• Title/Summary/Keyword: Masonry

Search Result 569, Processing Time 0.106 seconds

Experimental investigation of masonry walls supported by steel plate-masonry composite beams

  • Jing, Deng-Hu;Chen, Jian-Fei;Amato, Giuseppina;Wu, Ting;Cao, Shuang-Yin
    • Steel and Composite Structures
    • /
    • v.28 no.6
    • /
    • pp.709-718
    • /
    • 2018
  • Masonry walls are sometimes removed in buildings to either make new passages or increase the usable space. This may change the loading paths in the structure, and require new beams to transfer the loads which are carried by the masonry walls that are to be removed. One possible method of creating such new beams is to attach steel plates onto part of the existing walls to form a steel plate-masonry composite (SPMC) beam, leading to a new structure with part of the masonry wall supported by a new SPMC beam. This paper presents an experimental investigation into the interaction between the SPMC beam and the masonry wall above. Five SPMC beams supporting a masonry wall were tested to study the influence of parameters including the height-to-span ratio of the masonry wall, height of the beam and thickness of the steel plates. The test results, including failure mode, load-carrying capacity, load-deflection curves and strain distribution, are presented and discussed. It is found that for developing better arching effect in the masonry wall the ratio of the in-plane flexural stiffness of the masonry wall to the flexural stiffness of the SPMC beam must be between 2.8 and 7.1.

Composite Action in Masonry Columns Due to Damage and Creep Interaction (손상과 크리프의 상호작용에 의한 조적조 기둥의 복합거동)

  • Kim, Jung Joong
    • Journal of the Korean Society for Advanced Composite Structures
    • /
    • v.5 no.2
    • /
    • pp.27-32
    • /
    • 2014
  • Since the collapse of historical masonry structures in Europe in the late 1990's, the interests in understanding the long-term effect of masonry under sustained compressive stresses have increased. That requires combining the significance of time-dependent effects of creep with the effect of damage due to overstress to realize the evolution of cracks and then failure in masonry. Meanwhile, composite analysis of masonry columns was proven effective for realizing ultimate strength capacity of masonry column. In this study, a simplified mechanical model with step-by-step in time analysis was proposed to incorporate the interaction of damage and creep to estimate the maximum stress occurred in masonry. It was examined that the interaction of creep and damage in masonry can accelerate the failure of masonry.

Analytical Study of the Effect of Full and Partial Masonry Infills on the Seismic Performance of School Buildings (조적채움벽 및 허리벽이 학교 건물 내진 성능에 미치는 영향에 대한 해석적 연구)

  • Kim, Tae Wan;Min, Chan Gi
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.17 no.5
    • /
    • pp.197-207
    • /
    • 2013
  • The seismic performance of school buildings has been a matter of common interest socially and academically. The structural system of the school buildings is representative of the domestic low-rise reinforced concrete moment resisting frames, which apply extensively infills in their masonry walls. The masonry infilled walls are divided into full masonry infill in the transverse direction and partial masonry infill in the longitudinal direction. The masonry infilled walls are usually not included in structural analysis during the design process, but affect significantly the seismic performance because they behave with surrounding frames simultaneously during earthquakes. Many researchers have studied the effect of the masonry infilled walls, but several issues have been missed such as the increase of asymmetry by adding the full masonry infill, the size of the mean strength of the full masonry infill, and short column effect by the partial masonry infill. The issues were analytically investigated and the results showed that they should be checked at least by nonlinear pushover analysis in the seismic performance evaluation process. The results also confirm the weakness of the guideline of Korean Educational Development Institute where the seismic performance is basically assessed without structural analysis.

New metal connectors developed to improve the shear strength of stone masonry walls

  • Karabork, Turan;Kocak, Yilmaz
    • Structural Engineering and Mechanics
    • /
    • v.50 no.1
    • /
    • pp.121-135
    • /
    • 2014
  • Stone masonry structures are widely used around the world, but they deteriorate easily, due to low shear strength capacity. Many techniques have been developed to increase the shear strength of stone masonry constructions. The aim of this experimental study was to investigate the performance of stone masonry walls strengthened by metal connectors as an alternative shear reinforcement technique. For this purpose, three new metal connector (clamp) types were developed. The shear strength of the walls was improved by applying these clamps to stone masonry walls. Ten stone masonry walls were structurally tested in diagonal compression. Various parameters regarding the in-plane behavior of strengthening stone masonry walls, including shear strength, failure modes, maximum drift, ductility, and shear modulus, were investigated. Experimentally obtained shear strengths were confirmed by empirical equations. The results of the study suggest that the new clamps developed for the study effectively increased the levels of shear strength and ductility of masonry constructions.

Discontinuous deformation analysis for reinforced concrete frames infilled with masonry walls

  • Chiou, Yaw-Jeng;Tzeng, Jyh-Cherng;Hwang, Shuenn-Chang
    • Structural Engineering and Mechanics
    • /
    • v.6 no.2
    • /
    • pp.201-215
    • /
    • 1998
  • The structural behavior of reinforced concrete frame infilled with a masonry wall is investigated by the method of discontinuous deformation analysis (DDA). An interface element is developed and it is incorporated into DDA to analyze the continuous and discontinuous behavior of the masonry structure. The numerical results are compared with previous research and possess satisfactory agreement. Then the structural behavior and stress distribution of a reinforced concrete frame infilled with a masonry wall subjected to a horizontal force are studied. In addition, the justification of equivalent strut is assessed by the distribution of principal stresses. The results show that the behavior of the masonry structure is highly influenced by the failure of mortar. On the basis of the distribution of principal stress of the masonry wall in the reinforced concrete frame, the equivalent strut can be approximately substituted for the masonry wall without separation and opening. However, the application of equivalent strut to the masonry wall with separation and opening needs further study.

