中文摘要：

将既有的模型试验研究得到的分块型K管片接触面轴力与弯矩临界包络线,作为分块型K管片用于盾构扩挖车站时的风险控制标准,以埋置深度、施工工况和扩挖错距作为关键影响因素,分析分块型K管片应用于盾构扩挖车站的风险控制问题。结果表明：分块结构的接触面经历了一个由上部区域转移到下部区域,再转移回到上部区域的受压复杂变化过程;扣拱扩挖对接触面的内力影响最大;随着扩挖错距的增大,接触面的内力也逐渐增大,且扣拱错距扩挖对接触面的内力影响较大;对3个关键因素共同作用下的接触面内力进行筛分,得到满足分块型K管片正常使用要求的不同扩挖工况下的埋置深度与临界错距的关系曲线,为分块型K管片应用于盾构扩挖地铁车站的施工风险控制提供理论参考。

英文摘要：

The axial force and critical moment envelope curves of the interfaces for partitioned key segment obtained from loading tests were taken as the risk control criteria for constructing metro station by enlarging shield tunnel with partitioned key segment.The risk control problem of applying partitioned segment to metro station constructed by enlarging shield tunnel was analyzed with the embedded depth,construction condition and the staggered distance of enlarging excavation as the key influencing factors.The results showed that the complex compression zone on the interface of partitioned key segment moved frequently from the top zone to the bottom zone,and then back to the top zone again.The effect of arch enlarging excavation was the greatest on the internal force of interface.The increase of staggered distance caused the internal force on the interface increase gradually.The arch excavation with staggered distance had great influence on the internal force of interface.By grading and analyzing the internal force of the interface under the interaction of three key factors,the relationship curve between embedded depth and staggered distance under different enlarging excavation conditions was obtained to judge whether the partitioned key segment could be used normally.Theoretical references have been provided for the risk control on metro station constructed by enlarging shield tunnel with partitioned segment.