多层混凝土建筑结构地震作用的计算

结合规范对地震作用计算的规定，从建筑结构的规则性判断，时程分析选波的方法等方面，提出了多层混凝土建筑结构设计在地震作用计算时应注意的问题。     

地震作用下隧道结构内力的统计分析

为了对隧道结构抗震设计实现以可靠度理论为基础的概率设计方法,必须首先知道地震作用下隧道结构的内力统计特征。为此,从隧道结构地震反应谱出发,基于地层反应位移法,运用误差传递函数,对隧道结构进行不确定性分析,得出隧道结构在地震作用下最不利内力的统计特征。文中以金州隧道Ⅱ类围岩浅埋段为例,运用提出的方法分别求解了小震、中震及大震作用下隧道结构最不利位置处的内力统计特征。     

地震作用下钢混结构桥梁的结构易损性分析

桥梁工程是国家经济发展的重点工程之一。该工程是一项复杂的系统工程,在其建设与使用过程中,极容易受到外界各种作用力的影响,其中,地震因素是影响桥梁工程正使用的重要因素之一,给当地经济造成较大的损失。为了提高桥梁工程的抗震性能,本文采用了一种在地震影响下钢筋混凝土桥梁结构易损性分析方法,通过分析,希望能够为相关技术人员提供参考性依据。     

高层建筑结构在地震作用下的扭转振动效应

研究了高层建筑结构在震作用下扭转与平移振动的平移振动的耦连反应及其近似计算,分析了影响扭转振动效应动力增大的主要因素,并提出考虑扭转振动效应的抗震设计建议。     

倒挂结构的地震作用计算分析

倒挂结构由于质量上移,地震作用引起的效应增大;按现有整体分析计算程序,计算各层重力荷载代表值(质量)的分布时,倒挂结构的竖向构件拉力未统计到各层重力荷载代表值(质量)中,造成地震作用引起的效应偏小。根据上述存在的问题,对各层重力荷载代表值(质量)的分布进行调整,重新计算各层水平地震作用,计算出调整前后各层水平地震作用的比值,对现有整体分析计算程序计算的各层水平地震作用进行调整,以满足结构的实际受力状态。     

多向地震作用下高层结构抗震性能研究

以某平面不规则的框支剪力墙结构为研究对象,采用有限元数值模拟的方法对其在不同地震波、不同输入方向条件下的抗震性能进行了研究.计算结果显示,罕遇地震作用下结构的动力响应和塑性变形与地震波的特性、地震波的输入方向密切相关.     

地震作用下建筑结构倒塌失效准则分析

通过分析总结房屋倒塌的震害特征,给出建筑结构倒塌定义;从结构倒塌失效的力学机理入手,将结构倒塌总结为强度失效倒塌、刚度失效倒塌及稳定性失效倒塌等三类,分别给出三种倒塌失效失效准则的具体计算公式及方法,并规定当结构满足其中任一失效准则时,即可判定结构进入倒塌临界状态;文末对结构倒塌判定的基础——构件损伤破坏的失效准则进行了探讨,提出并总结了构件地震损伤破坏的评判方法。算例表明,本文提出的结构倒塌失效准则概念清晰,应用方便,与已有倒塌准则相比,在没有显著增加计算量的同时,保证了结构地震倒塌判断的充分性与准确性。     

高层建筑巨型结构体系的竖向地震作用

为满足现代高层建筑的多功能和多用途需要,巨型结构体系在国内外高层层和超高层建筑中已 逐渐得到应用。本文建立了巨型框架结构体系在竖向地震作用下的分析模型及相应的分析方法,其中包括反应谱分析及时程分析,通过具体算例和分析表明竖向地震对此类结构的作用是十分显著的,在巨型结构体系的分析和设计中,竖向地震力是不可忽视,本文进一步地指出：在分析此类结构的地震作用时,“层模型”是不适用的。     

浅液矩形TLD对地震作用下高层振动的控制

在研究TLD减振耗能机理的基础上，分别分析了TLD的主要设计参数，即频率比、深度比及质量比对控制效果的影响，由此给出了对TLD进行有效设计的主要步骤，说明了只要对TLD各参数合理调整，就可以很好地控制结构在地震作用下的响应。     

