隧道地震超前预报技术的数值模拟研究

发布时间：2018-05-25 07:00

本文选题：隧道地震预报 + TSP　；参考：《西南交通大学》2015年博士论文

【摘要】：近年来,国内铁路、公路、水电等工程的深埋长大隧道施工中,隧道地震超前预报技术(TSP)已成为进行地质预报的主流方法。但是目前的文献主要着眼于对其实际应用效果分析,而对隧道复杂条件下的波场特征的理论认识,以及波场分离、速度分析和偏移成像等核心处理技术的有效性和影响因素的研究和分析方面,少见公开发表的相关研究成果文献。因此,展开隧道地震超前预报技术的数值模拟研究,提高隧道地质超前预报的准确率,具有十分重要的工程应用背景。同时,对于促进隧道地震超前预报方法的发展也具有重要的理论意义。本文的主要采用ANSYS有限元数值模拟软件对TSP隧道地震波全波场进行二维数值模拟,研究地震波传播在遇到不良地质体及隧道结构界面时,波的传播和转换模式的波场特征；基于数值模型研究了TSP系统中主要的核心处理技术：掌子面前方有效反射波提取技术以及速度分析和偏移成像技术；数值模拟和工程实际结合,研究分析数据采集中围岩松动圈中传感器埋深对接收信号的影响特征。主要的研究内容如下：文中首先对隧道工程中常见的地质灾害进行了分析归纳。对常见的重要煤层瓦斯、断层、高地应力、溶洞等地质病害的施工中的工程地质特征进行了详细的介绍。重点分析了断层和溶洞这两类典型隧道地质病害的工程地质和地球物理特征。基于地震波场理论和ANSYS软件动态结构分析模块,实现了二维隧道地震波场的数值模拟。较系统的对不同产状的断层模型,如直立单层、直立多层、倾斜60°、倾斜30°等模型的隧道地震波场进行数值模拟,分析其在隧道地震波场传播和记录特征。对不同尺度的溶洞模型,如3m,20m半径的溶洞的隧道地震波场进行数值模拟,分析其波场的传播和记录特征。研究中还重点对RSSR波的传播和记录特征进行了分析研究。为开展TSP中的波场分离、偏移归位方法等核心技术的数值模拟研究和评价奠定了可行性基础。首先通过对Radon变换的基本原理分析和讨论,分析和探讨了其在隧道地震超前预报波场分离中的应用基础。基于断层数值模型,研究分析和评价了了TSPwin中离散线性Radon变换的τ-p变换的应用有效性,影响因素和处理参数选取。研究表明,线性Radon变换可以用于分离反射波。从900、600、300这三个模型分离的反射波可以看到,直立情况F分离的最好,30。倾斜分离的最差。主要是由于直立或陡立模型的时距关系为线性,Radon变换时也是线性变换,分离效果相对较好。当模型为倾斜时,其时距关系为双曲,但处理中采用的Radon变换是线性的,故其分离效果较差。对于溶洞模型,τ-p变换的波场分离也存在强的干扰波,但随着溶洞的直径接近或大于第一菲尼尔带时,溶洞趋近于反射体,排列接收到的反射波能量越来越强,此外,还基于RSSR的动力学特征,对P-S波的空间方向滤波方法进行了研究,并对引入的空间方向滤波方法的可信性进行了分析和评价。将反射波滤波角度设为900,可以有效消除干扰波,分离P波和S波。且对溶洞模型而言,速度分析云图可以提供比较准确的定位。分析和讨论了速度分析和偏移成像基本原理。依据几何地震学的原理,研究和分析了隧道地震超前预报中基于反射界面与此检波器和各个炮点之间的时距关系的速度分析和偏移成像技术。基于数值模型研究和评价了断层和溶洞不良地质体的速度分析和偏移成像的有效性和影响因素。研究表明,对于直立断层模型,TSPwin提取的反射层位与模型实际层位基本一致,倾斜断层模型及溶洞模型均相差较大,这可能是前期波场分离时采用线性Radon变换所致。速度云图可以比较准确的对空洞定位。在速度分析和偏移成像网格划分时,对隧道地震超前预报来说,按照默认值1m来设置即可满足要求。基于数值模拟和工程实际相结合,研究分析了震源在松动圈内埋设与松动圈外埋设时的地震波场。依据检波器埋设的不同,组成四种情形的时间记录,采用TSPwin对时间记录进行了处理,提取到其相应的反射界面。研究表明：当震源与检波器都在或者其中之一在松动圈时,经过TSPwin软件处理提取到的反射界面位置比实际位置偏后。最后,应用前面章节的研究成果到实际工程的地质超前预报中,通过预报结果与开挖结果的对比,两者具有良好的符合性,提高了隧道地质超前预报准确率。进一步验证了研究成果有效性。
[Abstract]:In recent years, the tunnel earthquake prediction technology (TSP) has become the main method for geological prediction in the construction of deep and long tunnel construction in railway, highway and hydropower projects in China. However, the current literature mainly focuses on the analysis of its practical application effect, and the theoretical understanding of the wave field characteristics under the complex conditions of the tunnel and the separation of wave fields, The research and analysis of the efficiency and influencing factors of the core processing techniques such as velocity analysis and migration imaging are seldom published. Therefore, it is very important for the engineering application background to develop the numerical simulation of the tunnel earthquake prediction technology and improve the accuracy of the tunnel geological prediction. It is also of great theoretical significance to promote the development of the tunnel earthquake prediction method. In this paper, the ANSYS finite element numerical simulation software is used to simulate the two dimensional numerical simulation of the full wave field of the TSP tunnel seismic wave. The wave propagation and the wave propagation mode wave is studied when the seismic wave propagation is encountered in the bad geological body and the tunnel junction interface. Field characteristics; based on the numerical model, the main core processing techniques in the TSP system are studied: the effective reflection wave extraction technology in front of the face of the palm and the velocity analysis and migration imaging technology, and the combination of the numerical simulation and the engineering practice. The main characteristics of the influence of the embedded depth of the sensor in the surrounding rock loose circle on the received signal are studied and analyzed. The research contents are as follows: firstly, the common geological hazards in tunnel engineering are analyzed and summarized. The engineering geological characteristics of the common important coal seam gas, fault, highland stress, karst cave and other geological diseases are introduced in detail. The engineering sites of two typical tunnel geological diseases, such as faults and karst caves, are emphatically analyzed. Based on the theory of seismic wave field and the dynamic structural analysis module of ANSYS software, the numerical simulation of the two-dimensional tunnel seismic wave field is realized. The numerical simulation