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... The third step (3) was the dynamic analysis step. The time history input data from the Loma Prieta earthquake, as mentioned and described previously, were applied to the bottom of the clay soil at the base of the shaking table [35]. The displacements were restrained in the horizontal direction for the geostatic and static step and changed to the vertical direction for this dynamic analysis step, allowing free movement in the horizontal direction. ...
This paper is concerned with the calibration and validation of a numerical procedure for the analysis of pile performance in soft clays during seismic soil–pile–superstructure interaction (SSPSI) scenarios. Currently, there are no widely accepted methods or guidelines. Centrifuge and shaking table model tests are often used to supplement the available field case histories with the data obtained under controlled conditions. This paper presents a new calibration method for establishing a reliable and accurate relationship between full-scale numerical analysis and scaled laboratory tests in a 1g environment. A sophisticated approach to scaling and validating full-scale seismic soil–structure interaction problems is proposed that considers the scaling concept of implied prototypes as well as “modelling of models” techniques that can ensure an excellent level of accuracy. In this study, a new methodology was developed that can provide an accurate, practical, and scientific calibration for the relationship between full-scale numerical analysis and scaled laboratory tests in the 1g environment. The framework can be followed by researchers who intend to validate their seismic soil–structure interaction findings.
... The Finite Element Method is a numerical technique that is based on spatial discretization. In this technique, the body is discretized into a finite number of small parts called elements, and then the unknown variable fields are expressed in terms of assumed approximating functions that are contained within each element (Lucena, 2012). For a while, designers have used it to evaluate the effects of stress and strain scenarios on a design. ...
... To investigate the system's dynamic responses, the global matrices are initially generated using the elemental matrices, i.e. stiffness, mass, and damping matrices. Researches have effectively studied the dynamic responses of building using the finite element modeling technique (FEM) [74][75][76]. ...
Damages can originate in engineering structures due to various detrimental and hostile conditions that leads to calamitous occurrences. Structural damage monitoring has been formally established in the past few decades and is critical for sustaining and upholding the integrity of structures in its designated service life. Real time condition monitoring and damage detection needs to be necessitated for the appropriate functioning of the concerned entity. Vibration intensive damage identification techniques have been reviewed for identifying the actual material properties such as stiffness and damping for assessing authentic health condition of machine elements as well as structures. Acceleration, velocity and displacement-based signals are measured and processed further using vibration monitoring hardware and software. The structural dynamic responses are studied and analyzed to be correlated to the presence of damages. This paper reviews the use of mode-shapes, modal strain energy, wavelet transform, wave-form fractal dimension and finite element model updating in damage identification. The challenges encountered with each technique are discussed and the proposed methodology for overcoming them. Propositions have also been made with respect to the current scenario and downsides of respective technique. The paper will be helpful for practicing engineers and researchers working in structural damage identification and control related field for conceiving novel, reliable, effective, robust, and practical methods.
... (iii)Then, the static-friction loading step is employed for the application of gravity loads, which are assumed to be static and uniform, in accordance with the loading conditions in the reference case study. (iv) Next is the dynamic analysis step in which the time history input data are applied to the bottom of the clay soil (at the base of the shaking table) [27]. ...
Dynamic response records of pile performance during earthquakes are limited mainly due to the challenges of recording the seismic soil–pile response. This limitation has led to an inadequacy in providing a standardized basis for the calibration and validation of the available analytical and numerical methods developed for seismic soil–pile superstructure interaction problems. To bridge this gap, a series of numerical simulations of scaled, shaking table tests of model piles in soft clay has been developed in the current study. This paper aims to accurately identify all aspects and critical parameters in the numerical simulation and propose the most suitable soil constitutive model. Three soil constitutive models are selected as advanced models for soft soil, namely, the modified Mohr–Coulomb, Drucker–Prager/cap plasticity, and Cam–clay models. Similar to the physical test case study, this numerical analysis uses dimensional analysis techniques to identify scale modelling criteria and develop a scaled soil and pile-supported structure model correctly. The 3D nonlinear numerical models are developed using the Abaqus software.
