A Large-scale Coal Mine locates at this area. The problem of subsidence here is quite serious. Use TRANSIENT ELECTRO- MAGNETIC METHOD to analysis local geology.
The deep blue area shows low-resistivity zone which means aquifer. The rise of the level of ground water in recent years is due to excavated old tunnel. The collapsed post by this method has been confirmed by field drilling
Use stone columns as foundation. Some high-risk road decks were made of reinforced concrete to improve strength. Impregnate grout to fill possible hole under foundation and prevent future subsidence.
Cement mixing piles used to strengthen road sub-base. Designed to support road for 24 hours after subsidence. This allows remedial action(mostly grouting) to be taken.
Piles used to strengthen sub-base. Piles control settlement and prevent future subsidence.