• Title/Summary/Keyword: bearing walls

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Experimental evaluation of back-to-back anchored walls by double-plates anchors

  • Amir, Najafizadeh;AmirAli, Zad
    • Geomechanics and Engineering
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    • v.31 no.6
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    • pp.599-614
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    • 2022
  • One of the methods of stabilizing retaining walls, embankments, and deep excavations is the implementation of plate anchors (like the Geolock wall anchor systems). Back-to-back Mechanically Stabilized Earth (BBMSE) walls are common stabilized earth structures that can be used for bridge ramps. But so far, the analysis of the interactive behavior of two back-to-back anchored walls (BBAW) by double-plates anchors (constructed closely from each other and subjected to the limited-breadth vertical loading) including interference of their failure and sliding surfaces has not been the subject of comprehensive studies. Indeed, in this compound system, the interaction of sliding wedges of these two back-to-back walls considering the shear failure wedge of the foundation, significantly impresses on the foundation bearing capacity, adjacent walls displacements and deformations, and their stability. In this study, the effect of horizontal distance between two walls (W), breadth of loading plate (B), and position of vertical loading was investigated experimentally. In addition, the comparison of using single and equivalent double-plate anchors was evaluated. The loading plate bearing capacity and displacements, and deformations of BBAW were measured and the results are presented. To evaluate the shape, form, and how the critical failure surfaces of the soil behind the walls and beneath the foundation intersect with one another, the Particle Image Velocimetry (PIV) technique was applied. The experimental tests results showed that in this composite system (two adjacent-loaded BBAW) the effective distance of walls is about W = 2.5*H (H: height of walls) and the foundation effective breadth is about B = H, concerning foundation bearing capacity, walls horizontal displacements and their deformations. For more amounts of W and B, the foundation and walls can be designed and analyzed individually. Besides, in this compound system, the foundation bearing capacity is an exponential function of the System Geometry Variable (SGV) whereas walls displacements are a quadratic function of it. Finally, as an important achievement, doubling the plates of anchors can facilitate using concrete walls, which have limitations in tolerating curvature.

Enhancement of in-plane load-bearing capacity of masonry walls by using interlocking units

  • Kayaalp, Fatma Birinci;Husem, Metin
    • Earthquakes and Structures
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    • v.22 no.5
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    • pp.475-485
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    • 2022
  • This paper presents a comparative experimental study on structural behavior of the interlocking masonry walls under in-plane cyclic loading. The main purpose of this study is to increase lateral load-bearing capacities of masonry walls by using interlocking units. The interlocking units were designed by considering failure modes of masonry walls and produced using lightweight foamed concrete. To this end, three masonry walls which are hollow, fully grouted, and reinforced were constructed with interlocking units. Also, a traditional masonry brick wall was built for comparison reasons. The walls were tested under in-plane cyclic loading. Then, structural parameters of the walls such as lateral load bearing and total energy dissipation capacities, ductility, stiffness degradation as well as failure modes obtained from the tests were compared with each other. The results have shown that the walls with the interlocking units have better structural performance than traditional masonry brick walls and they may be used in the construction of low-rise masonry structures in rural areas to improve in-plane structural performance.

Micro modelling of masonry walls by plane bar elements for detecting elastic behavior

  • Doven, Mahmud Sami;Kafkas, Ugur
    • Structural Engineering and Mechanics
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    • v.62 no.5
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    • pp.643-649
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    • 2017
  • Masonry walls are amongst the oldest building systems. A large portion of the research on these structures focuses on the load-bearing walls. Numerical methods have been generally used in modelling load-bearing walls during recent years. In this context, macro and micro modelling techniques emerge as widely accepted techniques. Micro modelling is used to investigate the local behaviour of load-bearing walls in detail whereas macro modelling is used to investigate the general behaviour of masonry buildings. The main objective of this study is to investigate the elastic behaviour of the load- bearing walls in masonry buildings by using micro modelling technique. In order to do this the brick and mortar units of the masonry walls are modelled by the combination of plane truss elements and plane frame elements with no shear deformations. The model used in this study has fewer unknowns then the models encountered in the references. In this study the vertical frame elements have equivalent elasticity modulus and moment of inertia which are calculated by the developed software. Under in-plane static loads the elastic displacements of the masonry walls, which are encountered in literature, are calculated by the developed software, where brick units are modelled by plane frame elements, horizontal joints are modelled by vertical frame elements and vertical joints are modelled by horizontal plane truss elements. The calculated results are compatible with those given in the references.

