海堤加固及穿堤建筑物施工技术要点研究

海堤加固及穿堤建筑物大都建在深淤泥地基上，工程地质条件复杂，对施工技术要求很高。本文对堤防及穿堤建筑物施工的注意事项提出了详细的要求，具有很好的现实意义和可操作性，对解决深淤泥地基上的施工技术难题提出了探索。     

水泥粉喷搅拌桩在马鞍山江堤穿堤建筑物加固中的应用

马鞍山江堤穿堤建筑物大多建筑在淤泥质壤土层上，地基承载力低，压缩性大，因此采用水泥粉喷搅拌桩进行了加固处理。文章介绍了水泥粉喷搅拌桩在马鞍山江堤穿堤建筑物加固中的应用情况，籍以对类似工程提供借鉴。     

珠海海堤淤泥质软土地基处理方案实例解析及效果评价

通过对珠海市乾务赤坎大联围海堤加固达标工程90 km海堤及100多座穿堤建筑物淤泥质软土地基的多种处理方案进行实例解析及工程实施效果评价,归纳总结出具有一定实践指导意义的软土地基处理经验,供类似水利工程设计借鉴参考。     

穿堤建筑物存在的问题及解决措施

穿堤建筑物在沿江堤防工程防汛中,发挥着重要作用。由于经济高速发展,此时很多的穿堤建筑物都建在了江河上面,而穿堤建筑体和两侧的堤坝接洽的是不是固定,对于堤坝的防洪工作来讲意义非常重大。在穿堤建筑物多年的运行过程中会出现一些问题,如:南通市通州区项目所在地的穿堤建筑物部分段堤外坡及堤脚直接面临江水冲刷和长期浸泡,处于比较危险状态。一旦这些潜在的问题发生就会给项目的相关方带来严重的经济损失,还存在防洪安全隐患,不能满足防御标准洪水的要求,有时候还会引发生命财产问题。因此,南通市通州区根据穿堤建筑物存在问题有针对性进行改造加固。     

无为穿堤建筑物主要工程地质问题

对无为大堤穿堤建筑物水文、工程地质条件进行介绍，分析并提出无为大堤穿堤建筑物存在的主要工程地质问题及工程处理建议。     

灌浆技术在水闸除险加固工程中的应用

西江大堤上穿堤涵闸众多,由于大部涵闸地基土为深厚的淤泥层,在两侧连接堤堤身填土边荷栽作用下,涵闸两侧填土和地基土沉陷量大,而当涵闸采用桩基础时,涵闸沉降量相对较小,容易造成不均匀沉降,导致涵闸底板与地基土脱空,涵闸边墙与连接堤回填土之间出现较大缝隙或者疏松带,产生渗透破坏,严重威胁建筑物及大堤安全.本文主要介绍了在江新联围壳滘水闸除险加固工程中,采用灌浆技术加固涵闸基础,以防止涵基发生渗透破坏的工程设计实例.     

浅谈北江大堤除险加固整治的措施

北江大堤在1983－1987年间按百年一遇洪水对堤身加高培厚，现仍存在基础渗漏，河工险段及穿堤建筑物老化破残等问题。作者在此对北江大堤除险加固整治采取的工作措施作一回顾。     

黄河下游堤防安全管理技术探讨

黄河下游堤防的安全涉及堤防本身、穿堤建筑物、河道整治工程等.黄河下游存在"二级悬河",而且堤防多为沙性土构成,平时大多又不偎水,堤身、堤基存在的隐患难以显露,一旦洪水漫滩出槽,将可能引起渗水、崩塌等险情,对堤防安全构成严重威胁,有必要加强堤防安全监测预警工作.针对堤防隐患探测及安全监测、穿堤建筑物土石结合部渗水监测、河道整治工程根石探测与监测、堤防安全评估等存在的问题,探讨了解决途径.     

钢管在小型穿堤建筑物中的应用

防洪堤防工程中,有不少穿堤建筑物,对于大型建筑物,在设备条件、施工环境尚可条件下,一般采用现浇混凝土方法完成.但对于中小型穿堤建筑物,往往施工条件较差,工期要求急,采用现浇便有其各方面难度.介绍了采用钢板卷成管取替穿堤建筑物的洞身部分,通过工程实例获得成功.     

