永冻区低水头水利工程建设实践与分析

Experience and analysis in constructing lowhead water projects in permafrost

永冻区低水头水利工程建设以及维护其稳定性至今仍然是一个大的挑战,一个正确的设计和维护方案可以极大地造福人类。在梳理大坝类型、各种案例以及大坝各部分受损原因的前提下,对小型低水头工程的施工和性能进行分析。指出:(1)要成功地设计和修筑适合永久冻土区的小型低水头工程,需要对工程现场进行充分的调查。(2)在永冻土层上可以修筑冻结型、制冷型和解冻型堤坝,具体实施取决于堤坝的用途、环境条件及冻土条件。(3)实践表明,近年来的溃坝事故多由结构错误所致,因此需要特别注意水利工程的结构安排。(4)在设计低水头工程时,应特别注意一点,即土壤和结构性部件的工程特性在水利设施运转期间会发生变化。(5)针对运转结构的监测不应该局限于一系列标准化观测,且必须符合科学要求。

Constructing and maintain the stability of these water projects in permafrost remain still a challenge today. Correct design and maintenance solution are benefit to the mankind. The paper analyzes the construction and performance of small head water projects on the basis of combing the kinds of the dams, all kinds of cases and the reason of all parts of the dam damaged. It points out： （1）Adequate engineering site investigations are needed to successfully design and construct small head water projects in permafrost areas; （2）Dams built on permafrost can be of a frozen, unfrozen or combined type; depending on the purpose of the dam, and the environmental and permafrost conditions; （3）The practice has shown that the arrangement of structures for hydraulic projects requires special care, as the recent failures have been caused by errors in this aspect; （4）When designing low-head water projects, special attention should be given to the fact that engineering properties of soils and structural elements undergo changes during the operation phase of the facility; （5）Surveillance of operating structures should not be limited to a set of standard observations and must be scientific in nature.