| Karst geological hazards develops well in Shan Dong Province, such asunderground karst cavity, soft rock strata and unfavorable geology, the existenceof these makes a threat to pile foundations’ stability and safety.By researching the mechanism of tube wave spreading, this paper discussedgeneration mechanism, reflection propagation rule, particle displacement,amplitude, frequency, energy attenuation characteristics of tube wave. Throughintroducing and analyzing numerical simulation of tube wave propagation, thepaper point out the characteristics of tube wave probing profiles when differentgeohazards exists, makes scientific theoretical foundation for tube wave probingresult analysis and interpretation. Karst probe experiment in pile position wasimplemented, applied by tube wave probing tube well of water feed in JinanNational Games Village.In pile position karst probing, tube wave prospecting can find out karst,erosion, development of soft rock strata and integrity of supporting course underthe drill effectively, rapid and precisely. According the prospecting result we cantake measures to avoiding drill collapse, surface collapse and pile enginecollapse，put an end to potential safety hazard such as semi rock embedding, karstin supporting course, to guarantee investigation quality. According to geologicalcondition and requirement, detectability and range can be improved by changingtransmission frequency of hypocenter. The reflection characters of abnormalbodies in probing profile are visual and clear, data processing and datainterpretation simple and convenient. |