广利电排站穿堤涵地基处理设计

在软土地基上修建穿堤建筑物,基础处理是一个难点,基础设计的关键是解决变形协调的问题.广利电排站穿堤涵软土地基处理采用水泥粉煤灰碎石桩(CFG桩)复合地基技术.本文通过工程实例,介绍了穿堤涵软土地基设计以沉降控制为主的设计理念.     

对流－扩散方程反问题的控制论求解方法

本文从控制论角度将对流－扩散方程反问题提为分布参数系统的最优控制问题，并提出用计算机辅助优化法实现求解。针对环境工程中的污染排放控制问题，应用计算机辅助优化法分别求解了二维非恒定河道边界及源项控制反问题。计算结果表明，计算机辅助优化法对求解对流－扩散方程反问题是行之有效的；应用于污染排放控制计算，可基本解决多个或单个污染源反演问题；与现有的反问题求解方法相比，其优点是求解过程简单、通用性好，因而在环境水力学领域具有较大的实用价值     

水工结构泄流激励动力学反问题研究进展

针对我国水工结构运行过程中存在的诸多安全问题,本文结合泄流激励的特点,从动力学角度对水工结构的反问题进行全面总结。首先阐述了水工结构流激振动动力学正问题研究中所存在的问题以及对水工结构进行动力学反问题研究的必要性与迫切性,流激振动分析所涉及的四类结构动力学问题,以及流激振动动力学正、反问题之间的关系;然后对水工结构反问题从模态参数辨识、激励源辨识、损伤诊断与监测3个方面进行回顾与评述;最后对水工结构反问题研究所面临的问题及研究重点进行展望。     

Calibration of tipping bucket rain gauges

A tipping bucket rain gauge measures rain fall volumes with high resolution, thus enabling calculation of rain intensities. To ensure that the volume of one tipping is independent of the rain intensity a syphon is introduced. However, the syphon introduces problems with respect to both a time lag and problems when reconstructing the underlying rain intensities. This problem is studied in detail. The rain gauge in question is a RIMCO tipping bucket rain gauge, used by the Danish Water Pollution Control Committee (DWPCQ. The rain gauge has been tested in the laboratory and in the field. The study shows, that it is possible to reduce the syphon volume to a level where the problems of the syphon are small and yet maintain the same accuracy with respect to volume registrations.     

Algorithm for Increasing the Speed of Evolutionary Optimization and its Accuracy in Multi-objective Problems

Optimization algorithms are important tools for the solution of combinatorial management problems. Nowadays, many of those problems are addressed by using evolutionary algorithms (EAs) that move toward a near-optimal solution by repetitive simulations. Sometimes, such extensive simulations are not possible or are costly and time-consuming. Thus, in this study a method based on artificial neural networks (ANN) is proposed to reduce the number of simulations required in EAs. Specifically, an ANN simulator is used to reduce the number of simulations by the main simulator. The ANN is trained and updated only for required areas in the decision space. Performance of the proposed method is examined by integrating it with the non-dominated sorting genetic algorithm (NSGAII) in multi-objective problems. In terms of density and optimality of the Pareto front, the hybrid NSGAII-ANN is able to extract the Pareto front with much less simulation time compared to the sole use of the NSGAII algorithm. The proposed NSGAII-ANN methodology was examined using three standard test problems (FON, KUR, and ZDT1) and one real-world problem. The latter addresses the operation of a reservoir with two objectives (meeting demand and flood control). Thus, based on this study, use of the NSGAII-ANN integrative algorithm in problems with time-consuming simulators reduces the required time for optimization up to 50 times. Results of the real-world problem, despite lower computational-time requirements, show a performance similar to that achieved in the aforementioned test problems.     

