• International Journal of High-Rise Buildings
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• v.6 no.3
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• pp.261-269
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• 2017

Designed by star architect of Moshes Safdie, Raffles City Chongqing includes a total of 6 mega high-rise towers 250 to 380 m tall, a sky conservatory, a 5-storey high shopping mall and a 3-storey basement car parking. Located at the confluence of the Yangtze and Jailing Rivers, the site for the project is imbued with a significance that is immediately symbolic, both as a sign of Chongqing's important past and as a vivid indicator of the city's thriving present and future. The design for the project to be situated at this gateway takes as its governing idea the image of powerful sails upon the water. The outer facades of the project's eight towers - the transparent surfaces that will face the water to the north - are meant to recall a fleet of ancient Chinese ships, with their huge rectangles of white canvas filled by the wind. This is a $1.13million\;m^2$ mega scale integrated project of office, retail, hotel, service residence and high-end residence with the transportation hub and traffic circulation at various levels of the project. This paper presents the multi-dimensional hybrid design, engineering and construction of this mega scale project. The innovations and the cutting-edge technology used in this project are introduced and discussed benchmarking the design and construction of the skyscraper cluster in a major city like Chongqing of China.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.6
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• pp.22-28
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• 2005

The electrical characterstic of earth is the most dominant factor for grounding design and an earth is typically represented by a uniform medium with the specific earth resistivity, which is unique for a specific site. For a hand-working grounding design using a specific earth resistivity requires a process converting a real earth of complex medium into a simple uniform medium In this paper, we suggest a procedure to convert a multi-layered earth s into a simpler uniform earth for grounding design of Myanmar 500[kV] transmission towers.

• Journal of the Korean Institute of Rural Architecture
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• v.11 no.1
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• pp.9-16
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• 2009

This research surveyed the native resources which BiBo(replenishing shortages by helping each other) landscapes have been preserved by aiming at the village settlement spaces of five cities and counties in Gangwon Youngseo province. This research reveals that BiBo landscape patterns of 41 village forests, 23 BiBo symbols, and 6 BiBo ponds were surveyed. The village forests are all 41 places, and were mainly made on the plains in front of villages. BiBo functions of the forests were in the order of the land obstructing the view of the mouth of a river which is the most as 13 places, the land obstructing the view of the mouth of river, situation complements, village protection, and protection against wind. Bibo symbols were all 23 places. Towers, stone towers, menhirs, and Maitreya stones were 12 places, Jangseungs(a signpost raising on the entrance of the village or a temple) were 6 places, Sotdae(a pole raising at the entrance of the village as the symbol of a board or a village protecting deity) was 1 place, and the others were made multiply in 4 places. Bibo symbols were located at 21 places in front of villages. The village protection in Bibo functions was 6 places. 6 Bibo ponds were surveyed. Most Bibo ponds were made for earth power leakage prevention.

• Structural Engineering and Mechanics
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• v.31 no.6
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• pp.639-662
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• 2009

A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wave-passage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.1
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• pp.50-57
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• 2001

The thermal performance of cooling towers is affected by the temperature of inlet water, wet bulb temperature of entering air and water-air flow rate. In this stud${\gamma}$, the effects of these variables are simulated using NTU-method and experimentally investigated for the counter-flow cooling towers. The simulation program to evaluate these variables which affect the performance of cooling tower was developed. The maximum errors between the results of simulations and experiments were 3.8% under the standard design conditions and 5.4% under the other conditions. The performance was increased up to 46~50% as the water loading was increased from 6.8$m^3/hr{\cdot}m^2$ to 159$m^3/hr{\cdot}m^2$. The range was reduced up to 56~42% when the wet bulb temperature of the entering air was increased from 22${\circ}C$ to 29${\circ}C$.

• Journal of Construction Engineering and Project Management
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• v.7 no.1
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• pp.37-49
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• 2017

The Jinshanling section of the Great Wall of China is a series of fortifications in northern China that was constructed for strategic military defenses. This section was first built in the beginning of the Ming Dynasty in AD 1368 and then underwent major construction, reconstruction and renovation during the late Ming Dynasty, approximately in AD 1569. The Jinshanling section is 10.5 km long, a very short section compared with the entire 21,200 km wall. The wall section is located in Luanping County, Hebei province, China. This research paper focuses on the construction methods and materials of the wall and the towers in the area. The research methodology includes site visits, knowledge acquisition of experts and 3D graphic modeling. This study reveals that the materials selected for the structure include rubbles and rammed earth, bricks, stones, timber, and mortar. The erection sequence of the wall and the towers was a bottom-up fashion using various ancient construction techniques, such as the fire-setting rock blasting techniques and the surveying techniques from the Sea Island Mathematical Manual.

