抄録
This article presents a case history of karst cave treatment technique to mitigate possible hazards during shield tunneling in karst region with caves. A field test of shield tunneling excavation was conducted using the karst cave treatment in the karst region of Guangzhou, China. The test site is a tunnel section on Metro line 9. 98 karst caves were found along the tunnel and 13.3% of karst caves are higher than 5 m. Construction program of karst cave treatment is introduced, which includes investigation, treatment determination, grouting and effectiveness check. Field investigation includes unconfined compressive strength (UCS) of borehole samples of grouted materials, standard penetration test (SPT), core recovery (CR). All of the UCS values of the borehole samples are greater than 0.2 MPa, the modified SPT values are more than 10 and the CR values are larger than 90%. These test results demonstrate the applicability of this treatment technology in karst region.
