Bearing Wall Buildings Research Articles

Seismic Design of Columns and Walls on Weak First Floor in Piloti-Type Bearing Wall Buildings

Seismic Design of Columns and Walls on Weak First Floor in Piloti-Type Bearing Wall Buildings

Replacing Electrical Wiring in Large-Panel Buildings

The article is devoted to complex solution of repair difficulties facing owners of apartments in old bearing-wall buildings. The example of the series 1-464A presents the experience of repairing apartments with the use of modern materials and technologies. On the basis of theoretical analysis of the range of problems in question the principal stages of repairing an apartment in a bearing-wall building are examined with total electric wiring replacement to improve the performance of the dwelling. The main technological operations are described; the features of the use of electrical components and finishing materials are given.

Considerations for Seismic Design of Low-Rise Residential Bearing Wall Buildings with Pilotis

In this study, the results of an analytical investigation on the seismic behavior of two residential 4-story bearing wall buildings with pilotis, each of which has symmetric or unsymmetric wall arrangement at their piloti level, are presented. The dynamic characteristics and lateral resistance of the piloti buildings were investigated through linear elastic and nonlinear static analyses. According to the results, the analytical natural period of vibration of the piloti buildings were significantly shorter than the fundamental period calculated in accordance with KBC 2016. In the initial elastic behavior, the walls resisting in-plane shear contributed to the lateral stiffness and strength, while the contribution of columns resisting flexural moments in double curvature was limited. However, after the shear cracking and yielding of the walls occurred, the columns significantly contributed to the residual strength and ductility. Based on those investigations, design recommendations of low-rise bearing wall buildings with piloti configuration are given.

Investigation of Structural Damage in Bearing Wall Buildings with Pilotis by 2017 Pohang Earthquake

Investigation of Structural Damage in Bearing Wall Buildings with Pilotis by 2017 Pohang Earthquake

Damage Reconnaissance of Unreinforced Masonry Bearing Wall Buildings after the 2015 Gorkha, Nepal, Earthquake

This paper documents and analyzes the seismic behavior of unreinforced masonry (URM) buildings that were damaged by the 2015 Gorkha earthquake in Nepal, and reports on the performance of palaces, giving an overview on the failures suffered by significant examples of these monumental buildings. Field reconnaissance was completed through both rapid, in-situ visual assessment and state-of-the-art procedures utilizing light detection and ranging (lidar) and virtual reality (VR) technologies. Both the visual and virtual assessments were compared for 20 structures and were generally consistent; however, the virtual assessment process enabled detection of damage that could not be captured or was difficult to distinguish in the field observations. Further, both in-plane and out-of-plane mechanisms were analyzed and attributed to specific structural deficiencies that usually characterize poorly detailed masonry buildings. Moreover, wall overturning was correlated with the peculiarities of the pseudo-accelerations and rocking response spectra of the earthquake.

Nonlinear finite element modeling and response analysis of the collapsed Alto Rio building in the 2010 Chile Maule earthquake

SummaryThe 15‐story Alto Rio building built in 2006 in the city of Concepción, Chile, was the only modern building that collapsed catastrophically during the February 27, 2010 Mw 8.8 Maule earthquake, resulting in eight human casualties. This building was typical of many medium rise reinforced concrete bearing wall buildings designed and built in Chile during the period 1996–2009. Understanding the mechanism that led to the collapse of the Alto Rio building is of high relevance in the earthquake engineering community. For this purpose, a detailed three‐dimensional nonlinear model of the as‐built Alto Rio building structure was developed in the OpenSees analysis framework using the beam‐truss modeling approach. The geometry of the structure was obtained directly from the architectural blueprints. Realistic cyclic material constitutive models were used for the reinforcing steel and concrete materials. This paper describes in detail the development of the building model. Furthermore, it presents the results obtained from a nonlinear pushover analysis and from a nonlinear time‐history analysis using a bi‐axial horizontal input ground motion generated by blending time‐history ground accelerations recorded at an accelerograph station located 1.2 km from the building and time‐history ground displacements recorded at a GPS station located 3.7 km from the building.

