TBM隧道围岩损伤区范围及渗透特性研究

发布时间：2018-05-19 18:28

本文选题：TBM + 花岗岩　；参考：《高校地质学报》2017年01期

【摘要】：开挖损伤区不仅对一般工程的稳定性具有重要影响,同时其渗透特性变化也是一些特殊工程(如高放废物地质处置工程)关心的重点。该文结合桓集隧道四标段工程,通过在隧道洞壁取样而后进行室内超声波波速和渗透试验测试的方法,研究了TBM开挖隧道围岩的损伤区范围和渗透特性变化,同时也对样品洞壁端面的粗糙程度进行了量测,结果表明:(1)该隧道围岩强度较高,且工程区地应力属于低—中等水平,围岩损伤主要由TBM开挖造成。(2)隧道围岩的原岩波速在4713~5376 m/s之间,损伤区波速在2943~4856 m/s之间,围岩质量较好处的原岩波速和损伤区波速均大于围岩质量较差处的对应值,而围岩质量较差处的最大波速降比比围岩质量较好处的数值略大;各样品的损伤区范围在11.0~52.0 mm之间,一般围岩质量越好,损伤范围越小。(3)围岩质量较好处的原岩和损伤样品渗透率均小于围岩质量较差处的对应样品值;同一岩芯的损伤样品渗透率大于原岩样品,本次研究的机械开挖损伤使围岩的渗透率提高1.94~3.75倍。(4)研究的隧道表面波谷和峰高范围在-5~4 mm之间,满足SKB对处置孔壁粗糙程度的要求。
[Abstract]:Excavation damage zone not only has an important influence on the stability of general engineering, but also the change of permeability characteristics is the focus of some special projects (such as geological disposal of high-level radioactive waste). In this paper, the damage zone and permeability characteristics of the surrounding rock of the tunnel excavated by TBM are studied by taking samples from the tunnel wall and testing the velocity and permeability of the ultrasonic wave in the laboratory, combined with the fourth section of Huanji tunnel. At the same time, the roughness of the end face of the sample wall is measured. The results show that the surrounding rock strength of the tunnel is high and the in-situ stress in the engineering area is of low to medium level. The damage of surrounding rock is mainly caused by TBM excavation.) the original wave velocity of tunnel surrounding rock is between 4713 ~ 5376 m / s, and the wave velocity of damage zone is between 2943 ~ 4 856 m / s. The wave velocity of the original rock and the damaged area are both higher than the corresponding value of the poor mass of surrounding rock. The maximum velocity drop ratio of surrounding rock mass is slightly larger than that of surrounding rock mass, and the damage zone of each sample is between 11.0 mm and 52.0 mm, the better the mass of surrounding rock is. The smaller the damage range is, the smaller the permeability of the original rock and the damaged sample is smaller than the value of the corresponding sample where the surrounding rock mass is poor, and the permeability of the damage sample of the same core is larger than that of the original rock sample. The damage caused by mechanical excavation in this study increases the permeability of surrounding rock by 1.94 ~ 3.75 times. (4) the range of surface wave trough and peak height of the tunnel studied is -5mm, which meets the requirement of SKB for the rough degree of the disposal hole wall.
【作者单位】：南京大学-华东有色地勘局地下空间与地质环境研究所;北京工业大学城市防灾与减灾教育部重点实验室;
【基金】：国家自然科学基金课题(41172241;41372266) 国防科技重点项目(科工二司[2012]492号)联合资助
【分类号】：U451.2

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