摘要
为研究我国西北内陆地区典型地貌下风扬沙环境及双坡低矮房屋的风沙荷载特征,通过风沙两相流的风洞测力试验,分析了风速、风向角、沙颗粒粒径等参数对低矮建筑整体受力的影响。结果表明:输沙率随风速正比例增大,随高度反比例指数递减;同一风速下,输沙率从大到小的不同沙粒径依次为混合粒径、细粒径、粗粒径。相比净风而言,风剖面只在高于沙床面约30 cm的范围内发生变化;风沙共同作用对低矮建筑基底合力系数和基底升力系数都有明显的增大作用,且输沙率越大,增大得越明显。
The given paper has done a series of wind tunnel tests in hoping to trace and determine the overall force impact of the wind-blown sand on the nearby low-rise buildings. In the above tests,we have modified the traditional wind tunnel experimental facilities by installing an additional sand basin,known as the sand trap or as a sand-recycle set. And,next,we can trace the different wind speeds,the wind-blowing angles as well as its particle sizes under the effects of the results of the wind force on the low-rise buildings via the data collected from the wind tunnel tests. The findings we have worked out can be shown as follows:(1) The sand bearing or carrying rate(the volume of the sand transferred per unit width and unit time) should be positively related to the wind speed but is negatively related to its height.And,(2) the sand bearing or transporting rate has to be dependent on the particle size of the sand,with the size relationship should be thus: the mixed particle size > the fine particle size > the coarse grain size. And,(3) As compared with that in the net wind field,the wind speed in the wind-sand flowing field tends to change only within a range of 30 cm above the sand bed.What is more,the wind profile has a significant weakening trend only in the range of height mainly due to the large amounts of sand particles within the related height range while the sand movement increases the friction and the turbulence near the ground. And,then,at a height of above 30 cm,the influence would be getting weaker. Furthermore,with the increase of the combined effect of wind and sand,the joint force coefficient and the base lift coefficient of the low building. Moreover,the effect of wind and sand can tend to get stronger when the sand transported rate is greater,with the average increase of the 2 coefficients being 2-10 percents and the standard deviation of them increase by 2-38 percents,as compared with the net wind,the windblown sand tends to produce more significant effects on the standard deviation than the average
作者
丛顺
李正农
宫博
王尚雨
黄斌
CONG Shun;LI Zheng-nong;GONG Bo;WANG Shang-yu;HUANG Bin(Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education,Hunan University,Changsha 410082,China;Key Laboratory of Solar Thermal Utilization and Photovoltaic System of the Chinese Academy of Sciences,Beijing 100190,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2019年第6期1989-2001,共13页
Journal of Safety and Environment
基金
国家自然科学基金项目(51478179,51678233)
关键词
安全工程
风沙荷载
测力试验
低矮建筑
整体受力
输沙率
safety engineering
wind-blown sand
wind tunnel test
low-rise buildings
overall force
sand transport rate