Hybrid Genetic Algorithm and Linear Programming Method for Least-Cost Design of Water Distribution Systems

The problems involved in the optimal design of water distribution networks belong to a class of large combinatorial optimization problems. Various heuristic and deterministic algorithms have been developed in the past two decades for solving optimization problems and applied to the design of water distribution systems. Nevertheless, there is still some uncertainty about finding a generally trustworthy method that can consistently find solutions which are really close to the global optimum of this problem. The paper proposes a combined genetic algorithm (GA) and linear programming (LP) method, named GALP for solving water distribution system design problems. It was investigated that the proposed method provides results that are more stable in terms of closeness to a global minimum. The main idea is that linear programming is more dependable than heuristic methods in finding the global optimum, but because it is suitable only for solving branched networks, the GA method is used in the proposed algorithm for decomposing a complex looped network into a group of branched networks. Linear programming is then applied for optimizing every branch network produced by GA from the original looped network. The proposed method was tested on three benchmark least-cost design problems and compared with other methods; the results suggest that the GALP consistently provides better solutions. The method is intended for use in the design and rehabilitation of drinking water systems and pressurized irrigation systems as well.     

Irrigation scheduling — Theoretical approach and application problems

The paper presents a theoretical approach to on-farm irrigation scheduling and discusses the problems of its real-life application to cotton farms in Israel. The theoretical approach is based on a loop of Linear Programming and Dynamic Programming problems which sequentially generate new irrigation schedules for the farm's crops in response to shadow prices of water.The major problems in the real-life application of this approach are (i) the lack of generally accepted estimates of cotton response to soil moisture, and (ii) the difficulty in adapting the LP results expressed in terms of continuous variables to the actual field layout and irrigation equipment of the farms. These problems are discussed and solutions are suggested and evaluated.The Hebrew University of Jerusalem, P.O. Box 12, Rehovot, Israel.     

蚁群算法在水科学中的应用研究进展

蚁群算法是优化领域中相对较新的一种随机启发式搜索算法,通过模拟蚂蚁的觅食行为来解决复杂组合优化问题,是迄今为止昆虫算法中较为成功的例子。主要介绍了蚁群算法的生物原理及其算法的基本模型,对近些年来蚁群算法在水土资源新领域中的多种应用研究进行了分析与归纳,并指出了存在的问题及其研究展望。     

Watershed management in Thailand: concepts,problems and implementation

Problems of water resource management are becoming increasingly severe in most countries of the developing world. Already from early in this century it was recognised, wherever water resource management problems began to manifest themselves, that the most appropriate level upon which to study and confront these problems was the river basin. This paper reviews various approaches that have been taken to river basin management and the way in which these have surfaced from the particular range of problems and the political context from which they emerged. Since the end of the 1970s, the rapid development of Thailand has brought into focus the need for integrated resource management as a basis for overcoming increasingly severe problems of drought and flood. Deforestation is seen as a major cause of these problems and so it is in watershed management that the first initiatives are being taken. The paper describes in some detail the system which has been adopted and finally discusses the political and administrative problems facing implementation of the system. © 1998 John Wiley & Sons, Ltd.     

对流域水文模型的再认识

讨论了流域水文模型的本质,指出模型只是原型的近似,不可能反映原型的一切特征,尤其像流域降雨径流形成这样复杂的现象。诠释了"分解"与"集成"的科学思维在流域水文模型建模中的作用。认为只有产汇流理论和集成基本水文现象为流域水文模型的方法有所突破,才会有流域水文模型的实质性进步。分析了流域水文模型反问题不适定的原因,提出了直接最优化方法用于解决流域水文模型反问题时应注意的事项,以及用"大数据"方法解决流域水文模型反问题的设想和初步思路。认为随着水文观测手段的进一步精准,"大数据"方法在解决流域水文模型反问题和正问题中均有美好的应用前景。     

接触问题有限元分析方法综述

从直接迭代法、接触约束法和数学规划法等方面综述接触问题有限元分析的基本方法 .直接迭代法是一种“试验误差”方法 ,概念清楚 ,实施方便 ,但计算工作量较大 ,而且不能保证迭代一定收敛 .接触约束法主要利用罚函数方法或Lagrange乘子法将接触问题转化为无约束问题求解 .数学规划法利用接触问题的互补条件、非穿透条件等 ,将其归结为二次规划 (线性互补 )问题求解 ,这是一种非迭代类解法 ,收敛平稳、迅速 ,计算工作量较小 .文末简单介绍接触问题研究的一些新趋势