Research On Gentle Slope Design Parameters Of Highway

With the rapid development of expressway, there are some continuous slope sections because of restricted natural conditions。In the mountainous highway,for the complex terrain, designer often use the abrupt slope design alternately with the steep slope in line scheme laid and longitudinal slope design in order to overcome difference level and control the project scale. This basically considering the truck moving on uphill gentle slpoe can recovery speed, Narrow speed difference between different models, Reduce traffic accidents, Improve traffic capacity; On the other hand, Considering the downhill gentle slpoe Settings in favour of control the speed limit Reduce the number of vehicle use main brake, Improve the downhill sections vehicle safety.But our current highway technical standard and road design specifications have no detailed provisions about gentle slpoe Settings, No mature study concluded. In the mountainous highway gentle slope design, Designers have no rule to abide,which lead to set parameters slope use not reasonable, could not reach the purpose of slope Settings, cannot completely meet the actual traffic capacity and driving safety requirements,so, Research the mountainous highway gentle slope design parameters, is very necessary to improve traffic capacity and safety, Also urgent need to address the problem.Based on a large collection of relevant information and literature, were studied on the mountain highway gentle slope design parameters, by analyzing longitudinal continuous uphill section on the different vehicle speed and capacity of the road, And to restore the truck's uphill speed as the starting point, Using the dynamic properties of leading model analysis and calculation method, Put forward the uphill gentle slpoe sections' grade and length design parameter values; On the analysis of the continuous downhill sections in light of the characteristics of braking performance and operation on the basis of speed, Aim for reduce the downhill speed, According to the leading car braking performance calculation, put forward downhill gentle slope sections' grade and length design parameter. Based on test the running speed of gentle slope sections data analysis, taking into account the parking ramp and a cooling pool setting requirements, respectively advance the mountainous highway slope sections of uphill and downhill gentle slope sections'grade and length design indicators suggest values, and put forward the unitary embankment slope and slope length design parameter values. Research conclusion to our country mountainous highway longitudinal slope design has certain directive significance, to "standard" revision has important reference value.