Sharif Digital Repository

Thread the bearing capacity of soil beneath the foundations of the main topics in Engineering is considered that main reason it is the more contact structures. if all the factors that are likely to impact on bearing capacity is more useful to consider more accurate results are obtained. This thesis has tried using FLAC software is a comprehensive review on the soil bearing capacity of foundations under certain conditions of Geotechnical and foundation strip, can be done .The modeling of soil layers and soil bearing capacity based on changes in properties (clay and sandy soils) and changes in depth are examined. The changes in the deep layer of soil and properties of soil, bearing capacity is... 

In previous studies, effect of certain parameters such as soil K0 on piled raft load sharing ratio α_pr was not considered. Here, α_pr is ratio of pile group load to total load. In this study, we consider the effect of pile length (L), pile spacing (s), raft thickness (t), raft modulus of elasticity (Er), pile modulus of elasticity (Ep), coefficient of lateral earth pressure, and pile concentration. Soil is undrained clay with typical properties. Raft is made of concrete and piles are cast in-place. Modeling is done in FLAC 3D. To determine the effect of these parameters we calculated load sharing ration of piled raft at 10 cm settlement which is typical for design. Based on the results of... 

MAPNA is a leading project oriented company in the field of power, water, oil and transportation in Iran. MAPNA has the policy of using quality management principles and tools to improve the company and in this regard has chosen EFQM excellence model as a tool to move towards excellence. EFQM requires a set of indicators to measure performances of the processes and their results. These indicators should be tailor made for the company.
The subject of this thesis is to evaluate the present indicators used in implementing EFQM in MAPNA and considering MAPNA’s characteristics propose any changes required. The study is limited to indicators for key results and customer results for certain... 

Productivity is the effective usage of input or resources for production or output. Input (including Energy, raw materials, capital and work force), which is being used for output (including final products or services performed by an organization). Productivity, increases gross domestic product and competitiveness, and improves level of living. Firms and related management levels play the main role in improving productivity. Using productivity cycle management brings the productivity to improve as a permanent process, specifies the rout for productivity and prepares the ground. The most important step in productivity cycle (PDCA) is the measurement of productivity. In this research several... 

Few years the traditional medicine in our society is considered: Traditional colleges have been established, Traditional medicine has been established and numerous media programs produced by experts in traditional medicine. All this indicates is that traditional medicine seek lost credibility and gain its rightful place in our society today. One of the most important aspects of the relationship between traditional medicine with modern medicine. On the one hand trying to make traditional medicine with modern medicine can be defined as complementary medicine. In this regard, first of all defined traditional medicine as a specialty, and efforts to rebuild the achievements of traditional... 

The main purpose of this study is to estimate the natural frequency and damping ratio for soil-structure systems with embedded foundation with sufficient accuracy. The results are then compared to guidelines in current seismic codes. This is done through an extensive parametric study using a set of non-dimensional parameters, which define the soil-structure systems. For this purpose a simplified soil-structure model is used. Although more rigorous models and numerical solutions are available, they are time consuming and not suitable for parametric study. Existing formula for seismic provisions for the equivalent period and damping ratio of soil-structure systems are based on studies on... 

Generally concrete dams have not been sited at location where there were faults classified as active. However, there may be sites suitable for concrete dams where there is some possibility of fault displacement occurring underneath the dam. In addition, there may be situations where an existing dam was constructed over a fault thought to be inactive and later determined to be active, due to different approaches of classification of a fault whether it is active or not. Also some discontinuities may be observed during construction. For these cases nonlinear analysis and criteria will be required to assess the capability of concrete dams to safely withstand fault displacements. In this thesis,... 

In this research the flexibility of subterranean levels on foundation input motion (FIM), especially rocking component is investigated through parameter analyses. The so-called motion is induced as a result of kinematic soil-structure interaction (SSI). The foregoing interaction reduces the translational component of foundation input motion in rigid embedded foundations when compared to the free-field motion (FFM), as well as yielding rocking component in the foundation. On the other hand, increasing the embedment depth which is equivalent to the presence of subterranean levels in a building decreases the commonly-held “rigid” assumption’s accuracy for the embedded part. Given this effect,... 

Up till now, various contributions of research to soil-structure-interaction context have been primarily focused on structural systems exhibiting elastic-perfectly plastic material behavior. In this paper, combined effects of material degradation, p-delta, and soil-structure-interaction considering foundation uplift have been deemed to determine seismic response of a single degree of freedom system. The system is composed of a column with a lumped mass on top that is placed on a rigid foundation. The foundation is mounted on Winkler springs and dashpots to account for soil-foundation compliance and material/radiational damping. The springs are tensionless to guarantee that uplift phenomenon... 

One of the most efficient methods in stiffening tall buildings to withstand lateral loads such as wind loading is to link the shear resisting core to the exterior columns using outrigger trusses. Many tall buildings such as Taipei 101 have benefited from outriggers. In this system, the outriggers force the perimeter frame to take part in resisting the bending moment of the lateral load acting on the structure by developing axial restraining forces in the windward and the leeward columns of the perimeter frame and forming a resisting moment.Most of the present analytical methods have studied the performance of outrigger braced structures neglecting shear deformation of the shear wall core and... 

