前言大型河道大落差大流量立堵截流,常碰到抛投方法与抛投强度的关系、立堵投料的稳定吨位选择和龙口护底等重大技术问题。这些问题往往难以单纯依靠模型试验解决。例如:立堵投料在龙口上游角的稳定较平堵复杂,因立堵自上游角下抛投料所遇到的是三向水流条件,常常和模型试验不可避免存在抛投部位的误差性,投料的稳定系数涉及水力因素也较复杂;抛投强度不单纯取决于龙口水力指标,还有龙口护底的要求;模型控制较易,而原型较难。这些问题对立堵截流的顺利与否又至关重要,因而原型所积累的丰富实践经验仍然是重要的参考依据。葛洲坝工程确定采用立堵方案截流。按最终落差3米规模,截流流量为7300～5200秒立米设计,未超过已有立堵实践经验水平,应有成功的把握。但是,以上一些问题,应继续研究。本文拟根据国内外几个原型立堵截流的经验总结,对上述问题加以讨论。 Preface The large-scale large-scale water diversion and blockage flow, often encounter throwing throwing method and cast the strength of the relationship between the standing plug feed stable tonnage selection and Longkou protection and other major technical issues. These problems are often difficult to rely solely on model tests to solve. For example: standing plug feeding stability in the upper corner of the Longkou more stable than the plugging, plugging from the upper corner of the thrown cast material encountered is the three-way flow conditions, often and model tests inevitably exist throwing parts of the error, feeding The stability factor involved in the hydraulic factor is also more complex; cast cast strength not only depends on the Longkou hydraulic indicators, as well as the Longkou protection requirements; model control easier, while the prototype is more difficult. It is also crucial that these issues are opposed to the success or failure of closure and the rich practical experience accumulated by the prototype remains an important reference. Gezhouba dam project to determine the use of legislation blocking closure. According to the final drop of 3 meters scale, intercepting flow of 7300 ~ 5200 seconds cubic meters of design, has not exceeded the level of practical experience plug, should be a success. However, some of the above problems should be further studied. This article will be based on the experience of several prototypes Closure Closure concluded at home and abroad, to discuss the above issues.