沉管隧道无缝伸缩缝材料设计及变形性能

Material Design and Deformation Performance of Seamless Expansion Joint of Immersed Tunnel

为提升海底沉管隧道管节接头处无缝伸缩缝材料在不同温度条件下的弹性性能及适应变形的能力,对具有代表性的沥青类和聚氨酯类无缝伸缩缝材料进行组成设计研究,并对比分析其变形性能。根据实际服役条件下无缝伸缩缝材料的循环拉伸和压缩变形特征,在多种温度条件下进行拉伸、拉伸恢复、压缩恢复等试验,分析沥青类和聚氨酯类无缝伸缩缝材料的拉伸性能、拉伸恢复性能以及压缩恢复性能。研究结果表明:1)2类材料的最佳油石比均为24%,油石比会显著影响沥青类材料的拉伸特性和高温性能,级配对聚氨酯类材料的拉伸性能具有显著影响;2)2类无缝伸缩缝材料都具有比较优异的适应拉伸变形的能力,且聚氨酯类材料的拉伸强度高于沥青类材料约70%;3)在20~40℃温度范围内,聚氨酯类材料和沥青类材料的拉伸恢复率在70%以上,压缩恢复率在60%以上,均可满足沉管隧道伸缩缝的要求;4)在0~60℃温度范围内,沥青类材料性能受温度影响显著,而聚氨酯类材料具有较低的温度敏感性。

To improve the elastic performance and deformation adaptability of seamless expansion joint materials at the joints of the subsea immersed tunnel under different temperature conditions,the representative asphalt and polyurethane seamless expansion joint materials are designed and their deformation properties are examined.According to the cyclic tensile and compressive deformation characteristics of seamless expansion joint materials under actual service conditions,the tensile,tensile recovery,and compression recovery tests are conducted under various temperature conditions,and the tensile,tensile recovery,and compression recovery properties of asphalt and polyurethane seamless expansion joint materials are analyzed.The results reveal the following:(1)The optimum oil to aggregate ratio of the these two kinds of materials is 24%.The oil to aggregate ratio will significantly affect the tensile properties and high temperature performance of asphalt materials,and the gradation has a significant effect on the tensile properties of polyurethane materials.(2)These two types of seamless expansion joint materials have excellent ability to adapt to tensile deformation,and the tensile strength of polyurethane materials is approximately 70%higher than that of asphalt materials.(3)In the temperature range of 20 to 40℃,the tensile recovery rate of two kinds of seamless expansion joint materials is more than 70%,and the compression recovery rate is more than 60%,which can meet the requirements of expansion joint of immersed tube tunnel.(4)In the temperature range of 0 to 60℃,the performance of asphalt materials is significantly affected by temperature,while polyurethane materials have lower temperature sensitivity.