Study On Correction Methods For Deflection Acceptance Standards Of Highway Subgrade And Pavement In Xinjiang Region

At present, it is difficult to determine the seasonal correction factor while correcting deflection acceptance standards of subgrade and pavement in Xinjiang region. Current deflection acceptance standards did not consider sufficiently the influences of seasonal variation, the change of material strength and the different time of quality inspection. Therefore this paper put forward new corrections for highways of Xinjiang region through systemic study to solve the problem of the acceptance standards about subgrade deflection and pavement deflection in different seasons.The paper got the current status of subgrade and pavement design parameter through broad investigating of the built and building highways of Xinjiang region, and analyzed the shortage exited in current design parameters of the mostly design parameters. On the base of studying the first-order and second-order nature-divisions for highway of Xinjiang region, the paper put forward the third-order nature-divisions for highway. it researched the influence factors to the subgrade modulus of resilience, such as soil, compactness and moisture content, and found that the moisture content was the key factor which made the modulus of resilience changed by seasons. According to the indoor and outdoor tests on subgrade modulus, moisture content and deflection, the paper obtained well correlations among them. Furthermore, the paper researched the seasonal change law of the subgrade moisture content and the subgrade modulus of resilience through tracking observation with the moisture sensors while subgrade is under working condition. The paper also studied the typical semi-rigid base materials' resilience modulus change law by ages as preserving separated in standard condition and in natural conditions. On the test data analysis, it was established that relationships between the rebound modulus and the synthesis variance of ages and temperature.Finally, the paper put forward three corrections of subgrade deflection acceptance standards for highways in Xinjiang: deflection variability correction, varying moisture content contrast correction and theoretical Maximum dry density correction, and two corrections of pavement deflection acceptance standards: simplified formula correction and layer-modulus change correction.