Research On Characteristics Of Wind Load Distribution On Low-rise Gable Roofs Building In Downburst

The downburst field is simulated by RNG k-? turbulence model.On the basis o f comparison b etween th e s imulation a nd th e e xisting t est data f or a single bui lding,t he effect of dow nburst on t he gable r oofs b uilding i s simulated and analysed.Downburst is a kind of common phenomena of severe convective weather.Because o f its specialty of wind p rofile,Downburst can easily c ause strong lo ad e ffect to s tructures.F or t he l ow-rise g able r oofs buildings in engineering,due to specialty of building shapes and application of n ew m aterials,us ually s uffering h eavy l oss c aused by w ind da mage.Especially w hen t he i mpact o f dow nburst,because c urrent c ode f or w ind resistance design is lack,is prone to structural damage and collapse.In recent years,e xtreme c limate a ppears f requently,dow nburst c auses amounts of structural damage.How to carry out the research and guide the building design against wind is the urgent problem to be solved.The downburst field is simulated by RNG k-? turbulence model.On the basis o f comparison b etween th e s imulation a nd th e e xisting t est data f or a single bui lding,t he effect of dow nburst on t he gable r oofs b uilding i s simulated and analysedFirstly,th e a ccuracy o f th e n umerical s imulation me thod is v erified b y combining with the existing experimental data.The results show that the RNG k-? turbulence m odel can b etter s imulate the b asic c haracteristics o f t he downburst wind field.and obtain the wind pressure load value of the building surface accurately.Secondly,CFD numerical method is used to simulate the wind load effect of gable r oofs bui ldings.Focus on t he vi cinity of radial l ocation(r/D =1.0)where wind velocity of downburst is maximum,analyzing that the influence of roof pi tch a nd append c ornice on t he di stribution of w ind l oad.Considering the e ffect of different w ind a ngle on t he di stribution o f w ind l oad i n e ach facade and roof of gable roofs buildings,the distribution law of wind load in the local area of building facades and roof is obtained.The results show that there are significant differences in the law of wind pressure distribution with the change of the slope and the eaves.In the vicinity of radial location(r/D = 1.0)w here w ind v elocity of downburst i s m aximum,t he i ncrease of roof pitch and append cornice have significant effect on t he windward side of the partition near the cornice and the windward roof.The increase in the length of the roof slope or the eaves will lead to an increase in the wind pressure,and the i nfluence o f t he eaves i s m ore pr onounced a nd little a ffect o n th e o ther zones.Under the different wind angle,the local wind pressure of the building have l arger v ariety,and t he p artial w ind p ressure i ncreases o r d ecreases greatly.Finally,for t he di fferent groups l ayout o f t wo-slope r oof buildings.Considering t hat t he c hange o f l ongtitudinal s pacing b etween bui ldings,t he influence of i nterfering bui ldings on wind pressure of i nterfered bui ldings facades and roof is simulated.Considering the effect of different wind angle on the distribution of wind load on gable roofs buildings.Obtaining the wind pressure disturbance law of interfered buildings facades and roof is simulated.