Effects of temperature variation through the depth of bridge girders on the structural responses

초록

It is widely acknowledged that daily or annual temperature change in a bridge structure continuously influences on the structural behavior but its effects on the structural responses have been limitedly investigated yet. Besides static or dynamic stresses developed by temperature change, modal properties including natural frequencies measured from field or laboratory tests also varied according to the temperature change. From the test data, we could observe that the variation of natural frequencies was relatively in a wide range depending on the measured case. Even though some field or laboratory tests were carried out with the consideration on the temperature change, most research works considering temperature effects have been limited to numerical analysis with an average temperature through the depth of bridge deck. In order to investigate the effects of temperature on the bridge responses and to apply the results to the design and maintenance of a bridge, however, it is necessary to apply and analyze various temperature variations to diverse bridge types. The current study compares the analytical results considering temperature variation through the depth of bridge girders. For the study, various types of bridge structures including box-girder bridges and PSC beam bridges have been analyzed. In the analysis, different temperature variations defined in some design codes were applied. In the modal analysis, to consider temperature effects analytically, three different types of parameters were considered; including initial stress, structural deformation, and change in the elastic modulus due to temperature change.