态时程分析 - 45 -
4.5.1 ANSY动态时程分析方法 - 45 -
4.4.2 一致激励地震动方程推导 - 46 -
4.5 一致激励下的地震响应结果 - 46 -
4.5.1 主梁一致激励时程分析 - 46 -
4.5.2 桥墩一致激励时程分析 - 59 -
4.6 本章小结 - 66 -
第五章 结论 - 68 -
参 考 文 献 - 69 -
致 谢 - 73 - |