Experimental Evaluation of PC Non-Bearing Wall System for the Damage Control of RC Wall Type Apartments (RC 벽식 아파트의 손상 제어를 위한 PC 비내력벽 시스템의 실험적 평가)

  • Moon, Kyo Young;Kim, Siyun;Kim, Sung Jig;Lee, Kihak
    • Journal of Korean Association for Spatial Structures
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    • v.19 no.4
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    • pp.77-84
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    • 2019
  • This study introduces a newly developed PC non-bearing wall system to prevent the damage of RC wall-type apartments that have been heavily damaged by the 2017 Pohang Earthquake. In order to evaluate the performance of the developed PC non-bearing wall system, a static cyclic test is conducted. The prototype of test specimen is from the RC wall-type apartment which has been severely damaged by the 2017 Pohang Earthquake. The specimen with the conventional non-bearing wall system showed the similar damage of RC wall type apartment suffered from the Pohang Earthquake. In case of the specimen with the developed PC non-bearing wall system, cracks and damages were not transmitted between the walls due to the seismic slit and there were almost no cracks in the non-bearing walls. Therefore, the proposed non-bearing wall system, separated from the structural walls, could prevent spreading cracks to bearing walls and make it possible to effectively control damage due to earthquake loads.

The Effect of Base Projecting Walls on the Bearing Capacity and Settlement of Shallow Foundations on Soft Ground (저면돌출벽을 이용한 연약지반상 얕은기초의 지내력 증대 효과)

  • Lim, Jongseok;Park, Seunghoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1523-1528
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    • 2013
  • It is necessary to develop the simple and efficient technique that ease entry of man and equipment and take the role of foundations of temporary or small structures on the soft ground. This study intends to verify the effects on the increase of bearing capacity of base projecting walls under shallow foundations and to investigate the variance of the bearing capacity of the foundations according to the interval and length of the walls. For this, model soft ground in the chamber equipped with loading apparatus is made and the loading tests on the model foundations with base projecting walls of various intervals and lengths using the apparatus are performed with measuring the loads and settlements. The results show that the base projecting walls under shallow foundations on soft ground are effective on the increase of bearing capacity and the more the number and length of the walls the larger the effects. And, when the ratio of interval to length of the walls is 1, i.e. the shape forming the base of the foundation and the walls is square, the bearing capacity is increased by 25% and the effect is optimum.

Mechanical behavior of steel tube encased high-strength concrete composite walls under constant axial load and cyclically increasing lateral load: Experimental investigation and modeling

  • Liang Bai;Huilin Wei;Bin Wang;Fangfang Liao;Tianhua Zhou;Xingwen Liang
    • Steel and Composite Structures
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    • v.47 no.1
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    • pp.37-50
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    • 2023
  • This paper presented an investigation into steel tubes encased high-strength concrete (STHC) composite walls, wherein steel tubes were embedded at the boundary elements of high-strength concrete walls. A series of cyclic loading tests was conducted to evaluate the failure pattern, hysteresis characteristics, load-bearing capacity, deformability, and strain distribution of STHC composite walls. The test results demonstrated that the bearing capacity and ductility of the STHC composite walls improved with the embedding of steel tubes at the boundary elements. An analytical method was then established to predict the flexural bearing capacity of the STHC composite walls, and the calculated results agreed well with the experimental values, with errors of less than 10%. Finally, a finite element modeling (FEM) was developed via the OpenSees program to analyze the mechanical performance of the STHC composite wall. The FEM was validated through test results; additionally, the influences of the axial load ratio, steel tube strength, and shear-span ratio on the mechanical properties of STHC composite walls were comprehensively investigated.

