【作者】 刘东；

【导师】 吕和林；

【作者基本信息】 西南交通大学 ， 岩土工程， 2009， 硕士

【摘要】 盾构法施工作为成都地铁施工中一种主要的施工方法,其施工过程中不可避免的会对周围岩土体产生扰动,引起的地表沉降可能影响地面建筑物和既有管线设施,当地表沉降达到一定程度时将影响地面建筑物的安全和地下管线的正常使用。为了减少由于施工引起的地表沉降对地面建筑物和地下设施的损害,有必要对施工引起地表沉降进行研究。本文以成都地铁一号线桐梓林站至火车南站区间段为背景,采用FLAC3D数值模拟的手段,对成都市特有地质条件下盾构隧道施工引起的地表沉降进行研究。重点研究了隧道埋深、盾尾注浆、掘进压力、双孔隧道中线间距以及双孔隧道不同开挖方案对地表沉降的影响,并运用灰色理论建立灰色模型,对地表一点不同时刻的地表沉降值进行预测。研究表明,在该盾构区间,在相同的开挖条件下,地表沉降随覆土厚度的增加而增大;盾构掘进压力的大小对地表沉降的影响比较大;注浆层弹性模量对地表沉降影响很大;在相同的开挖条件下,中线间距越小,地表沉降越大,当中线间距大于16m时,该区间隧道中线间距的增加对地表沉降的影响趋于稳定;在双孔盾构隧道施工时,左右两洞同时掘进的方案在控制地表沉降方面比先开挖完一线再开挖另一线的方案有利;运用灰色理论建模对地表一点不同时刻的沉降值进行预测是可行的。更多还原

【Abstract】 Shield tunneling is considered as one of the most important methods in the tunnel construction of Chengdu, which will disturb ambient rock mass inevitably, and the ground surface settlement is likely to influence the buildings and the existing pipelines. When the settlement gets to some extent, it will affect the safety of buildings overground and the normal utilization of pipelines underground. To reduce the damages to the buildings overground and facilities underground, which are induced by tunnel construction, it is essential to study the ground surface settlement. By applying FLAC3D numerical simulation, this paper mainly discusses the ground settlement caused by shield tunneling in terms of the particular geological condition in Chengdu, while taking the blocks between Tong Zilin Stop and Southern Train Station as background. And influences on the ground settlement due to buried depth of tunnel, grouting at the tail of the shield, tunneling pressure, the distance between double track tunnels and two-lane tunnel different shield excavation program are also studied. Besides, the application of Grey Theory in forecasting the ground surface settlement of a certain spot in different moments is introduced.The research shows that under the same shield excavating situation, the ground settlement of this shielding section increases as the the covering earth thickens; the strength of tunneling pressure bears relatively big impacts on the ground settlement; the elastic modulus of injected layer influences the ground settlement a lot; under the same excavating condition, the shorter the midline distance, the bigger the ground settlement; and when the former is longer than 16m, its effects on the latter level off; using the two-hole shield tunneling, the plan when holes on the both sides tunneling in the mean time benefits more in controlling the ground settlement than that of doing it one by one; and the application of Grey Theory in forecasting the ground surface settlement in a certain spot at different time is feasible.更多还原