研究目的:新疆金阳光铁路专用线主要承担沿线铁矿矿区的铁矿外运任务，项目位于新疆中部、天山中 低山地区，地形起伏大，相对高差达1 000 mm，拟建隧道大多为长大隧道，且连续设置，工程艰巨。结合金阳光 铁路专用线具体情况及运输特征，分析影响限制坡度选择的因素，最终确定金阳光铁路专用线的限制坡度，并 为类似项目的研究提供参考。 研究结论：( 1)本线通过设置回头曲线，降低最大限制坡度、隧道长度；（2)不同的限制坡度，工程投资差 异较大，通过工程投资等综合分析，研究推荐新疆金阳光铁路专用线采用“上行重车方向6‰、下行轻车方向 22‰”的限制坡度方案；（3)该研究成果能够为山区复杂地形条件下铁路限制坡度的选择积累经验。

Research purposes ： Xinjiang Jinyangguang railway special line mainly undertakes iron ore transportation task. Project is located in the centre of Xinjiang and middle - low mountains of Tianshan Mountainswith big rising and falling topography，the relative height diference of more than 1 000 m. The most of planed tunnels for the railway will be the large tunnels one after another，so it is difficult to build this railway. Ruling grade for Xinjiang Jinyangguang railway special line is determined by analyzing the factors which influence the choice of ruling grade wit!i concrete conditions of Xinjiang Jinyangguang special railway to provide the reference for the similar worlds. Research conclusions ：( 1 ) By setting switch - back curve， the maximum ruling grade and the tunnels length are reduced. (2) The ruling grade is different，the project investment is obviously different. Combining the comprehensive analysis of project cost，Xinjiang Jinyangguang railway special line has been recommended to adopt tiie ruling grade ： up line 6 ‰ and down line 22 ‰. ( 3 ) The research result can be as the basis for the selection of ruling grade for the mountain railway with the complex topographical conditions.