【作者】 易长平；

【导师】 卢文波；

【作者基本信息】 武汉大学 ， 水工结构工程， 2005， 博士

【摘要】 在水利水电工程中,存在大量的地下洞室开挖,越来越多的水电站采用地下厂房。地下洞室工程在其它领域也有广泛的应用。由于地下洞室主要采用钻爆法施工,不可避免地存在爆破开挖对邻近已开挖洞室和开挖洞室本身的影响问题。因此,研究爆破振动对地下洞室的影响,不仅具有重要的理论意义,同时也具有重要的工程意义。 本文主要研究爆破振动对邻近地下洞室和本洞围岩稳定性、混凝土衬砌及砂浆锚杆的影响。 利用波函数展开法,分析了爆破地震波与邻近圆形洞室的相互作用,讨论了洞径、入射波频率、围岩类型等因素对圆形洞室动态响应及安全振速的影响;利用保角变换方法,推导了不同频率的爆破地震波以不同角度入射于不规则洞室时,洞室围岩的应力和位移的一般解,并以直墙拱形洞室为例,求解了其围岩的应力和振速分布规律,进而求出其安全质点振速;采用复变函数法和多极坐标移动技术研究了爆破振动作用下浅埋圆形洞室的动力响应,研究了自由面的存在对地下洞室动力响应的影响。 研究了爆破振动对新浇混凝土衬砌的影响,采用有限元法求出了圆形洞室新浇混凝土衬砌内温度和温度应力在空间上的分布及其随时间的变化,采用波函数展开法求解了爆破地震波与有衬砌圆形洞室的相互作用,获得了考虑新浇混凝土衬砌内温度应力前提下不同龄期的新浇混凝土衬砌的安全振速;利用保角变换研究了爆破振动对直墙拱形有衬砌隧洞的影响,得到了爆破地震波以不同角度入射时混凝土衬砌的安全振速。 利用三维动力有限元,研究了地下洞室爆破开挖对本洞室围岩及喷射混凝土的影响,确定了喷射混凝土的安全距离,比较了掏槽孔、最外圈崩落孔和周边孔起爆时围岩的动态响应。 利用波函数展开法,研究了爆破地震波与砂浆锚杆相互作用的机理,推导了爆破地震波作用下锚杆、砂浆以及围岩内的应力和位移表达式,根据砂浆边界上的应力和振速分布,确定了不同爆破地震频率下砂浆的安全振速范围。更多还原

【Abstract】 In the construction of water resources and hydropower engineering, a lot of underground chambers and tunnels are to be excavated and more and more powerstations employ underground powerhouse. Underground chambers are also adopted widely in other fields such as mining, transportation and national defence engineering etc. The influence of blasting vibration on existed adjacent underground chambers or surrounding rock mass of the tunnel under excavating is inevitable if the method of blasting is employed for excavation. So the study of the influence of blasting vibration on underground chambers is of great importantance both in theory and practice.The influences of blasting vibration on the stability of surrounding rocks mass and concrete lining of existed adjacent chambers, or excavating tunnel and the grouted rockbolts are studied and analyzed in the thesis.The wave function expansion method is used to analyze the interaction of blasting seismic wave and the adjacent chambers, the influences of such factors as the radius of tunnel, the frequency of incident blasting seismic wave, rock mass types etc, on dynamic response and safe peak partical velocity (PPV)of circular tunnel are discussed. The conformal mapping method is adopted to deduce the general solution of stress and displacement of arbitrary shape tunnels under the acting of the incident blasting seismic wave with different frequency and incident angle. Taking the arch tunnel with vertical sidewalls as the example, the distribution of stress and vibration velocity of rock mass is presented and analyzed, and then the safe peak particle vibration velocity is decided. The multi polar coordinate transform and complex function are used to study the dynamic response of shallowly buried circular tunnels under the blasting vibration. The influence of free surface on tunnels is discussed.The influence of blasting vibration on fresh concrete lining is studied. The finite element method (FEM) is employed to analyze the spatial distribution of temperature and thermal stress of fresh concrete lining, the wave function expansion method is used to study the interaction of blasting seismic wave and the circular tunnel with lining, thenthe safe PPV of fresh concrete lining with different age is decided by taking into account the thermal stress of concrete lining. Using the conformal mapping method, the influence of blasting vibration on the arch tunnel with lining is studied and the safe PPV of concrete lining is deduced under different incident angle.The numerical simulation method of dynamic FEM is employed to study the influence of the excavation of blasting vibration on surrounding rock mass and shotcrete of the tunnel itself under excavating, the safe distance for shotcrete is decided. The different responses of surrounding rock mass of tunnel caused by cut-hole blasting, production blasting and perimeter blasting on the excavating chambers are alse compared.The stress wave theory and wave function expansion method are used to analyze the interaction mechanisms of blasting seismic wave and the grouted rockbolts and deduce the analytical solution of stress and displacement of rockbolt, grout and rock mass body. Based on the stress and velocity calculated, the safe PPV for grouted rockbolt is decided.更多还原