海塘越浪量风险分析

Risk analysis of overtopping rate of seawall

根据现有规范公式计算的海塘越浪量存在一定程度的风险,它主要来自越浪量计算参数的不确定性.对影响海塘越浪量计算不确定性的3种主要因素进行了分析,在此基础上给出了用Monte Carlo方法进行海塘越浪量风险模拟的步骤.一个实例海塘的计算结果表明:按<浙江省海塘工程技术规定>(1999)公式计算的海塘越浪量存在很大的不确定性,海塘越浪量分布在0.044～0.069 m3/(s·m),大于最大允许海塘越浪量[0.05 m3/(s·m)]的概率为88.93%.因此,对重要海塘的越浪量进行物理模型试验验证是十分必要的.

The risk of seawall overtopping rate exists based on the formulas given by the specification in operation, which comes from the uncertainty of the input factors. By analyzing three primary factors affecting the uncertainty of seawall overtopping rate, a model using by Monte Carlo method to measure the risk is provided. The result from an example seawall calculation shows that the distribution of overtopping rate, according to Zhejiang Seawall Engineering Specification （1999）, is ranged from 0. 044 m^3/（s · m） to 0. 069 m^3/ （s · m） , with 88. 93% of probability larger than the maximum allowed value of 0. 050 m^3/ （s · m）. Therefore, it is necessary to use the physical model to verify the overtopping rate for the important seawall design.