• Earthquakes and Structures
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• v.20 no.1
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• pp.55-70
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• 2021

In urban cities, buildings were built in the neighborhood, these buildings influence each other through structure-soilstructure interaction (SSSI) and seismic pounding due to limited separation distance in-between. Generally, the effects of the interaction between soil and structure are disregarded during seismic design and analysis of superstructure. However, the system of soil-base adversely changes structural behavior and response demands. Thus, the vibration characteristics plus the seismic response of a building are not able to be independent of those in adjacent buildings. The interaction between structure, soil, and structure investigates the action of the attendance of adjacent buildings to the others by the interaction effect of the sub-soil under dynamic disturbances. The main purpose of this research is to analyze the effects of SSSI and seismic pounding on the behavior of adjacent buildings. The response of a single structure or two adjacent structures with shallow raft base lying on soft soil are studied. Three dimensions finite element models are developed to investigate the effects of pounding; gap distance; conditions of soil; stories number; a mass of adjacent building and ground excitation frequency on the seismic responses and vibration characteristics of the structures. The variation in the story displacement, story shear, and story moment responses demands are studied to evaluate the presence effect of the adjacent buildings. Numerical results acquired using conditions of soil models are compared with the condition of fixed support and adjacent building models to a single building model. The peak responses of story displacement, story moment, and story shear are studied.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.1
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• pp.1-10
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• 2013

In this study, impact vibration tests are applied to analyze the vibration characteristics of caisson-type breakwater, and the results obtained from vibration tests are compared with numerical simulation results considering fluid-soil-structure interaction effects to verify the feasibility of a numerical analysis model. It is found that natural frequencies are reduced as amount of 1.7-4.3% after additional parapet structure is added to increase the height of breakwater, and the same results was observed from the numerical simulation study. Through the comparison, it was verified that the vibration tests and numerical simulation study can be applied to evaluate the vibration characteristics of caisson-type breakwater.

• Geotechnical Engineering
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• v.12 no.4
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• pp.61-74
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• 1996

Settlement induced by low -level vibration on granular soils is too complect to predict with one or two fact ors. Factors affecting vibration induced settlement were investigated, and a settlement prediction model on granular soils was developed using multifactorial experimental design(MED). Factors such as vibration amplitude, deviatoric stress, confining pressure, soil gradation, duration of vibration, moisture content, and relative density were considered in this study. A special vibratory frame was designed to shake a soil specimen within a triaxial cell. MED allowed the authors to investigate the effect of many factors using a relatively small number of experiments. The most significant factors on settlement were vibrati on amplitued, confining pressure, and defiatoric stress. Comparable settlement was occurred even under low-level vibration ranging from 2.5 to 18mm1sec, and stress am sotropy was found to be an important factor on settlement.

• Structural Engineering and Mechanics
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• v.5 no.1
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• pp.1-19
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• 1997

A numerical procedure for dynamic analysis of structures including lateral-torsional coupling, axial force effect and soil-structure interaction is presented in this study. A simple soil-structure system model has been designed for microcomputer applications capable of reflecting both kinematic and inertial soil-foundation interaction as well as the effect of this interaction on the superstructure response. A parametric study focusing on inertial soil-structure interaction is carried out through a simplified nine-degree of freedom building model with different foundation conditions. The inertial soil-structure interaction and axial force effects on a 20-storey building excited by an Australian earthquake is analysed through its top floor displacement time history and envelope values of structural maximum displacement and shear force.

• Earthquakes and Structures
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• v.11 no.1
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• pp.83-107
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• 2016

In this study, the response and behavior of machine foundations resting on dry and saturated sand was investigated experimentally. A physical model was manufactured to simulate steady state harmonic load applied on a footing resting on sandy soil at different operating frequencies. Total of (84) physical models were performed. The parameters that were taken into consideration include loading frequency, size of footing and different soil conditions. The footing parameters are related to the size of the rectangular footing and depth of embedment. Two sizes of rectangular steel model footing were used. The footings were tested by changing all parameters at the surface and at 50 mm depth below model surface. Meanwhile, the investigated parameters of the soil condition include dry and saturated sand for two relative densities; 30 % and 80 %. The dynamic loading was applied at different operating frequencies. The response of the footing was elaborated by measuring the amplitude of displacement using the vibration meter. The response of the soil to dynamic loading includes measuring the stresses inside soil media by using piezoelectric sensors. It was concluded that the final settlement (St) of the foundation increases with increasing the amplitude of dynamic force, operating frequency and degree of saturation. Meanwhile, it decreases with increasing the relative density of sand, modulus of elasticity and embedding inside soils. The maximum displacement amplitude exhibits its maximum value at the resonance frequency, which is found to be about 33.34 to 41.67 Hz. In general, embedment of footing in sandy soils leads to a beneficial reduction in dynamic response (displacement and excess pore water pressure) for all soil types in different percentages accompanied by an increase in soil strength.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.201-207
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• 2010

