Investigation of shear lag effect in high-rise buildings with diagrid system

Abstract

In the recent years, there have been many new skyscrapers built which soar into new heights. The most efficient building system for high-rises has been the framed tube system. However, the framed tube building suffers from shear lag effects which cause a nonlinear distribution of axial stresses along the face of the building. A particular structural system called a diagrid system has caught the attention of the public. The diagrid system is not a new invention. The idea had been around since 1960 and few buildings have been built with the diagrid system. However, the implementation in a larger scale of such tall building was not practical due to high cost related to the difficult node connections. It is only in recent years that the technology has allowed for more reasonable cost of making the diagrid node connections. Despite becoming the new trend in high-rise structures, there are not many technical publications related to diagrid building system. A recent thesis by Moon (2005) studied the various angles of the diagrid to find optimum angle. He has also reviewed the design considerations for diagrid building. This thesis attempts to build on the study by Moon related to the shear lag effect in diagrid building. Diagrid buildings of different configuration are modeled in SAP2000 and analyzed for shear lag effect and structural performance.