eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2013-06 1 1 10 article Hamid Heidary Torkamani Hamid_Heidary@ut.ac.ir 1 Khosrow Bargi kbargi@ut.ac.ir 2 Rouhollah Amirabadi rohollah@ut.ac.ir 3 Civil Engineering Department, School of Civil Engineering, College of Engineering, University of Tehran Civil Engineering Department, School of Civil Engineering, College of Engineering, University of Tehran Civil Engineering Department, School of Civil Engineering, College of Engineering, University of Tehran This study aims to develop seismic fragility curves for a typical pile-supported wharf. Fragility curve is one of the popular tools in seismic performance evaluation of a structure. The software FLAC2D was used to simulate the seismic performance of the wharf structure. Using eight time history records, occurred in past, as seismic loading, incremental dynamic analysis (IDA) was applied for seismic demand estimation. Based on the resulted seismic response matrix the analytical fragility curves were developed. As a prevailing tool, adopted fragility curves are useful for seismic risk assessment. They can also be used to optimize wharf-retrofit methods. http://ijmt.ir/article-1-211-en.pdf Fragility curve Incremental dynamic analysis Pile–supported wharves Seismic Vulnerability eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2013-06 1 11 22 article Amir Nikseresht nikser@sutech.ac.ir 1 Hossein Ghazizade-Ahsaee H.ghazizade@Gmail.com 2 Department of Mechanical & Aerospace Engineering, Shiraz University of Technology, Shiraz, Iran Department of Mechanical & Aerospace Engineering, Shiraz University of Technology, Shiraz, Iran In this research, numerical simulation of a symmetric impact of a 2-D wedge, considering dynamic equations in two-phase flow is taken into account. The two-phase flow around the wedge is solved based on finite volume method and volume of fluid (VOF) scheme. The dynamic mesh model is used to simulate dynamic motion of the wedge, thereby the effects of different dynamic meshes in both structured and unstructured meshes in simulating symmetric water impact phenomenon are investigated. Moreover, the effects of flow turbulence and fluid compressibility at the moment of water impact are studied. Also, the effects of different deadrise angles and body mass on the slamming force are investigated. At last, the impact problem of a wedge with constant velocity is calculated and the results are compared with the results of the impact problem solved considering dynamic equations of the motion. http://ijmt.ir/article-1-174-en.pdf Slamming Force Symmetric Water Impact Dynamic Mesh Dynamic Equations eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2013-06 1 23 34 article Mohammadreza tabeshpour tabesh_mreza@yahoo.com 1 aliakbar golafshani 2 mohammad saeid seif 3 sharif university sharif university sharif university Efficiency of numerical methods is an important problem in dynamic nonlinear analyses. It is possible to use of numerical methods such as beta-Newmark in order to investigate the structural response behavior of the dynamic systems under random sea wave loads but because of necessity to analysis the offshore systems for extensive time to fatigue study it is important to use of simple stable methods for numerical integration. The modified Euler method (MEM) is a simple numerical procedure which can be effectively used for the analysis of the dynamic response of structures in time domain. It is also very effective for response dependent systems in the field of offshore engineering. An important point is investigating the convergence and stability of the method for strongly nonlinear dynamic systems when high initial values for differential equation or large time steps are considered for numerical integrating especially when some frequencies of the system is very high. In this paper the stability of the method for solving differential equation of motion of a nonlinear offshore system (tension leg platform, TLP) under random wave excitation is presented. In this paper the stability criterion and the convergence of the numerical solution for critical time steps are presented. http://ijmt.ir/article-1-155-en.pdf Stability nonlinear TLP random wave eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2013-06 1 35 46 article Behrouz Asgarian asgarian@kntu.ac.ir 1 Mahdi Boroumand 2 Mohamad Zarrin mo_zarrin@yahoo.com 3 K.N.Toosi University of Technology, Civil Faculty K.N.Toosi University of Technology, Civil Faculty K.N.Toosi University of Technology, Civil Faculty In this paper, pile behavior embedded in layered soil deposits subjected to seismic loadings is analyzed using a nonlinear fiber element for simulation of soil – pile interactions. In the created model, both pile and surrounding soil are modeled using fiber elements in a practical Beam on Nonlinear Winkler Foundation (BNWF) concept. Herein, the features of DRAIN–3DX finite element software are utilized in order to develop the model. In the presented approach for performing of Seismic Soil-Pile-Superstructure Interaction (SSPSI) analysis, the constitutive behavior of soil and steel pile are assigned to fiber elements using available soil p-y backbone curves and steel stress-strain relationship. The effect of radiation damping is incorporated into the model by adding a dashpot in parallel with nonlinear p-y element. In order to consider the effects of free field site response in different soil layers, EERA and NERA programs are used. Results of the analyses are compared with available experimental data. The results are in good agreement with the available centrifuge test results. The main purpose of the proposed method is to make DRAIN–3DX software capable of performing SPSSI analysis of any pile supported structure especially Jacket Type Offshore Platforms (JTOP). http://ijmt.ir/article-1-195-en.pdf Nonlinear Dynamic Analysis Fiber Elements Jacket Type Offshore Platforms Seismic Soil-Pile-SuperStructure Interactions Centrifuge experiments eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2013-06 