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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Civil Engineering Infrastructures Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: earthquake,Pancake Collapse,Progressive Collapse Robustness Index,Zipper Collapse
- چکیده:
- چکیده انگلیسی: One of the aims of earthquake engineering is to build secure structures against random loads and also various damage types under lateral loads. Progressive collapse, a word that has attracted attention of many researches after the failure of the World Trade Center, can occur under abnormal loads such as explosion or natural causes like earthquakes. Resistance to progressive collapse is expressed by a parameter called Robustness. The purpose of this study is to survey various methods of calculating robustness index under lateral loads, especially seismic loads, in steel moment frames. So three steel structures with 4, 8 and 15-story and intermediate moment frames were designed and analyzed subsequently. Different methods of measuring the robustness indexes were compared and eventually presented a simple method to assess robustness index based on nonlinear dynamic analysis. Robustness index introduced using this method, which is based on the types of Pancake and Zipper collapses and energy parameters, tries to express an appropriate standard for structural strength against earthquakes.
- انتشار مقاله: 25-03-1398
- نویسندگان: Majid Moradi,Hamidreza Tavakoli
- مشاهده
- جایگاه : پژوهشی
- مجله: Civil Engineering Infrastructures Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: earthquake,Pancake Collapse,Progressive Collapse Robustness Index,Zipper Collapse
- چکیده:
- چکیده انگلیسی: One of the aims of earthquake engineering is to build secure structures against random loads and also various damage types under lateral loads. Progressive collapse, a word that has attracted attention of many researches after the failure of the World Trade Center, can occur under abnormal loads such as explosion or natural causes like earthquakes. Resistance to progressive collapse is expressed by a parameter called Robustness. The purpose of this study is to survey various methods of calculating robustness index under lateral loads, especially seismic loads, in steel moment frames. So three steel structures with 4, 8 and 15-story and intermediate moment frames were designed and analyzed subsequently. Different methods of measuring the robustness indexes were compared and eventually presented a simple method to assess robustness index based on nonlinear dynamic analysis. Robustness index introduced using this method, which is based on the types of Pancake and Zipper collapses and energy parameters, tries to express an appropriate standard for structural strength against earthquakes.
- انتشار مقاله: 25-03-1398
- نویسندگان: Majid Moradi,Hamidreza Tavakoli
- مشاهده
- جایگاه : پژوهشی
- مجله: Advance Researches in Civil Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Shear wave velocity,Frequency,Bender Element,Triaxial Apparatus
- چکیده:
- چکیده انگلیسی: Maximum shear wave velocity is one of the most important dynamic parameters of soils which contributes in estimating the dynamic behaviour of soils through the maximum shear modulus. There are different methods for measuring shear wave velocity either in laboratory or in the field. One of the laboratory methods that recently has become popular due to its simplicity, is use of Bender Elements in soil samples. Contrary to its simplicity, it has several uncertainties in its data interpretation. Frequency at which the shear wave velocity is measured is one of the effective parameters that significantly affects the clearance of received wave. This article presents results from a laboratory investigation into the shear wave velocity measurement of remolded specimens of Firoozkooh sand. Specimens were subjected to 13 different levels of frequency and 11 different levels of confining pressure. Results shows that by increasing the confining pressure, the frequency at which the received wave has the best clearance, increases. It also shows that frequency dependence of soils increases by increasing the confining pressure.
- انتشار مقاله: 01-02-1397
- نویسندگان: Sara Ataii,Abbas Ghalandarzadeh,Majid Moradi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advance Researches in Civil Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Shear wave velocity,Frequency,Bender Element,Triaxial Apparatus
- چکیده:
- چکیده انگلیسی: Maximum shear wave velocity is one of the most important dynamic parameters of soils which contributes in estimating the dynamic behaviour of soils through the maximum shear modulus. There are different methods for measuring shear wave velocity either in laboratory or in the field. One of the laboratory methods that recently has become popular due to its simplicity, is use of Bender Elements in soil samples. Contrary to its simplicity, it has several uncertainties in its data interpretation. Frequency at which the shear wave velocity is measured is one of the effective parameters that significantly affects the clearance of received wave. This article presents results from a laboratory investigation into the shear wave velocity measurement of remolded specimens of Firoozkooh sand. Specimens were subjected to 13 different levels of frequency and 11 different levels of confining pressure. Results shows that by increasing the confining pressure, the frequency at which the received wave has the best clearance, increases. It also shows that frequency dependence of soils increases by increasing the confining pressure.
- انتشار مقاله: 01-02-1397
- نویسندگان: Sara Ataii,Abbas Ghalandarzadeh,Majid Moradi
- مشاهده