At the start of the new year, as everyone welcomes the arrival of 2016, the Shandong Provincial Geological Prospecting Machinery Factory brings good news: its fully hydraulic multifunctional piling rig LGZ-40 has succeeded in cement composite soil mixing pile construction at a site in Dezhou, achieving effective coordination between pipe piles and cement-soil piles, reducing the cost per unit bearing capacity of the piles, and providing a new tool for pile foundation construction.

The Dezhou Development Zone site is a community construction project. The site terrain is flat and the stratum distribution is stable: the upper layer is miscellaneous fill, and the lower layers mostly consist of Quaternary Holocene alluvial cohesive soil, silt, and sand. For the cement-soil composite pipe pile construction, the fully hydraulic multifunctional piling rig LGZ-40 first drills in with a bore diameter of 800 mm and a hole depth of 26.2–28.5 m, taking about 2 hours. Three hours after the hole is formed, a static pile driver presses in a 400 mm diameter precast cement pile to a depth of 18.2 m.

Pressing in the precast pile

Bearing capacity test of cement composite pipe piles at the site

Bearing capacity test of ordinary static pressed piles at the site

The fully hydraulic multifunctional piling rig is a product independently developed by the Shandong Geological Prospecting Machinery Factory and has obtained a national invention patent. The rig is mainly used for bored cast-in-place pile construction in foundations for high-rise buildings, high-speed railways, expressways, and other projects. It can construct various pile types, including screw piles, bidirectional spiral soil-displacement piles, large-diameter rotary jet mixing cement-soil composite pipe piles, and large-diameter long spiral CFG piles penetrating into rock. It offers reliable pile quality, high efficiency, low noise, and no mud circulation, is unaffected by groundwater, and is especially suitable for urban infrastructure construction.