Research On The Special Soil Subgrade-Resilient Modulus Of The Scene Rapid Detection In The Highway Of Rui Gan

Subgrade resilient modulus is one of the main parameters of the structural design of road surface.Because by the soil,water content,degree of compaction,test methods and many other factors, make it more difficult to determine the value ,and bring a lot of the uncertainties problems to design and construction. The quality of Subgrade construction will direct effect the overall quality of the road,once the Subgrade have quality problems, the road will make a serious disease, therefore, accurate evaluation and test the quality of Subgrade is very important. At present, there is not has more research on the subgrade resilient modulus of special soil. And there has not given the recommendation value of the special soil subgrade in the norms. Therefore, the study of the subgrade resilient modulus of special soil is also important.Portable Falling Weight Deflectometer referred to as PFWD,it is a test equipment of Dynamic load-bearing capacity,and is a new rapid detection of dynamic modulus of non-destructive testing equipment after the FWD. PFWD can be used to determine the subgrade bearing capacity, access to the dynamics of subgrade resilient modulus. Compared with the traditional detection methods,it has the feature of a short time of test,less testing personnel,simple and lightweight.This paper is based on the Highway of Rui Gan, we select some typical Sections,carried on the scene detection of PFWD for the red sandstone,gravel soil and mucking debris from tunnels,Compared with the scene plate-bearing and Benkelman Beam,we made a corresponding analysis of the relevance of indicators,and got the conversion of the different indicators. Proved the superiority of PFWD and made a range of reasonable value of the three special soil in Highway of Rui Gan.We analyzed the effect to asphalt pavement structure from the subgrade resilient modulus on theory. Through analysis the change of the subgrade resilient modulus effect on the deflection on the surface,we get the subgrade resilient modulus is the important factor for the deflection on the surface. Through analysis the change of the subgrade resilient modulus effect on the compressive strain of the top of subgrade ,we found the effect on the compressive strain was very obvious, In addition, we found the thickness of the design structural layer was reduced when the subgrade resilient modulus was increased. However, when the subgrade resilient modulus increases to a certain extent, for the thickness of the design structural layer the rate of decrease is not very clear.