Through technological research of foundation treatments in the collapsible loess areas

we recommend a method of treating foundations in collapsible loess with quicklime piles. We set forth the basic principle of this expansive method. When a very thick foundation in collapsible loess is treated

the computational formula for the volume of expanding material in a quicklime pile is deduced based on cavity expansion theory. This theory is applied to engineering practice. Physical and mechanical properties of the compacted soil are tested. The result shows that the collapsibility of a foundation in loess has been eliminated

its physicomechanical indexes have been improved

and the soil compressibility and the modulus of compressibility also increase remarkably

demonstrating the correctness of the computation theory. The feasibility of the expansive method for very thick collapsible loess areas is further established.