• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.6
• /
• pp.973-987
• /
• 2018

Most of the previous seismic analyses have been carried out by separating the ground and structures, and there is a lack of comparative study on the dynamic behavior of high-rise and low-rise buildings. Therefore, in this study, the sensitivity analysis was performed with selected parameters by using a finite element analysis program in order to grasp the dynamic behavior of high-rise and low-rise buildings. As a result, it was turned out that the horizontal displacement, the interstory drift ratio, and the bending stress of a high-rise building were more affected by a long seismic wave than a low-rise buildings. Also, the weak parts of a high-rise and low-rise building were more affected by type of seismic wave than the ground conditions. Therefore, it is inferred that it will be helpful for seismic designs to consider the influence of ground conditions and seismic wave type on buildings.

• International Journal of High-Rise Buildings
• /
• v.12 no.2
• /
• pp.163-168
• /
• 2023

Today 55 percent of the population in the world lives in urban areas which is expected to increase to 68 percent by the year 2050. In the cities, high-rise buildings as symbols of the modern cityscape are dominating the skylines, but the data to demonstrate their embodied energy and environmental impacts are scarce, compared to low- or mid-rise buildings. Reducing the embodied energy and environmental impacts of buildings is critical as about 42 percent of primary energy use and 39 percent of the global greenhouse gas (GHG) emissions come from the building sector. However, it is an overlooked area in embodied energy and environmental impacts of high-rise buildings. Life cycle assessment (LCA) is a widely used tool to quantify the embodied energy and environmental impacts of the building sector. LCA combined with Building Information Modeling (BIM) can simplify data acquisition of the building as well as provide both tools with feedback. Several studies recognize that the integration of BIM and LCA can simplify data acquisition of the building as well as provide tools with feedback. This article provides an overview of literature on BIM-based of embodied energy and environmental impacts of high-rise buildings. It also compares with different LCA methodologies. Finally, major strategies to reduce embodied energy and environmental impacts of high-rise buildings, research limitations and trends in the field are covered.

• Structural Engineering and Mechanics
• /
• v.41 no.4
• /
• pp.479-494
• /
• 2012

This study explores a coefficient-based seismic capacity assessment method with a special emphasis on low-rise masonry in-filled (MI) reinforced concrete (RC) buildings subjected to earthquake motion. The coefficient-based method without requiring any complicated finite element analysis is a simplified procedure to assess the maximum spectral acceleration capacity of buildings. This paper first compares the fundamental periods of MI RC structures obtained, respectively, from experimental period data and empirical period-height formulas. The coefficient-based method for low-rise masonry buildings is then calibrated by the published experimental results obtained from shaking table tests. The comparison of the experimental and estimated results indicates that the simplified coefficient-based method can provide good approximations of the maximum spectral accelerations at peak loads of the low-rise masonry reinforced concrete buildings if a proper set of drift factors and initial fundamental vibration periods of structures are used.

• Wind and Structures
• /
• v.20 no.3
• /
• pp.469-488
• /
• 2015

A full-scale instrumented low-rise building with gable roof was built at a coastal site with a high incidence of tropical cyclones for monitoring of wind effects on the building during windstorms. This paper presents the field measurements of the wind velocity field around and the wind-induced pressures on the low-rise building during the passage of severe tropical storm Soudelor. Near-ground wind characteristics such as wind speed, wind direction, turbulence intensity, gust factor, turbulence integral length scale and wind velocity spectra were investigated. The wind-induced pressures on the roof of the building were analyzed and discussed. The results revealed that the eave and ridge edges on the roof were subjected to the most severe suction pressures under quartering winds. These suction pressures showed obvious non-Gaussian behavior. The measured results were compared with the provisions of ASCE 7-10 to assess the suitability of the code of practice for the wind-resistant design of low-rise buildings under tropical cyclones. The field study aims to provide useful information that can enhance our understanding of the extreme wind effects on low-rise buildings in an effort to reduce tropical cyclone wind damages to residential buildings.

• Wind and Structures
• /
• v.36 no.4
• /
• pp.277-292
• /
• 2023

Low-rise structures are generally immersed within the roughness layer of the atmospheric boundary layer flows and represent the largest class of the structures for which wind loads for design are being obtained from the wind standards codes of distinct nations. For low-rise buildings, wind loads are one of the decisive loads when designing a roof. For the case of cylindrical roof structures, the information related to wind pressure coefficient is limited to a single span only. In contrast, for multi-span roofs, the information is not available. In this research, the numerical simulation has been done using ANSYS CFX to determine wind pressure distribution on the roof of low-rise cylindrical structures arranged in rectangular plan with variable spacing in accordance with building width (B=0.2 m) i.e., zero, 0.5B, B, 1.5B and 2B subjected to different wind incidence angles varying from 0° to 90° having the interval of 15°. The wind pressure (P) and pressure coefficients (C_pe) are varying with respect to wind incidence angle and variable spacing. The results of present numerical investigation or wind induced pressure are presented in the form of pressure contours generated by Ansys CFD Post for isolated as well as variable spacing model of cylindrical roofs. It was noted that the effect of wind shielding was reducing on the roofs by increasing spacing between the buildings. The variation pf Coefficient of wind pressure (C_pe) for all the roofs have been presented individually in the form of graphs with respect to angle of attacks of wind (AoA) and variable spacing. The critical outcomes of the present study will be so much beneficial to structural design engineers during the analysis and designing of low-rise buildings with cylindrical roofs in an isolated as well as group formation.

