- 1 - Considering of Instrumentation Performance Results in Soil Dams and comparing with Numerical Analysis: a case study on Doosti soil dam in Iran Eiman Fathi 1* , Morteza Golestani 2 1) MS.Civil-Geotechnical Expert Engineering, Power Transmission & Distribution Department, Ghodsniroo Engineering Company, Motahari St, Tehran, Iran. Postal Code: 156677535. e-mail:efathi@ghods-niroo.com 2)MS. graduate student of civil engineering, Geotechnical Engineering, Azad Islamic university Tehran central branch. Tehran, Iran. *Corresponding author: Eiman Fathi, e-mail: efathi@ghods-niroo.com. ABSTRACT In this research performance of used instruments in the Doosti dam has been investigated and the efficiency of the cases is analyzed. For this purpose by reviewing the documents and technical reports of dam construction, six sections of instrumentation are selected and some gauges are used as index for considering of dam behavior and comparison of the theory behavior, which has resulted from numerical analysis, to real behavior due to instrumentation. Some of these instruments are Inclinometers, Total pressure cells and Piezometer. All the analysis are arranged according to three types of information; consultant reports, results of numerical analysis and also, technical implication of instruments inspection and finally comparing of them. By and large, the results show that performance of the installed instruments of Doosti dam by existence of these inspection methods is not trustful. KEYWORDS: Instrumentation; Inclinometer; Total pressure cell; Piezometer; Inspection. I NTRODUCTI ON One the most important steps of design and construction of hydraulic structures especially about dams is environmental and social impact assessment that a big factor in this issue is supervision by instrumentation (Costas et al, 2014). It can support this kind of structures in safety and good behavior assessment. The aim of these assessments is prediction of displacement, settlement, stress and other predictable cases in these structures. Due to importance of instrumentation function, it has looked essential to carry out a comprehensive study on the installed devices into dam (Moagedi et al, 2011). Information for considering in this issue is divided into three groups. I) Analyzing and interpretive data which they are delivered by the consultant engineer II) Numerical analysis results III) Interpretations in regard to instruments (Mainali et al, 2015). Finally, by conclusion of all these three groups of information in this investigation, would be tried to deliver comprehensive information about operating of instrumentation of Doosti dam and also some suggestion for the future projects.