Analysis Of Ability Of A Large-Span Continuous Rigid-Frame Bridge To Resist A Missile And Preliminary Research Of Rush-Repair Technique

Communication and transport is national large artery. It has double mission to serve national economy and war all along. Bridges are vital communication lines. The construction and technology of bridge engineering in our country are developed very fast from 1980s. Till the present, there are five hundred and thirty-four thousand bridges whose mileage is ten and four thousand kilometers only on highway lines. These bridges have very important use for economy development and preparation against war. However, based on local wars in ten and several years recently, destroying bridges in war is effective means by which the transport of railway and highway is cut off. Both sides of fighting attach full important to destroy bridges of enemy side in various wars. In the war of Viet Nam, the quantity of American army's airplanes bombing bridges holds eighty percent in totality of the airplanes bombing railway mstallation. In Gulf War, American army bombed transport installation of Iraq in deep. There are fifty-four bridges and fourty bridges are destroyed. Ten other bridges are damaged with different degree. In the war where North Atlantic Treaty Organization attacked the Federal Republic of Yugoslavia, the army of North Atlantic Treaty Organization emphasized to attack bridges of Yugoslavia at the beginning. Sixty-six bridges are destroyed, which affects seriously communication and transport in Yugoslavia. Destroying bridges can cut off communication lines and even influence success or failure in war situation. Therefore, how to evaluate quickly damage degree of damaged bridges and how to organize quickly to rush to repair them is a quite major research subject.Using LS-DYNA of large-scale nonlinear-dynamic finite element program, numerical emulation analysis of dynamic response of a large-span continuous rigid-frame bridge which is acted by shock and blast of a missile is researched in this paper. In the course of calculation, attacking weapon chooses BGM-109 missile and a large-span continuous rigid-frame bridge chooses Humen continuous rigid-frame bridge in war. Six working conditions (including main beam and pier etc.) are choosed when the missile attacks Humen continuous rigid-frame bridge. The section of span middle (section one), section two, zero block (section four), and section six of main beam and bearing support of side span and the third pier are choosed as the target attacked by the missile. After the missile attacks various kinds of different positions of Humen continuous rigid-frame bridge, damage degree of the bridge is evaluated to distinguish its damage states (including slight damage, moderate damage and severe damage).A preliminary method of rush-repair is raised based on its damage states. At the same time, a criterion of demarcation line by which the original bridge rushes to be repaired is established in accordance with various kinds of different damage states where the missile attacks Humen continuous rigid-frame bridge. Based on the criterion of demarcation line, a preliminary conclusion by which the original bridge can or can not rush to be repaired is drawn and a preliminary scheme of rush-repair to the original bridge is raised.