窗口坝是一种坝体开孔尺寸大于切口坝和水平格栅坝的新型透过型拦砂坝，近年来，已在我国开始大量应用。目前，国内外对窗口坝的研究较少，其调控粘性泥石流的拦淤机理尚未揭示，造成在设计过程中没有考虑泥石流的流体性质以及坝体的运行特点，其科学设计尚缺乏理论依据和关键技术参数的计算方法。.本项目以汶川地震灾区大量已实施的窗口坝工程为研究对象，采用野外调查、定点观测、模型实验、数值模拟和理论分析的综合分析方法，探明窗口坝调控粘性泥石流拦砂节流、回淤缓坡的过程和机理。在此基础上，分析窗口坝窗口形状和尺寸对其拦淤性能的影响规律。最后，建立容重降低率、峰值流量削减率、颗粒级配变化率、流速降低率、回淤长度、回淤纵坡等反映拦淤机理的关键性能指标，以及窗口坝临界闭塞条件、高宽比、开孔率等窗口关键设计参数的计算方法，为泥石流拦砂坝设计提供理论依据和技术支撑。

The window-frame dam is a new kind of opening dam type. The drain opening of the dam is larger than the slit dam and the horizontal-grid dam. Recently, the window-frame dam was widely used in China. However, the dam was seldom studied for current researches both at home and abroad. The trapping and back-silting mechanisms of window-frame dam for controlling viscous debris flow have not been revealed. Consequently, the fluid properties of debris flow and the working characteristics of the dam were not considered during the process of dam design. The theory evidence and the calculating method of related technical parameters are lacked for scientifically designing of the dam. . A large number of window-frame dams which were implemented in the Wenchuan Earthquake area are selected as research subjects in this proposed research program. The combined methods of field investigation, on-site observation, laboratory model experiment, numerical simulation and theoretical analysis are used for carrying out this research. Firstly, the trapping and back-silting processes and mechanisms of window-frame dam for controlling viscous debris flow are discussed and revealed. Then, the influence of the shape and size of the drain opening of the dam on the trapping and back-silting function is analyzed. Finally, the calculating methods for the key performance parameters reflecting the trapping and back-silting mechanism (including the change rate of density, peak discharge, velocity and grain composition; back-silting length and slope, etc.), and the key design parameters of the drain opening of the dam (including the critical block condition, height-width ratio, opening ratio, etc.) are established. The research results will provide theory basis and technical support for the design of debris dams.