The object of this paper is the evaluation of the seismic response of reinforced concrete frames designed according to the DDBD （direct displacement-based design） approach. The great part of research works about DDB...The object of this paper is the evaluation of the seismic response of reinforced concrete frames designed according to the DDBD （direct displacement-based design） approach. The great part of research works about DDBD has been dedicated to planar frames, but recently also some proposals for 3D structures have been presented, in particular for wall structures. This paper will give a further contribution to the extension of the procedure for the case of plan-asymmetric RC （reinforced concrete） frames. The extended methodology is aimed at accounting for the floor rotations on the basis of a given lateral strength distribution along the plan. The procedure was applied to two plan-asymmetric RC frames, characterized by the same geometry but different lateral strength distributions along the plan. The seismic behavior of the designed frames was studied by adopting a fiber model and by performing pushover and nonlinear dynamic analyses.展开更多
Based on the existing research, this paper presents an innovative methodology to realize direct damage-based seismic design for RC frame structures by mobilizing ESDOF theory and the damage-based strength reduction fa...Based on the existing research, this paper presents an innovative methodology to realize direct damage-based seismic design for RC frame structures by mobilizing ESDOF theory and the damage-based strength reduction factor（RD factor）. A design example is then followed to verify this method.展开更多
In design and construction of low/high rise buildings, different forms of construction can be applied such as concrete shear wall structural system and framed structural system without or with masonry infill walls. At...In design and construction of low/high rise buildings, different forms of construction can be applied such as concrete shear wall structural system and framed structural system without or with masonry infill walls. At present, most buildings in East Africa are constructed as reinforced concrete framed structures with strong masonry infill, but during design, engineers assume that the masonry infill panels have zero contribution in offering load resistance. Due to the problem above, a study with an objective of finding out the influence of masonry panels on the properties of reinforced concrete infilled frame under vertical load has been done. Three types of models： reinforced concrete frame model, masonry model and reinforced concrete frame with masonry infill, were investigated using finite element technique. In additional to the finite element analysis, laboratory models were prepared and tested so as to check the validity of the analytical results. The obtained results have led to an establishment of a mathematical model which may be useful to the design engineers since masonry wall panels can now be considered as load bearing elements. Such consideration of frame together with masonry leads to an accurate and optimal design of the frame, resulting into lesser amount of reinforcement and geometrical properties of the frame.展开更多
Global failure mechanism, i.e., the strong-column weak-beam mechanism, can provide higher total energy dissipation capacity with less ductility demand on components than other failure modes, and results in a more unif...Global failure mechanism, i.e., the strong-column weak-beam mechanism, can provide higher total energy dissipation capacity with less ductility demand on components than other failure modes, and results in a more uniform story drift distribution and higher resistance to earthquake loads at the system level. However, the current code-based elastic design method cannot guarantee the global failure mechanism of frame structures under severe earthquakes. In this paper, a simple, but practical design procedure is proposed to ensure the global failure mechanism of reinforced concrete(RC) frame structures by redesigning the columns using the column tree method(CTM). CTM considers the yield limit state of all beams and column bases. The code-based design is firstly carried out to determine the section information of all beams and base columns. Then, the internal force demands applied on the column tree can be derived. Lastly, the column moments, shear forces and axial forces are determined according to the free-body diagram of CTM to finish the column redesign. Two RC frame structures with 6 and 12 stories are illustrated to verify the design procedure. The analytical results demonstrate the proposed approach can realize the global failure mechanism.展开更多
文摘The object of this paper is the evaluation of the seismic response of reinforced concrete frames designed according to the DDBD （direct displacement-based design） approach. The great part of research works about DDBD has been dedicated to planar frames, but recently also some proposals for 3D structures have been presented, in particular for wall structures. This paper will give a further contribution to the extension of the procedure for the case of plan-asymmetric RC （reinforced concrete） frames. The extended methodology is aimed at accounting for the floor rotations on the basis of a given lateral strength distribution along the plan. The procedure was applied to two plan-asymmetric RC frames, characterized by the same geometry but different lateral strength distributions along the plan. The seismic behavior of the designed frames was studied by adopting a fiber model and by performing pushover and nonlinear dynamic analyses.
文摘Based on the existing research, this paper presents an innovative methodology to realize direct damage-based seismic design for RC frame structures by mobilizing ESDOF theory and the damage-based strength reduction factor（RD factor）. A design example is then followed to verify this method.
文摘In design and construction of low/high rise buildings, different forms of construction can be applied such as concrete shear wall structural system and framed structural system without or with masonry infill walls. At present, most buildings in East Africa are constructed as reinforced concrete framed structures with strong masonry infill, but during design, engineers assume that the masonry infill panels have zero contribution in offering load resistance. Due to the problem above, a study with an objective of finding out the influence of masonry panels on the properties of reinforced concrete infilled frame under vertical load has been done. Three types of models： reinforced concrete frame model, masonry model and reinforced concrete frame with masonry infill, were investigated using finite element technique. In additional to the finite element analysis, laboratory models were prepared and tested so as to check the validity of the analytical results. The obtained results have led to an establishment of a mathematical model which may be useful to the design engineers since masonry wall panels can now be considered as load bearing elements. Such consideration of frame together with masonry leads to an accurate and optimal design of the frame, resulting into lesser amount of reinforcement and geometrical properties of the frame.
基金supported by the National Natural Science Foundation of China(Grant Nos.51261120376 and 91315301)Scholarship Award for Excellent Doctoral Student granted by Ministry of Education of China
文摘Global failure mechanism, i.e., the strong-column weak-beam mechanism, can provide higher total energy dissipation capacity with less ductility demand on components than other failure modes, and results in a more uniform story drift distribution and higher resistance to earthquake loads at the system level. However, the current code-based elastic design method cannot guarantee the global failure mechanism of frame structures under severe earthquakes. In this paper, a simple, but practical design procedure is proposed to ensure the global failure mechanism of reinforced concrete(RC) frame structures by redesigning the columns using the column tree method(CTM). CTM considers the yield limit state of all beams and column bases. The code-based design is firstly carried out to determine the section information of all beams and base columns. Then, the internal force demands applied on the column tree can be derived. Lastly, the column moments, shear forces and axial forces are determined according to the free-body diagram of CTM to finish the column redesign. Two RC frame structures with 6 and 12 stories are illustrated to verify the design procedure. The analytical results demonstrate the proposed approach can realize the global failure mechanism.
