The invention discloses a method for compacting an
expansive soil roadbed. The method comprises the following steps: preparing test pieces by adopting a wet process, testing the CBR of the test pieces different in water contents one by one, drawing a CBR-
water content curve to obtain a curve for showing the change of the CBR of
expansive soil along with the change of the water contents
omega 1,
omega 2,
omega 3, omega 4 and omega 5, selecting a point with the CBR value being greater than or equal to 3% in the curve, wherein the
water content omega of the
expansive soil corresponding to the point is used as a control
water content of field compacted soil, and obtaining the soil sample
dry density corresponding to omega by performing a compaction test, wherein the soil sample
dry density corresponding to omega is used as a roadbed compacting control
dry density rho. Through the method, the expansive soil with the relative high
natural water content easily achieves the compaction control water content and dry density, so that the purposes of fully, reasonably and directly using expansive soil filler, guaranteeing the construction quality of the expansive soil roadbed and quickly constructing can be achieved. The method is simple, convenient to operate, good in water stability, suitable for compacting soil roadbeds manufactured by poor fine-grained soil such as expansive soil, high liquid limit soil, and red clay, and capable of greatly increasing the
utilization rate of the poor soil filler.