天池坪隧道水压致裂法地应力测量及三维地应力场宏观扩展分析

发布时间：2018-03-12 19:31

本文选题：隧道工程　切入点：天池坪隧道　出处：《硅酸盐通报》2017年01期 　论文类型：期刊论文

【摘要】：天池坪隧道是兰渝铁路兰州至广元段的一座特长单线隧道,位于甘肃省宕昌县境内,全长14.528 km。选择4个测孔、26个试验段进行水压致裂地应力测量。天池坪隧道各测点的共同特征是现今应力场以水平应力为主导,应力量级属于极高应力水平。最大主应力方向为北北西-北西-北西西向,与宏观应力场方向吻合。LY1测点的最大水平主应力方向为N40°W~N45°W,与隧道轴线方向夹角较大,对隧道围岩稳定不利。结合实际的地质条件和地层参数,在实测地应力结果的基础上,采用三维有限元多元回归分析方法,扩展分析隧道区域原始宏观地应力场。宏观地应力场的分析结果表明,隧道轴向位置的横向应力值大于10 MPa,横向侧压力系数处于1~2之间,且局部地段因地形等因素引起的应力集中而导致横向侧压力系数偏大。宏观地应力场的分析结果对工程设计与施工具有重要参考价值。
[Abstract]:Tianchiping Tunnel is an extra long single-line tunnel between Lanzhou and Guangyuan of Lanzhou-Chongqing Railway. It is located in Dangchang County, Gansu Province. The total length is 14.528 km. 4 holes and 26 test sections are selected to measure the in-situ stress induced by hydraulic fracturing. The common feature of the measuring points of Tianziping Tunnel is that the stress field is dominated by horizontal stress. The maximum principal stress direction is NNW-NW-NW direction, and the maximum horizontal principal stress direction is N40 掳WN45 掳W, which is consistent with the macroscopic stress field direction, and the angle between the maximum principal stress direction and the tunnel axis direction is larger, the maximum principal stress direction belongs to the extremely high stress level, and the direction of the maximum principal stress is NNW-NW-NW, and the maximum horizontal principal stress direction coincides with the macroscopic stress field. Combined with the actual geological conditions and formation parameters, based on the measured results of in-situ stress, the three-dimensional finite element multivariate regression analysis method is adopted, which is unfavorable to the stability of the surrounding rock of the tunnel. The results show that the transverse stress in the axial position of the tunnel is greater than 10 MPA, and the lateral pressure coefficient is between 1 and 2. Because of the stress concentration caused by topography and other factors, the lateral pressure coefficient is larger. The analysis results of macroscopic geostress field have important reference value for engineering design and construction.
【作者单位】：兰州交通大学土木工程学院;中铁第一勘察设计院集团有限公司;西北民族大学;长江科学院;
【基金】：国家自然科学基金(51268031) 铁道部科技开发计划项目(2009G009B4) 甘肃省基础研究创新群体(145RJIA332)
【分类号】：U452.1

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