隧道穿越第三系粉质黏土支护结构受力研究

发布时间：2018-08-15 16:30

【摘要】：研究目的:第三系粉质黏土在不同含水量状态下的力学特性发生较大的变化,如何有效地运用数值模拟、现场监控量测相结合的方法,使得工程中采取合适的措施、合理的支护时机来确保顺利通过该类地层是本文研究的主要目的。研究结论:(1)通过数值模拟分析,隧道开挖后围岩应力发生重分布,渗水导致土体强度大大降低,变形加大,初期支护能有效地控制围岩的变形,因此在隧道施工中应合理安排工序,及时地施作初期支护;(2)通过试验分析,随着围岩含水量的增加,围岩弹性模量、黏聚力及内摩擦角都逐渐变小,支护结构变形增大,因此应根据不同的含水量采取相应的支护措施,并及时封闭掌子面以保证施工安全;(3)施工中应根据监控量测数据进行动态设计,合理确定衬砌施作时机,总体上20 d后围岩受力及变形趋于稳定,施作二次衬砌较为适宜;(4)该研究成果可为隧道穿越同类地层的工程设计与实践提供借鉴和参考。
[Abstract]:Objective: the mechanical properties of Tertiary silty clay have changed greatly under different water content. How to effectively use the method of numerical simulation and field monitoring and measurement to make the appropriate measures be taken in the engineering? The main purpose of this paper is to ensure the smooth passage of this kind of stratum with reasonable timbering time. The conclusions are as follows: (1) through numerical simulation and analysis, the stress of surrounding rock is redistributed after tunnel excavation, the soil strength is greatly reduced and deformation is increased due to water seepage, and the initial support can effectively control the deformation of surrounding rock. Therefore, in the tunnel construction, the working procedure should be arranged reasonably and the initial support should be carried out in time. (2) with the increase of the water content of surrounding rock, the elastic modulus, cohesion and angle of internal friction of surrounding rock become smaller, and the deformation of supporting structure increases. Therefore, corresponding supporting measures should be taken according to different water content, and face of face should be closed in time to ensure construction safety; (3) dynamic design should be carried out according to monitoring and measuring data in construction, and reasonable timing of lining construction should be determined. On the whole, the stress and deformation of surrounding rock tend to be stable after 20 days, and it is more suitable to make secondary lining. (4) the research results can provide reference and reference for the engineering design and practice of tunnel passing through similar strata.
【作者单位】：铁道第三勘察设计院集团有限公司;
【分类号】：U455.7

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