Discrete element modeling of masonry structures: Validation and application

  • Pulatsu, Bora;Bretas, Eduardo M.;Lourenco, Paulo B.
    • Earthquakes and Structures
    • /
    • v.11 no.4
    • /
    • pp.563-582
    • /
    • 2016
  • The failure mechanism and maximum collapse load of masonry structures may change significantly under static and dynamic excitations depending on their internal arrangement and material properties. Hence, it is important to understand correctly the nonlinear behavior of masonry structures in order to adequately assess their safety and propose efficient strengthening measures, especially for historical constructions. The discrete element method (DEM) can play an important role in these studies. This paper discusses possible collapse mechanisms and provides a set of parametric analyses by considering the influence of material properties and cross section morphologies on the out of plane strength of masonry walls. Detailed modeling of masonry structures may affect their mechanical strength and displacement capacity. In particular, the structural behavior of stacked and rubble masonry walls, portal frames, simple combinations of masonry piers and arches, and a real structure is discussed using DEM. It is further demonstrated that this structural analysis tool allows obtaining excellent results in the description of the nonlinear behavior of masonry structures.

Experimental research on masonry mechanics and failure under biaxial compression

  • Xin, Ren;Yao, Jitao;Zhao, Yan
    • Structural Engineering and Mechanics
    • /
    • v.61 no.1
    • /
    • pp.161-169
    • /
    • 2017
  • This study aimed to develop a simple and effective method to facilitate the experimental research on mechanical properties of masonry under biaxial compressive stress. A series of tests on full-scale brick masonry panels under biaxial compression have been performed in limited principal stress ratios oriented at various angles to the bed joints. Failure modes of tested panels were observed and failure features were analyzed to reveal the mechanical behavior of masonry under biaxial compression. Based on the experimental data, the failure curve in terms of two orthotropic principal stresses has been presented and the failure criterion of brick masonry in the form of the tensor polynomial has been established, which indicate that the anisotropy for masonry is closely related to the difference of applied stress as well as the orientation of bed joints. Further, compared with previous failure curves and criteria for masonry, it can be found that the relative strength of mortar and block has a considerable effect on the degree of anisotropy for masonry. The test results demonstrate the validity of the proposed experimental method for the approximation of masonry failure under biaxial compressive stress and provide valuable information used to establish experimentally based methodologies for the improvement of masonry failure criteria.

Relation between Shear Strength of Masonry infills and Seismic Performance of Masonry-infilled Frames (조적채움벽의 전단강도에 따른 채움벽골조의 내진성능)

  • Yu, Eunjong;Kim, Min Jae;Lee, Sang Hyun;Kim, Chung Man
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.19 no.4
    • /
    • pp.173-181
    • /
    • 2015
  • In this study, material tests were performed on the masonry specimens constructed with bricks and mortar used in Korea. The specimens included two types of thickness(0.5B and 1.0B) and physical conditions (good and poor). It was shown that 1.0B specimens have 3.2~1.8 times larger shear strength than 0.5B specimens and shear strength of specimens in poor condition was 66%~38% of those in good condition. Average shear stress of masonry-infills was calculated from previous experimental studies, and relationships with failure mode, material strength of masonry, aspect ratio, and frame-to-infill strength ratio were investigated. In addition, the effects of masonry strength on the seismic performance of a masonry-infilled frame was studied using a simple example building. It can be seen that the obtained average shear stress were considerably higher than the default masonry shear strength recommended by the ASCE 41, and low values the strength of masonry does not guarantee conservative evaluation results due to the early shear failure of frame members.

Improvement and Evaluation of Seismic Resistant Performance of Reinforced Concrete Infilled Masonry Frame (철근콘크리트 프레임면내 조적벽체의 내진성능 평가 및 개선기술)

  • Shin, Jong-Hack;Ha, Gee-Joo;Jun, Ha-Suk;Lee, Jong-Chan
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.4 no.1
    • /
    • pp.147-155
    • /
    • 2000
  • Five reinforced concrete rigid frame and masonry infilled wall and cut off type masonry infilled wall were tesed during vertical and cyclic loads simultaneously. Experimental programs were accomplished to improve and evaluate the structural performance of test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. Test variables are hoop reinforcement ratio, with or without masonry infilled wall, and masonry method. All the specimens were constructed in one-third scale size. Based on the test results, the following conclusions can be made. For masonry infilled wall(IFB-1), maximum horizontal capacity was increased by 1.45 time in comparision with that of rigid frame(FB-0). For cut off masonry infilled wall (IFBC-1~3), maximum horizontal capacity was increased by 1.73~1.98 time in comparision with that of rigid frame(FB-0). For cut off masonry infilled wall(IFBG-1~3), ductility was increased by 1.48~2.08 time in comparision with that of masonry infilled wall (IFB-1).

  • PDF

Modeling of Old Masonry Lining in Railroad Tunnels (철도터널내 조적식 라이닝의 모형화에 관한 연구)

  • Lee, J.S.;Shin, H.K.;Kim, M.I.
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.3 no.3
    • /
    • pp.3-13
    • /
    • 2001
  • The behavior of the masonry lining is studied to gain basic information on how to reinforce the masonry tunnels. Apart from the previous works on the masonry structures, the multi-course masonry structure, realistic in field condition, is considered and the constitutive relationship of the masonry is, therefore, established. The design charts of the orthotropic material properties are proposed according to the stiffness ratio and the crack initiation and subsequent propagation model is also considered to model the brittle nature of the masonry. A numerical analysis on the masonry panel is investigated to verify the proposed model and future works of the masonry lining are briefly explained.

  • PDF