Study On Effectiveness Of Sunken Square As Fire Seperation

Nowadays, Super underground shopping mall is popular. But there is still a lack ofprovisions on verification for sunken square’s using as fire resistance measure. This papermainly studies the spread of fire smoke in the sunken square when underground shoppingcatches a fire.Firstly, the paper analyzes the fire risk of underground shopping mall and fire resistanceseparations, summarizes fire safety objectives and indicators according to present data. Byestablishing three form model of13×13no shelter, shelter overhead one meter semi-closedand full open,it analyzes the spread of fire and smoke in different wind conditions outside,.The results shows temperature, heat flow of the measuring point in3m high is far less than thecriterion in no shelter form at all speeds of wind, at2.5m/s measuring point gets the highesttemperature, at7m/s the5meters away measuring point gets the maximum heat flow, at5m/s the7m,9m,11m,13m away the measuring point gets the maximum heat flow; Whilesemi-closed model greatly increases the risk,within5m,7m,9m,11m,13m away the heat flowand temperatures of the measuring point excesses the risk criterion in different circumstances;The full open type risk reduced a lot compared with the semi-closed type, but at3.5~4.5m/sthe13meters measuring point is beyond the criterion. Finally, base on the design byimproving the height of overhead, the results show when the semi-closed type overheadheight is2.5m,13m measuring point is below the danger points, when the height is4m, allmeasuring points are under the criterion;11m,13m measuring points in the full open type of1.6m,2.5m height are lower than the risk criterion, when the height is4m,all the measuringpoints are lower than the risk criterion.