Research purposes: With the continuous development of the mountain rail transit in China, there is an urgent demand for laying turnouts on steep slopes.At present, China lacks construction experience in laying turnouts on steep slopes, and the slope limit that can be adapted to various turnoutsis lack of in-depth research.From the perspective of track geometry state control, the formula for calculating the branch line cross leveldeviation and lead curvereverse superelevation of turnouts on large slopes was derived.On this basis, the slope limits of different types of turnouts were proposed.The research results can be used to guide the design of mountain railway and rack rail railway in China.
Research conclusions: (1) The branch line cross level deviation and lead curve reverse superelevation of turnouts are equal to the product of the gauge, the sine value of switch angle and the sine value of slope angle. (2)From the perspective of track geometry state control, it is suggested that the slope limits of No.9, No.12 and No.18 turnouts should be 13‰, 16‰ and 24‰ respectively, and the slope limit of No. 7 turnout of rack railway should be 14‰. (3)The research results have guiding significances for the design of mountain railways and rack railways and the compilation of relevant codes.