【作者】 刘礼标；

【导师】 王成；

【作者基本信息】 重庆交通大学 ， 桥梁与隧道工程， 2009， 硕士

【摘要】 作为隧道工程的关键—围岩稳定性的分析评价是隧道工程设计、施工及后期安全有效运营的基础,围岩爆破损伤是影响隧道围岩稳定性的重要因素。爆破对围岩稳定性的影响主要体现在两个方面:一是使岩石的力学性能劣化,使岩石的强度和弹性模量降低;二是在岩体内产生裂纹或使岩体原有裂纹扩展等,从而影响岩石的完整性。按照岩石的破坏特征,爆破影响区域分成3个部分。爆破过程中形成的爆破近区(压碎区)、爆破中区(破裂区)、爆破远区(震动区)。爆破近区,围岩粉碎性破坏,可认为其损伤因子D=1;爆破中区,围岩损伤,裂纹发展,可认为其损伤因子0<D<1;爆破远区,仅引起弹性震动,可认为其损伤值D=0。作者以寸滩隧道为载体,研究爆破荷载下隧道围岩的损伤分析。本文采用爆破理论分析和数值模拟相结合的方法对寸滩隧道的实际情况进行相关的计算,结果表明:①根据岩石的破坏特征,在不考虑岩石初始损伤的情况下,采用理论方法计算得到寸滩隧道由于光面爆破而引起周边围岩的损伤范围约为炮孔半径的7~10倍。②根据现场监测结果,进行回归分析分别得到了爆破远区和爆源近区的质点峰值速度衰减公式,同时计算了在不考虑群孔影响系数的条件下,寸滩隧道光面爆破振动引起的损伤范围约为炮孔半径的6~8倍。③应用ANSYS/LS-DYNA非线性有限元程序对由于周边孔爆破对围岩和相邻隧道初期支护的损伤程度进行分析,估算得到寸滩隧道由于光面爆破引起围岩损伤范围基本为炮孔半径的5~9倍,与根据现场监测结果进行回归分析得到的损伤范围相比较误差均在15%以内。本文研究结果对合理选择爆破参数、围岩的稳定和保证邻近隧道已施作初期支护的安全起到了重要作用。更多还原

【Abstract】 Stability analysis and evaluation of the surrounding rock, as the key of the Tunnel Engineering, is the base of tunnel design, construction and its safe and effective operation. Rock blasting damage is the important factor that affects surrounding rock stability in the tunnel. Blasting influence on the stability of surrounding rock is reflected in the following two aspects. One is to deteriorate the mechanical properties of rock and reduce its strength and elastic modulus. The other is to produce cracks in the rock or expand its original cracks so that the rock integrity can be influenced. Blasting affected areas are divided into 3 parts according to the failure characteristics of the rock: blasting neighboring region (crush region), (fracture region) and blasting remote region (stretch region) during the blasting stage, and the difference of the damage is unlike. At the neighboring region, the value of the damage D can be considered as 1, and at the blasting midst region, the value of the damage D must be 0<D<l, while at the remote region, D can be seem as 0.In the thesis, The author take the example of the Cuntan tunnel to do some research on the damage analysis of surrounding rock under blast load. In the thesis, the author make some related calculation in Cuntan Tunnel by the means of combined blast theoretical analysis and numerical simulation and indicate the following three issues:①According to damage failure characteristics of rock, apart form its original damage, the damage zone by smooth blasting is about 7~10 times bigger than the diameter of explosive hole.②The results of monitoring and regression analysis indicate the attenuation formula of peak velocity of particles in different areas of blasting and the damage zone caused by the vibration of smooth blasting in Cuntan Tunnel is, without the consideration of affected coefficient of group-holes, 6~8 times bigger than the diameter of explosive hole.③After the analysis of damage extent caused by smooth blasting to surrounding rock and adjoining primary support with the help of ANSYS/LS-DYNA non-linear finite element program, the damage zone of smooth blasting is about 5~9 times bigger than the diameter of explosive hole. Deviation of damage zone is within 15 percent compared with that by the results of monitoring and regression analysis.The results of this study play an important role in reasonably choosing the blasting parameters, maintaining the stability of surrounding rock, ensuring the safety of adjoining primary support.更多还原