The SDDC pile construction for 60,000 tons carbon electrode project is located in Lanzhou City, Gansu Province, invested by Lanzhou Dongjin Carbon-based New Materials Co., Ltd. A total of 3,135 SDDC piles were completed, with a pile treatment depth of 15m, a borehole diameter of 1,200mm, and a tamping expansion to 1,800mm.
The stratigraphic distribution of the project is as follows: plain fill, loess-like chalk, gravelly sand, cementation layer, highly weathered mudstone, and moderately weathered mudstone. According to the investigation report, the fill soil is randomly filled without layering and compacting, and the fill soil is also loess, and the design requires the complete elimination of wet subsidence of foundation soil through foundation treatment. This project adopts the Super down-hole dynamic consolidation (abbreviated as SDDC method), which is a combination of high kinetic energy, ultra-pressure, and strong compacting effects, and completes the foundation treatment of various soils, such as miscellaneous fill, wet loess, and so on. This technology brings the tamping kinetic energy into the depth of foundation through the hole, and carries out high kinetic energy, ultra-pressure, strong compacting down-hole dynamic consolidation with the shaped heavy hammer on the filler in layers from the bottom to the top, so as to make the filler in the hole compacted and consolidated along the vertical depth and at the same time to carry out the transverse strong compacting consolidation on the soil around the piles. It is conducive to the close contact between the pile and the soil between the piles, increasing the friction force between each other, and the overall stiffness after foundation treatment is uniform, high bearing capacity, high deformation modulus, and small settlement deformation.
The SDDC pile construction for 60,000 tons carbon electrode project started on May 24, 2023 and concluded on June 23, 2023. After SDDC pile treatment, the loess problem of this project can be improved, and the bearing capacity of foundation is enhanced. This method is characterized by high efficiency and short construction period. The recycled loess was resourced and the project expenditure was reduced.
