Sesmic Performance Of Reinforced Concrete Latticed-frame Column With Steel Support

It is a difficult problem yet to be solved that how to achieve "strong column andweak beam" in the earthquake."the Chinese Code for seismic design of buildings"have the relevant provisions, to improve the ultimate bearing capacity of column. Butthe method with increase in the seismic coefficient did not achieve the intended goal,In most of the casses, the plastic hinge came into being in the column, and evendevastating collapsing occured in the concrete frame structure.Many scholars have discussed this issue, some scholars believe that thereinforced concrete frame structure is not suitable for seismic prevention, whichmeans no matter how much the value of the coefficient of columns is,"weak beamstrong column" is difficult to realized, unless the section of column has the sameorder of magnitude as shear wall. some scholars have done further research of thecoefficient to increase the capacity based on column design values, the results showedthat the coefficient need to take2.0or greater. There are two main factors that makethe coefficient larger than the value in Chinese Code, one is that the actual earthquakesometimes will be greater than expectation, the other is the stiffness of the floormakes the effective stiffness of the beam becomes larger.Based on the previous studies, this paper proposed the "reinforced concretelatticed-frame column" concept that the support are used between short span columns,the short span columns and the support may form a whole, this whole system is calledthe "reinforced concrete latticed-frame column". The "reinforced concretelatticed-frame column" has far greater stiffness than a single column, and isfavourable to realizing the "strong column and weak beam". Failure pattern,load-bearing and seismic behavior were studied for further study that weather or notthe reinforced concrete frame structures with "reinforced concrete latticed-framecolumn" can achieve the "strong column and weak beam".A reinforced concrete frame with no support, a reinforced concrete frame withX-shaped steel support and a reinforced concrete frame with inverted V-shaped steelsupport were tested under horizontal low cyclic loading. The stiffness, ultimatebearing capacity, energy consume ability and failure pattern were studied, and finiteelement analysis software were used to carry out simulated analysis. The resultsshowed that the reinforced concrete frame structure without supports didn’t implement strong column-weak beam, and the rebars of the column yielded anddamaged earlier than that of the beam; two reinforced concrete latticed-framecolumns’supports yielded and damaged first, then the rebars of the beams yielded, andthe concrete of the support to beam joints spalled severely and the cracks are verywide, rebars of the columns didn’t yield till the end of the experiment; to some extent,the “strong column-weak beam” is realized.