The Probe Technology and Counter Measures of Goaf of Colliery Area in Tongluoshan Tunnel

During the construction of Tongluoshan Tunnel of the 6th light rail line in Chongqing, collapse of goaf of colliery area occurred which affects the construction and permanent safety heavily. Advanced geological prediction were done with ground penetrating radar to probe the goaf’s location, scale and characters of underground water and filling articles, then countermeasures such as advanced pipe roof supporting, goaf stowing, wall rock and filling articles’ voids grouting was applied；after that，supporting plan was adjusted to ensure construction safety with the data from monitoring whose result proves the availability of above prediction technology and countermeasures to similar goaf.