【摘要】 地震液化可能诱发极为严重的破坏,已成为工程领域的重要研究课题。目前,在可液化地层下地铁工程抗地震液化设计及施工经验较少,且现行规范针对液化地层所给定的处理原则在工程实际应用中较难操作。本文以天津地铁5号线穿越中等-严重液化粉土层区段为工程背景,同时以地震液化机理、影响因素及抗液化规范的应用为基础,结合数值模拟及现场试验,给出了地铁工程抗地震液化处理措施建议,并对各项措施的适用性进行了分析。研究结果表明:抗液化措施应结合地铁结构型式、结构与液化土层的相互位置关系、液化土层的厚度、液化等级以及周边环境等因素综合确定;在结构承载力及抗浮稳定性验算中应计入土层液化引起的土压力增加、摩阻力降低以及浮力增加等因素的影响;注浆加固对盾构区间抗地震液化有利。更多还原

【Abstract】 The earthquake liquefaction, which may induce extremely serious damage, has become an important issue in the field of engineering. At present, the practice in designing and construction of anti-liquefaction measures for subway engineering in liquefaction layers is few, and it is difficult for the existing specifications to provide processing principles of for liquefied stratum to operate in practical engineering application. Combined with a practical engineering of Tianjin metro line#5 with station and interval shield crossing the middle-seriously liquefied silty soil, this paper gives the recommendations of anti-liquefaction measures and the applicability of the measures by the means of numerical simulation and field test which based on the theoretical results of liquefaction mechanism,influence factors and effects. The research results show that the determination of anti-liquefaction measures should be combined with the subway structure pattern, the relative relationship of structure and the liquefiable layers, the thickness of the liquefiable layers, liquefaction grade and the surrounding environmental conditions and other factors. The structure capacity and anti floating stability checking should consider the impaction of liquefaction,such as the increase of inner pressure, the decrease of friction, the increase of buoyancy and etc. Grouting reinforcement is favorable for interval shield to resist seismic liquefaction.更多还原