The applications of GPR to civil engineering in China

Chinese civil engineering has developed rapidly. At the same time, some geotechnical problems are urgently waiting to be solved. Ground penetrating radar (GPR) can be used in many ways. It is very effective in solving some engineering geological problems and detecting buried objects under the ground. Since 1989, GPR has demonstrated its ability in proving, consulting, surveying and designing over 200 key projects all over China. This includes stratigraphic division, outlining of filled stones in a muddy beach, geotechnical prospecting of old walls, karst detection in limestone terrain, cave detection, landslide and slope surveying, the division of weathering zones, onion weathering zones, fracture zones and faulted zones in granite areas, detection of buried objects (cable, metal and nonmetal pipes, channels, air raid shelters etc.) in the urban city, archaeology, tracing of ore bodies, coal measures strata division, testing of dam and grouting sites, quality checking of the surface and foundations of highways. In the field, we always conduct GPR surveys in two ways: they are the reflect profile method and the common depth profile method. With regard to the different tasks and different dielectric features of the objects, we choose different methods and different antennas to conduct the surveys. Through years of practical experience with GPR surveys, we have summed up a suit of techniques to solve various engineering geotechnical problems with GPR in China.