Experimental investigation of slab joints between existing buildings and new frames for vertical expansion; [Part I

Vertical additions can be made to existing buildings to provide more residences while avoiding the need to fully dismantle and reconstruct the buildings. Super-structural frames consisting of shallow composite beams and steel columns can be prefabricated as modular units, replacing the wall frames that are conventionally constructed in existing bearing wall buildings. A lightweight modular construction introduced in this study minimizes the needed structural reinforcement of frames below, enabling quicker and safer assembly of frames relative to traditional wall frame construction. This paper introduces joint details between added steel columns and existing slabs. Extensive experimental investigations were performed to study the structural behavior of the suggested joints. Eight full-scale specimens were loaded to failure to evaluate the structural applicability and reliability of the connecting methods introduced in this study, and to identify any problems with the vertical additions. The present work was also intended to find effective design procedures to those issues, and to provide test data for use in detailed analytical investigation of the structural behavior. Regardless of the connection method and the failure mode, all specimens demonstrated stable structural performance within the range of loadings that are expected during the service life of vertically extended buildings.

In-plane strengthening of clay brick unreinforced masonry wallettes using ECC shotcrete

New Zealand’s stock of unreinforced masonry (URM) bearing wall buildings was principally constructed between 1880 and 1935, using fired clay bricks and lime or cement mortar. These buildings are particularly vulnerable to horizontal loadings such as those induced by seismic accelerations, due to a lack of tensile force-resisting elements in their construction. The poor seismic performance of URM buildings was recently demonstrated in the 2011 Christchurch earthquake, where a large number of URM buildings suffered irreparable damage and resulted in a significant number of fatalities and casualties. One of the predominant failure modes that occurs in URM buildings is diagonal shear cracking of masonry piers. This diagonal cracking is caused by earthquake loading orientated parallel to the wall surface and typically generates an “X” shaped crack pattern due to the reversed cyclic nature of earthquake accelerations.Engineered Cementitious Composite (ECC) is a class of fiber reinforced cement composite that exhibits a strain-hardening characteristic when loaded in tension. The tensile characteristics of ECC make it an ideal material for seismic strengthening of clay brick unreinforced masonry walls. Testing was conducted on 25 clay brick URM wallettes to investigate the increase in shear strength for a range of ECC thicknesses applied to the masonry wallettes as externally bonded shotcrete reinforcement. The results indicated that there is a diminishing return between thickness of the applied ECC overlay and the shear strength increase obtained. It was also shown that, the effectiveness of the externally bonded reinforcement remained constant for one and two leaf wallettes, but decreased rapidly for wall thicknesses greater than two leafs. The average pseudo-ductility of the strengthened wallettes was equal to 220% of that of the as-built wallettes, demonstrating that ECC shotcrete is effective at enhancing both the in-plane strength and the pseudo-ductility of URM wallettes.

Uniaxial Compressive Strength and Stiffness of Field-Extracted and Laboratory-Constructed Masonry Prisms

AbstractMasonry material characteristics such as compression stress-strain behavior and the relationships between brick, mortar, and masonry compressive strengths are required for the detailed analysis and assessment of masonry structures. These properties have been investigated previously, but most past studies were laboratory based and did not include within their scope the testing of existing masonry buildings. This study aimed to characterize the compressive strength and the compression stress-strain relationship of vintage clay brick masonry used in New Zealand unreinforced masonry (URM)-bearing wall buildings that were generally constructed between 1880 and 1940. Testing was performed on 45 masonry prisms that were extracted from eight New Zealand historic URM buildings and on 75 masonry prisms that were constructed in the laboratory using 14 different brick/mortar combinations. It was found that the laboratory-constructed sample test results adequately replicated those from the field-extracted samp...

Masonry in the seismic areas of the Americas, recent investigation and developments

Masonry, the oldest construction method, has become one of the major competing systems in modern construction. The great interest in its use around the world is due to its metamorphosis from a brittle and fragile material to one that can successfully withstand earthquake and wind forces while maintaining those features that in the past made masonry the preferred construction material. This paper reviews in general terms, the use of reinforced masonry in the construction of bearing wall buildings. It describes the different ways used to reinforce masonry walls to withstand earthquake forces. It discusses current issues of interest and areas of research, related in particular to the seismic resistance capabilities of the system. The paper also reviews the current situation in countries located in seismic areas of the Americas, with particular emphasis in Latin American countries.

