大底盘多塔结构的住宅小区，可以在建筑物之间的地面设置庭院、道路和绿化，地下部分设计为地下车库，用以解决逐渐突出的绿化与停车的矛盾问题。地下车库作为建筑物的附属建筑，已经成为必不可少的配套设施，但在地下车库设计过程中，由于车库顶板结构形式和覆土厚度的差异，设计规范对消防车荷载的规定比较模糊，有必要进行深入研究。 论文根据《建筑结构荷载规范》关于消防车荷载的相关规定，考虑等效均布荷载的条件、最不利布置，进行理论计算，分析荷载与板跨、覆土厚度的关系，结合有限元分析软件，研究了单、双向板在不同板跨及覆土厚度作用下的等效取值范围，得到不同工况下消防车等效均布活荷载的合理取值。 研究结果表明，现有荷载规范对地下车库消防荷载的取值规定过于笼统，并且在跨度较小、覆土厚度较薄的情况下，板上等效均布活荷载取值偏小。在足够覆土条件下，单、双向板的等效均布活荷载可按竖向轮压荷载统一取值 。 根据《汽车库建筑设计规范》之相关规定，参照其他相关规范条文，考虑汽车运行规律，对比常用柱网取值，通过理论计算，得到了柱网优化的建议参数。 以某工程实例为背景，对主次梁结构、反梁结构、井字梁结构、空心楼盖和无梁楼盖等几种车库顶板结构方案的经济性能进行对比分析，讨论了各方案的优劣，并对组合楼盖体系做了简要的介绍。

Residence communities with multi-tower structure and enlarged base have already became essential building facility. They take the advantage of the courtyards’ underground parts to form a space, in where underground garage can be designed to solve the increasingly prominent contradiction between greening and parking. However, during the design process, because of the differences between the roof structure of garage and the thickness of covering earth, as well as the vagueness in fire load description of our design specifications, it is necessary to make an intensive of it. In this paper, considering from relevant provisions of the fire load in “Loading code for design of building structures”, and the fact of the equivalent uniform live load and its most unfavorable arrangement, we can get the reasonable value of fire loading under different conditions through the way of theoretical calculations, relationship analysis of load, cross-board as well as the thickness of covering earth with the help of the FEM analysis software and the equivalent value range of one-way slab and two-way slab from a situation of small span and laminated covering earth. The results show that the present load code for the fire loads of underground garage are too general, and the value is also less than normal value on the condition of small span and laminated covering earth. If there is sufficient covering earth, the equivalent uniform live load of one and two-way slab could be collected from the load of vertical wheel, that is . Based on the principle of the “Code for design of garage buildings” as well as other relevant provisions, it is essential to combine the Vehicle Operation Law with the contrast of common column values to achieve the purpose of optimizing column grid through theoretical calculations. Then, this paper, taking an example of certain project, makes a contrastive analysis of the economic perfor By these examples, this paper will give a brief introdction of composite slabs. mance of several garage roof structure, such as principal and subordinate-beam structure, inverted beam structure, cross beam structure, hollow slab structure and the flat slab structure. Through the study of the optimization design of underground garage, the author hope that it will give some help in selecting schemes of underground garage.