Buffeting response analysis of long-span suspension bridge's stiffening girder under wind-rain combined action

In view of the basic characteristics of rainfall, the acting force of raindrops on bridge deck is calculated, and the acting force is further decomposed into rainfall impact load and damping force. The element impact load and element damping matrix of rainfall are derived based on shape function, and then the dynamic response equation of long-span suspension bridge considering rainfall effect is put forward. Taking a long-span suspension bridge in the East China Sea as research object, the buffeting response of its stiffening girder under wind-rain combined action is analyzed. The results indicate that, under the joint action of wind and heavy rainstorm (strong), the mean values of the displacements of the stiffening girder at mid-main span along wind and vertical directions increase 16.24% and 4.81% respectively, which indicates that raindrops play a major role in the impact on the structure along wind direction under strong wind-rain combined action. The structural responses are reduced to a certain extent due to the damping effect of rainfall. The mean square deviation values of displacement response of stiffening girder at mid-main span along wind, vertical and torsional directions have been decreased 7.38%, 2.28% and 5.57% respectively by the additional damping effect of rainfall.