For assessing the consolidation settlement, it is mainly used by Terzaghi and Janbu theories. Main of this study is evaluation of the Janbu settlement modulus in clayey soils based on shear wave velocity with using down hole test. In continue, results with using artificial neural network analyses and statistical methods verified. The study area is The city of Tabriz is located in the northwestern part of Iran and has a variety of clayey soils, silty and marl types (yellow, green and gray) with different consolidation potential. In this research, by drilling three machine boreholes at depths up to 8 meters, complete physical, plasticity and consolidation experiments were carried out on 20 undisturbed samples. The in-field Downhole test was also used to determine the shear wave velocity in the boreholes. Moreover, shear wave velocity was evaluated in study area with using down hole test and based on effective vertical stress on study depths normalized. Results showed that the Janbu settlement modulus and normalized shear wave velocity in study area respectively are between 14.38 to 41.39 and 234 to 694 m/s. With considering that results of existing practical relationships for determining the Janbu settlement modulus were not appropriate in study area. In order to improve the practical relationships between the Janbu settlement modulus and normalized shear wave velocity artificial neural network and statistical methods with applying linear, logarithmic and exponential functions was performed. Results showed that exponential function for determining the Janbu settlement modulus in study area is favorable.

One of the most effective parameters in economics of open-pit mines is the pit slope angle, so that the slope angle more than the optimum value increases the probability of a large failure in the pit wall and the slope angle less than the optimum value leads to increasing stripping ratio and reducing net present value of mine. Therefore, in this paper, considering the limit equilibrium methods of modified Bishop and modified Janbu and numerical models of the slope stability analysis, the effect of overall slope angle on the Economics of open pit mines was investigated. In addition, it was shown that selecting the overall slope angle less than the optimum value leads to reducing the depth of open-pit mining (the ultimate pit depth) and consequently, reducing the net present value of mine. Finally, in homogenous and Isotropic media, the results of Bishop and Janbu and numerical modeling are close together.

1. Soil slope stability depends on different parameters such as layers geometry, types of layers, layers condition (saturated, wet or dry), underground water level, static and seismic loads and also many other parameters. There are many solutions to stabilize the soil slopes; e.g. nailing method, using drainage, changing the slope’s geometry, and using a retaining wall. One of the newest methods is using geosynthetics. In this research, geo-fabric is used to stabilize the soil slope and the static and pseudo slope stability analyses are performed. Since the tensile strength of soil is not usually acceptable, geo-fabric can increase the tensile strength of soil and hence the safety factor of slope stability increases. Low and Tang developed a limit equilibrium method for the analysis of soft soil slope stability [1]. Ghazavi and Amel Sakhi used the 30*30 direct shear tests to evaluate the internal soil-rubber friction angle [2]. 2. Experimental study:In this research, the Geo-Slope software is used for soil slope stability analyses. Different pseudo static earthquake factors are selected. Slope’s height is 15 m constant, the slopes are 1V:1.75H, and the foundation’s depth is 3 m. There are two different layers in foundation, soft and stiff, and their combinations are varied in different analyses. The analyses are static and pseudo static. The slope and its foundation are analyzed in dry condition, so the water table level is ignored in this research. The Mohr-Coulomb model is used in all static and pseudo analyses.3. Results and discussion3.1. Static numerical In Fig.1, an example of static analysis results are presented. In Fig.2, the result is concerned with the soft layer on top of the stiff layer in foundation. It can be seen that the safety factor increases as the number of geo-fabric layers increases. The obtained results show that the Janbu method gives the minimum safety factors in comparison with other slope stability methods used in this research. 4. Obtained results in this research show that in both static and pseudo static slope stability analyses, as the number of geo-fabric layers increases, the safety factor increases in all different slope stability methods. The safety factor increases in all different methods as the spacing between the geo-fabric layers decreases. The results show that when the strong layer of foundation is located on top of the weak layer of the foundation, the safety factors are greater. The Janbu method gives the lowest safety factor against the other methods studied in this research.

Resilient modulus of asphalt concrete is one of the key input parameters in design of flexible pavements using mechanistic-empirical methods. Resilient modulus of asphalt mixes in laboratory is usually measured by applying a haversine pulse with a constant duration which could not be an actual simulation of stress pulse in field. In this paper، the effect of various parameters of loading pulse consisting of the shape، duration; the ratio of the pulse duration to rest period as well as the number of pre-conditioning cycles on the resilient modulus of asphalt concretes was investigated. For this purpose، complex modulus of four different asphalt mixes were utilized and after validating results of numerical method based on viscoelastic theory، resilient modulus of these mixes was computed under different conditions. Results of this research showed that the shape and duration of loading pulse affects the resilient modulus of asphalt concrete، significantly and these parameters should be considered in analysis and design of flexible pavements. In addition، the ratio of the loading duration to rest period must be equal to 9 or greater values to achieve the minimum accuracy of 3% in measurement of resilient modulus. In this paper، two models with high generalization ability have been presented to predict the resilient modulus of asphalt mixture with respect to loading duration and temperature. By taking advantage of these models، it is possible to carry out a limited number of resilient modulus tests and calibrate the model for the desired asphalt mix and then the resilient modulus of asphalt mix can be predicted in any temperature and loading frequency، accurately. It was also observed that there is a good relation between the resilient modulus under haversine pulse and resilient modulus under square pulse and after calibration of model in basis of limited number of experimental tests and known resilient modulus under Haversine pulse، the resilient modulus under square pulse can be predicted، accurately.

