Скачать или смотреть Performance of Anchorages Under Predominant Moment Loading: An Experimental Investigation

Presented By: Gaurav Somnath Chobe, Purdue University - West Lafayette

Description: Post-installed mechanical and chemical anchors offer a large flexibility for the design of connections in concrete structures. Such fastening systems are extensively used to connect structural or non-structural elements to concrete. Moreover, they are used to join new structural elements to existing structures in earthquake retrofit schemes. Frequently anchorages are subjected to predominantly moment loading either alone or in combination with axial or shear loads. Some of the examples include anchorages used to form column-foundation connections, beam-column connections, beam-wall connections, wall-foundation connections, etc. Current design guidelines such as EN1992-4 and fib Bulletin 58 consider the positive influence of bending moment on the anchorage capacity through the factor ????=1.0. However, the formulations provided in the guidelines are rather limited in applications. For example, when the anchorage is positioned close to the edge, this factor assumes a value of 1.0. For the cases with more than 2 anchors in a row or biaxial moment, the rules for determining the behavior of anchorages under predominant moment loading are not clear. This paper presents the results of an experimental program, executed to investigate the behavior of anchorages under predominant moment loading. The tests are conducted on column-foundation joint sub-assemblies formed by connecting a steel column to concrete foundation using 2 x 2 anchor groups of post-installed anchors. The sub-assemblies are loaded monotonically under lateral loading at a pre-defined lever arm representing the point of contra-flexure of a frame of a structure under lateral loads. Columns are located close to and away from the edge and tested under loading towards the edge and away from the edge. The test results clearly bring out the differences in the behavior of different sub-assemblies subjected to predominant moment loading.