This paper proposes a nonlinear spring restraint structure to overcome the limitations of the static thrust test method in evaluating underground structure systems. Considering the difficulties of soil-structure interaction, high costs, and limited observability of test phenomena, the proposed approach integrates basic principle of the reaction displacement method for underground structures. It recognizes that the traditional elastic spring fails to capture soil state changes during loading, thus prompting the introduction of a more dynamic spring-structure system. It suggests using nonlinear springs instead of soils for analyzing seismic performance. Through Pushover analysis on a single-span underground structure model, the influence of factors such as the axial compression ratio and spring-structure interaction on mechanical performance is investigated. Comparing bending moment capacity curves of key sections shows that the static thrust overlay model for spring-underground structures is suitable for seismic analysis of underground structures. Up to an inter-story displacement angle of 1/200, both the linear and nonlinear spring models are highly accurate, but beyond this threshold, the nonlinear spring model is significantly superior. The simplified analysis method for seismic performance of nonlinear spring-underground structure systems provides insights into the complex force behaviors of underground structures.
| 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 |