地震作用下盾构隧道环缝单向振动防水性能试验

Unidirectional Vibration Waterproof Test of Ring Joint of Shield Tunnel under the Action of Earthquake

为研究盾构隧道管片接缝弹性密封垫在地震作用下的防水性能,以在高烈度地震区修建的大断面海底盾构隧道——苏埃通道工程为依托,根据隧道环缝防水指标,研制了可模拟地震作用下的管片环缝单向振动防水试验装置,通过不同环缝张开量下单向振动防水试验,与未考虑地震作用时对应的张开与错动工况下静态防水试验结果进行对比,得出了张开量增大对密封垫防水性能的影响,并提出了弹性密封垫振动防水与静态防水的对应指标.结果表明:单向振动作用下弹性密封垫发生渗漏时,水呈喷射状而非缓慢流出,张开量的增大较错动量增大更易使弹性密封垫防水性能显著降低;随着环缝张开量的变化,单向振动耐水压值为0.2~1.4 MPa,静态耐水压值为0.1~1.1 MPa;单向振动作用下环缝弹性密封垫的防水性能约为静态时防水性能的45%~78%.

In order to study the waterproof performance of the elastic sealing gasket of shield tunnel segment joint under seismic action,on the basis of the large section subsea shield tunnel—Su’ai Channel project in highintensity seismic region,a unidirectional vibration waterproof test device for segment ring joint under the action of simulated earthquake was developed according to the waterproof index.The unidirectional vibration waterproof test under different ring joint openings was carried out,compared with the static waterproof test under the corresponding working conditions of opening and offset,the influence of openings on waterproofing performance of sealing gasket is obtained,and the corresponding indexes of the vibration and static waterproof of the gasket were put forward.The results show that when water leakage happens under the unidirectional vibration condition,the water spurts rather than slowly flows out through the sealing gasket,and the increase of the opening is more likely to reduce the gasket waterproof performance significantly than that of the offset.With the changes of ring joint openings,the hydraulic resistance value under unidirectional vibration is 0.2-1.4 MPa and the static hydraulic resistance value is 0.1-1.1 MPa.The waterproof performance of the sealing gasket is about45%-78%of its static water resistance under unidirectional vibration.