STRENGTH AND BEHAVIOR OF COMPOSITE FRAMING SYSTEMS.

Abstract

An investigation of the behavior of multistory composite frames is presented. The investigation includes a review of the state-of-the-art of composite frame analysis and design methods, and also details the features of the response of composite frames during the construction phase. In an original development, solution procedures that incorporate the effects of construction sequencing on the strength and stability of composite frames are developed. This is extended to define the new concept of a construction limit state for use in design of such structures. These procedures are intended for use by designers and contractors as guidelines. In order to achieve a certain quality of construction, the builder must comply with a set of specific erection sequences. These sequences may vary from one structure to another, depending on a number of factors. Although general standards of construction that include the effects of sequencing do not exist, and would likely be very difficult to develop, it is clear that designers and contractors must consider the influences. From the viewpoint of economy and efficiency, it is necessary to specify sequences that satisfy the structural behavior and stability requirements. The primary purpose of this study is the development of a numerical procedure for the determination of the behavior of composite frames during erection. A second objective is that the procedure developed will be such that it would lend itself to improved construction economy by taking into account the effects of construction sequencing. It will be demonstrated that simple calculations of construction sequencing, together with the given frame response, may be used by the contractor during erection to establish the different activities required for the erection of a building frame.