The Research Of Lateral Stiffness Of Wall In Brick Buildings With Bottom-framed

Because of economical and practicability, Brick building with bottom framed was applied to structure that is near to streets, but because it is rigid in upper layer and soft in bottom layer, if we don't make aseismic design proper, its aseismic behavior will not be so well.Many examples indicate that the coefficient of ultimate shear strength in bottom layer and the position of weak layer and elastic-plastic deformation is related directly to stiffness ratio in layer and layer. The calculating computing of lateral stiffness is base on the calculating computing of all walls, but all methods now have more or less disadvantages. So the article primary research the several point as below.(1) Summarize all the methods in stiffness ratio calculating, set up FEM model in calculating stiffness ratio, and base on the result of FEM, comparing and analyzmg the applicability and the limitation of all methods.(2) As to the wall without opening, the methods now is material mechanics based on rod model which is not fit to wide walls, so base on the FEM result, a correction coefficient is obtained that take height-width ratio of wall into consideration. which provide reference for the stiffness calculating of wall without opening.(3) As to the wall with opening, finding that the position of opening in wall influence prominent to the lateral stiffness, when the opening is move along horizontal or upright direction, the lateral stiffness is varied. And finding that the series-parallel method can reflect the varied position in some extent. So base on the series-parallel method , takes the height-width ratio of wall, dimension and position of opening into consideration, Obtaining a formula through mathematic fitting. Compared with the FEM result, the modified lateral stiffness is reasonable.(4) As to the wall with constructional column, dividing the whole wall into small wall according to series-parallel method, calculating the stiffness of small wall according to the method of calculating wall without opening. assembling the stiffness of small wall, and using the modified formula at last, Compared with the FEM result, the modified lateral stiffness is rapid and reproducible.(5) Compiling the calculating module of brick building with bottom framed, and taking the new method into PKPM system. As to stiffness radio problem, many practical examples were calculated, Compared with the result of another method, proving the modified lateral stiffness is reasonable.