A Survey on Effective Factors in Accidents of Geisour-Gonabad Water Supply Pipeline

Document Type : Research Article

Authors

1 M.Sc. in Civil Engineering Dept., Ferdowsi University of Mashhad, Iran

2 Professor, Civil Engineering Department, Ferdowsi University of Mashhad, Iran

Abstract

In this paper main factors associated with the accidents of Geisour-Gonabad water supply pipeline are investigated including continuous and transient pressures, water hammer control devices, air-valves, environmental conditions, and pipe material quality. The pipeline system is modeled for steady state condition, using WaterGems software, to calibrate Hazen-Williams roughness coefficient. A transient flow is initiated and the pressure heads are measured and compared with the computational pressures from Hammer software. More numerical tests indicate satisfactory performance of the system in the presence of surge control devices. Air-valves have no significant effect on transient flow. Laboratory tests demonstrate that water is neither corrosive nor scale forming.  Finally, ensuring the satisfactory performance of protective devices, corrosion and low quality of pipe material are suggested as the predominant causes in the accidents of this pipeline. Estimating the maximum allowable length of corrosion and failure stresses based on ASME-B31-2009 code and comparing with the measured values confirm this assumption. 

Keywords


گزارش عملکردی برنامه­ وزارت نیرو در بخش آب و فاضلاب طی سال‌های 1385، 1386 و 1387، (1388). دفتر برنامه ریزی تلفیقی و راهبردی.
گزارش واحد بهره‌برداری شرکت آب و فاضلاب استان خراسان رضوی، (1388). آرشیو اسناد شرکت آب و فاضلاب استان خراسان رضوی.
نقشه های چون ساخت خط انتقال آب گیسور-گناباد، (1381). آرشیو اسناد شرکت آب و فاضلاب استان خراسان رضوی.
 
ASME. (2009). Manual for determining the remaining strength of corroded pipelines, ASME B31G-2009, Supplement to ASME B31 Code for Pressure Piping. 
Ghidaoui M., Zhao M., Mclnnis D. A. and Axworthy D. H. (2005). "A review of water hammer theory and practice", Applied Mechanics Reviews, ASME, 58(49), pp. 49-76.
Hyuk J. K. and Jiin-Jen L. (2008). "Computer and exprimental models of transient flow in pipe involving backflow preventers", J. of Hydraulic Eng., 134(4), pp. 426-434.
Larock B., Jeppson W. and Watters G. (2000). Hydraulics of pipeline systems, CRC Press.
Larry W. M. (2000). Water distribution system handbook. McGraw-Hill Press, USA.
Makar J. M. (2002). "Investigating large gray cast-iron pipe failures: a step by step approach", NRC Institute for Research in Construction, National Research Council Canada, pp. 126-139.
Morris, R. E. (1967). "Principal causes and remedies of water main breaks”. J. Am. Water Works Assoc., 59(7), pp 782-792.
Pozos Estrada O. (2007). "Investigation on the effects of entrained air in pipelines", PhD Thesis, Institute of Hydraulic Eng., University of Stuttgart.
Rajani B. and Zhan C. (1996). "Pipe-soil interaction analysis of jointed water mains", Can. Geotech. J., 33(3), pp. 393-404.
Stephenson D. (1989). Pipeline design for water engineers, Elsevier Science Publishers, The Netherlands.
Stephenson D. (1997). "Effect of  air valves and pipework on water hammer pressures", J. Transportation Eng., 123(2), pp. 101-106.
Yilmaz F., Cevher O. and Bayraktar M. (2010). "Ductile iron pipe surface characterization and pinhole formation", 5th Ankiros Foundry congress, Turkey.
Zloczower N. (2009). "Control of transient induced contaminant leakage and infiltration by implementation of air valves", A.R.I. Flow Control Accessories, pp. 164-192.