Investigating the Influence of Penetration Length of Cut-off Wall on its Dynamic Interaction with Core and Foundation of Earth Dam

Mehran Javanmard, Reza Mottaghi, S. M. Mir Mohammad Hosseini

Abstract


Seepage and flow of water in the soil is one of the most important issue and effective elements in designing embankment dams. One of the methods to control seepage in alluvial foundation of earth dams is to use a plastic concrete cutoff-wall. For better seepage control, the cutoff-wall extends inside the clayey core as the one of common method of connection of cut-off wall and the core. Due to the stiffness difference of the core material and cutoff-wall, and also due to geological situation, physical and mechanical properties of rock and foundation, interaction of core and foundation with cut-off wall in different static and dynamic load cases is very considerable. Failure of cut-off wall occurs in cut-off wall and core joint.  So the study of their interaction, especially during an earthquake is very important. Karkheh dam cut-off wall with an area of about 150000 m2 is chosen for this study. FLAC software has been used to study the effect of cutoff-wall penetration length variation, inside the clay core of Karkheh earth dam under dynamic loading.  In numerical analysis of Karkheh earth dam model, all construction stages and seepage through dam are modelled. The model is first calibrated according to the results obtained from the dam instrumentations. After calibrating, according to available seismic studies of region, a suitable acceleration was selected and applied to the model. In this research, in order to find the optimum length, the effect of 0, 5, 10, 15 and 20 meters penetration length of cut-off wall in aforementioned conditions has been investigated. The results of the numerical study showed that the horizontal displacement and the maximum shear strain in the cutoff-wall is occurred adjacent to the clay core and the interface of core and foundation is a critical point for the cut-off wall, and also the stress in cut off wall joint increases with the elongation of penetration depth of the wall.


Keywords


Karkheh; Dam; Cut-off Wall; Core; Plastic Concrete; Seepage; Earthquake.

References


Ebrahimzadeh, Issa, Maasume Barari, and Ebrahim Dehani. "An Analysis on the Rate of Realization of Sustainable Urban Development Indicators in Middle the Cities Case Study: Iranshahr City., Geography and Development Iranian Journal, Vol. 16, Issue 50, 1397, 1-22, doi:10.22111/gdij.2018.3549.

Kazemian, S., and S. Ghareh. “Effects of Cement, Different Bentonite, and Aggregates on Plastic Concrete in Besh-Ghardash Dam, Iran.” Journal of Testing and Evaluation 45, no. 1 (December 22, 2016): 20160161. doi:10.1520/jte20160161.

Kazemian, S., and S. Ghareh. “Effects of Cement, Different Bentonite, and Aggregates on Plastic Concrete in Besh-Ghardash Dam, Iran.” Journal of Testing and Evaluation 45, no. 1 (December 22, 2016): 20160161. doi:10.1520/jte20160161.

Mahboubi, Ahmad, and Ali Ajorloo. "Experimental study of the mechanical behavior of plastic concrete in triaxial compression." Cement and concrete research 35, no. 2 (2005): 412-419.

Kazemian, S., Ghareh, S., & Torkanloo, L. “To Investigation of Plastic Concrete Bentonite Changes on it's Physical Properties” Procedia Engineering 145 (2016): 1080-1087. doi:10.1016/j.proeng.2016.04.140.

Hekmatzadeh, Ali Akbar, Farshad Zarei, Ali Johari, and Ali Torabi Haghighi. “Reliability Analysis of Stability against Piping and Sliding in Diversion Dams, Considering Four Cutoff Wall Configurations.” Computers and Geotechnics 98 (June 2018): 217–231. doi:10.1016/j.compgeo.2018.02.019.

Liu, Si-hong, Liu-jiang Wang, Zi-jian Wang, and Erich Bauer. “Numerical Stress-Deformation Analysis of Cut-Off Wall in Clay-Core Rockfill Dam on Thick Overburden.” Water Science and Engineering 9, no. 3 (July 2016): 219–226. doi:10.1016/j.wse.2016.11.002.

Aghajani, Hamed Farshbaf, Mahsa Mousavi Anzabi, Zahra Sheikhi, and Rahele Shokri. "Selecting Optimum Cutoff Wall Position for Rehabilitation of an Inclined Core Earthfill Dam." In GeoShanghai International Conference, pp. 252-260. Springer, Singapore, 2018. doi:10.1016/j.compgeo.2018.02.019

ICOLD, (1985). Filling Materials for Watertight Cutoff Walls, Bulletin 51, International Committee on Large Dams.

Zoorasna, Zakaria, Amir Hamidi, and Ali Ghanbari. "Mechanical and hydraulic behavior of cut off-core connecting systems in earth dams." Electronic Journal of Geotechnical Engineering 13, no. K (2008): 1-12.

Mahab Ghodss Co., Karkheh Dam Section Engineers, Karkheh Dam Cutoff Wall Technical Specification, Eng., Tehran, (1995).

Mahab Ghodss Co. Karkheh Dam Section Engineers, Karkheh Project Technical report of Dam-Body and Foundation Eng., Tehran, (1998).

FLAC Version 6 User's Manual, Itasca Consulting Group, Inc., Fast Lagrangian Analysis of Continua, Minneapolis, Itasca, (2007).

Khan, M. Y., J. T. Kolawole, W. P. Boshoff, and R. Combrinck. "Influence of relaxation and cyclic loading on the tensile material properties of plastic concrete." 2nd International RILEM/COST Conference on Early Age Cracking and Serviceability in Cement-based Materials and Structures (EAC2), 12-14 September 2017, ULB-VUB, Brussels, Belgium.

Yu, Xiang, Xianjing Kong, Degao Zou, Yang Zhou, and Zhiqiang Hu. “Linear Elastic and Plastic-Damage Analyses of a Concrete Cut-Off Wall Constructed in Deep Overburden.” Computers and Geotechnics 69 (September 2015): 462–473. doi:10.1016/j.compgeo.2015.05.015.

Ghaderi, Roonak, Sam Helwany, Jonathan T. H. Wu, Philip Meinholz, and Vahid Alizadeh. “Seismic Behavior of Geosynthetic-Reinforced Soil (GRS) Bridge Abutments with Concrete Block Facing—an Analytical Study.” Transportation Infrastructure Geotechnology 4, no. 2–3 (July 17, 2017): 52–83. doi:10.1007/s40515-017-0041-y.

Mahvelati, Siavash, Alireza Kordjazi, and Joseph Thomas Coe. “A Review of Seismic Geophysical Testing in Iran for Building Near-Surface Velocity Models.” The Leading Edge 37, no. 1 (January 2018): 68a1–68a10. doi:10.1190/tle37010068a1.1.


Full Text: PDF

DOI: 10.28991/cej-03091217

Refbacks

  • There are currently no refbacks.




Copyright (c) 2018 Mehran Javanmard, Reza Mottaghi, S. M. Mir Mohammad Hosseini

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
x
Message