Study On The Loading Performance Of Long And Steep Longitudinal Slope Sections Under Heavy Truck

In recent years, many highway construction projects are focused in mountain area inChina. And a lot of sections have been constructed whose gradient is big and slope length islong. Seen from the survey of constructed highway, serious premature destroy has appeared inthese sections, especially rut and slippage. So the premature destroy must be related with theload characteristics of the steep and long longitudinal slope, the steep and long longitudinalslope pavement bear not only the vertical direction force, but also the much bigger horizontalforce than flat pavement. Furthermore, the speed of vehicle moving on the steep and longlongitudinal slope is always decline, especially heavy truck. So the time of load on thepavement becomes longer, the steep and long longitudinal slope pavement much more easilybe destroyed. This paper mainly research the characteristic of speed and the characteristic ofload.Firstly, based on the automobile dynamic theory and multi-body system dynamic theory,consider of the engine’s characteristics and the regular of shift,1+2and1+2+5truck modelsare set up in the multi-body system dynamic simulation software ADAMS which are suitableto the steep and long longitudinal.Secondly, study on the speed characteristic by using the1+2and1+2+5truck model.Taking the truck of DONG FENG EQ1108G and DONG FENG EQ4163W+DONG FENGEQ9280P for example, The influences of axle load, entrance speed, grade and gradelength,pavement unevenness on the truck speed are analyzed. Based on the above analysis,the control indicators of grade and grade length are put forward, and then a function model onthe relationship between grade and grade length is built up. The result could provide referencefor route design of highway in mountain area.Thirdly, study on the truck dynamic characteristic by using the1+2and1+2+5truckmodel. Taking the truck of DONG FENG EQ1108G and DONG FENG EQ4163W+DONGFENG EQ9280P for example, The influences of axle load, entrance speed, grade and gradelength,pavement unevenness on the truck vertical dynamic load coefficient and horizontaldynamic load coefficient are analyzed. The rate of change of horizontal dynamic load coefficient is put forward which aim at special case, the result could provide theory referencea certain extend for structural design of asphalt pavement of highway in mountain area.