• Structural Engineering and Mechanics
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• v.50 no.2
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• pp.215-229
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• 2014

Due to the lack of effective longitudinal constraint for center tower, structural stiffness of three-tower suspension bridge becomes less than that of two-tower suspension bridge, and therefore it becomes more susceptible to the seismic action. By taking a three-tower suspension bridge-the Taizhou Highway Bridge over the Yangtze River with two main spans of 1080 m as example, structural dynamic characteristics and seismic performance of the bridge is investigated, and the effects of cable's sag to span ratio, structural stiffness of the center tower, and longitudinal constraint of the girder on seismic response of the bridge are also investigated, and the favorable structural system is discussed with respect to seismic performance. The results show that structural response under lateral seismic action is more remarkable, especially for the side towers, and therefore more attentions should be paid to the lateral seismic performance and also the side towers. Large cable's sag, flexible center tower and the longitudinal elastic cable between the center tower and the girder are favorable to improve structural seismic performance of long-span three-tower suspension bridges.

• Wind and Structures
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• v.22 no.3
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• pp.369-391
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• 2016

Electricity is transmitted by transmission lines from the source of production to the distribution system and then to the end users. Failure of a transmission line can lead to devastating economic losses and to negative social consequences resulting from the interruption of electricity. A comprehensive in-house numerical model that combines the data of computational fluid dynamic simulations of tornado wind fields with three dimensional nonlinear structural analysis modelling of the transmission lines (conductors and ground-wire) is used in the current study. Many codes of practice recommend neglecting the tornado forces acting on the conductors and ground-wires because of the complexity in predicting the conductors' response to such loads. As such, real transmission line systems are numerically simulated and then analyzed with and without the inclusion of the lines to assess the effect of tornado loads acting on conductors on the overall response of transmission towers. In addition, the behaviour of the conductors under the most critical tornado configuration is described. The sensitivity of the lines' behaviour to the magnitude of tornado loading, the level of initial sag, the insulator's length, and lines self-weight is investigated. Based on the current study results, a recommendation is made to consider conductors and ground-wires in the analysis and design of transmission towers under the effect of tornado wind loads.

• International Journal of High-Rise Buildings
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• v.5 no.4
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• pp.243-250
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• 2016

Today's architectural design trend based on the recognition of pluralism has led to multiple design directions for all building types including tall buildings. This contemporary design trend has produced many complex-shaped tall buildings, such as twisted, tilted, tapered and freeform towers. Among many different structural systems developed for tall buildings, the diagrid system, with its powerful structural rationale and distinguished aesthetic potential, is one of the most widely used systems for today's tall buildings. This paper studies structural performance of diagrid systems employed for complex-shaped tall buildings. Twisted, tilted, tapered and freeform tall buildings are designed with diagrid structures, and their structural performances are investigated. For the twisted diagrid study, the buildings are twisted up to 3 degrees per floor. In the tilted diagrid study, the angles of tilting range from 0 to 13 degrees. The impact of eccentricity is investigated for gravity as well as lateral loads in tilted towers. In the study of tapered diagrid structures, the angles of tapering range from 0 to 3 degrees. In the study of freeform diagrid structures, lateral stiffness of freeform diagrids is evaluated depending on the degree of fluctuation of free form. The freeform floor plans fluctuate from plus/minus 1.5 meter to plus/minus 4.5 meter boundaries of the original square floor plan. Parametric structural models are generated using appropriate computer programs and the models are exported to structural engineering software for design, analyses and comparative studies.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1119-1122
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• 2009

The use of cooling towers in the air conditioning systems of buildings is increasing. In closed wet cooling towers, the heat transfer between the air and surface tubes can be composed of the sensible heat transfer and the latent heat transfer. The latent heat transfer is affected by the air and spray water. This study provides a designing methodology of heat exchanger for closed wet cooling tower. The correlation equation was derived to interpret the mass transfer coefficient based on the analogy of the heat and mass transfer and the experimental results. The results from this correlation equation showed fairly good agreement with experimental data.