伊春鹿鸣钼矿尾矿库坝体抗震稳定性能研究

鹿鸣尾矿库属于山谷型尾矿库,设计坝高198m,是黑龙江省目前设计库容最大、筑坝最高的尾矿库。作为重要的生产设施和重大危险源,伊春鹿鸣矿业有限公司开展了尾矿库洪水和地震方面的工作,对坝体抗震性能方面的研究成果作简要介绍。     

浅谈三维地震勘探技术的应用

在加快可再生能源开发与应用的同时还要加快勘探技术的研究应用,运用现代勘探技术快速找出能源并准确定位。三维地震勘探技术的应用提高了我国能源勘探的效率,有效保障了我国经济发展所需能源。本文即阐述了三维地震勘探技术应用的关键环节,并通过实例详细探讨了三维地震勘探技术应用中的要点。     

箍筋锈蚀足尺混凝土构件抗震性能

为研究箍筋锈蚀对钢筋混凝土构件抗震性能的影响,通过对6个箍筋锈蚀率(质量分数)的大尺寸钢筋混凝土受弯构件进行低周反复荷载试验,得到各试件滞回曲线及骨架曲线,分析了箍筋锈蚀率对试件承载力、刚度、延性及耗能能力等的影响规律,并讨论了绣胀裂缝对试件受力性能的影响.结果表明:随箍筋锈蚀率的增大,试件滞回曲线捏拢现象显著,滞回环面积逐渐减小,刚度、延性和耗能能力逐步降低;当箍筋锈蚀率大于10.3%时,试件抗震性能降低更为显著.试验发现箍筋锈蚀导致混凝土约束作用减弱,试件达到极限荷载后呈现较明显的脆性性质,破坏形态逐渐向延性较差的剪切破坏转变.     

上覆分数阶粘弹性饱和场地土位移地震放大系数

考虑土体液相和固相的耦合作用,将基岩上覆场地土视为两相饱和多孔介质。为了考虑饱和场地土的粘弹性特性,其固相土骨架的应力应变关系利用分数阶Kelvin粘弹性模型来描述,建立了上覆分数阶粘弹性饱和场地土在简谐地震波作用下的运动控制方程。运用分数导数的性质并考虑上覆场地土的边界条件和透水性条件求解了上覆分数阶粘弹性场地土在简谐地震波作用下的振动问题,得到了饱和场地土的位移地震放大系数。采用数值算例分析讨论了分数导数的阶数、液固耦合系数、土体模型参数、基岩土体剪切模量比等参数对位移地震放大系数的影响。研究结果表明,分数导数的阶数、液固耦合系数、土体模型参数、基岩土体剪切模量比对饱和场地土的地震响应有较大的影响,通过压实场地土,可以达到增大液固耦合系数减小地震响应的作用,通过增大饱和场地土的粘性和剪切模量也可以减小地震反应。     

偏心框架结构在水平地震动作用下的弹塑性分析

通过单层质量偏心体系钢筋混凝土框架结构,运用ANSYS软件,建立钢筋混凝土有限元空间实体整体式模型结构,输入罕遇地震波进行弹塑性时程分析,研究在单向水平地震作用下结构弹塑性侧扭耦合扭转地震响应。     

都江堰市钢筋混凝土楼梯的震害分析

楼梯是房屋的出入通道和重要的紧急逃生通道,本文根据对地震现场考察的情况,介绍了汶川地震中都江堰市建筑结构（多层框架结构、多层砌体结构）钢筋混凝土楼梯的破坏情况,分析了破坏原因,并对钢筋混凝土楼梯的抗震设计与施工提出一些建议。     

以位移为基础的连续梁桥抗震设计

以4跨连续直桥为背景,在地震作用下,其横桥向的弹塑性位移需求和弹性位移需求分别由非线性时程分析方法和弹性反应谱分析方法计算得到;然后采用参数统计分析方法对弹塑性位移需求和弹性位移需求的比值进行了研究。结果表明,对于主要振型周期相对较长的桥梁,其弹塑性位移需求与弹性位移需求接近,可采用相对简单的弹性分析方法(如弹性反应谱分析)得到的位移需求,近似代表地震作用下结构的弹塑性位移需求,进而简化了连续梁桥基于位移的抗震设计。     

Predicting geological hazards during tunnel construction

The complicated geological conditions and geological hazards are challenging problems during tunnel construction,which will cause great losses of life and property.Therefore,reliable prediction of geological defective features,such as faults,karst caves and groundwater,has important practical significances and theoretical values.In this paper,we presented the criteria for detecting typical geological anomalies using the tunnel seismic prediction（TSP） method.The ground penetrating radar（GPR） signal response to water-bearing structures was used for theoretical derivations.And the 3D tomography of the transient electromagnetic method（TEM） was used to develop an equivalent conductance method.Based on the improvement of a single prediction technique,we developed a technical system for reliable prediction of geological defective features by analyzing the advantages and disadvantages of all prediction methods.The procedure of the application of this system was introduced in detail.For prediction,the selection of prediction methods is an important and challenging work.The analytic hierarchy process（AHP） was developed for prediction optimization.We applied the newly developed prediction system to several important projects in China,including Hurongxi highway,Jinping II hydropower station,and Kiaochow Bay subsea tunnel.The case studies show that the geological defective features can be successfully detected with good precision and efficiency,and the prediction system is proved to be an effective means to minimize the risks of geological hazards during tunnel construction.     

Performance-based seismic design of steel frames using ant colony optimization

In this paper, a performance-based optimal seismic design of frame structures is presented using the ant colony optimization (ACO) method. This discrete metaheuristic algorithm leads to a significant improvement in consistency and computational efficiency compared to other evolutionary methods. A nonlinear analysis is utilized to arrive at the structural response at various seismic performance levels, employing a simple computer-based method for push-over analysis which accounts for first-order elastic and second-order geometric stiffness properties. Two examples are presented to illustrate the capabilities of ACO in designing lightweight frames, satisfying multiple performance levels of seismic design constraints for steel moment frame buildings, and a comparison is made with a standard genetic algorithm (GA) implementation to show the superiority of ACO for the discussed optimization problem.     

钢混结构地震损伤评价多元联系数模型

基于集对分析理论,选取整体损伤指数、最大层间位移角、滞回耗能循环次数和楼层能量集中指数作为评价指标,建立了钢混结构地震损伤评价的多元联系数集对分析模型。模型将多指标表示成一个能从总体上衡量损伤级别的n元联系数,用层次分析法确定指标权重,从主客观两方面定量计算地震损伤程度。将模型应用于对4种不同型式的结构进行分析,该评价模型严谨,评价结果合理、分辨率高,是钢混结构地震损伤评价的有效方法。