Heng Yang Area Of Rural Highway Pavement Disease Analysis And Structure Optimization Research

In recent years, rural road construction in Hengyang has been developing rapidly, however, constrainted from topography, geology, climate, technology and traffic volume, different regions of rural highway pavement structure tend to be different. After using a few years, many diseases such as off the board, the roadbed collapse, dislocation, mud and arch appeared in part of the rural roads. It not only has a bad influence on the operation of rural highway safety but also restricts the development of local economy.Therefore, adopting measures suiting local conditions and seeking for economic, reliable, durable and suitable pavement structure of rural road in Hengyang is inevitable.Hengyang area is located in the south of Hunan province. The muggy rainy climate causes highway disease such as mud, roadbed landslide and pavement suspending.Through the investigation on geographical environment, the use of materials, economy and transportation environment, roadbed width, step with the structure, construction method and disease characteristics in Hengyang area. Explore road materials as well as construction conditions used by the rural roads and survey the size of rural highway traffic volume and possible traffic type, Analysis of the Cause of the highway diseases and the situation of the pavement structure. On the basis of the cement concrete pavement at home and abroad, using ABAQUS finite element software modeling, setting foundation assumption for the winkler foundation, analyzing the sensitivity of the typical IV parameters of concrete pavement and the stress value in Hengyang area, we find following conclusions:(1) the survey data shows that all road diseases for some reasons :non-standard construction, unreasonable structure design, large traffic volume, overload, and muggy rainy climate, which caused pavement suspending. Under the combine action of vehicle load, temperature and humidity, pavement structure diseases arise.(2) the greater of the panel thickness, layer thickness, the cushion thickness, modulus of soil base and modulus of base layer, the less of concrete pavement slab bottom on-board stress. Panel thickness should be not less than 20 cm; in poor foundation conditions and serious water disease road section, we should carry on the foundation reinforcement and set cushion layer in order to improve the foundation conditions;(3) Panel stress value increase as the increasing size of concrete slab void in condition of concrete slab void,that has seen an even greater rise when overload;(4) On the basic analysis of the status quo of rural highway in Hengyang as well as the typical pavement structure finite element, the rural road pavement structure is optimized. Several rural highway pavement structures which are suitable for humid and rainy environment under different traffic classes in Hengyang city within economical consideration are recommended. a). The number of standard design period cumulative axle 20 ~50 million times, The recommending pavement structure is 23 cm concrete +15cm cement stable macadam +10cm Graded Macadam. b). For 3 ~20 million times, the recommending pavement structure is 22 cm concrete +15cm cement stable macadam +10cm Graded Macadam, when subgrade condition Is good and the cost of construction is limited, 23 cm concrete +15cm cement stable macadam can be adopted. c). For 0.5~3 million times, the recommending pavement structure is 21 cm concrete +15cm cement stable macadam +10cm graded Macadam, when subgrade condition is good and the cost of construction is limited, 21 cm concrete +18cm cement stable macadam can be adopted. d). When less than 0.5 million times, the recommending pavement structure is 21 cm concrete +15cm graded Macadam, when subgrade condition is good and the cost of construction is limited, 22 cm concrete + leveling layer can be adopted.