The design standards for the roadbed structure of the metro depot have not been clearly defined in the Metro design specification (2013)," and the current practice of using the main line standard results in high and unreasonable costs. This study relies on the Zhengzhou Metro Tieluxi Depot project to conduct a numerical simulation analysis of dynamic loads under different subgrade structures and to study the variation law of the dynamic load distribution. The dynamic load generated by the ballastless track at the same train speed was smaller than that generated by the ballasted track. An increase in the thickness of the subgrade surface layer has a more substantial impact on reducing the dynamic load generated by the train operation. However, an excessively thick foundation increases roadbed stiffness, which is not conducive to stress dissipation. Hence, when the foundation thickness increases to a certain extent, the effect of reducing the dynamic loads gradually becomes less significant. The numerical simulation results show that the design scheme of the metro depot subgrade can appropriately adjust the parameters on the basis of "0.3 m+0.9 m" and "0.4 m+0.7 m", ensuring that the dynamic and static stress ratio of the subgrade is strictly less than 0.2, attaining the best level of safety and economy.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |