Method for testing compactness of pre-paved ballast track bed

The invention relates to the field of foundation compactness testing, in particular to a method for testing compactness of a pre-paved ballast track bed, including the steps of carring out plate loadtest on test surface of test site to obtain foundation coefficient K of the test surface of test site, and substituting foundation coefficient K into polynomial regression equation p=AK2+BK+C to obtain compaction density po. The polynomial regression equation is obtained by the following steps: carrying out plate load test on a plurality of samples taken from the test site to obtain the foundationcoefficient K = theta/S; testing the above samples by both irrigation and sand pouring methods, and then obtaining the average value of the results of the two tests to obtain the compaction density Rho; taking the foundation coefficient K and compaction density Rho as the transverse and longitudinal coordinates respectively to establish the coordinate system, and fitting the discrete points linearly to obtain the polynomi