地裂缝对不同结构形式桥梁桥面的破坏试验研究

根据相似原理，建立了两种支承形式的大比例尺桥梁模型，并在桥面板的上下表面分别布设应变片，通过人工模拟地裂缝的活动，采集了在地裂缝活动下桥面板上产生的应力和应变数据。对试验数据详细分析发现，简支桥由地裂缝引起的附加应力较小，地裂缝活动时主要破坏型式为落梁或落板破坏，因而地裂缝活动时，主要加强对桥梁梁、板位移量的监测，防止出现此类现象发生；固接桥作为一种超静定结构，在地裂缝的影响下产生较大的附加拉、压、剪等应力及扭矩，有可能导致结构性破坏。因此，笔者建议在地裂缝影响带范围内，桥梁以采用简支结构为宜。

Damage test study of different types structures of bridge decks by ground-fissure

Based on similar principles, two large-scale bridge models were established and carried out. It is the first time artificial simulated the effect on bridges under activities of ground-fissure; and strain gauges were laid on the bridge decks’ up and down surfaces. The test results show that the different construction bridge decks have different damage forms under the activities of ground-fissure. simply-supported bridge due to unbound, the bridge stress and strain mostly caused by the load on the bridge deck, and the additional stress caused by the activities of ground-fissure is very small; so the possible type of damage is off the beam or off the deck, as for this type of bridge, the most important measure is monitoring the bridge during the activities of ground-fissure to forecast the damage situation before the bridge destroyed by the activities of ground-fissure. While the fixed bridge due to be bound, big additional stress such as pressure, shear and tensile stress maybe be caused by the activities of ground-fissure and turns to damage of the bridge construction. At last, it is pointed out that the simply supported bridge is more suitable than the fixed-bridge over the regional of ground-fissure.