In the process of quantifying optimum seismic design parameters, the losses implying the failure of the system must be assessed. Intangibles such as human lives may lie among indirect losses. In this paper, we propose...In the process of quantifying optimum seismic design parameters, the losses implying the failure of the system must be assessed. Intangibles such as human lives may lie among indirect losses. In this paper, we propose a model to calculate the value of the investment that society should be willing to make for saving lives. In order to do this, we analyze both individual and social problems. However, special treatment is given to the individual problem where the value of the life of a human being is inferred by what the person should be willing to pay or willing to accept to reduce the risk of dying. Due to the use of utility curves in the calculation of this kind of intangible, we pay special attention to shape and requirement conditions of these curves. We also pay attention when personal impact and legacies or bequests are considered in utility curves. The results are shown through some applications, especially in the computation of optimum seismic design coefficients at a low seismicity site.展开更多
Currently, second generation intact stability criteria are being developed and evaluated by the International Maritime Organization(IMO). In this paper, we briefly present levels 1 and 2 assessment methods for the cri...Currently, second generation intact stability criteria are being developed and evaluated by the International Maritime Organization(IMO). In this paper, we briefly present levels 1 and 2 assessment methods for the criteria of pure loss of stability and parametric roll failure modes. Subsequently, we show the KG_(max) curves associated with these criteria. We compute these curves for five different types of ships and compare them with the curves embodied in the current regulations. The results show that the safety margin ensured by the first level-1 method of calculation for both pure loss of stability and parametric roll seems to be excessive in many cases. They also show that the KG_(max) given by the second level-1 method and by the level-2 method may be very similar. In some cases, the level-2 method can be more conservative than the second level-1 method, which is unanticipated by the future regulation. The KG_(max) curves associated with parametric roll confirm that the C11 container ship is vulnerable to this failure mode. The computation of the second check coefficient of parametric roll level 2(C2) for all possible values of KG reveals the existence of both authorized and restricted areas on the surface formed by both the draft and KG, which may replace the classical KG_(max) curves. In consequence, it is not sufficient to check that C2 is lower than the maximum authorized value(R_(PR0)) for a fixed ship's loading condition.展开更多
合理的地震灾害经济可接受风险水平可以有效管理防灾减灾的投入。基于1991~2020年中国内地地区地震灾害经济损失数据,利用F-D曲线法(Frequency-Damage curve),建立不同震级(M S<5.0、M S 5.0~5.9、M S 6.0~6.9和M S≥7.0)和不同灾情...合理的地震灾害经济可接受风险水平可以有效管理防灾减灾的投入。基于1991~2020年中国内地地区地震灾害经济损失数据,利用F-D曲线法(Frequency-Damage curve),建立不同震级(M S<5.0、M S 5.0~5.9、M S 6.0~6.9和M S≥7.0)和不同灾情等级(微灾、小灾、中灾、大灾和巨灾)的地震灾害经济可接受风险曲线,并以此为标准讨论30年间由地震产生直接经济损失事件的可接受风险等级。研究结果表明:中国内地地区地震灾害造成0.020亿元直接经济损失的灾损率不超过1.29×10-2/a为可接受经济风险,直接经济损失超过14.763亿元其灾损率为任意值均是不可接受经济风险。由此判断,30年间有18.07%的地震灾害属于不可接受经济风险事件。同理,不同震级和不同灾情等级地震灾害的可接受经济风险水平也被确定,并得到M S<5.0、M S 5.0~5.9、M S 6.0~6.9和M S≥7.0地震灾害分别有23.91%、27.45%、34.78%和30.77%的事件属于不可接受经济风险,微灾、小灾、中灾、大灾和巨灾地震分别有56.00%、48.62%、41.73%、40.00%和44.44%的事件属于不可接受经济风险。该研究结果可以为我国地震灾害经济风险的防范提供相关的理论和实践支撑。展开更多
文摘In the process of quantifying optimum seismic design parameters, the losses implying the failure of the system must be assessed. Intangibles such as human lives may lie among indirect losses. In this paper, we propose a model to calculate the value of the investment that society should be willing to make for saving lives. In order to do this, we analyze both individual and social problems. However, special treatment is given to the individual problem where the value of the life of a human being is inferred by what the person should be willing to pay or willing to accept to reduce the risk of dying. Due to the use of utility curves in the calculation of this kind of intangible, we pay special attention to shape and requirement conditions of these curves. We also pay attention when personal impact and legacies or bequests are considered in utility curves. The results are shown through some applications, especially in the computation of optimum seismic design coefficients at a low seismicity site.
文摘Currently, second generation intact stability criteria are being developed and evaluated by the International Maritime Organization(IMO). In this paper, we briefly present levels 1 and 2 assessment methods for the criteria of pure loss of stability and parametric roll failure modes. Subsequently, we show the KG_(max) curves associated with these criteria. We compute these curves for five different types of ships and compare them with the curves embodied in the current regulations. The results show that the safety margin ensured by the first level-1 method of calculation for both pure loss of stability and parametric roll seems to be excessive in many cases. They also show that the KG_(max) given by the second level-1 method and by the level-2 method may be very similar. In some cases, the level-2 method can be more conservative than the second level-1 method, which is unanticipated by the future regulation. The KG_(max) curves associated with parametric roll confirm that the C11 container ship is vulnerable to this failure mode. The computation of the second check coefficient of parametric roll level 2(C2) for all possible values of KG reveals the existence of both authorized and restricted areas on the surface formed by both the draft and KG, which may replace the classical KG_(max) curves. In consequence, it is not sufficient to check that C2 is lower than the maximum authorized value(R_(PR0)) for a fixed ship's loading condition.
文摘合理的地震灾害经济可接受风险水平可以有效管理防灾减灾的投入。基于1991~2020年中国内地地区地震灾害经济损失数据,利用F-D曲线法(Frequency-Damage curve),建立不同震级(M S<5.0、M S 5.0~5.9、M S 6.0~6.9和M S≥7.0)和不同灾情等级(微灾、小灾、中灾、大灾和巨灾)的地震灾害经济可接受风险曲线,并以此为标准讨论30年间由地震产生直接经济损失事件的可接受风险等级。研究结果表明:中国内地地区地震灾害造成0.020亿元直接经济损失的灾损率不超过1.29×10-2/a为可接受经济风险,直接经济损失超过14.763亿元其灾损率为任意值均是不可接受经济风险。由此判断,30年间有18.07%的地震灾害属于不可接受经济风险事件。同理,不同震级和不同灾情等级地震灾害的可接受经济风险水平也被确定,并得到M S<5.0、M S 5.0~5.9、M S 6.0~6.9和M S≥7.0地震灾害分别有23.91%、27.45%、34.78%和30.77%的事件属于不可接受经济风险,微灾、小灾、中灾、大灾和巨灾地震分别有56.00%、48.62%、41.73%、40.00%和44.44%的事件属于不可接受经济风险。该研究结果可以为我国地震灾害经济风险的防范提供相关的理论和实践支撑。
