Analysis Model Of Void Grouting Amount Beneath The Slab For Airfield Concrete Pavement

In recent years, with the increase of annual airport run times and the operation of the large aircraft, it is serious that the voids beneath slab of airport rigid pavement. If not handled in time, the voids will easily lead to fracture and broken of the panel; and increasing voids' volume will seriously affect the quality of flight, and even great safety hidden trouble. At present, the generally analysis of voids is qualitative analysis, which always has flaws, and quantitative analysis rarely. How to accurately analyze the severity of the road surface pavement and better guide grouting repair is a big problem troubled for management department of runway. Based on extensive collection and analysis of domestic and foreign relevant data on the void beneath slab, this paper preliminary quantitative analyzed the voids for airport rigid panel.The main content of this paper includes:(1) The systematical analysis of the slab bottom cavity formation and evolution mechanism, pointed out that without considering the large area of the settlement of the foundation or foundation in karst cave and soil cave, the voids' surface should be continuous and smooth. Based on the above hypothesis, put forward the analysis method using different temperature gradient of pavement warping shape to simulate void beneath slab shape,which is unable to resolve the conflict in the past between the pavement deflection and bottom vertical void volume.(2) By numerical simulation method Void deflection plate deformation characteristics were analyzed, and concluded that the influence factors of assessed void are flat panel size,slab thickness and elastic modulus, response modulus of subgrade soil and joint load transfer capacity. On the basis of the multivariate nonlinear regression analysis to get the plate bottom vertical cavity volumeanalysis model and finally the reliability of the theoretical model was verified by the data of field drilling core and deflection detection.(3) Based on the foregoing the cavity beneath slab surface is continuous and smooth surface and bottom vertical space void volume theory analysis model, the cylinderbody integral way is used to calculating void volume of void slab. The paper further analysis the correlation between the grouting amount and rigid pavement deflection detecting parameters,and establish a reinforcement engineering quantity theory model of rigid pavement slab void.Finally, the engineering experience value of grouting was carried out to verify the reliability of the theory model.