... In order to investigate the effect of the most possible risks which are mentioned in the past paragraphs a real offshore structure shall be selected so that the dolphin of khor Al-Amaya berth no. 8 which shown infigure 6.1 is taken as case study for the following reasons. The first because this structure is a real structure with optimal dimensions and components, and the second associated with many researchers who used this structure with different formulations[17],[ 23]. Finally, this structure has two pile types that are vertical and battered piles because the foundation consist of 8 piles with a different piles orientations vertical and batter one and two directions.Table 1shows the variation of maximum deck deflection and maximum base axial force (noting that the maximum shear force and maximum bending moment have similar trend to axial force therefore their results are not given here) with wave length using Airy, Stoke, and Cnoidal wave theory noting that Ursell number is used as a criteria or a constraint in applying different wave theories. ...
This paper focuses on two main matters. The first deals with the risks have been found in the dynamic analysis of offshore structures while the second is related to the proposed solutions of these risks. The main reasons of these risks are usually resulted from the simplifications of the domain of the whole problem (fluid-structure-soil) into subdomains (fluid-structures and structure-soil) so that these risks can be classified into three categories which are the loads estimation methods, the structural behavior assumptions, and the type of soil molding. The proposed solutions involve conservative method in load estimation, the investigation of imperfection of constructed structure, and the selecting accurate method for molding the soil condition including the seabed state and gap formation effect.
... For the present paper, the dolphin of khor Al-Amaya berth no. 8 is analyzed to impact loads by considered an oil tanker of 330000 DWT at 60% cargo and using a Bridgestone C2000 H cell as fender type. This structure is taken as case study because this structure is actual structure and was analyzed by many researches with different formulations of soilstructure interaction [6,7]. The Structure, soil, and interface formulation are presented in next paragraph. ...
... For the current study, the dolphin of khor Al-Amaya berth no. 8, is analyzed to impact loads that is given by Al- Jasim [6] for three cases which represent the same energy but different berthing velocities. From previous studies [6,7], the maximum dynamic response is associated with velocity 1. therefore, the dynamic analysis is carried for this velocity only. The obtained results are summarized in tables 1-2 and figures 2-6. ...
... It is noted that the loading time of velocity 1 has small effect in which the maximum effect is less than 4% associated to maximum base bending moment for stiff clay. This effect may be explained due to large contact time that reduced dynamic response as indicate by the previous studies [6,7].For zero time connect, the response increased by different amount according to deck displacement and base reactions. The maximum influence is aroused for maximum base bending moment that increased by more than 90% compared with velocity time 1. ...
The main object of this paper is to fit with high degree of accuracy the true structure response by considering the concept of interface element which is used to simulate three dimensional soil-structure interaction in the dynamic analysis, therefore the dolphin of khor Al-Amaya berth no. 8 is analyzed as a case study. The (p-y), (t-z), and (q-z) curves which are adopted by American Petroleum Institute (API) are used to find normal and tangential interface moduli and end bearing modulus. For this purpose, a computer Fortran program Offshore_Inter has been built to obtain the required solution. The subspace iteration method is used to find the free vibration solution while Newton-Raphson modified method combined with Newmark's method is applied to get the nonlinear forced vibration solution. For both solutions, the conjugate gradient algorithm is used as a solver of the dynamic problem. A parametric study has been carried out including different soil type, soil engineering properties, loading time effect and the results are given in tables and graphs. The dynamic structural response is compared with the results of previous studies on the same structure and with elastic and Reese solution to show the difference between the different formulations. From obtained results, it is shown the interface solution increases the structure response by more than 80% comparing with Winkler method based on same curves mentioned above. Pile deflection and bending moment values along pile length are relatively increased many times than the solution obtained from elasticity theory and Reese solution. Finally, the increased soil strength will largely degrease the structure response for all soils.
