裂隙岩体隧道渗流场特征研究

发布时间：2018-11-11 16:30

【摘要】：采用数值分析方法,对高水压富水区裂隙岩体隧道渗流场进行分析。根据裂隙岩体隧道的特点,结合三维离散元软件3DEC的功能特性,建立三维离散元模型。首先,研究了裂隙的不同产状与裂隙岩体等效渗透系数的关系。在假定为光滑、平行裂隙的基础上,建立了相应的数值模型并进行运算。结果表明,通过3DEC软件计算出来的裂隙岩体等效渗透系数与用渗透系数张量公式计算出来的结果非常一致。因此,当假定裂隙为光滑、平行时,可通过渗透系数张量来研究裂隙产状对渗流场的影响,可使模型简化、运算效率提高。在此基础上,建立了隧道主要施工过程(开挖、喷混凝土、衬砌)中渗流场的数值模型,对隧道开挖、喷混凝土、施作二衬后的渗流场进行了数值模拟,并分析了其变化特征。最后,采用施作喷混凝土后的裂隙岩体隧道数值模型,分析了围岩裂隙宽度、注浆圈厚度、注浆圈渗透系数及喷混凝土渗透系数等因素对裂隙岩体隧道渗流场的影响。结果表明,裂隙宽度在一定范围内(0.2 mm~1.8 mm)变化时对影响较小;注浆圈的厚度及其渗透系数是影响渗流场的关键因素,在一定范围内(注浆圈厚度为0~8 m;注浆圈等效渗透系数为0~2.0×10-7 m/s)对喷混凝土背后水压力及隧道渗水量影响非常显著,超出此范围后,影响减弱;喷混凝土的渗透系数也是影响渗流场的重要因素,它对背后水压力和隧道渗水量的影响同注浆圈渗透系数的影响一样,在一定范围内(0~4.0×10-8 m/s)影响显著,超出4.0×10-8 m/s后,影响减弱。
[Abstract]:The seepage field of fractured rock mass tunnel in high water pressure and rich water area is analyzed by numerical analysis method. According to the characteristics of fractured rock mass tunnel and the functional characteristics of 3D discrete element software 3DEC, a 3D discrete element model is established. Firstly, the relationship between the occurrence of fractures and the equivalent permeability coefficient of fractured rock mass is studied. Based on the assumption of smooth and parallel fracture, the corresponding numerical model is established and calculated. The results show that the equivalent permeability coefficient of fractured rock mass calculated by 3DEC software is in good agreement with that calculated by Zhang Liang's formula. Therefore, when the fracture is assumed to be smooth and parallel, the influence of fracture occurrence on seepage field can be studied by the permeability coefficient Zhang Liang, which can simplify the model and improve the operation efficiency. On this basis, the numerical model of seepage field in the main construction process of tunnel (excavation, shotcrete, lining) is established. The seepage field of tunnel excavation, shotcrete and two-lining is simulated numerically, and its variation characteristics are analyzed. Finally, the influence of the crack width, the thickness of grouting ring, the permeability coefficient of grouting ring and the permeability coefficient of shotcrete on the seepage field of fractured rock mass tunnel is analyzed by using the numerical model of fractured rock mass tunnel. The results show that the thickness of grouting ring and its permeability coefficient are the key factors affecting seepage field in a certain range (0. 2 mm~1.8 mm), and the thickness of grouting ring is 0 ~ 8 m. The equivalent permeability coefficient of grouting ring is 2.0 脳 10 ~ (-7) m / s). The permeability coefficient of shotcrete is also an important factor affecting the seepage field. The influence on the back water pressure and tunnel seepage is the same as that on the grouting ring permeability coefficient, and in a certain range (0 ~ 4.0 脳 10 ~ (-8) m / s), the influence is significant. After 4.0 脳 10 ~ (-8) m / s, the effect weakened.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U451

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