• Title/Summary/Keyword: differential settlements

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Behavior of wall panels in industrial buildings caused by differential settlements

  • Fernandez, Suyai;Jaca, Rossana C.;Godoy, Luis A.
    • Structural Engineering and Mechanics
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    • v.56 no.3
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    • pp.443-460
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    • 2015
  • This paper presents the analysis of mechanical behavior of metal wall panels of storehouses and industrial buildings subjected to differential settlements. The storehouses considered are representative of those used in the agricultural activity. A small-scale model was built and tested in order to have evidence of the behavior and to validate computational models. The numerical investigation is carried out through finite element analysis using a general-purpose software, by modeling buildings with different geometries and evaluating different settlements of the ground. To obtain an adequate model, geometric non-linearity has to be taken into account. Models that represent the most usual geometric typologies were investigated under support settlements. The deflected shape of the wall panel and the relationship between the horizontal displacements and the settlement of the foundations are evaluated. The results show that there are large out-of-plane displacements caused by settlements that would be admitted by design recommendations.

Remaining Service Life Estimation Model for Reinforced Concrete Structures Considering Effects of Differential Settlements (부등침하의 영향이 반영된 철근콘크리트 구조물 잔존수명 평가모델)

  • Lee, Sang-Hoon;Han, Sun-Jin;Cho, Hae-Chang;Lee, Yoon Jung;Kim, Kang Su
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.1
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    • pp.133-141
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    • 2020
  • Korea Infrastructure Safety and Technology Corporation (KISTEC) specifies that the safety inspection and precise safety diagnosis of concrete structures shall be conducted in accordance with the 'Special Law on Safety Management of Infrastructure'. The detailed safety inspection and precise safety diagnosis guidelines presented by KISTEC, however, gives only the grade of members and structures, and thus it is impossible to quantify remaining service life (RSL) of the structures and to quantitatively reflect the effect of differential settlements on the RSL. Therefore, this study aims to develop a RSL evaluation model considering the differential settlements. To this end, a simple equation was proposed based on the correlations between differential settlements and angular distortion, by which the angular distortion of structures was then reflected in nominal strengths of structural members. In addition, the effects of the differential settlements on the RSL of structures were analyzed in detail by using the safety diagnosis results of actual concrete structure.

Model Tests for the Effect of Settlement Restraint of Adjacent Structure During Tunnel Excavation (터널굴착에 따른 인접 구조물 침하 억제효과에 관한 실내모형실험)

  • 유문오;임종철;고호성;박이근
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.141-148
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    • 2000
  • In this study, differential settlements of adjacent structure and behaviour of ground during tunnel excavation and the effect of micropile installed to preserve differential settlement of structure are measured and analyzed by model test. In the test results, the effective range of reinforcement is suggested.

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Three-dimensional Modeling Seismic Analysis of Circular Water Reservoirs considering Differential Settlement Effects (부동침하 영향을 고려한 원형 배수지 구조의 3차원 모델링 지진 해석)

  • Lee, Sang-Youl;Choi, Hyung Bae;Ahn, Kwang Sik;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.31 no.1
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    • pp.43-53
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    • 2021
  • Three-dimensional finite element analysis of 1,300 ton stainless water reservoirs was undertaken to consider differential settlement effects of the reservoir when subjected to earthquake loads. The earthquake load for large (>1,000 ton) water reservoirs are further determined using a specification established from the Korean Standards Association. The structural behavior of water reservoirs with differential settlements can be heavily dependent on seismic loading effects. Stress and displacement distributions are induced for various load combinations, including for with and without differential settlements. From numerical examples, the induced maximum displacements of the water reservoirs largely increase with differential settlements compared to those without differential settlements.

Nonlinear interaction behaviour of plane frame-layered soil system subjected to seismic loading

  • Agrawal, Ramakant;Hora, M.S.
    • Structural Engineering and Mechanics
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    • v.41 no.6
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    • pp.711-734
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    • 2012
  • The foundation of a tall building frame resting on settable soil mass undergoes differential settlements which alter the forces in the structural members significantly. For tall buildings it is essential to consider seismic forces in analysis. The building frame, foundation and soil mass are considered to act as single integral compatible structural unit. The stress-strain characteristics of the supporting soil play a vital role in the interaction analysis. The resulting differential settlements of the soil mass are responsible for the redistribution of forces in the superstructure. In the present work, the nonlinear interaction analysis of a two-bay ten-storey plane building frame- layered soil system under seismic loading has been carried out using the coupled finite-infinite elements. The frame has been considered to act in linear elastic manner while the soil mass to act as nonlinear elastic manner. The subsoil in reality exists in layered formation and consists of various soil layers having different properties. Each individual soil layer in reality can be considered to behave in nonlinear manner. The nonlinear layered system as a whole will undergo differential settlements. Thus, it becomes essential to study the structural behaviour of a structure resting on such nonlinear composite layered soil system. The nonlinear constitutive hyperbolic soil model available in the literature is adopted to model the nonlinear behaviour of the soil mass. The structural behaviour of the interaction system is investigated as the shear forces and bending moments in superstructure get significantly altered due to differential settlements of the soil mass.

