混凝土自锚式悬索桥模型试验研究

抚顺市万新大桥全长476.15m,主桥为15m 70m 160m 70m 15m的双塔双索面混凝土自锚式悬索桥.模型试验对万新大桥主桥模型的静力性能和动力特性进行了详细研究,并与理论计算结果进行了比较,模型试验结果与理论分析相吻合.试验表明中小跨度混凝土自锚式悬索桥的受力基本符合线弹性,可以用线弹性理论进行分析;用现有的有限位移理论分析混凝土自锚式悬索桥的静力和动力特性,并进行抗风、抗震设计是可靠的.     

结构参数变化对自锚式悬索桥动力特性的影响

自锚式悬索桥的动力特性主要包括体系的自振频率和主振型,它是自锚式悬索桥动力分析的基础和前提.通过建立空间有限元模型及工程实例,给出了前20阶频率和相应的振型,分别计算了恒载、加劲梁刚度、塔架刚度、矢跨比等结构参数变化对自锚式混凝土悬索桥动力特性的影响,并与相同跨径和结构参数的1座地锚式悬索桥进行了比较,对影响规律做了详细的讨论.     

自锚式混凝土悬索桥的动力分析

研究自锚式混凝土悬索桥的动力学性能 .以一新建自锚式混凝土悬索桥为背景 ,首先运用有限元分析获得其动力特性并与地锚式悬索桥进行比较 ,然后利用实桥环境振动试验验证有限元动力特性分析结果 ,最后由地震反应分析进一步考察自锚式悬索桥的振动特点 .结果表明 :自锚式悬索桥由于主缆直接锚固于主梁端 ,主塔纵向弯曲振动频率明显降低 ;因结构耗能方式也随之发生了变化 ,主塔和主梁在纵向地震输入下的各种反应均呈不同程度的增加 .     

虚拟激励法在自锚式悬索桥竖向地震反应分析中的应用

考虑压、弯耦合效应，建立了自锚式悬索桥的竖向地震动方程，并利用虚拟激励法来求解，由于虚拟激励法自动计及了参振振型的互相关项和激励之间的互相关项，是快速精确的CQC算法．文中以兰旗松花江混凝土自锚式悬索桥为例，计算了主梁、主塔和主缆的期望峰值响应，并对地震动空间效应对自锚式悬索桥的竖向地震反应影响规律作了详细的讨论．     

三塔自锚式悬索桥模型试验研究

介绍福州市螺洲大桥试验模型的设计、试验过程和试验研究结果.通过对实测结果与有限元计算结果的分析对比,研究三塔自锚式悬索桥这一新型结构形式的静力行为.结果表明,三塔自锚式悬索桥的结构变形和内力与外荷载基本呈线性关系,主梁挠度与主塔的水平位移之间存在密切关系,主塔刚度对多塔自锚式悬索桥的竖向刚度影响较大.     

下期文章摘要预报

测量透明颗粒形状及变形的显微干涉系统赵　兵 ,方如华　　结合激光干涉及图像处理技术研究测量透明颗粒形状及监测其变形的光学系统 ;对共路偏光干涉仪进行改进 ,使之更好地测量由温度场变化引起的小试件变形 ;对柱及球形试件进行理论和数值分析及实验研究 .自锚式混凝土悬索桥的动力分析张启伟 ,冯敏　　研究自锚式混凝土悬索桥的动力学性能 .以一新建自锚式混凝土悬索桥为背景 ,首先运用有限元分析获得其动力特性并与地锚式悬索桥进行比较 ,然后利用实桥环境振动试验验证有限元动力特性分析结果 ,最后由地震反应分析进一步考察自锚式悬…     

时变效应下自锚式悬索桥车载响应演变规律

为研究长服役期内混凝土收缩徐变、环境温度变化对车载作用下自锚式悬索桥主梁应力状态演变的影响规律,建立了山东省湖南路大桥ANSYS精细化实体有限元模型,分析了30 a运营期内混凝土收缩徐变、5 ℃~20 ℃温升工况下超宽箱梁底板的应力变化规律。结果表明：随着桥梁运营年限增加,箱梁底板纵向压应力逐渐减小,30 a期时部分位置出现0.085 MPa的纵向拉应力;箱梁底板与最外侧腹板交接处出现2 MPa的横向拉应力,需优化横向预应力筋的布置方式。桥梁运营30 a时,在1.0~1.6倍对称等效设计活荷载下,箱梁底板与内侧腹板交接处的纵向拉应力达到1.06~2.70 MPa。桥梁运营30 a并且环境温度升高5 ℃时,在对称等效设计活载下,箱梁底板部分区域的纵向拉应力超过混凝土抗拉强度,20 °C温升使得底板最大纵向拉应力达到8.65 MPa。     

大跨度自锚式悬索桥的颤振稳定性研究及风洞实验

研究大跨度自锚式悬索桥钢加劲梁的截面选形、结构动力特性分析、施工及运营状态的气动力性能等问题;以湘江三汊矶大桥为背景,基于多振型耦合颤振的气弹性理论,分析计算自锚式悬索桥的颤振临界风速;探讨截面形式、施工方法等对钢加劲梁的气动参数及颤振稳定性的影响;此外,与该桥的节段模型和全桥气弹性风洞实验的结果进行对比。研究结果表明:自锚式悬索桥的抗风稳定性主要与主梁的施工方法和架设过程有关;桥梁颤振临界风速随着结构体系的转换而变化,其抗风稳定性主要对结构频率比较敏感;该种桥式具有良好的抗风稳定性。     

大跨自锚式悬索桥颤振稳定性的敏感性分析

基于桥梁多振型耦合的气弹性理论,建立了基于特征值问题的气动参数敏感性分析方法,并结合目前国内最大跨度的独塔和双塔自锚式悬索桥的风洞试验资料,分别探讨截面形状、气动阻尼、模态耦合、颤振导数等对桥梁气动性能的影响.分析结果表明:对于具有扁平流线型钢箱梁的自锚式悬索桥,其颤振临界风速的计算结果比较接近于薄平板,且绝大部分能量都集中到扭转振型上,表明对颤振发生起主导作用的是扭转模态;结构阻尼的增加在一定范围内对抑制结构响应所起的作用明显.以上特点表明自锚式悬索桥的空气动力性能与斜拉桥更为接近.     

浅谈混凝土自锚式悬索桥施工监理的体会

江山北关大桥的主桥为自锚式混凝土悬索桥。作者通过做该桥现场监理,对钢筋混凝土自锚式悬索桥的监理体会进行总结。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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