• Title/Summary/Keyword: uplift history

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Thermal and uplift histories of Mesozoic granites in Southeast Korea: new fission track evidences

  • Shin, Seong-Cheon;Susumu Nishimura
    • The Journal of the Petrological Society of Korea
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    • v.2 no.2
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    • pp.104-121
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    • 1993
  • Fission track (FT) thermochronological analyses on Mesozoic granites provide new information about cooling and uplift histories in Southeast Korea. Twenty-nine new FT sphene, zircon and apatite ages and seven track length measurements are presented for eleven granite samples. Measured mineral ages against assumed closure temperatures yield cooling rates for each sample. Relatively rapid (7-$15^{\circ}C$/Ma) and simple cooling patterns from the middle Cretaceouss (ca. 90-100 Ma) granites are caused mainly by a high thermal contrast between the intruding magma and country rocks at shallow crustal levels (ca. 1-2.5 km-depths). On the contrary, a slow overall cooling (1-$4^{\circ}C$/Ma) of the Triassic to Jurassic granites (ca. 250-200 Ma), emplaced at deep depths (>>9 km), may mainly depend upon very slow denudation of the overlying crust. The uplift history of the Triassic Yeongdeog Pluton in the Yeongyang Subbasin, west of the Yangsan Fault, is characterized by a relatively rapid uplift (~0.4 mm/a) before the total unroofing of the pluton in the earliest Cretaceous (~140 Ma) followed by a subsidence (~0.2mm/a) during the Hayang Group sedimentation. Stability of original FT zircon ages (156 Ma) and complete erasure of apatite ages suggest a range of 3 to 5.5 km for the basin subsidence. Since 120 Ma up to present, the Yeongyang Subbasin has been slowly uplifted (~0.04 mm/a). The FT age patterns of Jurassic granites both from the northeastern wing of the Ryeongnam Massif and from the northern edge of the Pohang-Kampo Block indicate that the two geologic units have been slowly uplifted with a same mean rate (~0.04 mm/a) since early Cretaceous. Estimates of Cenozoic total uplifts since 100 Ma are different: Ryeongnam Massif (~6 km)=Pohang-Kampo Block (~6 km)>Yeongyang Subbasin(~4 km).

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Seismic response analysis of an unanchored vertical vaulted-type tank

  • Zhang, Rulin;Cheng, Xudong;Guan, Youhai;Tarasenko, Alexander A.
    • Earthquakes and Structures
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    • v.13 no.1
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    • pp.67-77
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    • 2017
  • Oil storage tanks are vital life-line structures, suffered significant damages during past earthquakes. In this study, a numerical model for an unanchored vertical vaulted-type tank was established by ANSYS software, including the tank-liquid coupling, nonlinear uplift and slip effect between the tank bottom and foundation. Four actual earthquakes recorded at different soil sites were selected as input to study the dynamic characteristics of the tank by nonlinear time-history dynamic analysis, including the elephant-foot buckling, the liquid sloshing, the uplift and slip at the bottom. The results demonstrate that, obvious elephant-foot deformation and buckling failure occurred near the bottom of the tank wall under the seismic input of Class-I and Class-IV sites. The local buckling failure appeared at the location close to the elephant-foot because the axial compressive stress exceeded the allowable critical stress. Under the seismic input of Class-IV site, significant nonlinear uplift and slip occurred at the tank bottom. Large amplitude vertical sloshing with a long period occurred on the free surface of the liquid under the seismic wave record at Class-III site. The seismic properties of the storage tank were affected by site class and should be considered in the seismic design of large tanks. Effective measures should be taken to reduce the seismic response of storage tanks, and ensure the safety of tanks.

Effect of Caisson Tilting on the Sliding Distance of a Caisson under Wave Impacts and Introduction of the Effect into Computation of Sliding Distance

  • Kim, Tae Min;Takayama, Tomotsuka
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.474-478
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    • 2004
  • Based on the recent laboratory experiments (Kim et al. 2004), comparisons of caisson sliding distance are made between the computations and experiments. The time history model of wave force, which is proposed by Tanimoto et al. (1996), is modified in the standing wave part of horizontal and uplift wave forces because of the overestimation of the time history model. The comparison between experimental and computational sliding distance has showed that the caisson tilting increases the resistant force to the horizontal sliding. Therefore, a titling resistant force, which is caused by caisson tilting, is introduced into computation of sliding distance.

