隔河岩坝GPS自动化监测系统总控软件设计

介绍隔河岩大坝外部观测变形 GPS自动化安全监测系统总控管理软件的总体设计、结构和功能。     

湖南镇大坝安全监测系统回顾及改进

本文通过对湖南镇大坝安全监测系统回顾及其精度剖析，指出监测系统设计和监测设备中存在的问题，并有针对性地结合该大坝的特点，阐述了精度相对较低的项目如何对其观测方法、设备进行改进或改造，以提高观测精度。本文对其他混凝土大坝安全监测系统的设计和改造具有一定的参考价值。     

小湾水电站拱坝混凝土温控措施研究

小湾水电站拱坝温控的重点在：三个方面：混凝土内部最高温度控制、混凝土表面保温和二期冷却。通过计算分析并参考其他工程经验，除采取常规的温控措施外，还需要加强浇筑过程的仓面隔热，严格控制浇筑温度；制冷水采用内循环式供水系统，并加强管理力度减少制冷水的损失，满足冷却水的温度和强度要求；混凝土保温被要粘贴牢固和紧密，拆模后及时进行保温。     

Stress distributions in 2-dimensional, wedge hoppers with circular arc stress orientation — A co-ordinate-specific Lamé-Maxwell model

A 2-dimensional model of stress distribution in a wedge hopper has been developed. This is a co-ordinate-specific version of the Lamé-Maxwell equations in a space frame dictated by the assumption of circular arc, principal stress orientation.A set of orthogonal, independent variables has been defined as x-ψ_o space. x is the vertical height of intersection of the circular principal stress arc with the wedge wall and the radius of the circular arc is proportional to x. ψ_o is the angle that the radius makes to the vertical at the lower arc in the system — lower boundary condition. The second principal stress follows ψ-lines through the vessel from ψ_o at the lower boundary, eventually passing through the vessel wall and leaving the system.The model has been used to integrate the stress equations along lines of principal stress using numerical techniques. An analytical solution has been found at ψ_o = 0 of the same mathematical form as the Enstad/Walker/Walters equations.The model can be used to predict the location of the stable, cohesive arch and to predict unviable stress states in terms of the Mohr-Coulomb yield criterion.There is a requirement for experimental data of internal stress distributions within bulk solids in hoppers and silos to validate this and other models.     

Explicit Schemes for Dam-Break Simulations

Dam-break problems involve the formation of shocks and rarefaction fans. The performance of 20 explicit numerical schemes used to solve the shallow water wave equations for simulating the dam-break problem is examined. Results from these schemes have been compared with analytical solutions to the dam-break problem with finite water depth and dry bed downstream of the dam. Most of the numerical schemes produce reasonable results for subcritical flows. Their performance for problems where there is a transition between subcritical and supercritical flows is mixed. Although many numerical schemes satisfy the Rankine-Hugoniot condition, some produce solutions which do not satisfy the entropy condition, producing nonphysical solutions. This was the case for the majority of first-order schemes examined. Numerical schemes which consider critical flow in the solution are guaranteed to produce entropy satisfying solutions. Second-order schemes avoid the generation of expansive shocks; however, some form of flux or slope limiter must be used to eliminate oscillations that are associated with these schemes. These limiters increase the complexity and the computational effort required, but they are generally more accurate than their first-order counterparts. The limiters employed by these second-order schemes will produce monotone or total variation diminishing solutions for scalar equations. Some limiters do not exhibit these properties when they are applied to the nonlinear shallow water wave equations. This comparative study shows that there are a variety of shock-capturing numerical schemes that are efficient, accurate, robust, and are suitable for solving the shallow water wave equations when discontinuities are encountered in the problem.     

山西省汾河二库枢纽工程建设简介

本文较系统地介绍汾河二库枢纽工程建设的基本情况，并就工程采用的新技术、新工艺、新设备、新材料以及工程建设的主要经济和教训作了简要分析和介绍。     

大坝加高试验温度应力仿真计算与原型监测对比分析

根据现场施工条件,对丹江口大坝2次加高试验进行了温度应力仿真计算,并对现场原型监测资料进行了分析,其计算结果与原型监测结果基本一致.通过对比分析后认为:施工期的温度应力不是控制因素,最大拉应力出现在试验块温度准稳定期,气温年变化是影响新老混凝土结合面应力状态的主要因素;新老混凝土结合面开度随年气温呈周期变化,并且任一时刻,结合面都是部分脱开部分接触.     

柘溪大坝1#支墩劈头裂缝处理及效果分析

本文介绍了柘溪大坝1#支墩劈头裂缝水下处理施工情况,通过施工期间漏水量的变化,分析了影响漏水量变化的因素,通过施工结束后漏水情况,对处理的效果进行了分析。     

寒冷地区面板堆石坝面板顶部止水研究

针对寒冷地区面板堆石坝面板顶部止水遭破坏情况，对破坏机理进行了分析。通过室内试验及现场试验，提出了适合寒冷地区的面板顶部止水结构和止水材料，成功地解决了莲花面板石坝面板止水缝表面防护问题，并为混凝土面板坝的面板顶部止水设计及巳建的面板顶部止水破坏修补提供参考。     

Remedial measures to control seepage problems in the Kafrein dam, Jordan

The Kafrein dam, 480 m long and 30 m high, is located on the Wadi Kafrein, a few kilometres from the active Jordan Valley fault. The Jordan Valley Authority proposed raising the crest of the existing dam by approximately 7 m and extending the length of the embankment to 554 m, in order to increase its storage capacity by 6 million m³ to a total of 8.5 million m³. The paper discusses the likelihood that existing seepage problems will be exacerbated when the dam is raised and proposes some remedial actions to increase the safety of the dam and minimise both the amount of seepage and any adverse effects. Electronic Publication