盾构隧道施工引起的超孔隙水压力变化规律研究

Study on Change Rules of Excess Pore Water Pressure Caused by Construction of Shield Tunnels

对现场实测盾构隧道施工引起的孔隙水压力值进行分析研究,总结出超孔隙水压力产生和消散的规律。在国内外流固耦合计算调研基础上,建立能够模拟盾构隧道动态掘进的三维弹塑性固结有限元模型。采用该模型对单条盾构隧道施工引起的超孔隙水产生和消散规律以及土体固结沉降规律进行充分研究,其结论与现场实测规律一致,也证明本文所建立的盾构隧道三维弹塑性固结耦合有限元模型的适用性,并总结得出近间距盾构隧道在淤泥质粘土和粉质粘土中的合理开挖面间距。

This paper analyzes and studies on-site measured pore water pressure values caused by construction of shield tunnels and concludes rules of generation and dissipation of excess pore water pressure.Based on fluid-solid coupling calculation and investigation at home and abroad,the paper establishes a 3D elastic-plastic consolidation finite element model that can simulate dynamic advancement of the shield tunnels.The model is applied for adequate study on generation and dissipation rules of excess pore water caused by construction of single shield tunnel and consolidation and sedimentation rules of soils,the conclusions obtained are consistent with the measured rules on site,and also prove the applicability of 3D elastic-plastic consolidation coupling finite element model established in this paper.In addition,the study gives reasonable spacing among excavation surfaces for short-space shield tunnels in sludge clay and silty clay.