给水管道地震作用下可靠度分析

Analysis of Seismic Reliability of Under Ground Water-Supply Pipe

目的研究给水管道在地震作用下地面运动具有很大非平稳性时的可靠度.方法将地面运动看作在时间和空间上分布的随机过程.建立地下供水管道在地震力作用下的力学模型、数学模型,地下供水管道在非平稳激励下的响应数学表达式,可靠度数学表达式.采用首次超越破坏理论分析管道的可靠度.结果7度地震作用下的接口可靠度为0.992;在8度地震作用下的接口可靠度为0.978;在9度地震作用下的接口可靠度为0.914.并且随地震烈度的加大,其可靠度降低幅度不大.结论U-PVC管道接口较铸铁管道接口有更高的可靠度,U-PVC管道可以在震害中更好地保证管网的供水功能.

The purpose of this paper is to study on seismic reliability of water- supply pipes under non- stationary earthquake. Considering the ground motion as random process on time and space. Establishing the dynamic and mathematic formula of buried pipes under earthquake, the mathematic formula of pipes under non- stationary process, and the formula of pipes＇ seismic reliabilities to use the first overpass probability theory to give analysis about pipes＇ reliability. As a result we get the seismic reliable degree of U- PVC under different seismic intensities： under 7 seismic intensities, the result is 0. 992;under 8 seismic intensities, the result is 0. 978;under 9 seismic intensities, the result is 0. 914. And we also find U- PVC pipes don＇t have much decrease with a higher seismic intensity. They have a higher reliable degree comparing to cast iron pipes. U - PVC pipes can protect web water supply function under earthquake.