埋地球墨铸铁供水管道柔性接口在不同轴向变形下供水功能试验

Test of the Flexible Interface of Ductile Iron Water Pipe Buried under the Water at Different Axial Deformation

目的研究覆土情况下埋地球墨铸铁管道在不同轴向变形下的破坏情况,确定地震作用下管道接口抗拉拔强度,以该指标作为判断管道抗震性能的依据.方法采用T型胶圈连接直径为200mm的球墨铸铁管道.管道埋深为0.6m,下部铺垫0.2m厚的砂土,左侧和右侧分别铺垫0.3m的砂土,进行6种不同位移工况下的静载拉拔试验.结果 48mm、52mm、58mm3个工况属于小位移不漏时的工况,此时水压基本稳定;65mm工况是微漏的工况,水压略微有下降,到0.15MPa仍能能满足供水;68mm是小漏的工况,水压明显下降,降到0.1MPa仍能满足供水;68mm工况以后是全程工况,此时已经大漏,水压迅速下降直至到0,不能满足供水.结论球墨铸铁管柔性接口管道抗震性能较好,胶圈质量对抗震性能有重要影响,增加承插式管道的承口深度有助于提高管道的抗震性能.

Based on the analysis of ductile iron pipe buried under different deformation, the drawing performance of the pipeline in the earthquake could be determined, which could also be taken as a basis for pipe＇s seismic performance. Taking the T-Aprons as the flexible interface of the ductile iron pipe ,pipe,diameter＇s 200 mm,is buried at 0. 6 m deep with 0. 2 m thick sand below, and 0. 3 m thick sand on the right and left sides. Six different displacement conditions were carried out in our tests. The results show that the working conditions of 48 mm,52 mm,58 mm are small displacements, indicating that pipe does not leak, water pressure is stable at this time. However,65 mm＇s condition is the micro-leakage condition, with water pressure dropping slightly to 0. 15 MPa but still meeting the water provision. The 68 mm＇s condition is the small leakage condition, with water pressure decreasing significantly to 0. 1 MPa and still meeting the water provision. When pipe＇s diameter over 68 mm,which led to a large leak,the water pressure decreased rapidly down to 0and it can not provide water at all. In a conclusion, the better flexible interface ductile iron pipe has, the better seismic performance it will produce. Meanwhile the aprons＇ quality places a major impact on the seismic performance,therefore,we make the socket-type pipe＇s socket depth longer to improve the seismic performance of pipelines.