滑落雪荷载是屋面雪荷载的重要组成部分，是雪荷载规范不可缺少的内容。本项目利用数值模拟、现场实测及风洞试验方法，对屋盖表面滑落雪进行模拟。拟建立建筑屋面雪荷载数值模拟方法，包括适合建筑屋面积雪特点的融雪模型以及考虑风吹雪迁移效应影响的两相流方法，为滑落雪荷载分析提供一种高效高精度的分析工具。在北方多雪地区搭建不同坡度不同覆面材料的斜坡屋盖模型，直接采用天然降雪对屋盖模型进行现场实测。现场实测研究结果将为数值模拟方法提供屋面积雪滑落的判断条件，并验证数值模拟结果的精度，是本项目的重要基础。开展风雪两相的风洞试验，并与考虑雪颗粒迁移堆积效应影响的数值模拟结果进行相互验证，是数值模拟的辅助手段。利用本项目提出的数值模拟方法对我国代表性地区的屋面滑落雪荷载进行模拟，分析气象条件、地域差异、建筑特点等因素及考虑雪迁移效应对滑落雪载的影响规律。最后，总结出方便结构工程师使用的滑落雪荷载简化计算方法。

Sliding snow load on roof surface is an important issue, which is indispensable in the current snow load codes. Thus, the project intends to simulate sliding snow load on roof surface, using numerical method, field observation and wind tunnel test. The numerical method proposed herein, which includes a snowmelt model for building roof and two-phase method considering the effects of snowdrift on sliding snow, is the major tool in the project. Slope roof models with different slope and surface covering materials are built in heavy-snow northern region, and natural snow is adopted to measure the snow sliding off the surface of the model roofs. The critical condition for snow sliding on roofs used in numerical method comes from the achievement of field observation. The field observation, which is the foundation of the project, can validate the results of numerical method. In the two-phase wind tunnel test, some sand-like particles are used to be as an alternative of snow particle. The wind tunnel test is a supplementary means for numerical method. Then the numerical method is used to simulate the sliding snow loads on roofs in several representative regions in China. At the same time, the influences of the features of climate, regional differences, building characteristics and snowdrift, are analyzed. Finally, a simplified method that can calculate the sliding snow loads is summarized for the convenient application of structural engineers.