基于等效场景的供水管网抗震可靠性评估

Seismic reliability assessment of water supply pipeline networks based on equivalent scenario

供水管网抗震可靠性是满足用户在可能地震作用下用水需求的能力。目前,多数供水管网抗震可靠性评估采用蒙特卡洛模拟产生大量的震损样本进行评估。然而,此方法在评估大型、复杂管网时,将带来极大的工作量和超高的时间成本。为了克服这些问题,提出等效场景方法以提高计算效率。首先,利用震损场景生成后验概率;然后,利用后验概率生成等效场景;最后,通过等效场景确定节点可靠性指数和系统可靠性指数。将文中所提算法与传统蒙特卡洛方法的模拟结果进行对比。研究结果表明:基于后验概率生成等效场景方法是可行的;地震烈度8度时采用100个等效场景评估其可靠性,存在少数评估误差超过10%的节点,其余小地震烈度评估误差均小于5%。将100个等效场景提高至250个,可将评估误差控制在5%以内。因此,该文提出的算法可以在保证结果准确的同时提高计算效率。

The seismic reliability of water supply networks refers to its capacity to satisfy water demands of customers in the presence of potential seismic events.Currently,the majority of seismic reliability assessments for water supply networks employ Monte Carlo simulations to generate numerous seismic damage samples for evaluation.However,this approach becomes highly demanding in terms of labor and time when assessing extensive and intricate networks.To address these challenges,the equivalent scenario method is proposed as a means to enhance computational efficiency.The proposed method involves the generation of posterior probabilities using seismic damage scenarios.Subsequently,these probabilities are employed to generate equivalent scenarios.Finally,the equivalent scenarios are utilized to determine both the node reliability index and the system reliability index.The simulation results obtained using the proposed algorithm are then compared with those obtained using the traditional Monte Carlo method.The results demonstrate the feasibility of generating equivalent scenarios based on posterior probabilities.Specifically,when evaluating the reliability of 100 equivalent scenarios at a seismic intensity of 8 degrees,a few nodes exhibit evaluation errors exceed 10%,while the evaluation errors for the remaining nodes at lower seismic intensities are below 5%.Additionally,the evaluation errors for small seismic intensities are all below 5%.Moreover,increasing the number of equivalent scenarios from 100 to 250 can further reduce the assessment error to less than 5%.Thus,the algorithm proposed in this paper ensures accurate results while enhancing computational efficiency.