软土地区盾构上穿越既有隧道的离心模拟研究

随着地铁网络不断完善，新建盾构隧道近距离穿越既有隧道的现象越来越多。盾构近距离穿越既有隧道的影响问题，比常规盾构施工的研究更为复杂。结合上海外滩通道盾构上穿越地铁 2 号线工程，采用离心模型试验与现场实测相结合的方法对盾构上穿越对周围地层及既有隧道的影响进行了研究。文中选用排液法在离心场中模拟盾构施工，在国内首次实现了在不停机状态下模拟隧道开挖卸载、地层损失和注浆过程，并分析了盾构上穿越施工引起的地层、新建隧道与既有隧道的纵向位移变化规律。通过现场实测数据分析了既有隧道在盾构上穿越过程中纵向变形与时程曲线的变化规律。

Centrifuge modelling of effects of shield tunnels on existing tunnels in soft clay

With the rapid development of the subway network,the phenomena of shield tunnels going across the adjacent tunnels are becoming more and more common.The interaction between shield tunneling and nearby tunnels is more complicated than the ordinary shield tunneling in intact soil strata.Based on the project of Shanghai Bund Passage crossing Metro Line 2,the method of centrifuge modeling together with the field measurement is employed to study the effects shield tunneling on nearby strata and existing tunnels.In centrifugal model tests,the effects simulation techniques considering the unloading of excavation,ground loss and grouting are developed to analyze the longitudinal settlement of the shield tunnel and the existing tunnel induced by the shield tunneling.Besides,the deformation distribution and settlement curves of the existing tunnels during shield construction are studied by using the monitoring data.