• Wind and Structures
• /
• v.27 no.6
• /
• pp.439-449
• /
• 2018

Wind loading of a tall building built amidst a group of buildings in urban environment is always greatly affected by shielding effects. Wind tunnel tests were carried out to assess the shielding provided by a row of low-rise or medium-rise buildings upstream a square-section tall building of height-to-breadth ratio 6. Mean and dynamic wind loads on the tall building were measured at different wind incidence angles and presented as interference factors (IFs). It is found that presence of a row of upstream buildings provides significant shielding to the tall building. At normal wind incidence, the mean along-wind loads and all components of fluctuating wind loads on the tall building are always reduced by shielding. Vortex shedding seems to still occur on the upper exposed part of the tall building but the vortex excitation levels are largely reduced. The degree of shielding is found to depend on a number of arrangement parameters of the row of upstream buildings. Empirical equations are proposed to quantify the shielding effect based on the wind tunnel data.

• International conference on construction engineering and project management
• /
• 2017.10a
• /
• pp.14-23
• /
• 2017

In high-density high-rise cities such as Hong Kong, buildings account for nearly 90% of energy consumption and 61% of carbon emissions. Therefore, it is important to study the design of buildings, especially high-rise buildings, to achieve lower carbon emissions in the city. The carbon emissions of a building consist of embodied carbon from the production of construction materials and operational carbon from energy consumption during daily operation (e.g., air-conditioning and lighting). An integrated analysis of both types of carbon emissions can strengthen the design of low carbon buildings, but most of the previous studies concentrated mainly on either embodied or operational carbon. Therefore, the primary objective of this study is to develop a holistic methodology framework considering both embodied and operational carbon, in order to enhance the sustainable design of low carbon high-rise buildings. The framework will be based on the building information modeling (BIM) technology because BIM can be integrated with simulation systems and digital models of different disciplines, thereby enabling a holistic design and assessment of low carbon buildings. Structural analysis program is first coupled with BIM to validate the structural performance of a building design. The amounts of construction materials and embodied carbon are then quantified by a BIM-based program using the Dynamo programming interface. Operational carbon is quantified by energy simulation software based on the green building extensible Markup Language (gbXML) file from BIM. Computational fluid dynamics (CFD) will be applied to analyze the ambient wind effect on indoor temperature and operational carbon. The BIM-based framework serves as a decision support tool to compare and explore more environmentally-sustainable design options to help reduce the carbon emissions in buildings.

• Wind and Structures
• /
• v.27 no.3
• /
• pp.163-173
• /
• 2018

The design wind pressure for low-rise buildings in the ASCE 7-10 is defined by procedures that are categorized into the Main Wind Force-Resisting System (MWFRS) and the Components and Cladding (C&C). Some of these procedures were originally developed based on steel portal frames of industrial buildings, while the residential structures are a completely different structural system, most of which are designed as low-rise light-frame wood constructions. The purpose of this study is to discuss the rationality (or irrationality) of the extension of the wind loads calculated by the ASCE 7-10 to the light-frame wood residential buildings that represent the most vulnerable structures under extreme wind conditions. To serve this purpose, the same approach as used in the development of Chapter 28 of the ASCE 7-10 that envelops peak responses is adopted in the present study. Database-assisted design (DAD) methodology is used by applying the dynamic wind loads from Louisiana State University (LSU) database on a typical residential building model to assess the applicability of the standard by comparing the induced responses. Rather than the postulated critical member demands on the industrial building such as the bending moments at the knee, the maximum values at the critical points for wood frame buildings under wind loads are used as indicators for the comparison. Then, the critical members are identified through these indicators in terms of the displacement or the uplift force at connections and roof envelope. As a result, some situations for each of the ASCE 7 procedures yielding unconservative wind loads on the typical low-rise residential building are identified.

• International Journal of High-Rise Buildings
• /
• v.7 no.3
• /
• pp.233-242
• /
• 2018

Since the response reduction effect on over 200-meter-tall resulting from the seismic isolation system is smaller in general than low-rise and mid-rise buildings, mid-story isolated buildings are considered to reduce the response in the upper part above the isolation story, however, in many cases, the acceleration response just below the isolation story is likely to be the largest. This paper presents the structural design schemes, the design of the main structural frames, and the constructions of a 230-meter-tall super high-rise building with mid-story isolation mechanism integrated in Roppongi, Tokyo. Moreover, this paper shows how the architectural and structural design for integrating a mid-story isolation system in a super high-rise building has been conducted and what solutions have been derived in this project. The realization of this building indicates new possibilities for mid-story isolation design for super high-rise buildings.

• Journal of Korean Association for Spatial Structures
• /
• v.17 no.3
• /
• pp.57-64
• /
• 2017

Recently, measuring instruments for SHM of structures had being developed. In general, the wireless transmission of sensor signals, compared to its wired counterpart, is preferable due to its absence of triboelectric noise and elimination of the requirement for cumbersome cable. Preliminary studies on the continuous vibration measurement of high-rise buildings using MEMS sensors have been carried out. However, the research on the low-rise buildings with relatively small vibration levels is insufficient. Therefore, in this paper, we used the wireless MEMS sensor to compare and analyze the vibration measurements of three low-rise buildings.