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为准确计算不同参数影响下供水管道的抗震可靠度,依据地震波作用机理,建立地下管道抗震可靠度的功能函数。首先,汲取BP神经网络较强的非线性映射的结构自组织性和自学习性等特点,建立基于神经网络的一次二阶矩可靠度智能计算方法;然后,针对国内最常用的灰口铸铁供水管道,研究剪切波速、特征周期、管径、管壁厚度、地震波入射角对埋地管道失效概率的影响;最后,以秦皇岛市DN300以上的815段地下管道为例,进行不同地震作用下的震害预测。结果表明:一类场地是对管道抗震最有利的地段,四类场地为最不利地段,地震波入射角对管道失效概率的影响在45°左右达到最大值。随着剪切波速的增大、特征周期的减小,管道失效概率随之降低。在二、三类场地条件下可以适当增加管径和管壁厚度,以提高管道抗震性能。秦皇岛市供水管网系统在小震和中震作用下是比较可靠的,在大震作用下损害会很大。
In order to accurately calculate the seismic reliability of water supply pipelines under the influence of different parameters, a function function of seismic reliability of underground pipelines is established according to the mechanism of seismic waves. First of all, based on the self-organization and self-learning characteristics of nonlinear mapping with strong BP neural network, the intelligent method of first-order moment reliability is established based on neural network. Then, according to the most commonly used gray cast iron water supply The influence of shear wave velocity, characteristic period, pipe diameter, wall thickness and incident angle of seismic waves on the failure probability of buried pipelines is studied. Finally, taking the 815-section underground pipe above DN300 in Qinhuangdao as an example, Earthquake damage prediction. The results show that the first type of site is the most favorable for the seismic resistance of the pipeline and the fourth is the most unfavorable location. The influence of the incident angle of the seismic wave on the failure probability of the pipeline reaches the maximum at 45 °. As the shear wave velocity increases and the characteristic period decreases, the probability of pipeline failure decreases. Under the conditions of two or three kinds of sites, the pipe diameter and the thickness of the pipe wall may be appropriately increased to improve the seismic performance of the pipe. Qinhuangdao City, water supply pipe network system in the small earthquake and moderate earthquake is more reliable, under the action of a great earthquake damage will be great.