Research On The Effect Of Upper Structure And Loads For Behaviors Of Composite Masonry Walls With Holes Which Are Eccentrically Compressed

The intension of this test is to research the behaviors of composite masonry walls with holes with structural concrete columns which are eccentrically compressed undering the upper structure and loads ,and research the co-work capabilities of each part.This paper reviews the tests and researches about the composite masonry walls in and out of country firstly,and find out that despite a number of researches have been done,and gained some useful results,but most of these were researched on the even layed loads and lateral forces,even what involved in criterion are oversimplified,so all those are still insufficient,and make a embarrassment in practice.so we should do more work to master the behaviors of composite masonry walls, especially in the aspect of eccentrically compress.Chongqing University has done some tests about eccentrically compress without the upper structure and loads,so this test designs 4 pieces walls for the study about composite masonry walls which have holes.In this paper, based on the tests of the composite masonry walls with holes with structural concrete columns bearing equably layed vertical loads and undering the concentrated loads out-of-plane, the influences of force and eccentricity on the coordination of columns,ring beams and masonry walls are discussed, the transfer and distribution rules of section stresses in the horizontal and vertical direction of the walls are revealed, the emergence and development of cracks, the deformation and failure mechanism of members are investigated, and the reasons and rules influencing the behaviors of masonry wall are discovered, at last, the spacial effects caused by the bracing and constraint out-of-plane are analyzed, some meanful conclusions are concluded as following:⑴The composite masonry wall with holes has obvious special effects under out-of-plane eccentric compression, its deformation is harmonious, masonry, structure concrete columns and ring beams bear the load together, and obvious stress redistribution happens during the loading process;⑵The greater the stiffness of beams are, the better the cracking-resistance,loading bearing and deformation capacity are. The influence of beams'stiffness is very important for the ultimate carrying capacity;⑶The level of material strengthen,the rate of steel and hole are very important for the ultimate anti-bend capacity; ⑷When the space between columns is definite,the more great stiffness of columns is in favor of thecomposite wall with holes to bear the out-of-plane eccentric load;⑸The vertical loads could reduce eccentric compression obviously,and minish the horizontal distortion of the walls with holes.⑹To analyze the performance of composite walls with holes under out-of-plane eccentric compression, the composite frame model with holes may be used.This study is a elementary course of composite walls with holes under out-of-plane eccentric- compression, for the performance of composite walls under out-of-plane eccentric- compression is also influenced by other aspects such as transverse bracing, stiffness of loaded beam ,the size and distribution of hole of walls and the amount of floor,the vertical imposed prestressing of walls and horizontal load,so the further study is needed to know the influence rules of the aspects above, put forward effective calculation method and appropriate structure measures, and provide enough testing and academic foundation for the present code of masonry structure to meet the need of seismic design.