The Effect Of Cast-in-place Board To The Yield Mechanism Of Strong Column Weak Beam For RC Frame Structure

The main advantages of in-situ reinforced concrete frame structure are:(1) the structure is lighter weight than the other, you can save materials;(2) the member is arranged more convenient, you can easily meet the requirements of the building layout plane;(3) can be flexible The division of space, the owners of the building space to meet the various requirements;(4) a clear force, stiffness, ductility and integrity are good. Because the frame structure has so many advantages, so it is widely used in industrial and civil buildings. But at the same time frame structure has obvious advantages and disadvantages are also more prominent, is its lateral stiffness is generally small, under strong earthquakes, the horizontal displacement of a large, easy to collapse. Therefore, in order to ensure safety in the use of frame structure under strong earthquake, so that the lives and property of residents from loss, our specification proposed a "strong column weak beam" design guidelines. But the discovery by observing whether or earthquake earthquake occurred elsewhere in our country, a large number of frame houses are there a lot of the column end plastic hinges, but intact beam end, a lot of framework to achieve a "strong beam weak column " The destruction of the form. The reason for this phenomenon is very complex, one very important factor is the presence of floor slab. Floor slab impact framework is mainly reflected in two aspects: enhancing the role of(1) casting slab on frame beam stiffness;(2) casting slab on frame beam end moment to enhance the role of anti- negative bearing capacity.For reinforced concrete slab for the anti- frame beam negative moment to improve the bearing capacity of the frame structure of the proposed specification can not be achieved "strong column-weak beam" yield mechanism problem, this paper summarizes the results of previous studies and the floor slab "effective wing margin width " two aspects do the following work:(1) Through a lot of reading literature, summed up the domestic and international normative framework for the realization of "strong column- weak beam" yield mechanism adopted provisions summarized scholars Progress impact casting slab on frame structure.(2) Non- linear elastic-plastic static analysis(Pushover) principles and implementation methods were introduced, for the late model paper analyzes the foundation.(3) Using SAP2000 software to consider four different "effective flange width" in the framework of the model did a comparative analysis Pushover interlayer compare four models of displacement, displacement and distribution of plas tic hinge floor.By analyzing the following conclusions:(1) Floor slab can significantly enhance lateral stiffness and bearing capacity of the frame structure. Under the existing standard design framework can not be achieved "strong column-weak beam" yielding mechanism under the lateral force loading mode.(2) In order to be considered for the floor slab flexural stiffness and increase the carrying capacity of the frame beam, the beam can be equivalent to ┳-section, while the beam is equivalent to ┏ shaped cross section.(3) Take six times the thickness of each side as "effective flange width" has a representative, can bring a certain extent reflect Zhang destruction floor frame structure, but still small.