... For the present paper, the dolphin of khor Al-Amaya berth no. 8 is analyzed to impact loads by considered an oil tanker of 330000 DWT at 60% cargo and using a Bridgestone C2000 H cell as fender type. This structure is taken as case study because this structure is actual structure and was analyzed by many researches with different formulations of soilstructure interaction [6,7]. The Structure, soil, and interface formulation are presented in next paragraph. ...
... For the current study, the dolphin of khor Al-Amaya berth no. 8, is analyzed to impact loads that is given by Al- Jasim [6] for three cases which represent the same energy but different berthing velocities. From previous studies [6,7], the maximum dynamic response is associated with velocity 1. therefore, the dynamic analysis is carried for this velocity only. The obtained results are summarized in tables 1-2 and figures 2-6. ...
... It is noted that the loading time of velocity 1 has small effect in which the maximum effect is less than 4% associated to maximum base bending moment for stiff clay. This effect may be explained due to large contact time that reduced dynamic response as indicate by the previous studies [6,7].For zero time connect, the response increased by different amount according to deck displacement and base reactions. The maximum influence is aroused for maximum base bending moment that increased by more than 90% compared with velocity time 1. ...
The main object of this paper is to fit with high degree of accuracy the true structure response by considering the concept of interface element which is used to simulate three dimensional soil-structure interaction in the dynamic analysis, therefore the dolphin of khor Al-Amaya berth no. 8 is analyzed as a case study. The (p-y), (t-z), and (q-z) curves which are adopted by American Petroleum Institute (API) are used to find normal and tangential interface moduli and end bearing modulus. For this purpose, a computer Fortran program Offshore_Inter has been built to obtain the required solution. The subspace iteration method is used to find the free vibration solution while Newton-Raphson modified method combined with Newmark’s method is applied to get the nonlinear forced vibration solution. For both solutions, the conjugate gradient algorithm is used as a solver of the dynamic problem. A parametric study has been carried out including different soil type, soil engineering properties, loading time effect and the results are given in tables and graphs. The dynamic structural response is compared with the results of previous studies on the same structure and with elastic and Reese solution to show the difference between the different formulations. From obtained results, it is shown the interface solution increases the structure response by more than 80% comparing with Winkler method based on same curves mentioned above. Pile deflection and bending moment values along pile length are relatively increased many times than the solution obtained from elasticity theory and Reese solution. Finally, the increased soil strength will largely degrease the structure response for all soils.
... For the present paper, the dolphin of khor Al-Amaya berth no. 8 is analyzed to impact loads by considered an oil tanker of 330000 DWT at 60% cargo and using a Bridgestone C2000 H cell as fender type. This structure is taken as case study because this structure is actual structure and was analyzed by many researches with different formulations of soilstructure interaction [6,7]. The Structure, soil, and interface formulation are presented in next paragraph. ...
... For the current study, the dolphin of khor Al-Amaya berth no. 8, is analyzed to impact loads that is given by Al- Jasim [6] for three cases which represent the same energy but different berthing velocities. From previous studies [6,7], the maximum dynamic response is associated with velocity 1. therefore, the dynamic analysis is carried for this velocity only. The obtained results are summarized in tables 1-2 and figures 2-6. ...
... It is noted that the loading time of velocity 1 has small effect in which the maximum effect is less than 4% associated to maximum base bending moment for stiff clay. This effect may be explained due to large contact time that reduced dynamic response as indicate by the previous studies [6,7].For zero time connect, the response increased by different amount according to deck displacement and base reactions. The maximum influence is aroused for maximum base bending moment that increased by more than 90% compared with velocity time 1. ...
