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Based on the temperature load on the wall slab of a large aqueduct when the temperature suddenly drops, the temperature self-confinement stress of the upper surface of the concrete slab was tested and analyzed. The temperature difference between upper and lower surfaces of concrete slabs at different cooling rates and the self-constrained principal stress of concrete slab surface temperature at 1 h at a cooling rate of 10 ℃/h were measured. The accuracy of finite element modeling was verified by comparing the numerical value of concrete transient temperature stress simulated by finite element method with the experimental test data. On this basis, the influence of cooling rate on transient temperature and stress field of aqueduct was analyzed. The impact of different insulation materials on surface temperature and stress field of aqueduct was discussed. The results show that the temperature tensile stress on the aqueduct surface will increase at a faster rate with the increase of the ambient temperature decreasing rate. Compared with the external surface temperature stress of the aqueduct without insulation measures, the tensile stress of the external surface temperature of the U-shaped aqueduct was reduced by 83%, 80% and 68%, respectively, when the polyurethane, polystyrene board and vitrified microbeads with 2mm thickness were adopted. Considering the cost and construction technology, vitrified microbead insulation materials are more suitable as thermal insulation materials on the outer surface of aqueducts.
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| 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 |
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