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。
Research purposes： Mechanical properties of Tertiary silty clay change greatly in different moisture conditions. The main purpose of the study is how to effectively combine the numerical simulation monitor with site monitoring measuring to determine the reasonable supporting time and appreciate measures to ensure the tunnel passing through the terrestrial layer smoothly. Research conclusions： （1） Through the analysis of numerical simulation, during the tunnel construction, stress of surrounding rock will redistribute, strengthen of soil will greatly reduced because of leakage, deformation will increase. Primary support can effectively control the deformation of surrounding rock, therefore reasonable process should be planned to ensure the primary support in time. （2） After testing and analysis, we know that with the increase of moisture content of surrounding rock, rock elastic modulus, cohesion and internal friction angle will become smaller, and the deformation of the support structure will increase. Therefore, in order to guarantee the safety during construction, reasonable support measures according to different moisture content should be used and the working faces should be closed timely. （3） During the construction, dynamic design should be done based on the supervision data to determine the reasonable time of the lining. Generally, it is better to do the secondary lining after 20 days, because the surrounding rock stress and deformation tend to be stable after 20 days. （4） The research results will be a reference for the design and construction of tunnel passing through the similar formation.
出处
《铁道工程学报》
EI
北大核心
2017年第2期59-64,共6页
Journal of Railway Engineering Society
关键词
重载铁路
隧道
第三系粉质黏土
支护结构
力学特性
heavy haul railway
tunnel
Tertiary silty clay
supporting structure
mechanical properties
