基于风险的液化烃罐区建筑物抗爆荷载评估方法

为合理确定液化烃罐区周边建筑物的抗爆设防荷载，有效进行抗爆设计和防护，建立1套系统的抗爆设防荷载定量评估方法。以某液化烃罐区建筑物为例，计算172个爆炸场景，获得4组累积爆炸频率曲线，基于风险控制标准确定抗爆设防荷载。结果表明:爆炸场景发生频率应包括初始泄漏频率、气象概率、泄漏方向概率和延迟爆炸概率；获得的爆炸超压-累积频率曲线是确定抗爆设防荷载的基础，在爆炸超压较低时，与爆炸源中心距离不同的4面墙体的超压累积频率曲线极为接近；随着爆炸超压的继续增大，累积发生频率的差异逐渐明显；液化烃罐区建筑物的抗爆设防荷载应同时满足2个准则，即万年1次的风险可接受准则和风险可接受范围内爆炸超压最大化准则；根据该准则确定的液化烃罐区附近建筑物东墙的爆炸冲击波峰值入射超压为44.6 kPa，正压作用时间为89.3 ms。

Risk-based evaluation method for blast resistant load of buildings in liquefied hydrocarbon tank farm

In order to reasonably determine the blast resistant fortification load of buildings around the liquefied hydrocarbon tank farm,and effectively conduct the blast resistant design and protection,a set of systematic quantitative evaluation method for the blast resistant fortification load was established.Taking a building in a liquefied hydrocarbon tank farm as an example,172 explosion scenarios were calculated,and 4 groups of cumulative explosion frequency curves were obtained.Finally,based on the risk control standard,the blast resistant fortification load was determined.The results showed that the occurrence frequency of explosion scene should include the initial leakage frequency,meteorological probability,leakage direction probability and delayed explosion probability.Obtaining the explosion overpressure cumulative frequency curve was the basis of determining the blast resistant fortification load.When the explosion overpressure was low,the cumulative frequency curve of overpressure was very close to that of four walls with different distances from the center of explosion source.With the continued increase of explosion overpressure,the difference of cumulative occurrence frequency bacame obvious gradually.Two criteria should be satisfied simultaneously for the blast resistant fortification load of buildings in the liquefied hydrocarbon tank farm,namely the risk acceptance criteria of once every 10 000 years,as well as the criteria of maximum explosion overpressure within acceptable risk standard.According to the established criterion,the peak incoming overpressure of blast wave at the east wall of the building near the liquefied hydrocarbon tank was 44.6 kPa,and the duration was 89.3 ms.