冻土区路桥过渡段模型改进试验研究

Experimental Study on the Model Improvement of Road and Bridge Transition Section in Permafrost Region

冻土对温度有极高的敏感性,在温度影响下其物理性质会产生冻结和融化,而冻土区路桥过渡段由冻土路基与钢筋混凝土结构组成,因其刚度、强度及材料的不同而引起差异性沉降和桥梁的变形,一直是影响青藏铁路安全运营的一大危害。因此,对传统路桥过渡段结构提出一种改进方法,并通过室内模型试验和传统的路桥过渡段进行比对分析。结果表明:经改进后的过渡段结构对地基具有良好的冷却效果,具有较强的自然对流换热效应,在荷载的作用下,新型结构差异性沉降有了明显改善,极大地减少了过渡段结构因差异性沉降所带来的铁路运输危害。

Frozen soil has high sensitivity to temperature, under the influence of the temperature and its physical properties will produce freezing and melting, and the road and bridge transition section in permafrost area by permafrost subgrade and reinforced concrete structure, because of its stiffness strength and deformation of different materials caused by differential settlement and bridge, has always been a great harm to the safe operation of the Qinghai Tibet railway. Therefore, this paper puts forward an improvement on the structure of the traditional road and bridge transition section, and compares it through the comparison between the indoor model test and the traditional road and bridge transition section. The results show that the transition section of the improved structure has good cooling effect on the ground with strong natural convection heat transfer effect under load, a new structure of differential subsidence has improved significantly, greatly reducing the transition structure because of differential subsidence brought by railway transportation hazards .