To study subway turnouts’ adaptability to steep gradients, a finite element model of a metro No. 9 simple turnout was established. The main works include: (1) The train’s most unfavourable loading condition was modelled. (2) The turnout’s longitudinal displacement and stress were analysed with different gradients under the train braking load, temperature change load and a combination of the two, to determine the structure’s safety and stability under the most unfavourable working conditions. (3) The turnout structure’s cumulative longitudinal deformation under reciprocating load was studied. Both a fastener longitudinal resistance-displacement experiment under reciprocating load and a numerical simulation of No. 9 turnout modelled by the finite element modelling software, ANSYS, were carried out to study the gradient’s influence on the turnout’s longitudinal mechanical characteristics. (1) The turnout’s longitudinal displacement and stress increase linearly with an increase in gradient and temperature change, both of which are unfavourable to the turnout structure. As the gradient increases from 0‰ to 30‰, the longitudinal stress and displacement increase by more than 10%. (2) The turnout’s rail strength and displacement on a 30‰ slope under the most unfavourable load conditions are within the specification limitations. (3) Under reciprocating load, the fastener longitudinal stiffness decreases and the maximum and residual longitudinal displacement of the switch rail increase; an increased gradient intensifies these effects on the turnout.

为研究地铁道岔对陡坡度的适应性，建立了地铁9号线简易道岔的有限元模型。主要工作包括： (1)对列车最不利的装载工况进行了建模。(2)对道岔在列车制动荷载、温变荷载以及两者组合作用下不同梯度下的纵向位移和应力进行分析，确定结构在最不利工况下的安全稳定性。(3)研究了道岔结构在往复荷载作用下的累积纵向变形。为了研究坡度对道岔纵向力学特性的影响，通过往复载荷作用下的扣件纵向阻力-位移试验和有限元建模软件ANSYS对9号道岔进行数值模拟。(1)道岔的纵向位移和应力随着坡度的增加和温度的变化而线性增加，这两者都不利于道岔结构。随着坡度从0%增加到30%，纵向应力和位移增加10%以上。（2）道岔在最不利荷载工况下的钢轨强度和30%坡度位移均在规定范围内。(3)往复载荷作用下，扣件纵向刚度降低，道岔最大纵向位移和残余纵向位移增大；梯度的增加会加剧这些对投票率的影响。