浅埋地下大跨空间的合理结构体系研究

深圳某大型地下轨道交通枢纽,位于城市主干道下,为地下3层4线换乘枢纽站,总深度30 m;枢纽呈“十”字形,横向长880 m,纵向长222 m,“十”字交叉处为公共区;公共区覆土2 m,公共区负一、二层核心区抽柱形成长、宽48 m跨度的大空间中庭,中庭范围外柱距12 m,中庭顶板开直径12 m大洞口。为确定安全稳妥、可实施性好、实施风险小的中庭结构方案,本文通过3种结构体系的有限元计算来进行比选。计算结果表明,平顶正交梁结构不能满足承载力要求,折板结构和拱形结构体系的受力性能好,满足承载力及正常使用的要求,其中,拱形结构尤其是交叉蝴蝶拱结构体系中不仅受力性能好,而且具有更好的建筑艺术效果。通过本文比选结构方案的结果,对浅埋地下大跨结构具有一定的工程参考价值。

Research on the Reasonable Structure System for Shallow Buried-long Span Underground Structures

A large underground railway transit hub with 4 lines transfer, locating under the main urban road, is a three layers underground station whose total depth is 30 m in Shenzhen. The shape of the hub looks like a “+”,whose lateral length is 880 m, and longitudinal length is 222 m , and the interchange of “+” is a public area. The depth of the soil on the public area is 2 m. In the center of the public area ,we bring into being a large atrium and its span reaches 48 m including length and width by removing columns. The column axle spacing is 12 m out of the atrium and there is a diameter 12 m big round hole on the roof of central atrium. In order to determine the safety, feasibility and risk management of the atrium structure scheme, we compare the pros and cons of three structural systems through finite element calculation. The calculation results show that ceiling and orthogonality beams structure can’t meet the requirement of bearing capacity, in addition, the folded plate structure and arch structure have an excellent mechanical behavior as well as meet the bearing capacity and normal use requirements. The arch structure, especially the crossed butterfly arch structure, not only has an excellent mechanical behavior but also has a better architectural effect. By comparing the results of the structural schemes, this paper has certain reference value for the shallow buried-long span underground structures.