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Integrating Study of Kidney on Left & Life Gate on Right(左腎右命門) and Moving Energy between two kidneys(腎間動氣) (좌신우명문(左腎右命門)과 신간동기(腎間動氣)의 통합적 이해를 위한 연구)

  • Kim, Jin-Ho
    • Journal of Korean Medical classics
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    • v.26 no.4
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    • pp.253-266
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    • 2013
  • Objective : There was no attempt to understand Moving Energy between two kidneys(腎間動氣) and Kidney on Left & Life Gate on Right(左腎右命門) by integration progress. So I have faced to study based on two parts with concerning as clues. One is 'Life Right (左 右)' and the other is 'Between(間)'. Methods : Revealing the source of the origin, Nanjingbenyi(難經本義) is given on the basis. Take a close look at publications related to Nanjing(難經) which is about Kidney on Left & Life Gate on Right and Moving Energy between two kidneys. Take a close look at Kidney, the Life Gate and Moving Energy between two kidneys. Look see the three-dimensional uplift movement of Gi(氣). Results : In Neijing(內經) and Nanjing, the basic point of view for Kidney is the same. That is explained in line with attributes of convergence(收斂). 'Life Gate(命門)' is a term to express the divergence feature(發散機能) of kidney. Moving Energy between two kidneys is used to mean the mainspring of human body activity. The Gi in human body loses altitude turning left(左旋而下降) and gains height turning right(右旋而上升). Conclusion : Watching on functional aspect, there are two names for kidney. One is 'Kidney(腎)' which collects the losing altitude turning left and the other is 'Life Gate' which rises turning right. Moreover, the fundamental power that effectuate the uplift movement is Moving Energy between two kidneys. This kind model is a way that can be understood syntagmatically the Kidney on Left & Life Gate on Right and the Moving Energy between two kidneys without any gainsaying the original of Nanjing.

Influence of Tectonic Uplift on Longitudinal Profiles of Bedrock Rivers: Numerical Simulations (융기가 기반암 하상하천의 종단곡선에 미치는 영향에 대한 연구 -수리 모형을 통한 연구-)

  • Kim Jong Yeon
    • Journal of the Korean Geographical Society
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    • v.39 no.5 s.104
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    • pp.722-734
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    • 2004
  • Longitudinal profiles of bedrock rivers play a fundamental role in landscape history by setting the boundary conditions for landform evolution. Longitudinal profiles are changed with climatic conditions, lithology and tectonic movements. Tectonic movement is an important factor controlling longitudinal profiles, especially in tectonically active area where uplift rates are regarded as a major factor controlling channel gradient. However study on bedrock channel has made little progress, because controls over bedrock river incision are yet to be clarified. Previous numerical simulations have used a simple diffusion model, which links together the overall processes of bedrock channel erosion as in other landform evolution models. In this study, previous bedrock incision models based on physical processes (especially abrasion) are reviewed and new modifications are introduced. Using newly formulated numerical model, the role of spatial pattern and intensity of tectonic uplift on changes in river longitudinal profile was simulated and discussed.

Three-dimensional numerical analysis of nonlinear phenomena of the tensile resistance of suction caissons

  • Azam, Arefi;Pooria, Ahad;Mehdi, Bayat;Mohammad, Silani
    • Geomechanics and Engineering
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    • v.32 no.3
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    • pp.255-270
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    • 2023
  • One of the main parameters that affect the design of suction caisson-supported offshore structures is uplift behavior. Pull-out of suction caissons is profoundly utilized as the offshore wind turbine foundations accompany by a tensile resistance that is a function of a complex interaction between the caisson dimensions, geometry, wall roughness, soil type, load history, pull-out rate, and many other parameters. In this paper, a parametric study using a 3-D finite element model (FEM) of a single offshore suction caisson (SOSC) surrounded by saturated soil is performed to examine the effect of some key factors on the tensile resistance of the suction bucket foundation. Among the aforementioned parameters, caisson geometry and uplift loading as well as the difference between the tensile resistance and suction pressure on the behavior of the soil-foundation system including tensile capacity are investigated. For this purpose, a full model including 3-D suction caisson, soil, and soil-structure interaction (SSI) is developed in Abaqus based on the u-p formulation accounting for soil displacement (u) and pore pressure, P.The dynamic responses of foundations are compared and validated with the known results from the literature. The paper has focused on the effect of geometry change of 3-D SOSC to present the soil-structure interaction and the tensile capacity. Different 3-D caisson models such as triangular, pentagonal, hexagonal, and octagonal are employed. It is observed that regardless of the caisson geometry, by increasing the uplift loading rate, the tensile resistance increases. More specifically, it is found that the resistance to pull-out of the cylinder is higher than the other geometries and this geometry is the optimum one for designing caissons.

