One of the important methods used by tunnel construction engineers to examine the design, construction safety factor, and tunnel boring procedures is convergence measurement. Larger convergences may lead to safety problems such as rock destruction, boring machines jamming, delays in projects, or even geological disasters, in which case convergence measurement is considered the best method. The goal of this research is introducing a new convergence criterion for water conveyance tunnel based on the data from 31 convergence measurement stations of the Chehel Chay water conveyance tunnel. To achieve this objective, three different methods including statistical (SPSS), artificial neural network (ANN) and numerical modeling (3DEC) have been used. Observation points are defined on the tunnel wall in a realistic numerical modeling to compare the convergence results. The results revealed the success of the artificial neural network and indicated that the network managed to estimate the test data with a high correlation coefficient.

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Careful monitoring in the earth dams, to measure deformation caused by settlement and movement has always been a concern for engineers in the field. In order to measure settlement and deformation of earth dams, usually the precision instruments of settlement set and combined Inclinometer that is commonly referred to IS instrument, will be used. In some dams, because the thickness of alluvium is high and there is no possibility of alluvium removal (technically and economically and in terms of performance), there is no possibility to place the end of IS instrument (precision instruments of Inclinometer-settlement set) in the rock foundation. Inevitably, have to accept installing pipes in the weak and the deformable alluvial foundation that this leads to errors in the calculation of the actual settlement (absolute settlement) in different parts of the dam body. The purpose of this paper is to present new and refine criteria for predicting settlement and deformation in earth dams. The study is based on conditions in three dams with a deformation quite alluvial (Agh Chai, Narmashir and Gilan-e Gharb) to provide settlement criteria affected by alluvial foundation. To achieve this goal, the settlement of dams was simulated by using finite difference method with FLAC3D software and then the modeling results were compared with reading IS instrument. In the end, the caliber of the model and validate the results, by using regression analysis techniques and scrutinized modeling parameters with real situations and then by using MATLAB software and Curve Fitting Toolbox, a new criteria for the settlement based on elasticity modulus, cohesion, friction angle, density of earth dam and alluvial foundation was obtained. The results of these studies show that, by using the new criteria measures, the amount of settlement and deformation for the dams with alluvial foundation can be corrected after instrument readings and the error rate in reading IS instrument can be greatly reduced.