The main object of this paper is to fit with high degree of accuracy the true structure response by considering the concept of interface element which is used to simulate three dimensional soil-structure interaction in the dynamic analysis, therefore the dolphin of khor Al-Amaya berth no. 8 is analyzed as a case study. The (p-y), (t-z), and (q-z) curves which are adopted by American Petroleum Institute (API) are used to find normal and tangential interface moduli and end bearing modulus. For this purpose, a computer Fortran program Offshore_Inter has been built to obtain the required solution. The subspace iteration method is used to find the free vibration solution while Newton-Raphson modified method combined with Newmark's method is applied to get the nonlinear forced vibration solution. For both solutions, the conjugate gradient algorithm is used as a solver of the dynamic problem. A parametric study has been carried out including different soil type, soil engineering properties, loading time effect and the results are given in tables and graphs. The dynamic structural response is compared with the results of previous studies on the same structure and with elastic and Reese solution to show the difference between the different formulations. From obtained results, it is shown the interface solution increases the structure response by more than 80% comparing with Winkler method based on same curves mentioned above. Pile deflection and bending moment values along pile length are relatively increased many times than the solution obtained from elasticity theory and Reese solution. Finally, the increased soil strength will largely degrease the structure response for all soils.
... For the current study, the dolphin of khor Al-Amaya berth no. 8 [13] is analyzed to impact loads that is given by Al-Jasim [14] for three cases which represent the same energy but different berthing velocities. From previous studies [13,14], the maximum dynamic response is associated with velocity 1. ...
... For the current study, the dolphin of khor Al-Amaya berth no. 8 [13] is analyzed to impact loads that is given by Al-Jasim [14] for three cases which represent the same energy but different berthing velocities. From previous studies [13,14], the maximum dynamic response is associated with velocity 1. Therefore, the dynamic analysis is carried for this velocity only. ...
The goal of this study is to prepare a new proposed method for the estimation of pile critical length in clayey soil for offshore structures. For this purpose the dolphin of Khor Al-Amaya berth No. 8 (in the Arabian Gulf, south of Iraq) is taking as a case study which subjected to dynamic load using the interface finite element method. A computer program has been written by Fortran 90 language to get the required solution. The (p-y), (t-z), and (q-z) curves which are adopted by American Petroleum Institute (API) are used to find normal, and tangential interface moduli and end bearing modulus. To get the required results, the Subspace Method is carried out for free vibration analysis and the Newmark method is adopted in direct integration time domain. The obtained results are compared with both elastic and Matlock and Reese solutions proved that the interface solution gives higher response values of vertical pile other than the two solutions because of the nonlinear effects of the interface solution. Also, the effect of the variation of soil strength is investigated in the problem. The proposed equation of pile critical length depends only on two parameters given as the bending stiffness of the pile and the soil cohesion.
... For the current study, the dolphin of khor Al-Amaya berth no. 8 [13] is analyzed to impact loads that is given by Al-Jasim [14] for three cases which represent the same energy but different berthing velocities. From previous studies [13,14], the maximum dynamic response is associated with velocity 1. ...
... For the current study, the dolphin of khor Al-Amaya berth no. 8 [13] is analyzed to impact loads that is given by Al-Jasim [14] for three cases which represent the same energy but different berthing velocities. From previous studies [13,14], the maximum dynamic response is associated with velocity 1. Therefore, the dynamic analysis is carried for this velocity only. ...
The goal of this study is to prepare a new proposed method for the estimation of pile critical
length in clayey soil for offshore structures. For this purpose the dolphin of Khor Al-Amaya berth No. 8
(in the Arabian Gulf, south of Iraq) is taking as a case study which subjected to dynamic load using the
interface finite element method. A computer program has been written by Fortran 90 language to get
the required solution. The (p-y), (t-z), and (q-z) curves which are adopted by American Petroleum
Institute (API) are used to find normal, and tangential interface moduli and end bearing modulus. To
get the required results, the Subspace Method is carried out for free vibration analysis and the Newmark
method is adopted in direct integration time domain.
The obtained results are compared with both elastic and Matlock and Reese solutions proved that the
interface solution gives higher response values of vertical pile other than the two solutions because of
the nonlinear effects of the interface solution. Also, the effect of the variation of soil strength is
investigated in the problem. The proposed equation of pile critical length depends only on two
parameters given as the bending stiffness of the pile and the soil cohesion.
Key words: Piles, pile length, soil interaction, offshore structures.
