-
Effect of Design Ductility on the Progressive Collapse Potential of RC Frame Structures Designed to Eurocode 8
Mark Adom-Asamoah,
Nobel Obeng Ankamah
Issue:
Volume 4, Issue 2, March 2016
Pages:
40-49
Received:
8 February 2016
Accepted:
18 February 2016
Published:
1 March 2016
Abstract: Progressive collapse is the cause of most structural failures around the world. The US General Service Administration (GSA) has presented guidelines for the assessment of the vulnerability of building structures to progressive collapse. It has been established in literature that the philosophy of ductility and redundancy used in seismic design is beneficial in resisting progressive collapse but not accounted for in these guidelines. The GSA methodology is particularly suited to seismic codes which allows for a constant member rotation but may be unsuitable to other codes that makes provision for ductility level. In this study, an investigation into the progressive collapse potential of RC framed structures designed to the seismic design code, EC 8, with varying design ground accelerations and ductility classes under different column loss scenarios was done. Based on the EC 8, a criteria for maximum plastic rotations and dynamic multiplies for progressive collapse analysis was proposed. These proposed criteria, together with the GSA criteria, were used to investigate the designed structures. The EC 8 criteria proved that buildings designed for higher ductilities yield at lower loads but undergo greater deformations and absorbs more energy to resist collapse. On the other hand, buildings designed for lower ductilities have higher yield loads but undergo lower deformations before collapse. Higher PGAs result in higher yield strengths but does not necessarily deformation capacity. This effect of ductility was not seen with the GSA criteria since a constant rotation capacity was recommended for all the buildings regardless of design ductility. It was also found that the removals of a corner column possess the greatest threat to progressive collapse on a building.
Abstract: Progressive collapse is the cause of most structural failures around the world. The US General Service Administration (GSA) has presented guidelines for the assessment of the vulnerability of building structures to progressive collapse. It has been established in literature that the philosophy of ductility and redundancy used in seismic design is b...
Show More
-
Study on the Influence of Chloride Ions Content on the Sea Sand Concrete Performance
Wu Sun,
Junzhe Liu,
Yanhua Dai,
Jiali Yan
Issue:
Volume 4, Issue 2, March 2016
Pages:
50-54
Received:
27 February 2016
Accepted:
9 March 2016
Published:
23 March 2016
Abstract: The influence of chloride ions content on the sea sand concrete performance was investigated through testing the sea sand mortar strength in this paper. The concrete strength rule was analyzed to discover the early strength for the sea sand concrete by the presence of chloride. In addition, the XRD microscopic analysis and TG/DTA were observed the composition of concrete to research the influence on hydration processes of concrete caused by sea sand, and from two aspects to find out the differences of the internal microcosmic structure and the chemical composition respectively. And Micro-technique was used to determine the water-soluble chloride ion concentration of different types of sea sand concrete which were maintained 28 days. The results show that the chloride ion can improve concrete strength value and the concentration of free chloride increases with the rise of extraction temperature.
Abstract: The influence of chloride ions content on the sea sand concrete performance was investigated through testing the sea sand mortar strength in this paper. The concrete strength rule was analyzed to discover the early strength for the sea sand concrete by the presence of chloride. In addition, the XRD microscopic analysis and TG/DTA were observed the ...
Show More
-
Experimental Study on the Quality of Concrete Strengthened by the Means of Infrared Thermal Imager
Fuchun Song,
Jie Zhao,
Mengchen Li
Issue:
Volume 4, Issue 2, March 2016
Pages:
55-60
Received:
6 April 2016
Published:
7 April 2016
Abstract: Testing of concrete quality of bonded steel reinforcement by the means of infrared thermal imager, study of sticky steel reinforcement concrete component under the irradiation of an external heat source surface temperature with time, spatial distribution and variation analysis internal hollowing defect thickness, size and thermal infrared imager vertical shooting angle and emission rate and other factors on the effect of infrared thermal imaging. The test results show that, the greater the thickness of internal defects, hollowing the greater area is easy to be detected. In the presence of internal defects, contrast the thickness of the site with no defect parts of the surface temperature, defect site temperature is significantly lower.
Abstract: Testing of concrete quality of bonded steel reinforcement by the means of infrared thermal imager, study of sticky steel reinforcement concrete component under the irradiation of an external heat source surface temperature with time, spatial distribution and variation analysis internal hollowing defect thickness, size and thermal infrared imager ve...
Show More
-
The Research of High Slope Instability Mechanism Based on Slide
Peng Qu,
Cong Li,
Xueming Jia
Issue:
Volume 4, Issue 2, March 2016
Pages:
61-67
Received:
10 April 2016
Published:
11 April 2016
Abstract: In the highway engineering, as lacking cognition of mechanism in high slope stability caused landslide and collapse, which brought great damage to highway operation. The high slope protection and disaster management are given more and more attention with the continuous development of highway construction. This paper focus on slope stability analysis, the application of anchorage is suitable to disaster prevention and control in high slope. The Slide software is adopted to simulate a high slope in Chongqing, calculating and analyzing its stability under different conditions.
Abstract: In the highway engineering, as lacking cognition of mechanism in high slope stability caused landslide and collapse, which brought great damage to highway operation. The high slope protection and disaster management are given more and more attention with the continuous development of highway construction. This paper focus on slope stability analysi...
Show More
