Monitoring Instrumentation Analysis of the Zayandeh-rood Dam during operation. Aein Horiyat Ae19_ho@yahoo.com 11 th April , 2009 Department of Mining Engineering Isfahan University of Technology , Isfahan 84156-83111, Iran Degree: M.Sc. Language: Farsi Dr. Lohrasb Faramarzi Dr. Morteza Tabaee Dams are very important as view of economic, social and political. Roll of dams in agricultural developments, villages and cities improvement, provide for drinkable water, production of hydroelectric energy, control and adjustment of water flow is very important. Because of high production cost of dams, and damage of them under affection of various events, maintenance of dams is too important. Nowadays, monitoring of big dams done by installation of necessary instruments. Therefore in this thesis, results of instrument, readings in Zayandeh-rood dam consist of pendulums, clinometers, pyrometers, joint meters…., at the beginning of operation and period of last 15years has been analyzed, and reaction of dam has been evaluated. Protection, maintenance and reaction control of dam, distinction of damage and on time repair to prevent of probable danger, at construction or operation time done by instruments. Finally, distinct element model of foundation and body of Zayandeh-rood dam has been product by determination of exact place of instruments, blocks of body dam and continuous assumption of foundation, and then analysis has done by exact geomechanic specifications of foundation. Mohr-coulomb criterion has been used in joints of foundation rock and body. Then measurement of deflection with instrument and calculations from numerical model were compared and a good result gained, so this research has showed that changing in water level produce a large effect on stress and deflection of foundation and body dam. Displacements in block body of dam show that dam have regular and normal behavior, and have desired stability. Key Words Concrete arch dam- Monitoring- Zayandeh-rood-Instrumentation- Numerical Analysis