Experimental Investigation of the River Materials Mining Effect on the Scouring Around Armed Pier Groups

Document Type : Research Paper

Authors

1 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, University of Maragheh, Maragheh, Iran.

2 Associate Professor, Department of Civil Engineering, Faculty of Engineering, University of Maragheh, Maragheh, Iran.

3 M.Sc. Student, Department of Civil Engineering, Faculty of Engineering, University of Maragheh, Maragheh, Iran.

Abstract

The scouring phenomenon around the bridge piers depends on the hydraulic properties of the flow, shape, and spacing of the pier relative to each other, the material and grading of the rivers bed. The purpose of this study was to investigate the effect of cavity, caused by materials mining, on scouring around the pier groups. Therefore, in order to reduce the negative effect of this mining, pier groups armed with cable were used. Pier groups were performed of three consecutive piers in the direction of flow. The experiments were carried out in two simple and armed modes (v shape), in sand bed with a median grain size of 0.78 mm, with a length of 4.25 meters, in a canal with 13 meters in length and 1.2 meters in width. The effect of materials mining on scouring in upstream and downstream of the mentioned pier groups was investigated under subcritical flow conditions (range 0.25-0.5). The results showed that in all experiments, materials mining from the upstream of the pier group reduced the scour maximum depth, but mining from the downstream of the pier group increased the scour maximum depth. Also, with increasing the Fraud number from 0.25 to 0.5, the scour depth was significantly increased in all piers and for two beds; without a pithole bed (a) and with a pithole bed (b). So that the least increase in scouring for A and B conditions was about 44 and 66%, respectively for the last pier in downstream pier group and the most increase in scoring was observed to be 75 and 76%, respectively for the first pier in upstream pier group.

Keywords

Main Subjects


Aghli, M. (2012). Effect of combination wrapping cable and collar on scouring depth cylindrical bridge pier groups on rivers meander. In Master's thesis, Shiraz University, Civil engineering department, Faculty of Engineering.(In Farsi)
Beg, M. and Beg, S. (2014). Scour hole characteristics of two unequal size bridge piers in tandem arrangement. J. Hydraulic Eng, 21(1), 85-96.
Chiew, Y. M. (1992). Scour protection at bridge piers. Journal of Hydraulic Engineering, 118(9), 1260-1269.
Chang, W. Y. Lai, J. S. and Yen, C. L. (2004). “Evolution of scour depth at circular bridge piers.” Journal Hydraul. Engineering. 1309, 905–913.
Dey, S., Raikar, R. V. and Roy, A. (2006). Scour at submerged cylindrical obstacles under steady flow. Journal of Hydraulic Engineering, 134(1), 105-109.
Debnath, K. and. Chaudhuri, S. (2010). Laboratory experiments on local scour around cylinder for clay and clay–sand mixed beds. Engineering Geology, 111(1-4), 51-61
Diab, R., Link, O. and Zanke, U. (2010). Geometry of developing and equilibrium scour holes at bridge piers in gravel. Canadian Journal of Civil Engineering, 37(4), 544-552
Desine, M. (2018). Laboratory review of the transfer of pits made under the influence of riverbed materials, in Master's thesis, Maragheh University: Civil engineering department, Faculty of Engineering.(In Farsi)
Elsebaie, I. H. (2013). An experimental study of local scour around circular bridge pier in sand soil. International Journal of Civil & Environmental Engineering IJCEE-IJENS, 13(01)
Graf, W. and Istiarto, I. (2002). Flow pattern in the scour hole around a cylinder. Journal of Hydraulic Research, 40(1): p. 13-20.
Henderson, F. (1966). Open channel flow. Macmillan seris in civil engineering. New York.
Heidarpour, M., Afzalimehr, H., and Khodarahmi, Z. (2008). Local scour protection of circular bridge pier groups using slot. Journal of Agricultural Sciences and Natural Resources, 14(3). (In Farsi)
Ismael, A., Gunal, M., & Hussein, H. (2015). Effect of bridge pier position on scour reduction according to flow direction. Arabian Journal for Science and Engineering, 40(6), 1579-1590.
Izadinia, E. and. Heidarpour, M. (2014). Investigation and comparison of efficiency of cable and groove in protection againest scouring.(in Farsi)
Kothyari, U. C., Garde, R. J. and Ranga Raju, K. G.(1992). “Temporal variation of scour around circular bridge piers.”J. Hydraul. Eng.,1188, 1091–1106.
Kondolf, G.M. (1997). Effects of dams and gravel mining on rivers. Environmental Management. 21(4), 533–551.
Karimaee Tabarestani, M. and Zarrati, A. R. (2012).  Effect of collar on time development and extent of scour hole around cylindrical bridge pier. Int. J. Eng, Transactions C, 25(1), 11-16.
Khwairakpam, P. and Mazumdar, A. (2009). Local scour around hydraulic structures. International Journal of Recent Trends in Engineering, 1(6), 59.
Melville, B. W. (1997). ‘‘Pier and abutment scour — an integrated ap-proach.’’J. Hydr. Engrg. ASCE, 123(2), 125 – 136.
Masjedi, A., Bejestan, M. S. and Esfandi, A. (2010). Experimental study on local scour around single oblong pier fitted with a collar in a 180 degree flume bend. International Journal of Sediment Research, 25(3), 304-312.
Mia, F. and H. Nago. (2003).Design Method of Time-Dependent Local Scour at Circular Bridge Pier.Journal of Hydraulic Engineering, ASCE,117(7:)891-904.
Najafzadeh, M. and Barani, G. A. (2014). Experimental study of local scour around a vertical pier in cohesive soils. Scientia Iranica. Transaction A, Civil Engineering, 21(2), 241.
 
Özalp, M.C. and Z. Bozkuş. (2013). Experimental investigation of local scour around bridge pier groups, MSc thesis, Department of Civil Engineering. The graduate School of Natural and Applied Sciences of Middle East Technical University.
Raudkivi, A.J. and R. Ettema. (1983). Clear-water scour at cylindrical piers. Journal of Hydraulic Engineering. 109(3): p. 338-350.
Rambabu, M. Rao, S. N. Sundar, V. (2003). Current-induced scour around a vertical pile in cohesive soil. Ocean Engineering, 30(7), 893-920.
Rezaei, M. Daneshfaraz, R. Dasine, M. (2018). experimental Investigation of Adding Clay and PAM on Scour Reduction Bridge Piers under the influence Removal of River materials. Journal of Iranian Hydraulic Association,13(3).
Sheppard, D. M. Miller Jr, W. (2006). Live-bed local pier scour experiments. Journal of Hydraulic Engineering, 132(7), 635-642.
Ting, F. C. Briaud, J. L. Chen, H. C. Gudavalli, R. Perugu, S.  Wei, G. (2001). Flume tests for scour in clay at circular piers. Journal of hydraulic engineering, 127(11), 969-978.
Vittal, N. Kothyari, U.C. and Haighghat, M. (1994). Clear Water Scour around Bridge Piers Group,, J. Hydr. Engrg. ASCE, 120(11), 1309-1318.
.