Uniformity evaluation standard of subgrade based on reliability

A new uniformity evaluation method of subgrade was proposed based on reliability.A 2D finite element model was established to compute the reliabilities of asphalt pavements with different moduli and variation coefficients by using Monte Carlo Method.A division basis of the reliabilities was set down based on the research on the influence of the coefficients on pavement reliabilities.Computation result shows that the coefficients are 0.05 and 0.10 as the critical values of reliabilities are 95% and 90% for expressway and first class highway.The coefficients are 0.05 and 0.15 as the critical values are 90% and 85% for second class highway.The coefficients are 0.15 and 0.25 as the critical values are 85% and 80% for third and fourth class highways.Subgrade uniformities are divided into three grades when 90% and 95%, 85% and 90%, 80% and 85% are taken as the evaluation standards of subgrade uniformities for different highways.