강박스거더교의 응력보정계수에 따른 내하력 평가

Abstract

When a load is applied to a structure, a displacement occurs. There exists a stiffness equation between the load and the displacement. The relationship between the load and the displacement can be defined as the stiffness. In this study, the stiffness by applying linear springs and rotary springs is defined, and the structural model similar to the actual behavior characteristics is generated by applying the actual data obtained from the load test to the stiffness equation. In single beam, the response ratio of conventional method is 1.570∼1.718, whereas the response ratio of the model with vertical spring and rotating spring is 0.934∼1.056, which is effective to show the actual behavior characteristics. This study is applied to a model that uses stiffness by linear springs and rotary springs considering a common bridge as a grid beam. The response ratio was the largest at 1.090∼1.255 in the conventional method, 0.891∼1.054 in the linear spring model and 0.770∼0.952 in the rotary spring model. In the conventional method, the basic load bearing capacity is small and the stress modification factor is large. However, when the spring force is considered, the basic load bearing capacity is large and the stress modification factor is small. In the safety evaluation, results similar to the load bearing capacity were obtained. The ultimate goal of design is to have the same design value as the measured value. If the actual behavior characteristics are described as much as possible in the structural analysis, the reliability of the load carrying capacity or safety evaluation determined from the structural analysis results is improved.