In this research the impact of the type of finger joints layout (no connection, surface connect, connect on all levels) and the number of layers (three layer, five layer) on the modulus of elasticity and modulus of rupture of layer beam made of Populus Nigra have been studied. Dimensions of the samples were 130 × 12/5 × 7/5 cm. By combining these factors, there were six treatments with four repetitions totally 24 beams has been made and the bending strength was measured using a mechanical testing machine. By increasing the number of layers in the layer beam, modulus of elasticity and modulus of rupture beams increases. Maximum modulus of elasticity and modulus of rupture was related to beams with 5 layers. Maximum modulus of elasticity and modulus of rupture was related to Beams which coupling in the surface layer. Maximum modulus of elasticity and modulus of rupture were related to beams with 5 layer and coupling in the surface layer. And minimum modulus of elasticity and modulus of rupture were related to the beams with 3 layers and connect on all levels. The effect of alignment on modulus of elasticity and modulus of rupture of finger joints were not significant but the influence of layer on modulus of elasticity and modulus of rupture on layer beams is significant.

In this work we simulated the representative volume element (RVE) of carbon nanotube (CNT) which is surrounded by high temperature superconductor (YBCO) by using ANSYS finite element software. First we considered perfect model (for YBCO and CNT) and investigated the effect of radius, length, and the number of nanotube in Young’s modulus of the YBCO by applying force on RVE. Then, a third region an interphase between CNT and YBCO were considered, the Young’s modulus of which is between CNT and YBCO. It is demonstrated that there is a critical radius around 6 nm for the CNT and by applying the CNT with a radius smaller than 6 nm, the Young's modulus of the YBCO increases. Also, by increasing the number of the CNTs with radius smaller than 6nm, the Young's modulus and strength of the matrix (YBCO) increases. According to the non-linear analysis, the Young’s modulus of the CNT doped YBCO matrix is increased 20-22% more than the undoped YBCO sample.

Resilient modulus of pavement materials is a key property required for the pavement thickness design. This paper describes the results of an experimental study on the effects of temperature and loading frequency on the resilient modulus of a SBS polymer modified asphalt concrete under dry and saturated conditions. Dynamic creep tests were conducted on dry and saturated specimens of the mixture over a range of temperatures (-5, 5, 20 and 40˚C) and loading frequencies of 0.5, 1, 5 and 10Hz, and the variation of resilient modulus with the number of loading cycles has been evaluated. The results show that, in dry condition, the resilient modulus increases with increasing loading frequency, while, in saturated condition, a slight increase of resilient modulus with loading frequency was observed only at 40˚C. It is also found that, in both the dry and saturated conditions, the effect of loading frequency on the resilient modulus decreases with decreasing temperature. Therefore, the temperature of 40˚C was recommended for investigating the effect of loading frequency on the resilient modulus. In addition, a three-stage model was used for the resilient modulus. It is found that the logarithmic function is more appropriate for prediction of resilient modulus in stage 1.

When upstream water surface of an earth dam falls down rapidly and the upstream slope of the dam cannot be drained, the rapid drawdown analysis is necessary. There are several methods for rapid drawdown analysis including; Bishop, Ordinary, Janbu, Morgenstern-Price, Spencer, Lowe-Karafiath, United State Army Corps of engineers (USACE) and modified USACE. Modified USACE is presented by Lowe and Karafiath and is modified by Duncan, Wright and Wong. For simulation two models of SEEPE/W and SLOPE/W, are used. Drawdown velocity of 1, 2, 4 and 6 m/day are used in simulation. Simulations show that increasing drawdown velocity causes decreasing safety factor. Rapid drawdown analysis by Bishop, Morgenstern-Price, Spencer, Lowe- Karafiath, USACE and modified USACE give the same results for safety factor. Safety factor of rapid drawdown analysis will decrease 26% compared to steady state analysis on the average.

Seepage in earth fill dams is one of the important factors that may cause the erosion and slope instability if it is ignored. Therefore, it is crucial to calculate the leakage discharge through the body of dam and foundation, to prevent economic and life hazards by considering technical and economical issues. In this research, the seepage analysis of the body and the stability of the upstream and downstream slopes of Golfaraj dam after construction, during steady state seepage, rapid drawdown of reservoir and OBE, MCE earthquakes have been investigated and compared by applying different limit state equilibrium methods including: Spencer, Bishop, Janbu, and Mohergenstren-Price, using built-in Geo studio software. The results showed that seepage discharge in a deep section without dike was 18.2 m3day-1 per unit width which was reduced in the case of applying a cutoff or a concrete blanket by 95 and 10 percent, respectively. Data obtained from the slope analysis indicated that the slope was stable under any circumstances and the limit equilibrium methods were convergent.

The aim of this study is to investigate the influence of structural defects on the mechanical properties of single-walled carbon nanotubes. During the growth process and functionalization of carbon nanotubes (CNTs)، the Carbon-Carbon bonds in their nano-structure are broken. To evaluate the influence of this defect on the Young’s modulus of CNT، the number of broken C-C bonds، distribution and their arrangements in the nano-structure of CNT are all treated as random parameters. In this study، the finite element model of the CNT is built using nanoscale continuum mechanics approach and then structural defects are applied randomly. The Young''s modulus of two defect types، known as Stone - Wales and Vacancy are investigated. The results reveal that the influence of Stone – Wales defect on the Young’s modulus of CNT is much less than that of Vacancy one. Moreover، a linear decrease in Young''s modulus with respect to the increase in defect density is observed. In contrast to the available researchers in open literature، three parameters consisting of the number، distribution and arrangement of defects are modeled on the basis of full stochastic simulation.