Damage Analysis Of Simply-supported PC T-Beam Bridge Under Impact Load Of Rockfall

As a typical geological disaster, rockfall has obvious adverse effects on traffic safety of mountain roads. The mountainous area in west of China has complex geological condition as well as frequent earthquakes. Earthquakes would induce rockfall directly or indirectly. The bridges in the mountain area are mostly concrete beam bridges. In the mountainous highway and high-speed railway bridges, the number of prestressed concrete bridges is great. Rockfall would impact the pier and beam of the bridge, it mostly causes local damage to the concrete. In severe cases, it can cause the structure collapsing. Therefore, the damage analysis of prestressed concrete bridges due to rockfall impact is extremely necessary.At first, it introduces the difference between impact analysis and static analysis. It also introduces the theoretical analysis method of beam and plate elements under impact load, which provides theoretical guidance for our practical application. Then It takes a prestressed concrete T-beam bridge in the mountain area for instance. It uses large-scale finite element software ANSYS/LS-DYNA to build the space model of this bridge, meanwhile introduces some skills to build model. Finally, based on this model, the different position of deck hit by rockfall is analyzed and a group of parameters, including impact velocity, rock’s mass, the impact angle and the impact contact area, are taken into account to study their effects on the damage degree of the bridge.The conclusions of this paper are as follows:when rockfall impact T beam flange plate, the damage of bridge focusing on the impact position; when rockfall impact the part of fine structural integrity (such as beam webs connected to transverse diaphragm), it having relatively large effect on the whole bridge. The greater impact energy the rockfall has, more serious the damage of bridge is.