Structural Optimization of Pavement Overlay of the Rock-filled Road Subgrade with Hardened Layer in the Bridge Precasting Yard
Taking the rock-filler subgrade with hardened layer of the bridge precasting yard of a high-way in Guangdong as the research object,this paper proposes the technology of utilizing the hardened layer in the bridge precasting yard.The optimization design and mechanical response analysis of the pavement overlay structure on the hardened layer are carry out.The results show that the measured bending and settlement value on the top surface of the hardened layer of the bridge precasting yard is smaller than the rhythmic bending and settlement value without the hardened layer of the bridge pre-casting yard,with an average value of 1.71×10-2 mm.Its equivalent rebound modulus of the top sur-face is much larger than the maximum equal rebound modulus of a rock-filled subgrade under the same elevation,the hardened layer,can be directly used and adds the pavement structure on top of the hardened layer.Based on the indoor dynamic triaxial test,the material modulus of the rock-filled subgrade is determined to be 308 MPa,PFWD measured the top surface equivalent rebound modulus of rock-filled subgrade without the hardened layer is 116 MPa.The equal rebound modulus of the top surface of the hardened layer of the bridge precasting yard is 1173 MPa.The equivalent rebound mod-ulus of the top surface of the rock-filled subgrade with hardened layer of the bridge precasting yard is 314 MPa.The verification and calibration of the optimization scheme of the hardened layer pavement of the girder yard meets the specification requirements,indicating that the optimized design of the hardened layer pavement of the girder yard is feasible,and the optimized scheme has the best me-chanical performance of CRC+AC composite pavement overlay structure,which can be use as the rec-ommended scheme for pavement overlay structure in physical engineering.
rock-filler subgradeutilization of hardened layer in the beam yardpavement overlaymechanical behavior analysisfinite element method