The Research And Application Of Integrated Geophysical In The Quality Inspection Of Jinping I Hydropower Dam

Hydroelectric dams, like other buildings, will also experience the process sequentially: the completion and use of buildings, gradually aging of the buildings during their service period, the failure of the buildings. Hence, the quality testing of the dam, including those that are under construction or have been built is necessary to extend the lifespan of the hydroelectric dam and obtain the effective control of the process of its demise. The efficient and economical use of geophysical methods can enable to survey and evaluate the foundation rock of the hydroelectric dam and then the suitable detective method proposed in this study can produce good economic and social benefits.Due to the complex geological conditions of Jinping Hydropower Dam, and the developed of faults, layer extrusion fault zone, joint fissure, deep cracks and so forth, the increased difficulty of the grouting technology will occur. Therefore, the safe operation of the dam will be directly influenced by the filling effects. Based on the foundation rock surface quality inspection of Jinping Hydropower dam, this study mainly focuses on the comprehensive geophysical testing of the dam foundation curtain grouting and consolidation grouting.The objective of this study is to conduct quality testing for the hydroelectric dams consolidation grouting with the detection methods of hole sonic act, seismic tomography CT, drilling TV and drilling variable modulus. In addition, the suitability and correlation of various geophysical methods are also studied and optimized.Geophysical methods can research and analysis integrated geological of the dam.the hole sonic act,seismic tomography CT method and drilling variable modulus can better reflect the physical parameters of rock and drilling TV reflect the characteristics of rock,geological defects have better reflected in the results of various geophysical methods.Hole sonic act is a double received detection technology, which has the following advantages, such as convenient layout of the detection holes, wide detection range, high detection precision, and quantitative evaluation of the quality of grouting. Additionally, the acoustic curve obtained by detection can strongly reflects in a fractured location, while it cannot reflect the structures in the parallel direction with drilling. Furthermore, the hole sonic is unable to detect the grout quality within a certain area. However, the seismic tomography CT method can detect the weakened zone and poor rock conditions between the two holes. Similarly, it also has some disadvantages, such as a large amount of data needed to be handled. Moreover, the borehole television panoramic imaging can visually observe rock mass quality classification and fractured circumstances, but it cannot quantitatively evaluate the quality of grouting. While for the drilling variable modulus, it is capable of reflecting the anti-mold deformation of rock directly. However, the detection process is considerable rigid. On the basis of the advantages and disadvantages of the geophysical methods mentioned above, quality testing of the Jinping Hydropower is conducted by using hole sonic act, which is aided by seismic tomography CT, drilling television and drilling variable modulus.