公路桥梁支座更换方法

文章结合在不中断交通情况下某大桥支座更换工程所采用的施工方案、施工方法和措施,总结一套可广泛应用的桥梁支座更换方法,保证桥梁支座在不中断交通情况下更换的安全性和质量。     

路桥专业工学结合职业教育教学模式探索

结合四川交通职业技术学院道路桥梁专业"工学结合"的教学实践,提出高职教育"工学结合"的教学思路,阐述了"引工地进校园"教学模式的基本形式、教学方法可以有效地安全地实现工学结合的教学思路。论文同时总结了"引工地进校园"教学模式实践效果。     

道路桥梁施工中高性能混凝土的应用探讨

随着科学技术的飞速发展,道路桥梁建设中的施工技术也在不断进步革新。利用高性能混凝土具有高耐久性、高工作性、高强度和高体积等良好品质铺设的高质量的道路和桥梁成为日后发展的趋势。近年来,高性能混凝土在道路桥梁工程中的应用日渐广泛,本文结合高性能混凝土自身的特点,对道路桥梁工程中高性能混凝土在道路桥梁建设中的应用问题进行了浅要分析。     

公路桥梁施工中预应力技术研究

本文分析了公路桥梁施工中预应力技术的适用范围和条件,并对公路桥梁建设中应用预应力技术存在的问题提出了相应的解决措施,以期对提高我国公路桥梁的施工建设提供借鉴性的参考。     

浅谈道桥施工中混凝土桥梁的常见问题

混凝土桥梁在我国已得到广泛的应用,它的施工方法、施工工艺与施工过程中都有其自身的特点。通过分析混凝土技术在桥梁施工中常见的问题及成因分析,提出了相关问题的解决措施。     

On peacocks and lyrebirds: Australian options,Brownian bridges,and the average of submartingales

We introduce a class of stochastic processes, which we refer to as lyrebirds. These extend a class of stochastic processes, which have recently been coined peacocks, but are more commonly known as processes that are increasing in the convex order. We show how these processes arise naturally in the context of Asian and Australian options and consider further applications, such as the arithmetic average of a Brownian bridge and the average of submartingales, including the case of Asian and Australian options where the underlying features constant elasticity of variance or is of Merton jump diffusion type.     

北运河病险闸桥改造相关问题探讨

通过对北运河(含温榆河)作为北京市排洪排污河道重要性以及北运河上病险闸、桥现状的论述,指出对北运河病险闸、桥改造的必要性和重要性,并对改造提出一些合理性建议.     

河道多桥连续壅水分析

在实际工程中，经常遇到河段多桥连续壅水计算问题，本文在单座桥梁壅水计算方法的基础上，给出了一种比较简单实用的关于多桥连续壅水高度的计算方法。对于上游任一断面，当其断面处于下游桥梁的壅水范围之内时，它的壅水高度应该是下游桥梁在这个断面产生的壅水高度之和。黄河府谷段多桥连续壅水的实例计算结果表明，多桥连续壅水高度的计算方法简便易行。     

不同水深条件下的带式浮桥水弹性特性

为了研究不同水深条件下的带式浮桥在移动荷载作用下的水弹性动力特性,采用基于梁式理论的解析模型和基于势流理论的边界元法模型。流体动力的影响利用基于势流理论的边界元方法来计算。将附加质量和阻尼系数分别与浮桥的质量和阻尼合并,恢复力与移动荷载合并,便可容易导出浮桥的振动微分方程。利用假设模态法,得出了水弹性固有频率及其动力响应的计算公式。结果表明,水深对浮桥的水弹性固有频率以及动力响应的影响不大,因此带式浮桥的设计和应用不必考虑水深的影响。     

Physiographic characteristics of bridge‐stream intersections

Bridges that cross streams can be greatly affected by channel instabilities, such as channel widening, lateral migration and channel bed degradation. Attention to channel conditions in the vicinity of bridges is an important aspect of bridge maintenance and safety. Channel stability is also critical to goals of multi‐objective river management. Given that channel stability is important for both river management and the structural stability of bridges, any river management scheme should consider the stability of bridge‐stream intersections. In this paper, the characteristics of bridge‐stream intersections across the United States are described based on existing literature and recent field observations. A set of recommendations for addressing and improving channel stability at bridges is suggested, including: (1) controlling water and sediment discharges at the catchment level; (2) revegetating channel banks with woody vegetation; (3) reshaping the channel cross‐section to a more stable, configuration; (4) removing disturbances from the stream channel, such as cattle and (5) using structures to control flow near channel beds and banks. The physiographic setting is a factor in the solution of at least the first three suggestions in this list. Attention to the physical characteristics of bridge‐stream intersections in the various physiographic regions can lead to sustainable solutions for stabilizing channels at bridge‐stream intersections. Copyright © 2006 John Wiley & Sons, Ltd.