Current Issue : January - March Volume : 2019 Issue Number : 1 Articles : 5 Articles
This paper aims at investigating the general axial behavior of long circular concrete-filled,\nfiber-reinforced polymer (FRP) tube (CFFT) columns internally reinforced with different longitudinal\nrebars. A total of seven CFFT and three reinforced concrete (RC) columns served as control specimens\nfor comparisons and were constructed and tested under cyclic axial loading until failure. The test\nparameters were: (1) internal reinforcement type (steel, glass fiber-reinforced polymer (GFRP) or\ncarbon fiber-reinforced polymer (CFRP)) and amount; (2) GFRP tube thicknesses; and (3) nature of\nloading. All columns had 1900-mm in height and 213-mm in diameter. Examination of the test results\nhas led to a number of significant conclusions in regards to the trend and ultimate condition of the\naxial stress-strain behavior, mode of failure of tested CFFT columns, and plastic strains. As expected,\nan increase in the FRP tube thickness (or stiffness) resulted in an increase in the strength and strain\nenhancement ratios. The validity of the available design provisions for predicting the ultimate\nload-carrying capacity of tested columns is also highlighted....
It is essential to determine rockmass mechanical parameters in stability assessment. The structural z is the main factor in this\nregard, and we know little about the relationship between mechanical parameters and multiple structure planes. In this paper, we\nhave conducted a series of numerical tests to obtain mechanical parameters for a dam foundation in Southwest China. The biaxial\nnumerical test was performed based on the discrete element method. This numerical test considers the spacing, types, dip angles,\nand size effect. We established a relationship of mechanical parameters between small size lab samples and large size field samples.\nWe forecasted the strength parameters for a spillway slope in Southwest China. The dip angle has a significant effect on the slope\nstrength and stability. In this case, the rockmass fracture stress-dip angle curve forms a U-shaped distribution. The X-shaped\ndouble structure plane demonstrates severe strength weakening relative to a single structure plane. As structure plane spacing\nreaches a certain level, its influence on rockmass strength diminishes. The elementary volume of the rockmass for dam foundation\nanalysis is about 4mÃ?4mÃ?4m....
Firstly, constitutive models of two unequal height adjacent ten-story and six-story reinforced concrete frame structures were\nestablished based on Open Sees software in which a series of separation distances are set for incremental dynamic analysis (IDA),\nrespectively. Secondly, the seismic vulnerability curves by postprocessing programming in Matlab software were obtained based\non IDA datum, and the optimal separation distances of adjacent buildings with and without connecting dampers were obtained by\ncomparing the seismic vulnerability of adjacent building at different separation distance and the seismic hazard analysis. Finally, a\nscaled model shaking table test of adjacent steel frame structures was performed.The conclusions are obtained by comparing the\nmeasured results of the test with those obtained by the Open Sees analysis, such as acceleration and displacement. The conclusions\nshow that when two adjacent buildings are not connected with a damper, the distance of adjacent structures is suggested to be 0.3m\nunder moderate and strong earthquakes and the distance of adjacent structures is suggested to be a specified value of 0.24m under\nrare earthquakes.When two adjacent buildings are connected with dampers, the separation distance is suggested to be 0.1m under\nvarious performance conditions....
Superlarge span structure is one of the important trends for future building development. Under the background of the 800-meter\nsuperlarge span dome project proposed by China Construction Group, this paper focuses on the structural optimization and\nperformance analysis of this superlarge span structure. The previous ideas of the superdome and the maximum span of existed\nspatial structures are reviewed, and some structural form selection principles are put forward which lay foundation for structural\nselection. The applicability of high-strength steel and aluminum alloy is also discussed. It is demonstrated that the high-strength\nsteel and aluminum alloy contribute little to structural comprehensive performances. Then, considering the effects of grid division,\nmembers topological relation, and surface shape, six kinds of rigid systems are contrastively studied to determine the optimal\nscheme. The structural performances along with the increasing span are explored in detail. To further reduce the structural weight\nand improve mechanical performance, a new composite scheme and the cable-stayed megastructure are proposed and studied.\nThe research methods and performance analysis results can provide significant references for the following research on the\nsuperlarge span structure....
The test lecture rooms on Katholieke Universiteit Leuven (KU Leuven) Ghent Technology\nCampus (Belgium) are a demonstration case of Annex 62: Ventilative Cooling of the International\nEnergy Agencyâ??s Energy in Buildings and Communities programme (IEA EBC). The building is\ncooled by natural night ventilation and indirect evaporative cooling (IEC). Thermal comfort and the\nperformances of ventilative cooling are evaluated. Long-term measurements of internal temperatures,\noccupancy, opening of windows and IEC were carried out in the cooling season of 2017. The airflow\nrates through the windows in cross- and single-sided ventilation mode were measured by both tracer\ngas concentration decay and air velocity measurements. In addition, the air flow pattern is visualized\nby measuring air temperatures in the room. The results show that good thermal summer comfort was\nmeasured except during heat waves and/or periods with high occupancy. Both nighttime ventilation\nand IEC operate very well. IEC can lower the supply temperature by day significantly compared to\nthe outdoor temperature. The Air Changes Rates (ACR) of the night ventilation greatly depends on\nwind direction and velocity. The air temperature profile showed that the air is cooled down in the\nwhole lecture but more in the upper zone. The extensive data monitoring system was important to\ndetect malfunctions and to optimize the whole building performance....
Loading....