Decentralized robust control of building structures based on sliding mode theory

In this paper, a decentralized control algorithm is proposed for actively controlling the response of the flexible tall building structures under earthquake excitations. In the proposed approach, tall building structure was divided into some substructures in the form of state equation. The interaction of the subsystems and external excitations is conducted as bounded generalized force acting on the subsystems. A decentralized control algorithm of tall building structures is established based on the sliding model control theory. The control structure is described based on unit vector control. The control law consists of two parts: a linear control law u_L and a nonlinear law u_N. The linear control is merely a linear state feedback controller, whereas the nonlinear feedback controller incorporates the discontinuous or continuous nonlinear elements of the control law. Using the advantage of match conditions of sliding mode theory and the bounded feature of generalized force, the overall stability of decentralized control is also investigated. The actuator arrangement and matching conditions are discussed. The effectiveness of the proposed method is demonstrated by the numerical simulation of the decentralized control of a 20-story benchmark structure under seismic excitations.     

城市污水系统分散与集中处理规划探讨

对深圳市深圳河（湾）流域污水系统规划中的分散与集中处理两种方案进行了分析比较，结果表明，城市污水系统分散处理方案比集中处理方案具有更显著的社会效益、环境效益和经济效益。指出在水资源紧缺和水环境恶化形势日趋严峻的情况下，要转变排水工程的规划理念，从收集处理、达标排放的旧理念转向提高处理深度、污水再生利用、促进水系统健康循环、实现水资源可持续发展的新理念。     

大型复杂结构模糊物理边界划分与多市场竞争控制

基于模糊均值聚类(Fuzzy clustering Method,FCM)理论提出大型复杂结构边界划分方法,通过建立大型复杂结构信息数据矩阵,进而确定数据中心,实现了基于FCM的大型复杂结构边界划分方法。与多市场竞争控制(Multi-Market Based Control,MMBC)理论相结合,形成大型复杂结构分散控制体系。将FCM方法和MMBC理论相结合,对某剪切型半主动控制结构在地震作用下的振动反应进行分析,验证提出的FCM理论应用于子结构边界划分中的有效性,虚拟价格时程曲线反应各子市场价格波动的合理性。分析结果表明,MMBC策略对离散后的子结构中阻尼器出力具有较好的控制作用,同时可以有效减小结构在地震荷载作用下的振动反应。     

Feedback-feedforward control of structures under seismic excitation

While the base acceleration resulting from a seismic activity on a civil engineering structure is not known a priori, it can be measured in real time. In this paper, it is shown that this extra information can be used for achieving a better control of the structure with little additional effort. The approach taken is to augment the equations of motion for the structural system with an appropriate model of the earthquake excitation based on filtering a Gaussian white noise process. The augmented equations of motion are used to determine a control which utilizes both feedback and feedforward compensation. The feedback loop incorporates measurements of the response of the structure into the control law. The information from both the structure and the earthquake excitation model is utilized in the feedforward control law with an observer designed to estimate the states of the eartquake model based upon the base acceleration measurements. A quadratic performance index is used as a measure of optimality of the control algorithms. Results are given which indicate that the proposed method offers advantages in performance over the control method employing only state feedback and that it is also able to improve upon results of the recently develped instntaneous control algorithms. It is also shown that the nostationarity in the earthquake excitation can often be neglected in practical design of linear systems. Finally, a discussion is given of how the method might be coupled with equivalent linearization techniques and extended for use with nonlinear structures.     

高层建筑地震反应的分散最优迭代学习控制研究

针对地震作用下高层建筑结构的振动控制方法进行研究,引入分散控制的策略,将线性二次型最优控制(LQR)与迭代学习控制(ILC)算法原理相结合,提出分散最优迭代学习控制(Decentralized OptimalIterative Learning Control,DOILC)算法并应用于高层结构振动控制中。对某20层钢结构Benchmark结构模型进行数值计算与分析,结果表明,采用分散控制策略的DOILC算法与传统集中控制策略一样可以有效地抑制结构地震反应,相对于集中控制的单一失效分散控制系统的可靠性更强且数据实时处理效率大为提高。     

