Field tests on improvement of collapsible loess by vibratory probe compaction method

The improvement of collapsible loess is one of the technical problems in the development and construction of western China. The collapsible loess covers a large area, and there are many ground treatment projects under construction. The vibratory probe compaction method is first proposed to treat collapsible loess. During the project of Zhongwei-Lanzhou high speed railway, the technology of pneumatic vibratory probe compaction method to treat collapsible loess is proposed by using the self-developed vibratory probe compaction equipment, and the treatment effect is evaluated. The results of the in-situ and laboratory tests show that the collapsibility of subsoil is eliminated after treatment, with an average collapsibility coefficient of 0.003. The cone resistance, sleeve friction and SPT blow counts in the treated soil are significantly higher than those before treatment. Moreover, the surface wave velocity of subsoil increases by 15% and its physical and mechanical properties are also significantly improved. The vibratory probe compaction method is effective for the treatment of collapsible loess. The new construction technique is energy-efficient, environment-friendly, fast in construction and low-cost, and it can be applied in loess areas.