中文摘要：

为保障车辆在驶离车道而冲下边坡以及从坡下返回路面的2个过程中能维持行车稳定且不发生侧滑和侧翻,对不设护栏公路的最大边坡坡率进行了研究。采用理论推导方法,对以一定角度冲下或爬上边坡车辆的行驶受力状态进行分析,确定车辆在边坡上能稳定行驶、不发生侧滑及侧翻现象所需的条件,并对重要参数的取值范围进行了界定。通过计算分析得到不同相对加速度条件下满足车辆稳定所需的最大边坡坡率,并进一步考虑边坡附着系数的变化对坡率的影响。结果表明：满足安全条件的最大坡率应随着边坡附着系数的变小而减缓;填料级配良好且水稳定性较高的路堤,其边坡附着系数较高,最大坡率可取为1∶4;填料强度和稳定性较低且受水影响较大的路堤,其最大坡率应减小,具体可根据边坡实际条件确定。

英文摘要：

In order to guarantee the driving stability and avoid sideslip or side tumbling when vehicles plunge down the slope and return road from the slope,the maximum highway slope rate without guardrail was analyzed.The stress states were analyzed with theoretical derivation method when the vehicles plunged down or climbed the slope at a certain angle.The required conditions of vehicles driving stability on the slope were determined and the value ranges of the important parameters were defined.In addition,the maximum rate of slope to meet vehicle stability was obtained through calculation analysis under the condition of different relative accelerated speeds,further considering the influence of adhesion coefficient change on slope rate.The results show that the maximum highway slope rate meeting the security condition would become smaller with the decrease of adhesion coefficient.For the packing embankment with good gradation and high water stability,the slope adhesion coefficient is higher and the maximum slope rate can be taken 1∶4.However,for the packing embankment with worse gradation and lower water stability,the maximum slope rate should be decreased and can be determined by the actual condition of slope.