• Steel and Composite Structures
• /
• v.31 no.1
• /
• pp.85-98
• /
• 2019

Nonlinear seismic performances of code designed Perforated Steel Plate Shear Walls (P-SPSW) were studied. Three multi-storey (4-, 8-, and 12-storey) P-SPSWs were designed according to Canadian seismic provisions and their performance was evaluated using time history analysis for ground motions compatible with Vancouver response spectrum. The selected code designed P-SPSWs exhibited excellent seismic performance with high ductility and strength. The current code equation was found to provide a good estimation of the shear strength of the perforated infill plate, especially when the infill plate is yielded. The applicability of the strip model, originally proposed for solid infill plate, was also evaluated for P-SPSW and two different strip models were studied. It was observed that the strip model with strip widths equal to center to center diagonal distance between each perforation line could reasonably predict the inelastic behavior of unstiffened P-SPSWs. The strip model slightly underestimated the initial stiffness; however, the ultimate strength was predicted well. Furthermore, applicability of simple shear-flexure beam model for determination of fundamental periods of P-SPSWs was studied.

• Earthquakes and Structures
• /
• v.20 no.3
• /
• pp.239-260
• /
• 2021

Torsional response of buildings is attributed to poor structural configurations in plan, which arises due to two factors - torsional eccentricity and torsional flexibility. Usually, building codes address effects due to the former. This study examines both of these effects. Buildings with torsional eccentricity (e.g., those with large eccentricity) and with torsional flexibility (those with torsional mode as a fundamental mode) demand large deformations of vertical elements resisting lateral loads, especially those along the building perimeter in plan. Lateral-torsional responses are studied of unsymmetrical buildings through elastic and inelastic analyses using idealised single-storey building models (with two degrees of freedom). Displacement demands on vertical elements distributed in plan are non-uniform and sensitive to characteristics of both structure and earthquake ground motion. Limits are proposed to mitigate lateral-torsional effects, which guides in proportioning vertical elements and restricts amplification of lateral displacement in them and to avoid torsional mode as the first mode. Nonlinear static and dynamic analyses of multi-storey buildings are used to validate the limits proposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.808-812
• /
• 2002

The feasibility of using elastic dampers to mitigate earthquake-induced structural response is studied in this paper. The properties of elastic dampers are briefly described. A procedure for evaulating the elastic damping effect when added to a structure is proposed in which the damping effect of elastic dampers is incorporated into modal damping ratios through an energy approach. Computer simulation of the damped response of a multi-storey steel frame structure shows significant reduction in floor displacement levels.

• Korean Institute of Interior Design Journal
• /
• v.14 no.1
• /
• pp.109-117
• /
• 2005

The women's roles In 21s1 century in Korea is increasing as the industry, economy is growing and changing rapidly; thus raising the necessity and importance of early learning. Naturally the importance and needs of children's day-care center is increasing both in quantitative and quality matters, there needs for much improvements. This study selected 8 workshop day-care centers in Seoul area, where most day-care centers are located, and analyzed interior spaces; thus presenting the appropriate model of interior space in child day-care center. Starting with, examining theologically, this study focused on the history of child day-care center and the 8 selected day-care centers in Seoul. By analyzing the operation status, blue prints, and picture, this study focused on improving the interior spaces in day-care centers. The presented improvement in spaces are the fellowing, First, half of day-care centers in workshops had independent buildings and most were multi-storey building. Second, running status vary. The open hours and number of teachers were fine but the budgets ratio of the employer and the worker ratio needed improvements. Third, there is need for detailed more improvement In managing area, educational area, and service area. It recommendable for spaces of day-care centers in workshops to be a single-storey building with managing and service space placed In center with educational rooms on each sides, with single hall way.

• Computers and Concrete
• /
• v.4 no.3
• /
• pp.167-186
• /
• 2007

Ductility based design of reinforced concrete structures implicitly assumes certain damage under the action of a design basis earthquake. The damage undergone by a structure needs to be quantified, so as to assess the post-seismic reparability and functionality of the structure. The paper presents an analytical method of quantification and location of seismic damage, through system identification methods. It may be noted that soft ground storied buildings are the major casualties in any earthquake and hence the example structure is a soft or weak first storied one, whose seismic response and temporal variation of damage are computed using a non-linear dynamic analysis program (IDARC) and compared with a normal structure. Time period based damage identification model is used and suitably calibrated with classic damage models. Regenerated stiffness of the three degrees of freedom model (for the three storied frame) is used to locate the damage, both on-line as well as after the seismic event. Multi resolution analysis using wavelets is also used for localized damage identification for soft storey columns.

