采暖建筑结构屋面雪荷载实测研究  

Actual measurement research on snow load of heated building roof

作　　者：章博睿 张清文[1,2] 范峰[1,2] ZHANG Borui;ZHANG Qingwen;FAN Feng(Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education,Harbin Institute of Technology, Harbin 150090, China;Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry ofIndustry and Information Technology, Harbin Institute of Technology, Harbin 150090,China)

机构地区：[1]哈尔滨工业大学结构工程灾变与控制教育部重点实验室,黑龙江哈尔滨150090 [2]哈尔滨工业大学土木智能防灾减灾工业和信息化重点实验室,黑龙江哈尔滨150090

出　　处：《建筑结构学报》2019年第6期24-31,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(51478147);国家杰出青年科学基金项目(51525802)

摘　　要：为考虑采暖建筑热环境对屋面雪荷载取值的影响,参考国外规范ASCE/SEI 7-10和ISO 4355:2013雪荷载章节中用以量化该影响的热力系数C_t的取值,设计一种装配式可变屋顶热阻及室内采暖温度的建筑实测模型,并完成对屋面自然降雪(低含水率)及人工造雪(高含水率)表观密度与雪荷载值在融雪期(日最高气温大于0℃)与非融雪期(日最高气温不大于0℃)的实测研究。结果表明,融雪期屋面积雪经历从下部融化湿润、湿润区上迁与融雪水外排的过程,其表观密度与环境温度呈正相关关系,而雪荷载值变化呈现出明显的"三段式"形式,即湿润段、质量损失段及再结晶段。相比而言,采暖建筑屋面积雪在非融雪期变化远小于融雪期的,但二者屋面雪荷载值均反映出随屋顶热量损失的增加而减小的规律。最后依据GB 50189-2015和JGJ 134-2010,计算出各组工况下用以量化计算建筑采暖影响的热力系数C_t值,并对室内需维持在0℃左右的建筑建议该系数取值1. 2。In order to explore the influence of the building thermal environment on the roof snow load,a prefabricated building model for actual measurement was designed based on the requirement of the law of thermal coefficient (C_t) in foreign building load codes (ASCE/SEI 7-10 and ISO 4355: 2013). The proposed model can change the heat resistance of roof and indoor temperature. In detail,the actual measurements of apparent density of snow and snow load under natural snow (with low moisture) and artificial snow (with high moisture) conditions in both the snowmelt period (with daily maximum temperature higher than 0 ℃) and the non-snowmelt period (with daily maximum temperature not higher than 0 ℃) were completed. The results show that the snow-layer on the building roof in the snowmelt period experiences the stages of the melt of lower surface snow,and then upward movement of melt layer with discharge of the snowmelt water. The apparent density and environmental temperature of snow show a positively correlated relationship while the variation of snow load appears a typical three-stage form,including the melting,the mass-loss and the recrystallization. Besides,the variation of snow-layer on the building roof in the non-snowmelt period is less than that in the snowmelt period,but the trend is highly consistent,where the snow load decreases with the increasing of roof heat loss. Finally,according to GB 50189-2015 and JGJ 134-2010,the thermal coefficient values of all measured conditions were calculated,and the C_tvalue of the building with the indoor maximum temperature about 0 ℃ was suggested to be 1. 2.

关 键 词：采暖建筑 屋面雪荷载 实测 表观密度 热力系数 

分 类 号：TU312.1[建筑科学—结构工程] TU317.1