• Title/Summary/Keyword: Ground movement

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Ground surface changes detection using interferometric synthetic aperture radar

  • Foong, Loke Kok;Jamali, Ali;Lyu, Zongjie
    • Smart Structures and Systems
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    • v.26 no.3
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    • pp.277-290
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    • 2020
  • Disasters, including earthquakes and landslides, have enormous economic and social losses besides their impact on environmental disruption. Iran, and particularly its Western part, is known as an earthquake susceptible area due to numerous strong ground motions. Studying ecological changes due to climate change can improve the public and expert sector's awareness and response to future disastrous events. Synthetic Aperture Radar (SAR) data and Interferometric Synthetic Aperture Radar (InSAR) technologies are appropriate tools for modeling and surface deformation modeling. This paper proposes an efficient approach to detect ground deformation changes using Sentinel-1A. The focal point of this research is to map the ground surface deformation modeling is presented using InSAR technology over Sarpol-e Zahab on 25th November 2018 as a study case. For surface deformation modeling and detection of the ground movement due to earthquake SARPROZ in MATLAB programming language is used and discussed. Results show that there is a general ground movement due to the Sarpol-e Zahab earthquake between -7 millimeter to +18 millimeter in the study area. This research verified previous researches on the advanced image analysis techniques employed for mapping ground movement, where InSAR provides a reliable tool for assisting engineers and the decision-maker in choosing proper policies in a time of disasters. Based on the result, 574 out of 682 damaged buildings and infrastructures due to the 2017 Sarpol-e Zahab earthquake have moved from -2 to +17 mm due to the 2018 earthquake with a magnitude of 6.3 Richter. Results show that mountainous areas have suffered land subsidence, where urban areas had land uplift.

3-D Behavior of Adjacent Structures in Tunnelling Induced Ground Movements (터널 굴착에 따른 지반 및 인접구조물의 3차원 거동)

  • 김찬국;황의석;김학문
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.663-670
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    • 2003
  • Urban tunnelling need to consider not only the stability of tunnel itself but also the ground movement regarding adjacent structures. This paper present 3-D behavior of adjacent structures due to tunnelling induced ground movements by means of field measuring data and nonlinear FEM tunnel analysis. The results of the analytical methods from Mohr-Coulomb model are compared with the site measurement data obtained during the twin tunnel construction. It was found that the location and stiffness of the structure influence greatly the shape and pattern of settlement trough. The settlement trough for Greenfield condition was different from the trough for existing adjacent structures. Therefore the load and stiffness of adjacent structures should be taken into account for the stability analysis of the structures.

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Behavior and Lateral Force of H-piles under lateral Soil Movement in Sand (측방변형을 일으키는 모래지반속의 H형 말뚝에 작용하는 수평력)

  • 김영인
    • Journal of Ocean Engineering and Technology
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    • v.16 no.6
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    • pp.44-48
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    • 2002
  • In lateral ground flow, slope stability, and land slide problems, H-piles have often been used, on a horizontally deforming ground, to prevent the failure of mass of soil in a downward and outward movement of a slope. Here, theoretical equations are derived to estimate the lateral force, assuming that the Mohr-Coulomb's plastic states occur in the ground, just around H-piles. In this study, some model experiments were performed to check the lateral forces determined from theoretical equations, using several pile widths, heights and various interval ratios between H-piles for sand specimens. The solution of the theoretical equation, derived from previous studies, showed reasonable characteristics for constants of soil, as well as for the interval, widths, and heights of H-Pile.

Analysis of Ground Movements due to Tunnel Excavation Considering Ground Conditions, Excavation Characteristics, and Ground Layer Formations (지반조건, 굴착특성 및 지층구성을 고려한 터널굴착 유발 지반변위 거동분석)

  • Son, Moorak;Yun, Jongcheol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5C
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    • pp.239-250
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    • 2009
  • Tunnelling-induced settlements and lateral ground movements have been investigated by numerical parametric studies considering ground condition, excavation characteristics, and ground layers. Before the numerical study the existing methods of ground movement estimation have been collected and analysed to have some information of ground movements and to improve them providing a fundamental material for the numerical study. Numerical model simulation has been performed of a physical model test of tunnel excavation in which the ground movements were measured reliably and the results have been used to determine the numerical approach and the appropriate soil constitutive mode. With this procedure done, the results of numerical parametric studies have been put together to analyze and understand tunnelling-induced settlements and lateral ground movements.

Lateral Displacement and Ground Rising Movement with Soil Embankment (성토에 따른 지반의 측방변위와 지표면 융기량)

  • Jeong, Ji-Cheol;Shin, Bang-Woong;Oh, Se-Wook
    • Journal of the Korean GEO-environmental Society
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    • v.5 no.2
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    • pp.63-69
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    • 2004
  • During and after the construction of embankment on soft ground, consolidation settlements and lateral displacements develop. But generally it's very difficult to predict the magnitude of lateral deformations and the correct distribution of lateral displacements with depth under the toe of embankment because the consolidation and the shear deformations of soft ground occur simultaneously. This study shows that later displacements of ground surface arise by embankment loading act on soft clay hight water contents in laboratory model testing. The results of model test are observed settlement of embankment, amount of maximum rising and displacement of ground surface with loading velocity. The formula were proposed to predict lateral movement by test series.

