盾构管片橡胶密封垫老化性能研究及服役寿命预测

Research on Aging Performance and Service Life Prediction of Rubber Sealing Gaskets for Shield Tunnel Segments

摘要:

为了研究密封垫在长期受压状态下接触应力的松弛规律,开展了密封垫在不同温度下的热氧老化试验。利用ABAQUS软件建立密封垫三维压缩数值模型,分析密封垫内部应力分布情况,并根据试验数据运用时温叠加原理预测密封垫的服役寿命。研究表明,密封垫的性能保持率随着老化时间的延长逐渐降低并趋于稳定,密封垫的性能保持率随老化温度的升高而减小;随着压缩量的增加,密封垫两端会翘起孔洞,且压缩量越大,翘起的孔洞越大,因此在满足防水要求的前提下,适当减小压缩量,有利于提升密封垫防水性能;密封槽-密封垫间的接触应力整体高于密封垫-密封垫间的接触应力,根据时温叠加原理计算可知,密封垫压缩9 mm可满足某地铁1号线100 a的防水要求。研究内容对于提高某地铁1号线的运营能力具有重要意义。

Abstract:

In order to study the relaxation law of the contact stress of sealing gaskets under long-term compression, the thermal-oxidative aging tests of the sealing gasket at different temperatures were carried out. ABAQUS software was used to establish a three-dimensional compression numerical model of the sealing gasket, so as to analyze the stress distribution inside the sealing gasket and predict the ser-vice life of the sealing gasket based on the test data and the time-temperature superposition principle. The research shows that the performance retention rate of the sealing gasket gradually decreases and tends to be stable with increasing aging time, while decreases with increasing aging temperature. With the increase of compression, holes tend to form at both ends of the sealing gasket due to warping, and the greater the compression, the larger the holes. Therefore, on the premise of meeting the waterproof requirements, the appropriate reduction of compression is conducive to improving the waterproof performance of the sealing gasket. The contact stress between the sealing groove and the sealing gasket is overall higher than that between the sealing gaskets. According to the calculations based on the time-temperature superposition principle, the compression of sealing gasket by 9 mm can meets the 100-year waterproof requirement of a certain subway Line 1. The present research is of great significance for improving the operational capacity of a certain subway Line 1.