综合物探法在铁路基底岩溶探测的应用研究

发布时间：2018-03-08 01:08

本文选题：岩溶　切入点：铁路基底　出处：《成都理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着我国铁路建设步伐的加快,在建设的过程中,不可避免的会建设越来越多穿越复杂岩溶地质条件的铁路线。这些线路的修建,当遇到某些复杂山地地形条件影响时还需要开挖隧道。为保障岩溶区铁路安全,对沿线的铁路进行勘察,查明岩溶发育位置,排除岩溶对铁路安全产生的影响。本文结合工区地质情况、地球物理特征与存在的限制条件排除其他岩溶物探方法,选取了高密度电法、探地雷达法、地震映像法、瞬态瑞雷面波法进行研究和应用。岩溶与地下水存在着密切的联系,溶洞或富水地质体与正常围岩存在着较大的电阻率差异,高密度电法可以较直观、准确的反映地下电阻率的分布和变化规律,是探测岩溶的有效方法;电磁波在不同介质中具有不同的传播和衰减规律,探地雷达法通过向地下脉冲电磁波对地下介质进行探测,其中岩溶洞穴中的空气或水与围岩介质存在较大波阻抗差异,这也使得探地雷达法能有效的探测岩溶洞穴。岩溶构造形成的空洞、破碎结构,使其与周围介质产生较大的弹性差异,通过研究弹性波的特征,地震映像法可以有效的发现地下溶洞。由于岩溶一般为充填松散黏性土溶洞、充水的溶洞及无填充的溶洞,在这些溶洞处的面波相较于围岩的面波,其波速较低,一般为低速体,所以可以通过面波来进行岩溶的有效探测。对不同填充型的溶洞进行了高密度电法、探地雷达法及地震映像法的数值模拟,并对其表现特征进行了分析和总结。通过将物探方法和工程地质情况的结合、方法优缺点结合及长短结合、物性参数的综合这三方面来考虑,选取最合适的综合及组合方法来满足探测要求,通过综合或组合物探的联合解释来提高探测精度,减少单一物探存在的多解性。通过上述研究,提出了针对工区岩溶探测的地球物理方法及最佳工作参数选择;对铁路基底岩溶进行了地球物理方法探测,进行了分析和解释,解释后对异常部位打钻验证,总结出了在特定地质条件下物探原始数据采集方法技术、工作参数选择及数据处理的解释方法。经过综合物探法的综合解释与打钻验证情况,证明采用综合物探方法进行铁路基底岩溶洞穴探测相对于单一方法具有更强的适应性和准确性,克服了单一物探方法存在的多解性,同时相比于其他勘察手段,物探方法具有勘探成本相对较低、勘探效率高和探测信息量丰富的特点。
[Abstract]:With the acceleration of railway construction in China, it is inevitable that more and more railway lines will be built through complex karst geological conditions in the process of construction. In order to ensure the safety of railway in karst area, the railway along the line is surveyed to find out the location of karst development. In this paper, combined with the geological conditions of the working area, geophysical characteristics and restricted conditions are excluded from other karst geophysical prospecting methods, and the high density electrical method, ground penetrating radar method and seismic mapping method are selected. The transient Rayleigh surface wave method is studied and applied. There is a close relationship between karst and groundwater, there is a great difference in resistivity between karst cave or water-rich geological body and normal surrounding rock, and high density electrical method can be more intuitionistic. Accurately reflecting the distribution and variation of underground resistivity is an effective method to detect karst, electromagnetic wave has different propagation and attenuation law in different media, ground penetrating radar method detects underground medium by means of underground pulsed electromagnetic wave. The difference of wave impedance between air or water in karst cave and surrounding rock makes the ground penetrating radar method can effectively detect the cavity and broken structure formed by karst structure. By studying the characteristics of elastic waves, the seismic mapping method can effectively find underground caverns. Because karst is usually filled with loose clay caverns, water-filled caverns and unfilled caverns can be found. Compared with the surface waves of surrounding rock, the surface waves in these caverns are relatively low in velocity and generally low in velocity, so they can be effectively detected by surface waves. The high density electric method for different filled caverns is carried out. The numerical simulation of ground penetrating radar method and seismic mapping method is carried out, and its characteristics are analyzed and summarized. By combining the geophysical prospecting method with the engineering geological conditions, the advantages and disadvantages of the method are combined with the length and length of the method. Considering the three aspects of the synthesis of physical parameters, selecting the most suitable synthesis and combination method to meet the detection requirements, and improving the detection accuracy through the combined interpretation of synthetic or combined geophysical exploration. Through the above research, the geophysical method for karst exploration in the working area and the selection of the best working parameters are put forward, and the geophysical method for detecting the karst in the railway basement is analyzed and explained. After interpretation, the paper summarizes the original geophysical data acquisition technology, the selection of working parameters and the interpretation method of data processing under specific geological conditions. After comprehensive interpretation and drilling verification of comprehensive geophysical exploration method, It is proved that the comprehensive geophysical exploration method is more adaptable and accurate than the single method in detecting the railway basement karst cave, which overcomes the existence of multiple solutions of the single geophysical prospecting method, and at the same time, it is compared with other prospecting methods. Geophysical exploration method is characterized by relatively low exploration cost, high exploration efficiency and abundant exploration information.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U212.22;P631

【引证文献】