Behavior and design of steel-plate composite wall-to-wall corner or L-joints

Abstract

Steel-plate composite (SC) walls used in the containment internal structures of safety-related nuclear facilities intersect each other at corners of compartments to form wall-to-wall corner or L-joints. This paper focuses on joint shear behavior and strength of wall-to-wall corner L-joints, the understanding of which is imperative for the design of wall-to-wall joints irrespective of the failure mode. This paper presents the results of a large-scale test conducted on an SC wall-to-wall corner or L-joint. The test specimen was designed to undergo joint shear failure prior to flexural yielding of the connected SC walls. The test specimen did not include any tie bars in the joint shear region, which would represent the lower bound case for these joints. The specimen was subjected to cyclic loading until failure, and the test results included the joint shear force-displacement and joint shear force-shear strain responses of the specimen along with observations of concrete cracking and crushing in the joint region. The results and observations were evaluated to establish the joint shear strength and governing failure mode. The experimentally measured joint shear strength was compared with the ACI 349-06 code equation for calculating the joint shear strength of comparable reinforced concrete beam-to-column joints. A detailed nonlinear finite element model was developed to gain additional insight into the observed behavior. The model was benchmarked using experimental results. The experimental and analytical results were compared with ACI 349-06 code provisions for calculating the joint shear strength of reinforced concrete beam-to-column joints. The results from experimental and analytical investigations indicate that the ACI 349-06 code equation could be used for estimating the joint shear strength of steel-plate composite wall-to-wall L-joints with γ of 8.