• Earthquakes and Structures
• /
• v.10 no.6
• /
• pp.1369-1389
• /
• 2016

The soil-structure interaction effect significantly influences 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 loads. In the present work, the nonlinear soil-structure analysis of a G+5 storey RC shear wall building frame having isolated column footings and founded on deformable soil is presented. The nonlinear seismic FE analysis is carried out using ANSYS software for the building with and without shear walls to investigate the effect of inclusion of shear wall on the moments in the footings due to differential settlement of soil mass. The frame is considered to behave in linear elastic manner, whereas, soil mass to behave in nonlinear manner. It is found that the interaction effect causes significant variation in the moments in the footings. The comparison of non-interaction and interaction analyses suggests that the presence of shear wall causes significant decrease in bending moments in most of the footings but the interaction effect causes restoration of the bending moments to a great extent. A comparison is made between linear and nonlinear analyses to draw some important conclusions.

• International Journal of High-Rise Buildings
• /
• v.4 no.3
• /
• pp.161-169
• /
• 2015

Experience on the construction of several 100-plus-story skyscrapers including Guangzhou West Tower, Guangzhou East Tower, and Shenzhen's KK100 is described considering the increasingly strong development trend of 100-plus-story skyscrapers in China. Difficulties in the construction of 100-plus-story skyscrapers are investigated. Four innovative construction technologies receive detailed descriptions: intelligently and entirely-jacked work platforms, formwork and suspension scaffolding systems ("jacking and formwork systems"), multi-function low-carbon concrete, 5D-BIM ("five-dimensional building information modeling"), and safe and rapid vertical transport, as they have found successful applications in actual projects. Popularized systematically as technical achievements, these technologies will significantly influence the construction of similar projects in the future, and produce more social and economic benefits.

• Structural Monitoring and Maintenance
• /
• v.3 no.2
• /
• pp.175-194
• /
• 2016

Based on the change of traditional viscoelastic damper structure, a brand-new damper is designed to control simultaneously the translational vibration and the rotational vibration for platforms. Experimental study has been carried out on the mechanical properties of viscoelastic material and on its multi-dimensional seismic response control effect of viscoelastic damper. Three types of viscoelastic dampers with different shapes of viscoelastic material are designed to test the influence of excited frequency, strain amplitude and ambient temperature on the mechanical property parameters such as circular dissipation per unit, equivalent stiffness, loss factor and storage shear modulus. Then, shaking table tests are done on a group of single-storey platform systems containing one symmetric platform and three asymmetric platforms with different eccentric forms. Experimental results show that the simulation precision of the restoring force model is rather good for the shear deformation of viscoelastic damper and is also satisfied for the torsion deformation and combined deformations of viscoelastic damper. The shaking table tests have verified that the new-type viscoelastic damper is capable of mitigating the multi-dimensional seismic response of offshore platform.

• Earthquakes and Structures
• /
• v.18 no.2
• /
• pp.185-199
• /
• 2020

A computationally-efficient method for multi-criteria optimisation is developed for performance-based seismic design of friction energy dissipation dampers in RC structures. The proposed method is based on the concept of Uniform Distribution of Deformation (UDD), where the slip-load distribution along the height of the structure is gradually modified to satisfy multiple performance targets while minimising the additional loads imposed on existing structural elements and foundation. The efficiency of the method is demonstrated through optimisation of 3, 5, 10, 15 and 20-storey RC frames with friction wall dampers subjected to design representative earthquakes using single and multi-criteria optimisation scenarios. The optimum design solutions are obtained in only a few steps, while they are shown to be independent of the selected initial slip loads and convergence factor. Optimum frames satisfy all predefined design targets and exhibit up to 48% lower imposed loads compared to designs using a previously proposed slip-load distribution. It is also shown that dampers designed with optimum slip load patterns based on a set of spectrum-compatible synthetic earthquakes, on average, provide acceptable design solutions under multiple natural seismic excitations representing the design spectrum.

• Human Ecology Research
• /
• v.54 no.1
• /
• pp.13-26
• /
• 2016

The purpose of this paper is to investigate the rationale behind the transformation process of unique shophouse spatial organization in Phnom Penh. We selected 20 representative shophouses located in the Chinese district of Phnom Penh according to construction period. A qualitative study methodology was applied and field surveys were conducted that included interviews with residents, photographs, sketches, measurements, collecting historic photos, and cataloging maps. Selected cases were analyzed in terms of: basic house data, urban block analysis, and unit analysis. Cases were then classified into two types: private courtyard shophouse (PCS) and shared courtyard shophouse (SCS). PCS refers to shophouse typology that maintains most of the characteristics of early shophouses while being transformed into a modern multi-story apartment within a limited one bay plot. However, SCS refers to shophouses adapted from the indigenous forms of PCS that evolved into a multi-storey and multi-family housing typology that includes features that might have been adapted from Western apartment buildings such as sharing a big courtyard, staircase and corridors. We conclude that shophouses in Phnom Penh have positively adopted a Western building typology, adapted it to local traditions, and finally formulated a new building type that represent indicators of a modernization process gradually accepted by society.