Seismic Performance of Precast Concrete Bearing Walls with Hollow Core (유공 PC 벽체의 내진 거동에 관한 연구)

  • 이리형;한상환;조순금;남기룡;최근도
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.10a
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    • pp.425-430
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    • 1996
  • The purpose of this study is to investigate the behavior of the bearing precast concrete (pc) wall structure with hollow core based on experimental tests. In order to evaluate the cyclic performance of the pc walls. Too one story pc walls and ond one reinforced concrete wall are made. The experimental results of pc walls were compared with those values of reinforced concrete (rc) wall. The structural behaviors of pc wall structure with hollow core are similar to those of reinforced concrete bearing wall structure. This study shows that the pc wall with hollow core could be treated as rc wall when designs the pc wall structure against lateral loads

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A Study on Thermohydrodynamic Turbulent Lubrication of High Speed Journal Bearing Considering Various Thermal Conditions on Walls (다양한 열전달 경계조건을 고려한 고속 저어널 베어링의 난류 열유체 윤활 연구)

  • 전상명;장시열
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.06a
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    • pp.93-98
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    • 2000
  • Turbulence on the journal bearing operation is examined. And the thermal variability is studied for isothermal, convective and adiabatic conditions on the walls within some degree of journal misalignment. An efficient algorithm for the solution of the coupled turbulent Reynolds and energy equations is used to examine the effects of the various factors. The calculation data of turbulent analysis are compared with the ones of laminar analysis. Heat convection is found to play but a small role in determining friction and load. The friction distribution patterns through inside a journal bearing now appear different with high values at the front part of the bearing due to the high speed and low temperature, and a sudden decrease past the pressure maximum.

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A Study on Thermohydrodynamic Turbulent Lubrication of High Speed Journal Bearing Considering Thermal Conditions on Walls (열전달 경계조건을 고려한 고속 저어널 베어링의 난류 열유체 윤활 연구)

  • 전상명;장시열
    • Tribology and Lubricants
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    • v.16 no.3
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    • pp.208-217
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    • 2000
  • Turbulence in journal bearing operation is examined and the thermal variability is studied for isothermal, convective and adiabatic conditions on the walls within some degree of journal misalignment. An efficient algorithm for the solution of the coupled turbulent Reynolds and energy equations is used to examine the effects of the various factors. The calculation data of turbulent analysis are compared with those of laminar analysis. Heat convection is found to play but a small role in determining friction and load. The friction distribution patterns through the journal bearing are now different with high values at the upstream region of the bearing due to the high speed and low temperature, and a sudden decrease past the pressure maximum.

Experimental Study on Low Cyclic Loading Tests of Steel Plate Shear Walls with Multilayer Slits

  • Lu, Jinyu;Yu, Shunji;Qiao, Xudong;Li, Na
    • International journal of steel structures
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    • v.18 no.4
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    • pp.1210-1218
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    • 2018
  • A new type of earthquake-resisting element that consists of a steel plate shear wall with slits is introduced. The infill steel plate is divided into a series of vertical flexural links with vertical links. The steel plate shear walls absorb energy by means of in-plane bending deformation of the flexural links and the energy dissipation capacity of the plastic hinges formed at both ends of the flexural links when under lateral loads. In this paper, finite element analysis and experimental studies at low cyclic loadings were conducted on specimens with steel plate shear walls with multilayer slits. The effects caused by varied slit pattern in terms of slit design parameters on lateral stiffness, ultimate bearing capacity and hysteretic behavior of the shear walls were analyzed. Results showed that the failure mode of steel plate shear walls with a single-layer slit was more likely to be out-of-plane buckling of the flexural links. As a result, the lateral stiffness and the ultimate bearing capacity were relatively lower when the precondition of the total height of the vertical slits remained the same. Differently, the failure mode of steel plate shear walls with multilayer slits was prone to global buckling of the infill steel plates; more obvious tensile fields provided evidence to the fact of higher lateral stiffness and excellent ultimate bearing capacity. It was also concluded that multilayer specimens exhibited better energy dissipation capacity compared with single-layer plate shear walls.