Seismic control of concrete buildings with nonlinear behavior, considering soil structure interaction using AMD and TMD

  • Mortezaie, Hamid;Zamanian, Reza
    • Structural Engineering and Mechanics
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    • v.77 no.6
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    • pp.721-734
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    • 2021
  • The seismic analysis of structures without applying the effects of soil can undermine functional objectives of structure so that it can affect all the desired purposes at the design and control stages of the structure. In this research, employing OpenSees and MATLAB software simultaneously and developing a definite three-dimensional finite element model of a high-rise concrete structure, designed using performance-based plastic design approach, the performance of Tuned Mass Damper (TMD) and Active Mass Damper (AMD) is both examined and compared. Moreover some less noted aspects such as nonlinear interaction of soil and structure, uplift, nonlinear behavior of structure and structural torsion have received more attention. For this purpose, the analysis of time history on the structural model has been performed under 22 far-field accelerogram records. Examining a full range of all structural seismic responses, including lateral displacement, acceleration, inter-story drift, lost plastic energy, number of plastic hinges, story shear force and uplift. The results indicate that TMD performs better than AMD except for lateral displacement and inter-story drift to control other structural responses. Because on the one hand, nonlinear structural parameters and soil-structure interaction have been added and on the other hand, the restriction on the control force applied that leads up to saturation phenomenon in the active control system affect the performance of AMD. Moreover, the control force applied by structural control system has created undesirable acceleration and shear force in the structure.

Seismic response evaluation of concentrically rocking zipper braced frames

  • Sarand, Nasim Irani;Jalali, Abdolrahim
    • Structural Engineering and Mechanics
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    • v.73 no.3
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    • pp.303-317
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    • 2020
  • In this study an innovative rocking zipper braced frame (RZBF) is proposed to overcome the deficiencies of common concentrically braced frames. RZBF is an improved rocking concentrically braced frame which is based on combination of rocking behavior and zipper columns. The base rocking joints and post-tensioned bars provide rocking response and restoring force, respectively. Also, zipper columns distribute the unbalance force over the frame height and reduce the damage concentration. To evaluate seismic performance of RZBF, a comparison study is carried out considering concentrically braced frame, zipper braced frame, rocking concentrically braced frame and RZBF. Thereby, a suite of non-linear time history analyses had been performed on four different types of archetypes with four, six, eight, ten and twelve stories. Frames were designed and non-linear time history analyses were conducted in OpenSees. To compare the seismic behavior of the archetypes, roof drifts, residual roof drifts, story drifts, the forces of first and top story braces, PT bars forces, column uplift and base shears were taken in to consideration. Results illustrate that using RZBF, can reduce the damage due to reduced residual drifts. Zipper columns enhance the seismic performance of rocking systems. As the number of stories increase in the RZBF systems, larger top story braces were needed. So the RZBF system is applicable on low and midrise buildings.

Calculation of Expected Sliding Distance of Wave Dissipating Caisson Breakwater (소파케이슨 방파제의 기대활동량 산정)

  • Kim, Dong-Hyawn
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.17 no.4
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    • pp.213-220
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    • 2005
  • An approach to calculate expected sliding distance of wave dissipating caisson breakwater is proposed. Time history of dynamic wave pressure for the calculation of sliding distance is made by extending conventional static wave pressure developed for the wave dissipating caisson breakwater. Construction of impact wave and standing wave was done by using duration time and maximum wave pressures of themselves. In the numerical analysis, the sliding distance for an attack of single wave and expected sliding distance for 50 years of wave dissipating breakwater by proposed method were compared with those by conventional method for uplift caisson breakwater. It was found that the sliding distance of wave dissipating breakwater by the proposed method is smaller than by conventional method.

Marine terrace and its implications to paleoenvironment during the Quaternary at Suje-ri - Suryum-ri of the East coast of Gyeongju, SE Korea (한반도 남동부 경주시 수제리-수렴리의 해안단구와 제4기 환경변화)

  • HWANG, Sangill;SHIN, Jaeryul;YOON, Soon-Ock
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.3
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    • pp.97-108
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    • 2012
  • During the last few decades, the ever-increasing knowledge of coastal morphogenic processes has made marine terraces the most recognizable, widespread and scientifically reliable records to determine both qualitatively and quantitatively the vertical movements that have affected the tectonically active coastal regions during the Quaternary. This study first aims to address the marine terrace records from Suje-ri to Suryum-ri along the coast of Gyeongju, SE Korea. Eight distinct flights of terraces, including HH YC, elevated up to 160 m above present sea level have been mapped along the coast of the study areas, and are designated $L_{II}$ to HH YC from the youngest to oldest. Based on the elevation of paleo-shoreline and inferred formation age for HH YC uplift rate since the middle Pleistocene has been estimated at 0.23 mm/year. Establishing the nature and timing of the uplift history derived from marine terraces provide a better understanding of neotectonic framework for explain enigmatic, complex landscape evolution in the Korean peninsula.