Reciprocating Machinery are one of the key components of chemical and petrochemical plants and their down time cause loss of production. Therefore condition monitoring in these machinery is of special interest and high value. In this thesis first, different methods of condition monitoring for reciprocating compressors are introduced then the main cause of high vibrations of three compressors in a refinery is investigated. Finally by using the foundation model prepared, it would be shown that insufficient strength of foundation block has lead cracks initiation and development in these foundations. Therefore high vibration is consequence of weak design  

In this study, the linear dynamic response of an inclined FGM Timoshenko beam on linear viscoelastic foundation subjected to a traveling mass with constant and variable velocity is investigated. Timoshenko beam theory and von-karman strain-displacement relations are utilized to model the problem. the FGM beam is made of metal and ceramic and it is assumed that material properties of the beam vary continuously in the thickness direction according to the exponential law and the power-law form. The kelvin-voigt damping model is applied to model the internal damping of the FGM beam. The partial differential equations of motion for the bending rotation of cross-section, longitudinal and... 

Dynamic impedance functions method is most recent approach in the analysis of soil-foundation dynamic interaction, and presented for massless rigid foundations. Impedance functions are frequency dependent functions, and used to obtain dynamic response of foundation with arbitrary mass subjected to dynamic loading of any frequency and magnitude. The important assumptions for appropriate useof mentioned method are rigidity of foundation and visco-elastic behavior of the soil beneath the foundation. In this study, experimental vertical impedance functions of square and circular foundations have been investigated,using physical modeling tests. A granular soil layer with finite thickness... 

The simultaneous effect of uplift phenomenon and vertical vibration of soil-structure system is investigated in this study. The super-structure is modeled as an equivalent single-degree of freedom with bilinear behavior mounted on a rigid foundation resting on distributed tensionless Winkler springs and dampers. The effect of vertical excitation on the response of soil-structure systems allowed to uplift is investigated parametrically through time history analysis for a wide range of systems subjected to sine pulse and a group of ground motions recorded on the soil type of C. The results consist of maximum displacement of the uplifting system and ductility demand of the super-structure as a... 

Concrete arch dams, because of their special shape as a 3-D huge shell which is fixed from three sides, are very sensitive to temperature and its variation. Therefore, it is required to include the temperature variations and their related thermal stresses and strains in the safety analysis of dams. In this research, the effect of applying the thermal gradients caused by the most critical thermal conditions, on dynamic behavior of concrete arch dams was studied. For this purpose, first a roughly exact 3-D finite element model of Karoon ІV arch dam was prepared by ANSYS program. Then, the temperature distribution through the dam thickness was determined by Stucky-Derron method and in a more... 

Safety assessment of existing dams and analysis and design of new dams as an important part of infrastructures of any country, hinges on proper and precise modeling of coupled system of dam-foundation-reservoir under appropriate seismic excitation. In this dissertation, effective methodology for seismic analysis of concrete dam, using finite element method, is presented which takes account for numerical modeling of wave propagation from excitation source to site and interactions between dam, foundation and reservoir. To model the effects of mass, wave propagation and radiotional damping in unbounded foundation as well as modeling the fault itself, two boundary conditions namely, free-field... 

The behavior of a beam under moving mass has been always interested in the dynamic of structures. In this study, the dynamic response of beam and plate with general boundary conditions under moving mass were investigated using the Dynamic Green Function. Since the majority of previous studies did not consider the Coriolis acceleration, therefore, this acceleration was used in the present study. Boundary conditions are modeled by the rotational and translational restraint. By moving close to the spring constants of the rotational and translational restraint to extreme values (zero and/or infinity), the boundary conditions can be attained for the desired combinations of end boundary conditions... 

The most important step in current dynamic analysis of machine foundations is determining dynamic impedance functions. Impedance functions are defined as ratios of applied force or moment to induced displacement or rotation angle of foundation. In this research, horizontal dynamic response of foundation on homogeneous halfspace was investigated using physical modeling. Soil medium was built in a 1mx1mx0.8m steel box whose interior walls were covered by 0.1m of sawdust (a material with high damping). In order to prevent possible reflection of waves, this cover was extended to the box bottom with 0.2 m thickness. Sand raining method was used to build soil medium. In this method, with... 

Experimental investigations in the subject of dynamic response of machine foundations for verification of many theoretical studies are scant. The effects of several factors, namely, shape and weight of foundation, frequency of vibration, depth of embedment, dynamic load levels and type of loading (harmonic and impact) on dynamic response of foundation were studied experimentally.Also, the current methods of machine foundation analysis mostly are based on the concept of the dynamic impedance function. Therefore, using these tests results, impedance functions for the model are calculated and presented. The physical model tests were carried out in a steel container with dimension of 1×1×0.9 m.... 

This thesis investigates the dynamic response of a viscoelastic plate resting on a viscoelastic Winkler foundation subjected to the excitation of a moving mass. Through application of the Laplace transform, the governing equation of the problem is derived for a general viscoelastic material. Thereafter, an analytical-numerical method is proposed in order to determine the dynamic response of the viscoelastic plate. The method is based on transforming the governing partial differential equation into a new solvable system of linear ordinary differential equations. To that extent, the proposed solution proves to be applicable to plates made of any viscoelastic material and with various boundary...