Experimental Study On Cement Concrete Pavement Force Condition In Steep Slope Road Sections Of Highway In Mountainous Areas

In Western areas of China, there are a large proportion of highway is in mountain areas. Besides the reasons of design,construction,maintenance and long-term overload ,the early damage of the pavement is also influenced by factors of Large longitudinal slope and low criterion design on alignment. The analysis of loading stress of cement concrete pavement on longitudinal slope is favorable to the precise design and construction so as to ensure the quality of cement concrete pavement in mountainous areas and promote development of cement concrete pavement.Through creating test model based on various longitudinal slopes and testing stress of cement concrete slab in the indoor laboratory, the thesis explores stress variation law of cement concrete pavement under the static load on longitudinal slope of 0%, 6%, 9% and 12% by selecting and loading corner of slab and middle of slab edge. Maximum flexural-tensile stress of slab is located in the inferior part of the middle of slab edge regardless of slope variation and it slightly decreases as slope increases.Then the paper carry through the contrast analysis about the maximum flexural-tensile stress of surface slab loading corner of slab and the maximum flexural-tensile stress of the inferior part of the middle of slab. The result indicate that in cement concrete pavement force condition in steep slope road sections, the maximum flexural-tensile stress of the inferior part of the middle of slab is bigger then the maximum flexural-tensile stress of surface slab, so it is feasible to adopt the inferior part of the middle of slab as the critical load position when design the pavement in steep slope road sections.Through mechanics analysis model based on ANSYS finite element analysis software, variation of maximum tensile stress of slab bottom and interlaminar shear stress on longitudinal slope subject to axle load is studied by applying three dimensional finite element methods. By comparing theoretical calculation results and measured results, conclusion that tensile stress increases as longitudinal slope decreases and shear stress increases as longitudinal slope increases is drawn. When the longitudinal slope increase 3%,the maximum tensile stress of slab bottom decrease 1.5%, interlaminar shear stress increase 6.5%.Therefore, the main influence factor arouse the pavement early damage in steep slope road sections is interlaminar shear stress. In the last, the paper analysis the influence factors which would arouse the stress change of cement concrete pavement in steep slope road sections, such as the thickness of surface course and base course, the modulus of resilience of base course and soil base. Then the paper put forward the reasonable advice to prevent the interlaminar shear stress become too big.