水利水电工程专业英语——水工结构篇

水利水电工程专业英语——水工结构篇

1. Planning Approach and its Physical Factors

1.规划方法和物理因素

Dams are one of the groups of important civil engineering work constructed by man for his physical, economic, and environmental betterment. This list also includes waterways, highways, bridges, pipelines, electrical transmission lines, dikes and levees, railroads, tunnels, jetties, breakwaters, docks, irrigation structures, recreational lakes, and others.

大坝是重要的土建工程组之一，由人们以改善其物质、经济和环境的目的而建设。其中还包括航道、公路、桥梁、管道、输电线路、堤坝和防洪堤、铁路、隧道、导流堤、防波堤、码头、灌溉建筑物、旅游湖泊，等等。

In almost every water project plan or situation one or more dams are important elements of a project plan. However, it is seldom that the dam is the sole or only facility. In a flood control plan, a dam and reservoir may be the only project works, but it is more likely accompanied advantageously with levees and other channel control works. In water supply-irrigation, municipal, industrial, and domestic-and in power generation, dams are one of a combination of project features needed to accomplish the desired project. In such cases, the dam cannot be justified independently of the other project facilities. To be economically, financially, socially, and environmentally justified it must be evaluated jointly with the group combination of project features and the total plan evaluated and judged as to its merit. Planning for a dam is one part of the planning process for the total project objective. The location, size, and design of a dam will be influenced, and often controlled, by the selection of the attainable and best warranted overall project plan.

Physical factors of plan formulation include the followings:

在几乎所有的水工程计划或选址中，一个或多个大坝对于一个项目计划来说是非常重要的因素。但是，大坝也很少是唯一的设施。在一个防洪计划中，一个大坝和水库可能是仅有的工作工程，但是它很可能更有效地配有堤坝和其他渠道控制工程。在灌溉供水、市政、工业和生活以及发电中，大坝是为了达到设计目的的项目功能组合之一。因此，大坝孤立于其他的工程设施是不合理的。为了从经济、财政、社会和环境方面证明其合理性，就必须结合项目特点和整个计划对其优点进行评估和判断。对大坝的规划是对整个项目目标规划过程的一部分。大坝的坝址、规模和设计将会受到可达到的和最佳选择的整个项目计划的影响，并且经常受到其控制。

计划制定的物理因素包括以下几个方面：

1.1 Water Supply Available for Development

1.1 可供水量

Except for flood control projects water is the essential commodity; in flood control projects its sudden excess is the problem. The occurrence of surface runoff stream flows results from weather phenomena which are understood only in general principle. For water project planning purposes reliance is placed on the premise of recurring stream flows with future quantities and variations similar to those that have occurred in the past. Direct measurements of flows of some streams over several decades, together with measurements of precipitation over periods of a century or more at some locations, support the premise. Acknowledging that a more extreme flood or drought can occur than has actually been measured or observed in a few recent time periods, the historical measurements of stream flows are accepted as the best available forecasts of stream flow supplies for water conservation developments. Theories and principles of probability of variation of stream flow quantities are sometimes applied, but most commonly an actual record of some years of duration is used, unmodified, for calculating the water conservation accomplishment of a plan. Where measurements have not been made, or only a very few made, at a specific dam site it is possible to estimate or synthesize stream flow statistics at any dam site by reliable correlation methods.

除防洪工程外，水都是必需品；在防洪工程中洪水突然过量则是问题。地表径流河流流量的发生是由仅在一般原则下理解的天气现象引起的。水工程规划目的的依据是基于经常性水流且其未来的水量和变化与过去已经发生过的相类似的前提下。该前提可以靠某些河流径流几十年间的直接测量以及某些地点一个世纪或更长时间的降雨测量来支持。认识到可能发生一个比近段时期所测量或观测更加极端的洪水或干旱，所以河流流量的历史测量值是对水保持发展中河流流量供应现有最佳的预测。径流量变化概率的理论和原则有时是被应用的，但是更常见的是应用多年实际记录、未经修改的值，来计算一个计划中水保持的成就。在某些无测量或少测量数据地区，在某个特定坝址，根据可靠的相关方法可以估计或综合退出任何坝址处的径流数据。

1.2 Flood Flows

1.2 洪水流量

Because of the enormous damage or potential damage caused by a flood of the magnitude that occurs once in a hundred years or less, stream gaging records of 10,20 or 30 years are inadequate, although of some use, in planning flood control projects or for the spillway design of any dam. In addition to any actual measurements of peak flood flows (usually difficult to obtain even when a stream is being gaged) the project planner uses other techniques of estimating the magnitude of floods. These include (1) observations of high water marks evidenced by previous floods and computations of the probable flow from flood channel dimensions, (2) records of actual measurements (including duration time) of high rainfall intensities at weather stations in the watershed area above a dam site or nearest comparable location, applied to computations of runoff resulting there from.

因为由百年一遇或更低的洪水所造成的巨大损害或潜在损害，10、20或30年的流量计量记录是不够的，尽管其在规划防洪工程或在任意大坝溢洪道的设计中有些用处。除了洪峰流量的实际测量值（通常难以获得，即使在流量被测量时）外，项目规划者使用其他评估洪