城市供水管网抗震功能评估与指标对比

Seismic Function Evaluation of Urban Water Supply Network and Comparison of Evaluation Indexes

摘要:

为了对城市供水管网抗震功能作出合理评估，从居民日常生活和城市火场消防两个角度，建立了城市供水管网抗震功能评估方法。该方法首先根据设定的场地峰值加速度并基于管线的地震易损性模型和用户节点的火灾风险模型生成供水管网地震灾害物理破坏情景，然后据此修改供水管网水力模型并利用压力驱动的节点配水量模型进行管网水力平差，最后根据水力平差结果进行了供水管网震后生活需水功能评估和消防需水功能评估，探讨了消防需水对生活需水的影响；同时，揭示了不同峰值地面加速度作用下服务性指标与可靠度指标之间的关系。研究结果表明：在相同峰值地面加速度作用下，基于服务性指标的评估数值均要大于基于可靠度指标的评估数值。在较小峰值地面加速度（0.2 g、0.25 g）作用下，震后生活需水和消防需水均可同时得到满足，消防需水对生活需水影响不大；在较大峰值地面加速度（0.40 g、0.45 g）作用下，由于管网破坏比较严重，震后生活需水和消防需水均不能得到较好的满足，消防需水对生活需水影响也不大；而在中等峰值地面加速度（0.30 g、0.35 g）作用下，消防需水对生活需水有较大影响，约7 %左右。

Abstract:

A novel methodology is established for the reasonable seismic function evaluation of urban water supply network from the perspectives of supplying water for daily living and firefighting. First， based on the seismic fragility model of pipelines and the fire risk model of user nodes， the physical seismic damage scenario of water supply network is generated for the target peak ground acceleration. Next， the hydraulic model is modified according to the physical seismic damage scenario of water supply network while the hydraulic adjustment of water flow in the water supply network is performed based on the pressure-dependent demand model. Afterwards， the function of water supply network for post-earthquake daily living and firefighting is evaluated， and the influence of firefighting water demand on daily living water demand is discussed. Finally， the relationship between serviceability indexes and reliability indexes at different peak ground acceleration is revealed. The numerical results show that at the same peak ground acceleration， the evaluation values based on serviceability indexes are greater than those based on reliability indexes. Under the action of small peak ground acceleration （0.2 g and 0.25 g）， both daily living and firefighting water demand can be met at the same time， and firefighting water demand has little effect on daily living water demand. Under the action of large peak ground acceleration （0.40 g and 0.45 g）， due to the serious damage of the water supply network， both daily living and firefighting water demand can not be well satisfied， and firefighting water demand has little impact on daily living water demand. Under the action of medium peak ground acceleration （0.30 g and 0.35 g）， firefighting water demand has a great influence on daily living water demand， about 7 %.