洪水侵袭作用下沿海化工储罐失效机制及概率研究

Failure mechanism and probability of coastal chemical storage tanks under flood attacking

为了研究在洪水侵袭作用下沿海化工罐区储罐的失效机制,基于强度-应力干涉理论,分别建立了装量水平为0.25和0.5时的储罐失效模型,绘制失效曲线,并进一步实现了储罐失效概率的计算,根据洪水流速和淹没深度划分不同的储罐失效概率区域。结果表明,装量水平取0.25和0.5时,立式储罐的临界淹没深度分别为1.805 m和3.339 m,卧式储罐的临界有效淹没深度分别为2.833 m和2.992 m,可知装量水平对立式储罐的影响比卧式储罐更为明显。洪水淹没深度对立式储罐是否失效的影响要大于洪水流速的影响,而洪水流速对卧式储罐是否失效的影响要大于洪水有效淹没深度的影响。

In order to determine the risk of the coastal chemical tanks farm,this paper investigated the failure mechanism and failure probability of chemical tanks under flood attacking.Firstly,the failure models of storage tanks under flood attacking were established based on the strength-stress interference theory.When the stress on the wall of storage tanks is greater than or equal to the critical stress,the storage tanks fail,otherwise,the storage tanks are normal.The two failure models can be established with different types of chemical tanks respectively.The failure mode of vertical tanks is mainly instability collapse,and that of horizontal tanks is mainly failure of anchor bolts.Specifically,for vertical tanks,the tanks fail when the stress on the wall of the tanks is greater than or equal to the critical stress.For horizontal tanks,the failure model was obtained comparing the flood force on the tanks transformed into the stress on the anchor bolts with the allowable stress.Secondly,the failure decision functions of the tanks can be obtained based on the failure models of the first step,and the failure curves of the tank under different flood velocity and flood submergence depths can be drawn.Thirdly,the failure probability of storage tank was calculated,and the different flood flow velocity and flood submergence depths were divided into different failure probability regions finally.After study,the conclusions are as follows:The stability of the tanks can be obviously increased by increasing the critical filling level.When the filling level is 0.25 and 0.5,the critical submergence depth of vertical tanks is 1.805 m and 3.339 m respectively,and that of horizontal tanks is 2.833 m and 2.992 m respectively.By comparison,it is known that the influence of filling level on vertical tanks is more obvious than that on horizontal tanks.For vertical tanks,the influence of flood submergence depth is greater than that of flood velocity.For horizontal tanks,due to the existence of minimum flood velocity,the effect of flood velocity is greater than that of flood effective submergence depths.