1 47 55 article Mir-Ahmad Lashteh-Neshaei maln@guilan.ac.ir 1 Mohammad Ali Lotfollahi-Yaghin a_lotfollahi@yahoo.com 2 Morteza Biklaryan mrtz_b@yahoo.com 3 Sadegh Nadimy sadegh.nadimy@yahoo.com 4 Department of Civil Engineering, Guilan University, Rasht, Iran Civil Engineering Faculty, University of Tabriz, Tabriz, Iran Civil Engineering Faculty, University of Tabriz, Tabriz, Iran Langroud Islamic Azad University, Langroud, Iran Although there exist advanced models which predict beach profile for natural beaches, the behavior of the beaches in front of seawalls still suffers from the lack of appropriate theoretical models and sufficient measured data. In this paper, following the results obtained from the measurements, a beach profile evolution model is developed, using the measured probability distribution of the near-bed horizontal velocities as input, to predict the short-term bed level changes in the vicinity of a partially reflective seawall. The present model introduces a new approach in which based on integrating the probability density functions of the near-bed horizontal velocities, the sediment displacements and consequently bed level changes are calculated in front of a partially reflective structure. The results obtained from the model in comparison with the experiments are promising and encouraging for further developments of the proposed model. http://ijmt.ir/article-1-89-en.pdf Seawall Beach Sediment Probability density functions (PDF) eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2013-06 1 57 66 article Mohsen soltanpour soltanpour@yahoo.com 1 Nimal Wijayaratna 2 Zohreh Hajisalimi hajisalimi.zohreh@yahoo.com 3 Civil Eng. Department, K. N. Toosi University of Technology Faculty of Engineering, University of Ruhuna, Galle, Sri Lanka Civil Eng. Department, K. N. Toosi University of Technology An oil spill model coupled with a hydrodynamic model was developed to simulate the spread of oil slick in real marine conditions considering the effects of tidal currents, wind and wave. The hydrodynamic model is verified using the measurements of tidal elevations and current speeds at the Persian Gulf. Effect of various governing factors on oil slick movement, tidal currents, wind and wave, are examined. It is concluded that the wind action is the predominant factor for the spreading of oil while the overlaying waves are the second important driving force. Although the tidal currents spread the oil slick on a wider area, they have limited influences on the net transformation of slick. The performance of the model on a field data in the Persian Gulf shows that the present model is capable to predict the spread of oil in early days of the oil spill. http://ijmt.ir/article-1-225-en.pdf Oil slick Persian Gulf Numerical modeling Trajectory Spill eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2013-06 1 67 72 article Ahmad Shanehsazzadeh ahmad.shanehsaz@yahoo.co.uk 1 University of Isfahan Quasi-Static analysis of moored vessels is vastly used for engineering designs, as a substitute to the numerical simulation of dynamic mooring analysis. Yet, the level of validity of the results of quasi-static analysis is a matter of discussion. In the present study, the validation of the assumptions behind the quasi-static analysis of mooring vessels is examined with application of a dynamic model for a number of vessel sizes and mooring configurations. The results show that in the moderate wave condition (wave height less than 1.2m), the main assumption of not applicability of wave forces in prediction of line forces is acceptable the differences being less than 5 percent. However, distribution of forces between spring and breasting lines is not coincided with the anticipation of response of the system. The parametric study shows that the critical condition for line tensions is not necessarily corresponding to the exact coincidence of directions of wind, current and wave forces. Also, the forces exerted on fenders in some cases are maxima in direction, different from the perpendicular to the vessel. This means that the mooring line arrangement considerably dictates the distribution of the tension in mooring lines and reaction in fenders. Hence, the accuracy of the quasi-static analysis highly depends on the mooring lines configuration. http://ijmt.ir/article-1-217-en.pdf quasi-static mooring analysis dynamic mooring analysis vessel mooring line eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2013-06 1 73 78 article mohammad haghighi 1 tahmores Hassangholi Pour h.yousefi@kmsu.ac.ir 2 homayun yousefi 3 College of Management, Tehran University College of Management, Tehran University Khoramshahr Maritime University In this paper, we are going to investigate the growth of the Iranian maritime transport with a focus mainly on the North - South transit Corridor, review of dry ports in order to support the Iranian container terminals at the south ports in order to increase the volume of container storages at the terminals. For the purpose of assessing the outcome of port operational management, the Balanced Scorecard System is recommended for development of the Iranian South Ports and further consideration. Balanced Scorecard system is known as the most effective tool that successfully communicates strategic goals of the company with its operational management. Balanced Scorecard visualizes company strategy and links it to operational level. The main part of this paper is dedicated to evaluate the role of container transit from the North - South transport corridor with a focus on the Iran North South transport corridor in order to improve Maritime Transport of Iran and increase the Iranian transit market share. Next part of this paper will be designated to consider the Iranian Southern Container Terminals at Khoramshahr, Imam Khomani, Busher, Bandar Abbas and Chabahar port which have suitable strategic position as transit base in the region. http://ijmt.ir/article-1-218-en.pdf Container transit Dry port Balanced Scorecard Container terminals North South transport corridor