Applied Research of Carrier Pile in Pebble Stratum in Caotang Area of Fengjie

As a new form of pile foundation, carrier pile has been widely used in engineering in recent years. Its basic principle is to tamp the hole through column hammer and tamp the soil layer and filler below the pile end to form a composite bearing body, so as to greatly improve the vertical bearing capacity of single pile. At present, the carrier pile has achieved some research results in sandy soil, cohesive soil, silt and soft soil, but there is less research in pebble stratum. Taking the carrier pile project of a standard plant as an example, the design and construction of carrier pile in pebble stratum in Caotang area were studied, and the stress mechanism of carrier pile combined with the load test results was analyzed. The results show that the carrier pile using pebbles as the bearing layer has good applicability in the Caotang area of Fengjie. Static load tests and settlement observations indicate that the carrier pile has good bearing performance and is a safe and economic foundation form. the Q-s curve is generally of slow variation type, indicating that the stress form of carrier pile in pebble stratum is closer to that of end bearing pile. The applicability of carrier pile in pebble stratum is closely related to pebble composition and gradation. Large particle boulder in soil may hinder the tamping of column hammer. Pile test and advance geological drilling should be carried out before construction.