Differential settlements in foundations under embankment load: Theoretical model and experimental verification

  • Wang, Changdan;Zhou, Shunhua;Wang, Binglong;Guo, Peijun;Su, Hui
    • Geomechanics and Engineering
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    • v.8 no.2
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    • pp.283-303
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    • 2015
  • To research and analyze the differential settlements of foundations specifically, site investigations of existing railways and metro were firstly carried out. Then, the centrifugal test was used to observe differential settlements in different position between foundations on the basis of investigation. The theoretical model was established according to the stress diffusion method and Fourier method to establish an analytical solution of embankment differential settlement between different foundations. Finally, theoretical values and experimental values were analyzed comparatively. The research results show that both in horizontal and vertical directions, evident differential settlement exists in a limited area on both sides of the vertical interface between different foundations. The foundation with larger elastic modulus can transfer more additional stress and cause relatively less settlement. Differential settlement value decreases as the distance to vertical interface decreases. In the vertical direction of foundation, mass differential settlement also exists on both sides of the vertical interface and foundation with larger elastic modulus can transfer more additional stress. With the increase of relative modulus of different foundations, foundation with lower elastic modulus has larger settlement. Meanwhile, differential settlement is more obvious. The main error sources in theoretical and experimental values include: (a) different load form; (b) foundation characteristics differences; (c) modulus conversion; (d) effect of soil internal friction.

Experimental Evaluation of Construction Performance and Long-term Settlements in Soft Ground Breakwater (연약지반 방파제의 시공성능 및 장기침하에 관한 실험적 평가)

  • Kwon, O-Soon;Jang, In-Sung;Park, Woo-Sun;Yum, Ki-Dai
    • Ocean and Polar Research
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    • v.25 no.spc3
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    • pp.385-392
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    • 2003
  • A new type of soft ground breakwater was recently developed, which does not need ground improvement because of light weight and structural characteristics. The various studies about consolidation settlements and lateral behavior of proposed soft ground breakwater have been conducted. But, the systematic investigations on the construction performance and long-term settlements of new type breakwater has not been accomplished. In this study, construction simulation of soft ground breakwater with soil box model test and experiments of the long-term wave loaded breakwater were performed. The results of test shows that it is possible to compensate differential settlements by dead loading and/or suction pressure, and to reduce the consolidation settlements by preloading method. It was also found that the vertical and lateral displacements of long-term wave loaded breakwater were negligible.

Analysis of settlements of space frame-shear wall-soil system under seismic forces

  • Jain, D.K.;Hora, M.S.
    • Earthquakes and Structures
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    • v.8 no.5
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    • pp.1255-1276
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    • 2015
  • The importance of considering soil-structure interaction effect in the analysis and design of RC frame buildings is increasingly recognized but still not penetrated to the grass root level owing to various complexities involved. It is well established fact that the soil-structure interaction effect considerably influence the design of multi-storey buildings subjected to lateral seismic loads. The shear walls are often provided in such buildings to increase the lateral stability to resist seismic lateral loads. In the present work, the linear soil-structure analysis of a G+5 storey RC shear wall building frame resting on isolated column footings and supported by deformable soil is presented. The finite element modelling and analysis is carried out using ANSYS software under normal loads as well as under seismic loads. Various load combinations are considered as per IS-1893 (Part-1):2002. The interaction analysis is carried out with and without shear wall to investigate the effect of inclusion of shear wall on the total and differential settlements in the footings due to deformations in the soil mass. The frame and soil mass both are considered to behave in linear elastic manner. It is observed that the soil-structure interaction effect causes significant total and differential settlements in the footings. Maximum total settlement in footings occurs under vertical loads and inner footings settle more than outer footings creating a saucer shaped settlement profile of the footings. Each combination of seismic loads causes maximum differential settlement in one or more footings. Presence of shear wall decreases pulling/pushing effect of seismic forces on footings resulting in more stability to the structures.

Reduction of Differential Settlements due to Deep Excavation Using the Micro-piling Method (마이크로 파일을 이용한 가설 벽체 인접 구조물의 침하 억제에 관한 연구)

  • Huh, In-Goo;Hwang, Tae-Hyun;Lee, Sang-Ryeong;Shin, Jong-Ho;Kwon, Oh-Yeob
    • Journal of the Korean Geotechnical Society
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    • v.24 no.10
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    • pp.71-81
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    • 2008
  • Wall displacements caused by earth pressure, rainfalls, rise in ground water level, inappropriate deep excavation and structural defects of the wall may produce differential settlements to existing buildings, which often result in damages and/or collapses of the building structures. In this case, measures to protect the walls and nearby structures would be required. One of the recent measures to reduce differential settlements and protecting walls is to reinforce the ground using micro-piles. In this study physical model tests were carried out to evaluate the performance of the micro-pile method. It is revealed that reduction of the settlement was maximized when the length of micro-pile is twice of the foundation width, distance between piles is twice of the pile diameter and the distance to wall is one tenth of the foundation width. Based on the test results some design recommendations were made.

Subsidence Measurements of Reclaimed Coastal Land using Satellite Radar Interferometry (위성 레이더 인터훼로메트리를 이용한 연안 매립지의 지반침하량 측정)

  • Kim, Sang-Wan;Won, Joong-Sun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.219-226
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    • 2004
  • We measure subsidences occurred in a reclaimed coastal land, Noksan industrial complex, by using JERS-1 SAR (1996-1998) and RADARSAT-1 SAR (2002-2003) dataset. SAR with a high spatial resolution (about several or several tens meter) can reveal the two-dimensional distribution of settlement that would be bardly estimated from in situ measurements. The DInSAR results show significant deformation signal associated with soil consolidation. Accuracy of the settlements estimated by 2-pass differential interferometry (DInSAR) is evaluated using the measurements of settlement gauge. A two-dimensional subsidence map is constructed from 7 qualified pairs. Comparing the JERS-1 radar measurements with the ground truth data yields the correlation coefficient of 0.87 (RMSE of 1.44 cm). The regression line shows the gradient of 1.04 and intercepts close to the origin, which implies that the unbiased settlement can be measured by DInSAR technique. The residual settlements are also detected from RADARSAT-1 pairs. The extent and amount of the settlements are matched well with ground truth data.

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