In response to the increasing speed and strict requirements for bridge smoothness in the design of railelevated bridges, this study is based on the design of the elevated bridge of Beijing Metro Line 22 at a speed of 160 km/h. A new type of adjustable height device is developed and designed based on a lowmeltingpoint alloy as the height adjustment medium. A series of experimental studies are conducted, including the structural design of the device, indoor temperature and pressure tests, fullscale pressure adjustment performance tests of the compression shear machine, and onsite beam erection tests. The findings indicate that the new adjustable height device enables stepless bidirectional height adjustment with a rapid adjustment speed, completing height changes within 30 s. The device achieves millimeterlevel accuracy, and the alloy demonstrates excellent stepless adjustment performance and compression stability once cooled and solidified. The accuracy and stability of this adjustable height device not only ensure the smoothness of elevated bridge beams but also offer valuable guidance for engineering applications, such as replacing deteriorated bearings and adjusting for differential settlement in bridges.
| 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 |