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Collaborating Authors
Islamic Azad University Tehran Science and Research Branch
Numerical Modeling of the Effect of Rock Mass Characteristics on the Stability of a Shallow Underground Structure (Due to Cruise Missile Impacts)
Ghaemi, Masoud (Sepasad Group) | Shaker, Masoud (Shams Higher Education Institute) | Ahangari, Kaveh (Islamic Azad University Tehran Science and Research Branch)
Abstract The results of drawing an interaction diagram in an analytical method and numerical calculations (using FLAC and UDEC software) indicates that the boundary points of tunnel are located in fracture envelope. Furthermore, there is a better compatibility between the results of analytical method and FLAC software. Considering the results obtained by genetic algorithm, we can conclude that the propagation of waves caused by missiles collision in mass rock tunnels, will be in applied single spot at the beginning and then in an extensive form. This confirms the results of numerical modeling to a great extent. Considering the results obtained by genetic algorithm, we can conclude that the propagation of waves caused by missiles collision in mass rock tunnels, will be in applied single spot at the beginning and then in an extensive form. This confirms the results of numerical modeling to a great extent. 1 Introduction At the present time, it can be said that there are three methods for evaluating such problems:Physical modeling which is fairly simple. In this respect, Wei & Li (2007) carried out some researches about the effect of dynamical loads on joint's behavior. Using experimental relations for collision conditions, on the basis of repetitive experiments and developing simple dynamic models for collision and penetration by means of motion rules and principles ruling the behavior of materials. Numerical methods that include all real aspects of modeling and lead to more acceptable results. This is the method which is frequently used. Zhao and et al. were the first scientists who, using UDEC software, examined the explosion shock in mass rock environment in 1998. In addition, this group continued their comprehensive studies. For more information, we can refer to the sources mentioned at the end of the article. This study aimed to investigate the stability of underground structures influenced by both conditions, continues (without gaps and cracks) and discontinuous (with gaps and cracks) environments under Cruise missile collision by using FLAC, UDEC numerical software.
- North America > United States (0.16)
- Asia > Middle East > Iran (0.16)
- Government > Military (0.74)
- Energy (0.48)
Intelligent Back Analysis Using Data from the Instrument
Ghaemi, Masoud (Sepasad Group) | Shaker, Masoud (Shams Higher Education Institute) | Ahangari, Kaveh (Islamic Azad University Tehran Science and Research Branch)
Abstract As substitution method, artificial neural network instructed based on numerical analyzed patterns except than more feasibility and speed than other methods can also reach the accuracy required in numerical modeling. In this paper a model based on Perspetron multilayer artificial neural network have been presented for intelligent regressive analysis of Narmab water conveyance tunnel base on monitoring data. Our input data were 27 parameters categorized in three classes including: tunneling data, geological data and average of in situ horizontal stress. For network instruction, data bank of regressive analysis results of 18 Survey Convergence stations was prepared in 980 classes by using FLAC3D software. Then according to network behavior in instructing step, optimum values for medial layers number, neurons number and, activity functions obtained. By this way a model was mad based on artificial neural network that was able to regressive analyzing of displacements in future Survey Convergence station projects in every time of monitoring. In back analysis algorithms, for example, with a large number of correct answers received and produce plans with a problem. If properly used, for example, new programs will work correctly. The neural network may improve the accuracy of the analysis. This is where the advantage of neural networks or ANN determined. 1 Introduction Neural Network abilities in learning from widely dispersed and erroneous data caused this technique to be successful in solving problems related to geotechnical engineering. Although, teaching a neural network is a time-consuming process, when running at high speed, it can be time-saving, though. Therefore, it can be taken into account as an appropriate alternative for time-consuming and complex numerical back analysis of monitoring results. This research is aimed at using ANN technique for learning relations between geological engineering parameters, tunneling methods and monitoring results in instrumented sections and geomechanical parameters of average horizontal in situ stress as well as elasticity module of rock masses surrounding Narmab Water Conveyance Tunnel using to estimate geomechanical parameters for similar future monitoring stations in non-excavated sections of Narmab Tunnel.
- Telecommunications > Networks (0.35)
- Information Technology > Networks (0.35)
Analyzing Schmidt Hammer in Evaluating Compressive Strength of Rock Mass
Ghaemi, Masoud (Sepasad Group) | Shaker, Masoud (Shams Higher Education Institute,) | Ahangari, Kaveh (Islamic Azad University Tehran Science and Research Branch)
Abstract Uniaxial compressive strength is regarded as one of the most significant factors in designing underground constructions, which can be determined through different factors, one of the simplest and most nondestructive of which is using Schmidt Hammer. Schmidt Hammer comes in different types, the N and L are the most useful ones, though. In this study, the N and L types were used to determine compressive strength of rock mass in Emamzadeh Hashem Tunnel lot II. The uniaxial compressive strength of rock mass was calculated. The standards presented by ISRM and ASTM were used to achieve a logical relationship between the uniaxial compressive strength and the rebound factor. The results showed that Schmidt Hammer type L had better uniaxial compressive strength estimation in Emamzadeh HashemTunnel lot II. 1 Introduction Schmidt hammer was first invented in 1948 to estimate concrete hardness and then it was used to evaluate compressive strength of rock mass. Availability, low cost, quick in situ and in laboratory control and reliability of results are among factors can be named for its increasing use. Schmidt hammer comes in different types, types N and L were used in this research to first understand the compressive strength of rock mass and second choose the best type using statistical results. Schmidt Hammer Schmidt hammer is used for evaluating compressive strength of rock mass and concrete materials. In order to have a reliable estimate of compressive strength, Schmidt hammer should be first calibrated using a calibration test anvil, the mean of 10 readouts should be calculated on the standard anvil and used to determine the correction factor. In order to do that, plunger is placed on the sample; by pressing it, plunger goes into the hammer. It presses the spring inside the hammer. The spring toggle is released at a specific compression energy level and hits (impacts) the piston placed on the plunger. The rebound height of piston is read on the ruler and used as a criterion for determining hardness. The floating piston affects the surface and the sample returns to the initial state. The rebound distance is dependent on energy absorbed by the affected surface. The rebound value of floating piston is read as the rebound number directly from the numerical criterion available on the device body. Under figure show function Schmidt hammer in rock mass of tunnel.
- Geology > Rock Type (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)