Addressing the challenge of shallowburied box tunnel machine passing under significant risk sources, this study takes the closerange underpass of the expressway by the underground passage box tunnel machine at Sanyuanqiao Station of Beijing Subway Line 12 as the background. Numerical simulation was used to precisely model the roadbed pavement structure layer of the expressway and simulate the entire construction process of the underpass. The ground surface deformation patterns caused by the box tunnel machine under the expressway were analyzed, and a parameter sensitivity analysis was conducted on construction parameters such as the support pressure at the pipe head, ground loss, and grouting pressure during the pipe jacking construction. Finally, video monitoring was used to monitor and verify the settlement of the expressway. The results show that the ground surface deformation caused by shallowburied box tunnel machine can be summarized into three stages: slight surface uplift, rapid surface settlement, and final settlement stabilization. Changes in ground loss and grouting pressure are the most sensitive to settlement variation. The established numerical model can reflect the basic patterns of surface deformation caused by pipe jacking construction, as indicated by onsite video monitoring data. The maximum settlement of the highway surface meets the control standard of ≤15 mm.
| 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 |