Research And Application Technology About The Stiffness Instrument Of Soil Modulus Controlling The Variability Of Subgrade Construction

The quality variability of road construction is always present. It is the variability of building materials and construction that causes the pavement diseases which occurs at different areas and periods. It is important and significance to reduce the variability of engineering quality and promote the lower limit quality of construction for prolonging the service life of pavement.Although the importance of quality is stressed during the current quality management of highway engineering, there haven't produced a kind of new idea that takes special engineering measures to reduce or control the quality variability. The assessment of engineering quality is often done based on the existing construction level and in recognition of the quality status. If the variability is not reduced, the quality fluctuation range then cannot be lowered, and the disease occurrence of pavement can't be slowed, accelerating the early damage, reducing the investment efficiency, and producing the negative social influence.The construction of subgrade as an example was presented in this study. The H -4140 soil stiffness/modulus tester was employed to determine resilience modulus of subgrade. The construction variability of subgrade is understood timeliness by the "2 sigma" principle of mathematical statistics. And the necessary measures, such as local rolling, and changing the filling materials are taken in time according to the variability to solve the weak of local stiffness of subgrade, and reduce or even eliminate the hidden dangers, guaranteeing the high quality project of road engineering construction. Through the real-time detection of characteristic parameters of subgrade construction process and timely evaluation construction variability, the construction defects should be found in time, so as to take actions to correct the quality defects, to improve quality parameters, ensuring road overall construction quality and the stability of behavioral parameters, and enhancing the service level and the service life.