In this study, the SIP (Soil-cement Injected precast Pile) method among the Low-vibration & Low-noise pile driving methods was decided into study compensation. Ground vibrations by the SIP methods step by step divide and were analyzed. Quantitative response values and ground vibration equations with reliability were presented from findings of this study. Also, vibration responses that are occurred by the SIP method of construction were compared as quantitative with vibration responses by general method of construction that are presented in existent study. Ground vibration values by the SIP method correspond to level of 17 ~ 57% of values that are assumed by the Attewell & Famer's equation, respectively, and these result compares in reliability 50% and separated distance 10 ~ 50 m. Also, those values were analyzed that correspond to level of 14 ~ 96% of ground vibration values by the Prof. Park's equation, respectively. Construction limit extents, separation distances from vibration occurs position, were presented that can satisfy domestic criteria for vibration control for the SIP methods. Those presented in this paper were divided newly according to reliability.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1900-1906
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• 2000

In this study, the vibration screening effectiveness of barriers which can isolate structures from ground-transmitted vibration generated by harmonic forces is performed. For high frequencies, the vibration screening effectiveness of barriers is analyzed from field tests, and compared with the results from numerical analyses using a commercial program, ANSYS. Using these numerical analysis procedures, the effectiveness for vibration with various low frequencies is predicted. The frequency analysis tests of surface waves are performed in order to estimate the dynamic material properties of soil for 100 Hz, 150 Hz, 200 Hz, and 250 Hz. Three-dimensional solid elements are used in order to consider the diffraction of waves in all directions. Spring-damper combination elements are used in order to avoid the reflection of waves on the boundary. The results of numerical analysis agree with those of field tests. From the results of this numerical analyses, the reduction of vibration for low frequencies induced by the traffic loads can be predicted.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.597-602
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• 2002

This study reviews several of the procedures that have been used to predict ground-born vibration. The vibration responses are measured at three sites that have different soil qualities. The measured vibration levels are compared with the predicted results by previously used vibration level prediction models. In this study a numerical method, which is based on explicit differential method, is used to compensate tot existing prediction models. Although numerically computed results are not quantitatively in good agreement with the measured results, the trends are comparable in the sense that vibration level does not decrease monotonically with distance. Also, The site with the deepest tunnel gives the highest vibration level.

• Structural Engineering and Mechanics
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• v.10 no.4
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• pp.299-312
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• 2000

The response of an embedded body to dynamic loads is greatly influenced by the reactions of the soil to the motion of the body. The properties of the soil surrounding embedded bodies (e.g., piles) may be different than those of the far-field for a variety of reasons. It may be weakened or strengthened according to the method of installation of piles, or altered due to applying one of the soil strengthening technique (e.g., electrokinetic treatment of soil, El Naggar et al. 1998). In all these cases, the shear strength of the soils and its shear modulus vary gradually in the radial direction, resulting in a radially inhomogeneous soil layer. This paper describes an analysis to compute vertical and torsional dynamic soil reactions of a radially inhomogeneous soil layer with a circular hole. These soil reactions could then be used to model the soil resistance in the analysis of the pile vibration under dynamic loads. The soil layer is considered to have a piecewise, radial variation for the complex shear modulus. The model is developed for soil layers improved using the electrokinetic technique but can be used for other situations where the soil properties vary gradually in the radial direction (strengthened or weakened). The soil reactions (impedance functions) are evaluated over a wide range of parameters and compared with those obtained from other solutions. A parametric study was performed to examine the effect of different soil improvement parameters on vertical and torsional impedance functions of the soil. The effect of the increase in the shear modulus and the width of the improved zone is investigated.

• Coupled systems mechanics
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• v.9 no.5
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• pp.455-471
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• 2020

This paper presents the results of the study of vertically natural frequency of tractor tires are effected by changing different ground contacts and inflation pressures using the Free Decay Method. The results show that the natural frequencies of the tire are not affected while the vertical acceleration increased strongly due to the increase of inflation pressure when the tire performs free decay vibration on rigid ground. In addition, the number of natural frequency peaks of the tire also increases with increasing tire inflation pressure. On the other hand, the natural frequencies of the tractor tire increases strongly while the vertical acceleration decreases slightly with the increase of tire inflation pressure as the tire performs free decay vibration on soft soil. Further, the natural frequencies of tire-soil system are always higher than that of tire only, and it changed with changing the soil depth. Results also show the natural frequency of tire and tire-soil system is in the range of 3.0 to 10.0 Hz that lie within the most critical natural frequency range of the human body. These findings have to be mentioned and used as design parameters of the tractor suspension system.