Quasi-Static Lateral Design Loads for Earthquake Resistant Structures.

摘要

Different types of structures including frames,shear walls,box systems,chimneys,towers,masts,etc.,were simulated by means of a mathematical model. The structural properties of the model such as mass and stiffness matrices were defined using matrix compression techniques. Equations of motion were then formulated and solved using a digital computer to obtain eigenvalues and eigenvectors. Finally,after performing a modal analysis,quasi-static loads were evaluated for the various responses of interest,namely displacements,accelerations,shears,and overturning moments. These forces were such that when applied to the model they would produce an equivalent dynamic response of the structure. The effect of parameters such as earthquake magnitude,rigidity of the structures,shear-flexural ratio,stiffness and mass distribution,and number of stories,upon the responses of the structure,were analyzed independently. From the data obtained, a method of predicting a set of design quasi-static lateral loads that would yield responses greater than or equal to those given by a complete modal analysis was developed. The recommended systematic method of predicting quasi-static loads for earthquake resistant structures is presented and illustrated by means of an example. (Author)