摘要
以狮子洋隧道砂性地层段地质条件和施工资料为基础,建立有限差分数值计算模型.通过比较不同断面监测点随开挖进程的位移值,结果表明:先掘隧道围岩向中心收缩,上下部围岩变形明显大于两侧;后掘隧道对先掘隧道有横向外挤的作用,但对纵向几乎没有影响.对有、无渗流作用的2种工况的比较分析说明,起初渗流对围岩变形影响不大,但最终加剧了围岩的变形程度.提出了开挖面前方土体扰动的累积效应和累积效应曲线的确定方法,通过该曲线可确定土体扰动范围和程度,经过理论分析,认为影响土体位移速率的2个因素是土体与开挖面间距和盾构推力.
Based on the geological conditions and construction data in the sandy stratum of Shiziyang tunnel, the numerical model was established. By the comparison on the displacement of monitoring points in different sections during the excavation, it concluded that： the surrounding rock of the antecedence tunnel shrink to the centre, and the deformation of the top ＆ bottom rock is obviously larger than that of the two sides. The antecedence tunnel has applied external force on the later ttlnnel; however, it has applied little longitudinal force. By the comparison on the two conditions with seepage and without seepage, it concluded that the early effects of the seepage are limited, but the deformation of the surrounding rock is aggravated to a large extent eventually. The method was put forward to determine the cumulative effects and cumulative effect curves of the soil disturbance in front of the excavation face, and the disturbance scope and extent were determined by the cumulative effects curves. Finally two factors affect the soil displacement rate were obtained, there were the distance between the soil and the excavation face and shield thrust.
出处
《湖南科技大学学报（自然科学版）》
CAS
北大核心
2011年第4期37-42,共6页
Journal of Hunan University of Science And Technology：Natural Science Edition
基金
铁道部科技研究开发计划重点项目(2006G007-E)
关键词
盾构围岩
砂层
数值模拟
累积效应
tunnel surrounding rock
sandy stratum
numerical simulation
cumulative effects
