Force Analysis Of Prefabricated Concrete Slab For Prefabricated Road Base

Traditional subgrade structures made of crushed stone and cement can cause serious noise pollution during construction,which can affect nearby residents.In contrast,prefabricated road base can be prefabricated indoors in a production line,which is not constrained by external environmental factors.This ensures the quality of the prefabricated road base and reduces pollution to the environment,while also accelerating the construction speed and allowing for faster opening of traffic.Currently,most research on prefabricated road base on finite element simulation analysis and related experiments on materials,but there are relatively few studies on mechanical testing of prefabricated road base.To improve the accuracy of prefabricated road base research,a combination of testing and finite element analysis was used to analyze the stress of prefabricated cement concrete subgrade slabs.A 1:3 scale model of the prefabricated road base was designed and manufactured,and static loading tests were conducted to analyze the effects of load position and load level on the mechanical behavior of the prefabricated subgrade.Based on the experimental results,a finite element model of the prefabricated road base was established using ABAQUS software,and the finite element calculation results were verified with the experimental results.Using the verified finite element model,the effects of bottom voids on the concrete prefabricated slabs were analyzed,and the effects of changes in the prefabricated slab modulus,prefabricated slab thickness,and soil modulus on the mechanical behavior of the subgrade concrete prefabricated slabs were studied.The main research results are as follows.(1)Under load,the maximum tensile strain at the bottom of prefabricated slab and the deflection at the load application point of the slab increase with increasing load,and the maximum tensile strain varies approximately linearly with load,while deflection increases significantly under heavy load.The single point load application position has a greater influence on the deflection of the prefabricated base,while the double point load application position has a smaller influence,and the strain of the prefabricated slab is significantly affected by the load application position.(2)The results of the finite element model and the experimental results were compared,and the calculated strains and deflections of the prefabricated base finite element model were in good agreement with the experimental results,which fully verifying the accuracy and feasibility of finite element calculations.The influence of voids radius on the mechanical behavior of prefabricated base prefabricated board is greater than that of voids depth,and the position of the void at the bottom of the slab does not have a significant effect on the mechanical behavior of the prefabricated road base.(3)The results of the finite element model calculations indicate that changes in the thickness of the prefabricated slab have the most significant effect on the mechanical behavior of the concrete prefabricated slab,followed by changes in the elastic modulus of the prefabricated slab and relatively smaller changes in the elastic modulus of the subgrade.Increasing the thickness of the prefabricated slab,elastic modulus,and subgrade elastic modulus is beneficial for reducing the maximum tensile strain and deflection at the load application point of the prefabricated road base,improve the carrying capacity of the prefabricated road base.