Study on Properties of CFG Pile Composite Foundation with Large Diameter

The CFG pile is composed of cement, flyash and gravel (abbreviation CFG), the application of CFG piles with a diameter of 400 mm is a commonly used method for foundation treatment. It is suitable for the treatment plain fill with self-weight consolidated, cohesive soil, silt, sand and other foundation soil whose strength or deformation cannot meet the building load requirements. For buildings requiring high bearing capacity and with strict deformation requirements, the application of CFG piles with a diameter of 400 mm for foundation treatment cannot meet the requirements. For a building with the composite foundation bearing capacity of 600–1000 kPa and the maximum settlement of 50 mm after treatment according to the design requirements, the CFG piles with a diameter of 800 mm were used for foundation treatment, a steel stress meter was used at the pile buried depth to study the load transfer law of CFG piles, and pressure cells are buried at the pile top and in the soil between piles to study the pile-soil stress ratio of CFG piles composite foundation. The foundation deformation was studied by FLAC3D. According to the settlement observation results of the building, the maximum settlement was 23.33 mm. The load test results showed that the composite foundation bearing capacity meeted the design requirements and the maximum settlement observed was less than the design value of 50 mm.