某大型城市地下空间项目楼板应力分析

Floor stress analysis of a large city underground space project

大型城市地下空间结构平面尺度大、功能多样,结构楼板在温度作用、楼板开洞等复杂因素的影响下呈现出较为复杂的应力状态。以某大型地下空间项目为例,对地下结构温度荷载取值需要考虑的因素进行了详细的介绍,采用MidasGEN建立了有限元模型,对超长结构在温度荷载作用下的楼板应力进行了分析。同时,针对地下室顶板开设较大的洞口,对土压力作用下洞口周边板带的受力进行了较为深入的研究。结果表明:在温度作用下,结构楼板在较大洞口周边、墙体转角处存在应力集中的现象,在下沉广场处温差较大,楼板应力相对较大,结构设计应进行有针对性的加强。在土压力的作用下,局部板带呈现出平面内受弯的受力特点,应加强楼板的配筋构造,对靠近洞边区域楼板根据计算应力进行配筋设计。有关分析方法和结论可供同类工程项目参考。

The large-scale urban underground space structure has a large plane scale and diverse functions.The structural floor presents a more complex stress state under the influence of complex factors such as temperature action and floor openings.In this paper,taking a large underground space project as an example,the method of calculating the temperature load of underground structure is introduced in detail.The finite element model is established by Midas GEN,and the floor stress of superlong structure under temperature is analyzed.At the same time,in view of the large opening of the basement roof,the stress of the plate belt around the opening under the action of earth pressure is studied in depth.The results show that under the action of temperature,the structural floor has stress concentration around the larger hole and at the corner of the wall.The temperature difference at the sinking square is large,and the stress of the floor is relatively large.The structural design should be strengthened in a targeted manner.Under the action of earth pressure,the local slab presents the stress characteristics of in-plane ben-ding.The reinforcement structure of the floor should be strengthened,and the reinforcement design of the floor near the edge of the hole should be carried out according to the calculated stress.The analysis method can be used as a reference for similar projects.