A new explosive method for soil improvement

A highway was constructed in Jiangxi Province, China, through a mountainous area. Some sections of the highway went through valleys where a soft clay layer 6–8·5 m deep was encountered. A new explosive method was developed and adopted for this project. The method uses the energy of the explosion to remove the soft clay and replace it with crushed stones. Explosive charges are placed in the soil to be improved according to a specific pattern. Crushed stones are piled up next to the area where the charges are installed. The explosion creates cavities in the soil and causes the pile of crushed stones to slide into the exploded area. The detail of the method and its application to the highway project are described. The effectiveness of the method is evaluated using borehole exploration, plate load tests and groundprobing radar tests.