A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pr...A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mmx28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.展开更多
The multiplication of heavy vehicle axles and road overloads are phenomena that are becoming increasingly important on the road network of the WAEMU community. These phenomena, although framed by standards, have an im...The multiplication of heavy vehicle axles and road overloads are phenomena that are becoming increasingly important on the road network of the WAEMU community. These phenomena, although framed by standards, have an impact on the durability of pavements. In this manuscript it is a question of evaluating the life of the road under the effect of traffic of these multi-axle vehicles and the different tolerances of overloads observed on the road network. To achieve this, a modeling of a bituminous pavement was made with the software ALIZE Lcpc Version 231 based on the principle of the French method of sizing. An inventory of multi-axle heavy goods vehicles was also made on a road with a weighing station. This traffic counting made it possible to classify heavy goods vehicles into three categories, namely: 1) trucks, 2) dual-wheeled semi-trailers and 3) single-wheeled semi-trailers. The results obtained show that in terms of aggressiveness, single-wheeled semi-trailers are the most aggressive, followed by heavy goods vehicles in the category of trucks with more than five axles and semi-trailers with dual wheels with more than seven axles. The durability of the road depends on the aggressiveness of heavy goods vehicles, it was found that the tolerance threshold for overloads of 15% of the total permissible rolling weight (TARW) or the total permissible laden weight (TALW) currently granted in the Community area needs to be reviewed. For durable road surfaces, this tolerance may only be allowed for heavy goods vehicles of type P11, P12 and P13. The 5% tolerance can be applied to all vehicles except heavy goods vehicles with single wheels.展开更多
文摘A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mmx28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.
文摘The multiplication of heavy vehicle axles and road overloads are phenomena that are becoming increasingly important on the road network of the WAEMU community. These phenomena, although framed by standards, have an impact on the durability of pavements. In this manuscript it is a question of evaluating the life of the road under the effect of traffic of these multi-axle vehicles and the different tolerances of overloads observed on the road network. To achieve this, a modeling of a bituminous pavement was made with the software ALIZE Lcpc Version 231 based on the principle of the French method of sizing. An inventory of multi-axle heavy goods vehicles was also made on a road with a weighing station. This traffic counting made it possible to classify heavy goods vehicles into three categories, namely: 1) trucks, 2) dual-wheeled semi-trailers and 3) single-wheeled semi-trailers. The results obtained show that in terms of aggressiveness, single-wheeled semi-trailers are the most aggressive, followed by heavy goods vehicles in the category of trucks with more than five axles and semi-trailers with dual wheels with more than seven axles. The durability of the road depends on the aggressiveness of heavy goods vehicles, it was found that the tolerance threshold for overloads of 15% of the total permissible rolling weight (TARW) or the total permissible laden weight (TALW) currently granted in the Community area needs to be reviewed. For durable road surfaces, this tolerance may only be allowed for heavy goods vehicles of type P11, P12 and P13. The 5% tolerance can be applied to all vehicles except heavy goods vehicles with single wheels.
