One of the most important issues in the design and implementation of engineering structures is to evaluate and investigate their durability against processes of consecutive wear, wet and dry. The durability of rock is resistance against chemical and physical weathering, the shape, size and status of the initial appearance in a long time and environmental conditions prevailing in the rock, hence it is important to evaluate the durability of rock. Since the device of standard durability (Franklin & Chandra, 1972) designed to evaluate and investigate durability of soft and argillites rocks. So, appears to be essential to design a durability device, which can evaluate hard rocks. For this purpose, Researchers of the Department of Geological Engineering, Tarbiat Modares University, durability device as «large-scale durability device» was designed and built which the length and diameter of the device, is 6 and 4.3 times standard durability device, respectively, and needs 10 samples with weight of 400 to 600 g. In order to investigation the applicability of this device for hard rocks durability, we selected 17 building rocks samples of the igneous, sedimentary, metamorphic and pyroclastic rocks. Then their mineralogical, physical and mechanical properties were investigated. More, experiments of standard and large-scale durability up to 15 cycles were performed and data obtained were analyzed. The results show that, the large-scale durability device than standard durability, have more applicability for evaluating the durability of hard rocks.

Discontinuities usually rule the mechanical behavior of a rock mass. The free surface of geotechnical structures such as dam foundations, powerhouses, slopes, and tunnel walls, are also significantly affected by discontinuities. Besides, when the intact material is relatively strong, the effect of discontinuities and their properties would even increase. The direct shear test is a well-known test for determining the shear strength of saw-cut surfaces and natural joints of rocks, which provide the most valuable results for engineering design parameters. The shear strength of concrete layers in Rolling Compacted Concrete dams (RCC dams) is also considered a crucial engineering design parameter. This parameter is additionally determined by direct shear testing on the cored samples of a dam body. The in-situ direct shear test is the most precise direct shear test, among other direct shear test types. However, due to the enormous costs and difficult executive operations of the in-situ direct shear test at sites, the direct shear test would be conducted in the laboratory most of the time. The laboratory direct shear test could be conducted at small and large scales. In case that the subjected project has great importance, by using the large scale laboratory direct shear test, more precise results would be acquired. For this purpose, the Azmouneh Foulad Consultant Engineers Co. has designed and manufactured a large scale direct shear box that can be used for more accurate simulation of the in-situ direct shear test. This shear box, which is unique in its category, is capable of 35×35 cm samples testing.

North Atlantic Oscillation (NAO) is one of large-scale signal that affects the north hemisphere. Various studies have investigated the correlations between Iran’ s precipitations and North Atlantic Oscillation from monthly to yearly scales. This study has considered weekly time scale. The daily precipitation variable was obtained from the ERA-Interim database (grid) and its compliance with ground reference points (synoptic) were investigated (1979-2016). The results showed that the amount of annual precipitation in regions with more humidity, especially in the Caspian region, is underestimated. Also, the correlation between grid and synoptic precipitation data in the western, northeastern and southeastern area of the country is the highest and in the strip parallel to the western-eastern line (the middle areas) is the lowest (weekly average). This correlation decreases from winter to autumn and spring, respectively. A review of the time series of the sever events of NAO during the year with the weekly scale showed that this signal had two peaks, which was used to select the time period of assessing the relationship between precipitation in Iran and NAO. The results showed that the correlation between grid precipitation and NAO is not completely direct and relative frequency of direct correlation is more than non-direct type and decreases from north to south.

In this research, a truss model is introduced to simulate the in-plane behavior of masonry walls in different failure modes. In the proposed model, the structural members are divided into smaller two-dimensional panels and then a truss system is used to model each panel. How to determine the geometry, dimensions and behavioral model of these truss elements are introduced according to the behavioral mechanism and failure modes of the masonry wall. The dimensions of the truss members are determined in such a way that the stiffness of the truss model is the same as the stiffness of the initial panel, under different loads. In this regard, the computational method introduced by Aghababaei is used. The elasto-plastic-fracture model developed at the University of Tokyo is used for compressive behavior of elements. Barimani et al. evaluated and verified the accuracy of this model. Also for tensile and post cracking behavior of masonry, the tension softening model of Maekawa et al. is used. In order to apply the effects of cracking on the compressive behavior of the diagonal elements, a softening model dependent on the crack width is introduced. The idea used is generally based on the smeared crack approach. In this model, after identifying the pair of each diagonal element and as soon as a crack occurs in one diagonal element, the behavior of the other diagonal element is modified by multiplying the force values ​​in a proposed function. Then, the results of the analysis are evaluated based on ASCE41 code in different failure modes. Also, for verification, two I-shaped masonry walls, three masonry walls with rectangular cross-section and an arched walls are numerically analyzed using the proposed model and the results of numerical and experimental tests are compared. The results show that the proposed model, while simple, has a good ability to estimate the nonlinear behavior of masonry wall.

The large and small Coronal Mass Ejections (CMEs) and mini-CMEs are observed by the Extreme Ultra Violet Imager (EUVI) on the Solar Terrestrial Relation Observatory (STEREO). These eruption events are usually associated with dimming and wave-like brightenings. Here, the images of the full sun on 26 Apr 2008 with STEREO spacecraft (behind) with the cadences of 10 minutes and 150 seconds and pixel size of 1.59 arc second in pass band 195 and 171 Å were analyzed. The velocities of the large and small wave-like brightening were 221 km.s-1 and 6 km.s-1, respectively. The zernike moments of events and non-events were computed and these features were fed to the Support Vector Machine (SVM) classifier. Using this method, 697 mini-CMEs on three different regions of solar corona were detected. The number of mini-CMEs was increased when the CMEs occurred. The average velocity of mini-dimmings was 13.8 km.s-1.

The classic traveling - salesman problem is to determine a tour that will minimize the total distance or cost involved in visiting several cities and returning to the starting point. This paper describes a new algorithm for accelerating the computational performances of branch exchange heuristics for symmetric traveling salesman problem. The improvement in performance is obtained by considering only exchanges that have a good chance of producing a better solution. This algorithm is faster than other heuristics' algorithms and computation times increase much less rapidly with problem size. The new algorithm makes it possible to solve large-scale traveling salesman problems.