高拱坝动力特性与动力响应模型试验研究

高拱坝的动力破坏特性越来越受到关注,动力特性和动力响应是其研究的一个重要方面。通过模型试验的方法研究高拱坝动力特性和动力响应的特征,动力特性试验比较了完好结构与有施工横缝结构的基阶动力特性,表明当结构存在施工横缝时,结构基阶频率降低,阻尼增大。结构动力响应采用振动台模拟地震波激励,试验结果表明,完整结构与有施工缝结构动力响应具体数据不同,但规律相同。加速度最大响应沿拱顶水平向在坝中拱顶的值最大,向两边的坝肩处,加速度最大响应逐渐减小。沿拱坝垂向加速度最大响应从坝顶到基础,响应均逐渐减小。试验结果可为高拱坝结构动力安全研究提供技术依据。     

A PREDICTIVE CONTROL METHOD TO OPERATE WATER GATE OF DAM

A new predictive control method for operating water regulating gate of dams is presented based on a hydraulic model. To consider the hydrodynamic behavior of surface waves through a reservoir, the shallow water equation is used with the discretization by the finite element method. This method provides the appropriate solution of outflow discharge which prevents the overflow of dam by the operation of water gate assuming that the inflow discharge is known as a function of some moment in the future. To show the applicability of this method, one dimensional channels with single and with multiple dams and Moriyoshizan dam reservoir have been computed as the numerical examples. It is shown that the water surface elevation of a reservoir is sufficiently controlled by the present method.     

混凝土面板堆石坝面板缝隙渗流计算模型研究

针对混凝土面板堆石坝面板接缝与面板裂缝的特点,基于等宽缝隙稳定流的运动规律,结合混凝土面板堆石坝的渗流机理,研究建立了面板接缝及面板裂缝的渗流计算模型,并用实例进行了验证。结果表明将等宽缝隙稳定流运动规律应用到面板接缝止水失效且面板产生裂缝情况下面板堆石坝的渗流分析中,可以获得较为准确的结果。且此方法计算过程简单,计算效率高,具有很大的实用性。     

接触爆炸荷载作用下溢流坝的抗爆性能

以黄登重力坝的溢流坝为研究背景,考虑混凝土的高应变率效应,运用Lagrange-Euler耦合算法建立大坝-库水-空气-炸药全耦合数值模型,研究溢流坝在接触爆炸荷载作用下的抗爆性能。分析满库与空库时溢流坝在爆炸冲击波作用下的动力响应及损伤程度,并进一步研究满库时大坝在不同炸点的水下接触爆炸荷载作用下的动力响应及损伤分布。研究结果表明,满库时水下爆炸比空库时爆炸的动力响应及损伤程度大得多;溢流坝的抗爆薄弱部位主要集中在溢流道顶部及坝体上游折坡处。研究溢流坝的抗爆性能时应重点研究满库时水下爆炸对大坝的破坏特性。     

Shape optimal design of arch dams including dam-water–foundation rock interaction using a grading strategy and approximation concepts

Optimal design of arch dams including dam-water–foundation rock interaction is achieved using the soft computing techniques. For this, linear dynamic behavior of arch dam-water–foundation rock system subjected to earthquake ground motion is simulated using the finite element method at first and then, to reduce the computational cost of optimization process, a wavelet back propagation neural network (WBPNN) is designed to predict the arch dam response instead of directly evaluating it by a time-consuming finite-element analysis (FEA). In order to enhance the performance generality of the neural network, a dam grading technique (DGT) is also introduced. To assess the computational efficiency of the proposed methodology for arch dam optimization, an actual arch dam is considered. The optimization is implemented via the simultaneous perturbation stochastic approximation (SPSA) algorithm for the various conditions of the interaction problem. Numerical results show the merits of the suggested techniques for arch dam optimization. It is also found that considering the dam-water–foundation rock interaction has an important role for safely designing an arch dam.     

Polymer Crystallization Influenced by Initial Orientation of Cylindrical Diblock Copolymers in Thin Films

The effect of the initial states (disordered perpendicular cylinder structure vs. parallel cylinder structure) on the crystallization of polystyrene‐block‐poly(ethylene oxide) (PS‐b‐PEO) thin films during cyclohexane annealing was investigated. The cylindrical domains perpendicular or parallel to the surface were obtained by controlling the film thickness. During solvent annealing, for the film with the perpendicular cylinders, the ordering degree of cylinders was increased. The enthalpic increase is large enough for the forming of square‐shaped crystals, and subsequently the square‐shaped single crystals surrounded by the ordered hexagonally packed perpendicular cylinders evolved to the dendrite ones. For the film with the parallel cylinders, the parallel cylinders were translated to the perpendicular ones. The increased enthalpy was not large enough for the formation of square‐shaped single crystals. Instead, the dendrite‐like crystals started at the edge of terraces.

     

赞比西河水资源调度

研究了赞比西河水资源的调度决策问题。赞比西河上的卡里巴大坝年久失修,赞比西河管理局给出了3种方案:维修、重建或用多个大坝代替现有的卡里巴大坝。通过查阅赞比西河相关资料及沿岸的地形地貌信息,首先确定了11个大坝的地理位置及每个大坝发电机组的装机容量,目标是满足水库附近居民及工农业的用水和用电需求;其次,根据投入产出比对管理局提出的3种方案进行了评价,以确定最优决策方案;最后,基于多坝替代系统建立了梯级水库的水资源调度模型,利用坐标轮换方法分别对平水年、丰水年和枯水年进行了水资源调度。模型的敏感性分析表明调度方案模型是稳健的,建立的调度模型符合实际,使得多坝系统水管理能力增强。     

水坝崩溃的计算机模拟

本文用求解化学流体力学基本方程组的方法研究了不可压自由表面问题,着重引入了流体体积分数技术,建立了水坝倒塌问题的物理模型,运用该技术和模型,计算得到了水流的速度和压力在空间的分布及其随时间的变化,与实验观测一致.     

在电厂贮灰场上修建10．50米高灰坝的一个成功实例

本文以工程实践,论述了电厂废料粉煤灰渣这种特殊类土的形成,物理力学特征,以及应用其修建我国最高的灰坝的经验。这个灰坝经过三年的安全贮灰运行验证,证明是成功的,创造了应用电厂粉煤灰渣修建国内最高灰坝,并安全贮灰的新纪录。