Wind-induced Fragility Analysis Of Low-rise Buildings Considering Door & Window Damage

Low-rise buildings are easily destroyed by strong wind for their own characteristics like light weight and small stiffness.A lot of post-disaster damage survey have shown that the serious and highest Wind-induced damage of Low-rise Buildings is usually the damage of building envelope in strong winds.The serious economic losses could be caused by infiltrating rainwater into the internal spaces of the houses when the wall or roof have been damaged,and even people's lives could be threaten by damage and collapse of the houses.In addition,damaged components of building envelope and debris(such as glass,room plate,stone,garbage and other debris)around the house would become wind-borne debris in strong winds,thus threatening the safety of houses is located in the downwind area.Therefore,these studies,which on the damage of the enclosure structure caused by the strong wind and the influence of the wind-borne debris on building envelope,will be of great importance and necessity for disaster prevention,mitigation,and risk control.The main works done in the paper are listed below:(1)The model of wind-borne debris damage for outside door&window was introduced,and the meaning and value of each parameter in the model was defined.The failure probability of the model is very sensitive to the wind speed,the influence of door&window area ratio on the damage probability is not significant,and with the increasing of wind speed,the influence of door&window area ratio on damage probability becomes larger.(2)The internal pressure governing equation for the multiple openings situation was derived through unsteady Bernoulli equation,wind-induced dynamic characteristic of internal pressure response for a building with single,double,triple openings on windward wall were investigated respectively.The study show that the internal pressure response for a building with single opening is consistent with the corresponding external pressure in the opening,and the amplitudes of the internal pressure is slightly larger than one of the external pressure,and the apparent resonance peak can be seen from the power spectral density(PSD).The internal pressure response for a building with double opening is controlled by two openings simultaneously,and is dominated by the larger opening if the sizes of two openings is different,and is close to the average of the two external pressure if the two openings have same size.The internal pressure response for a building with triple openings also has a strong correlation with three external pressures at the openings,and the resonance peak can't be seen from the power spectral density(PSD).(3)The failure probability of roof will increase when the internal pressure response was induced by the damage of Out-side doors and windows,because of the enhancement of lift forces of roof for superimposing internal pressure over the corresponding external pressure.The failure probability of roof is greatest when the wind direction is perpendicular to the wall with doors and windows,and is the least when the wind direction is parallel to the wall with doors and windows.