of the tunnel seismic wave field of different modes, such as vertical single layer, vertical multi layer, 60 degree tilt and 30 degrees, is simulated and analyzed in tunnel. Seismic wave field propagation and recording features. Numerical simulation of tunnel seismic wave fields of different scales, such as 3M and 20m radii, is carried out to analyze the propagation and recording characteristics of the wave fields. The study also focuses on the propagation and recording characteristics of RSSR waves. The feasibility foundation of the numerical simulation research and evaluation of heart technology is laid. First, the basic principle of Radon transformation is analyzed and discussed, and its application foundation in the wave field separation of the tunnel earthquake prediction is analyzed and discussed. Based on the numerical model of the fault, the tau -p transformation of the discrete linear Radon transformation in the TSPwin is studied and evaluated. The application validity, the influence factor and the processing parameter selection. The study shows that the linear Radon transformation can be used to separate the reflected waves. The reflection waves separated from the 900600300 three models can be seen that the erect case F separation is best and the 30. tilt separation is the worst. The main reason is that the time distance relation of the erect or the steep model is linear, and the Radon transform is When the model is inclined, the time distance relation is hyperbolic when the model is inclined, but the Radon transformation used in the treatment is linear, so the separation effect is poor. For the karst cave model, the wave field separation of the tau -p transformation also has strong interference waves, but as the diameter of the cave is close to or larger than the first Phoenix belt, it dissolves. The cavity is closer to the reflector and the reflected wave energy is getting stronger and stronger. In addition, based on the dynamic characteristics of RSSR, the spatial direction filtering method of P-S wave is studied and the credibility of the proposed spatial direction filtering method is analyzed and evaluated. The filtering angle of the reflected wave is set to 900, which can effectively eliminate the interference wave. Separation of P and S waves. And for the karst cave model, velocity analysis can provide more accurate positioning. The basic principle of velocity analysis and migration imaging is analyzed and discussed. Based on the principle of geometric seismology, the relationship between the reflection interface and the time distance between the geophone and the various gun points in the tunnel earthquake prediction is studied and analyzed. Velocity analysis and migration imaging technology. Based on the numerical model, the validity and influence factors of velocity analysis and migration imaging of faults and karst cave bodies are studied and evaluated. The study shows that for the vertical fault model, the reflection horizon extracted by TSPwin is consistent with the actual base of the model, the oblique fault model and the cave model are homogeneous. The difference is larger. This may be caused by linear Radon transformation in the early phase separation. The velocity cloud map can be more accurate for the cavity location. When the velocity analysis and migration imaging grid are divided, the default value 1m can be set up to meet the requirements. The seismic wave field which is buried outside the loose circle in the loose circle is analyzed. According to the difference of the geophone embedding, the time record of four cases is formed. The time record is processed by TSPwin and the corresponding reflection interface is extracted. The study shows that when the source and detector are in or one of them are loosened, TS The location of the reflected interface extracted by the Pwin software is less than the actual position. Finally, using the research results of the preceding chapters to the geological prediction of the actual project, the comparison between the prediction results and the excavation results has a good coincidence, which improves the accuracy of the tunnel geological prediction. Further verification has been made of the research results. Efficiency.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U452.11;P631.4

【参考文献】