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Earthquake response of isolated cable-stayed bridges under spatially varying ground motions

  • Ates, Sevket;Soyluk, Kurtulus;Dumanoglu, A. Aydin;Bayraktar, Alemdar
    • Structural Engineering and Mechanics
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    • v.31 no.6
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    • pp.639-662
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    • 2009
  • A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wave-passage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.

Urban Excavation - Induced Ground Movement in Water Bearing Ground Using Stress-pore Pressure Coupled Analysis (응력 -간극수압 연계해석을 이용한 흙막이 굴착시 지하수저하에 따른 지반침하에 관한 연구)

  • Choi, Go-Ny;Yoo, Chung-Sik
    • Journal of the Korean Geotechnical Society
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    • v.27 no.5
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    • pp.17-31
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    • 2011
  • This paper presents the results of a numerical investigation on the behavior of earth retaining wall system with emphasis on the groundwater lowering. Using the 2D stress-pore pressure coupled analysis, the effects of ground excavation and groundwater interaction were examined using wall horizontal deformation, ground surface movement, plastic strain pattern, effective stress distribution and axial stress of strut. In addition, based on the results from a parametric study on a wide range of soil profile and initial ground water table level, the ranges of wall displacement and ground deformation were suggested quantitatively.

A Study on Influence of Constructed Bridge Abutment in Landfill Slope under Laterally Displacing (측방유동 발생 시 성토사면에 시공된 교대의 영향에 대한 연구)

  • Lee, Hangyu;Hong, Jongouk;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.12
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    • pp.31-41
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    • 2013
  • The damage caused by lateral movement occurs frequently on site where abutment or retaining wall was built on soft ground along with embankment behind and the study on stability of abutment against lateral movement has been mostly focused on soft ground. However lateral movement occurs not only on soft ground but also on embankment slope which causes the impact on structure. The bridges built in Korea are mostly on mountainous area than soft ground. This study is intended to analyze the ground behavior resulting from lateral movement using finite element analysis method to the section as well as propose the basic data for abutment design on embankment slope through the analysis of the outcome of reinforcement method. As a result, when it comes to the reinforcement with soil surcharge and stabilized pile in slope, lateral movement was reduced by 4~30% and displacement on bearing shoe on abutment was reduced by 2~13%. On the contrary, when reinforced with EPS, lateral float was reduced by 97% and maximum horizontal displacement of bearing shoe on abutment was reduced by 95%. Thus, it's necessary to identify the design technique which is applicable to domestic condition through additional tests and more reliable study using numerical analysis and comparing the measured values shall follow.

Evaluation of Lateral Flow in Soft Ground under Embankment (성토하부 연약지반의 측방유동 평가)

  • Hong, Won-Pyo;Cho, Sam-Deok;Lee, Jae-Ho;Lee, Kwang-Wu
    • Journal of the Korean Geotechnical Society
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    • v.22 no.10
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    • pp.93-100
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    • 2006
  • The lateral soil movement in soft grounds undergoing improvement with application of vertical drains is analyzed on the basis of monitoring data at three fields, in which fifty six monitoring sites are located. Based on the investigations, the criterions are suggested to predict the lateral soil movement. In order to predict the lateral soil movement in the improved soft grounds by using the dimensionless parameter R suggested by Marche & Chapuis (1974), it is desirable that the maximum lateral displacement in the soft ground below the toe of embankment should be applied to calculate R instead of the lateral displacement at the toe of embankment. The lateral soil movement may increase rapidly, if the safety factor of slope is less than 1.4 in case of high ratio of H/B (Thickness of soft ground/Embankment width) such as 1.15 or is less than 1.2 in case of low ratio of H/B such as 0.05. Also, the graph suggested by Tschebotarioff (1973), which illustrates the relationship between the maximum height of embankments and the undrained shear strength of soft grounds, can be applied to the evaluation for the possibility of the lateral soil movement due to embankments on soft grounds.

A Note on Under ground water (지하수에 대한 소고)

  • 최귀열
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.8 no.1
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    • pp.1055-1063
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    • 1966
  • Ground water hydrology may be defined as the science of the occnrrence, distribution, and movement of water below the surface of the earth. Geohydrology has an identical connotation, and hydrogeology differs only by its greater emphasis on geology. Ground water referred to with out further specification is commonly understood to mean water occupying all the voids with in a geologic stratum. This saturated zone is tobe distinguished from an unsaturated, or aeration zone where voids are filled \yith water and air. Water contained in saturate:! zones is important for engineering works, geologic studies, and water supply developements Conseqently, the occurrence of water in these zones will be emphasized here. Un-saturated zones are usualiy found above saturated zones and extending upward to the ground surface. Because this water includes soil moisture with in the root zone, it is a major concern of agricultlre, botmy and soil science. No rigid demarcation of waters, between the two zones is possible, for they possess an iriterdependent boundary and water can move from zone to zone in either science, including eology, hydrology, meteorology, and oceanography are concerned with earths water, but ground water hydrology may be regarded as a specialized science combining elements of geology, hydrology, and fluid mechanics. Geology governs the occurrence and distribution of ground water, hydrology determines the supply of water to the ground, and fluid mechanics explains its movement. To provide maximum development of grofnd water resources. for benefical use requires thinking in terms of an entire ground water basin. In order to inorease the natural supply of ground water, man has attempted to artifially recharge ground water basins. Coastal aquifers come in contact with the ocean at seawater of the coastline. Fresh ground water is discharged in to the ocean. the seaward flow of ground water has been decreased or even reversed, Sea water penettating in land in aquifer.

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