Optimal control of structures under earthquake excitation based on the colonial competitive algorithm

The active control of engineering structures is one of the best methods to reduce structural responses under seismic excitation for the best performance of structures. This study presents an effective approach for the optimal control of structures under strong ground motion using the colonial competitive algorithm. The colonial competitive algorithm was developed over the last few years in an attempt to overcome the inherent limitations of traditional optimize method. The colonial competitive algorithm has been applied due to its ideal performance in optimal control problem. The effectiveness and performance of the proposed method have been investigated through two numerical examples for the response control of earthquake‐excited structures. The obtained results have been compared with the Linear Quadratic Regulator (LQR) control algorithm, and the performance of the proposed control approach has been found to be better than the LQR controller. Copyright © 2012 John Wiley & Sons, Ltd.     

污水采用集中或分散处理再生回用的经济比较

以费用函数为依据、以临界距离作为污水集中或分散处理再生回用的经济性判据，可以较为简单地解决再生回用水厂的厂址选择问题，提高再生水规划的科学性、合理性和经济性。采用该方法对某市污水再生回用水厂的规划布局进行了分析，结果表明，以所研究区域内集中式污水再生回用水厂为中心，在半径约为5km的范围内可考虑采用集中处理再生回用的方式，此范围外则可采用分散处理再生回用的方式，且分散式回用水区的再生水需水量可达1．25×10^4m^3／d。     

Modified predictive control of structures

A modified predictive control algorithm for the active control of structures is developed in the discrete-time formulation. Before the control algorithm is modified, the predictive control forces are kept constant throughout the predictive time-steps in the predictive control algorithm so that dynamic instability is induced to the control systems for certain numbers of predictive time-steps. After the control algorithm is modified, the predictive control forces are assigned to be linearly related with the predictive structural states so that dynamic stability of the control systems is guaranteed. In addition to the dynamic stability of the control systems, the control performance of the modified control algorithm is also superior to that of the original one. The feasibility of the modified control algorithm is verified through eigenvalue analysis, frequency-domain analysis and time-domain analysis. The tendon control systems of a single-degree-of freedom structure and a three-degree-of-freedom structure are illustrated to demonstrate the control effectiveness of the modified predictive control algorithm.     

极罕遇地震作用下建筑结构一致风险抗倒塌设计方法研究

结合当前国际上以“抗倒塌”为目标进行地震动参数区划和以“一致倒塌风险”为设防目标进行结构抗震设计的发展趋势,针对我国现行建筑抗震设计规范体系中抗倒塌能力评估的局限性,建议了四种一致风险抗倒塌设计方法,详细介绍了四种方法的评价指标与计算过程。考虑极罕遇地震作用,基于极罕遇地震一致风险谱对地震动记录进行了挑选与调幅。以RC框-剪结构作为典型案例,采用四种抗倒塌设计方法进行验算,结果表明：同时考虑地震危险性与结构不确定性影响的全概率方法验算未通过,其余验算方法均通过,这说明了忽略结构所在场地危险性影响会造成结构倒塌性能评估的不准确性,未考虑结构体系多种不确定性影响会高估结构的抗倒塌性能,因此有必要推行“一致风险”的结构设计理念。     

基于一致倒塌风险的建筑抗震评价方法研究

建筑结构的抗震能力、尤其是抗倒塌能力设计目标应根据其所在场地未来一定设计使用年限内可能遭遇的地震危险性来设定。首先介绍了基于动力增量分析（IDA）的结构倒塌易损性分析方法,随后结合地震危险性分析,分别给出了结构抗倒塌能力和结构所面临地震危险性的概率模型,进而根据结构在未来一定设计使用年限内的倒塌概率,对建筑结构的抗地震倒塌风险进行定量评价,并给出了相应的计算方法。以一座7度抗震设防的RC框架结构为例,计算了该RC框架结构在3个同为7度抗震设防而地震危险性不同地区的地震倒塌风险,指出仅以抗震设防烈度作为建筑结构抗震设计的依据所存在的不足,建议应基于一致倒塌风险进行结构抗震设计,并提出了相关结构抗震设计方法需开展的研究工作。