Seismic evaluation of unreinforced masonry buildings — a state-of-the-art report

The potential vulnerability of old unreinforced masonry buildings, designed with little or no consideration for seismic-design requirements, is well documented. In regions without seismic retrofit ordinances prescribing a specific method to evaluate existing unreinforced masonry buildings, engineers have generally resorted to either conservative methods or various advanced analytical models. Although some approaches have received broader acceptance than others, there is still no consensus among practising engineers in North America. To provide perspective on the spectrum of strategies available and a clear overview of the state-of-the-art on this topic, this paper (i) presents the theoretical background and practical applications of a new procedure to evaluate unreinforced masonry bearing wall buildings, developed in California and recently integrated into the new Canadian Guidelines for the Seismic Evaluation of Existing Buildings, and (ii) summarizes the findings from other recent experimental and analytical research activities on the seismic behaviour of unreinforced masonry buildings, and from advances in their modelling. Key words: unreinforced masonry, masonry, earthquake, seismic response, state-of-the-art, evaluation, rehabilitation, analysis, models, buildings.

An Evaluation of Ductility and Detailing Requirements of Bearing Wall Buildings Using Data from the March 3, 1985, Chile Earthquake

The expected earthquake response of bearing wall buildings is investigated using data from the March 3, 1985 Chile earthquake. The study includes an examination of proportioning and detailing requirements for Chilean and U.S. bearing wall construction. Based on the requirements, minimum stiffnesses and strengths are characterized. Recorded ground motions in Vin~a del Mar, Chile and the western U.S. are analyzed and compared. Drifts and global displacement ductilities are estimated. Based on the findings related to drift and ductility, the need for concrete confinement at wall boundaries is investigated analytically. The analytical studies indicate that boundary confinement is not always necessary at wall boundaries. The performance of bearing wall buildings in the Chilean earthquake and the analytical studies conducted herein indicate that the form of construction used in Chile is a viable construction option in the United States.

Ductility and Detailing Requirements of Bearing Wall Buildings

An analytical procedure to determine the need for concrete confinement at the boundaries of structural walls in a building subjected to earthquakes is described. The procedure is based on comparing directly the expected displacement capacities and displacement demands for the building. For bearing wall buildings, relatively simple expressions are derived that enable the need for confined boundary elements to be evaluated. The expressions are verified using observations from the laboratory and from postearthquake response studies. The primary variables that determine the need for confined boundary elements are found to be the ratio of wall cross‐sectional area to the floor‐plan area, the wall aspect ratio and configuration, the wall axial load, and the wall reinforcement ratio. The study concludes that concrete confinement in walls of bearing wall buildings may be necessary at the extremities of walls having T, L, or other similarly shaped cross sections. Confinement is typically not required for symmetrically reinforced, rectangular wall cross sections. Current U.S. code requirements for confinement do not properly discern those cases where concrete confinement is or is not required, and are generally quite conservative.

Developing Structural Integrity in Bearing Wall Buildings

The prestressed concrete industry provides large volumes of precast floor and wall units for use in bearing wall buildings. In addition to the wide interest in precast panel bearing wall buildings, the industry has a vital interest in brick and concrete masonry bearing wall buildings which often utilize precast prestressed concrete floor units. For decades, relatively little engineering research and development attention was paid to bearing wall construction. It is heartening to note that the Prestressed Concrete Institute has taken a lead in this important

Reader Comments: Considerations for the Design of Precast Concrete Bearing Wall Buildings to Withstand Abnormal Loads

Reader Comments: Considerations for the Design of Precast Concrete Bearing Wall Buildings to Withstand Abnormal Loads

Reader Comments: Considerations for the Design of Precast Concrete Bearing Wall Buildings to Withstand Abnormal Loads

This Discussion (on page 105) of a previously published article was cited by ACI 318-19(22).

Connections and Integration of Components in Precast Bearing Wall Buildings

The report thus focuses on the purpose of the connections and on their relations to the building components rather than on the mechanics of the connection. The Committee is suggesting that the structural integration of components be accomplished through four tie systems (see Fig. 1) and gives specific forces for which the ties are to be design ed. In this article, the purpose and magnitudes of these tie systems are examined and compared to other recommendations.

Considerations for the Design of Precast Concrete Bearing Wall Buildings to Withstand Abnormal Loads

Considerations for the Design of Precast Concrete Bearing Wall Buildings to Withstand Abnormal Loads