基于高强钢筋的人防地下室顶板结构选型分析

Selection and analysis of civil air defense basement roof structure based on high strength steel bars

人防地下室顶板因设计荷载大,梁板截面配筋率高,在人防工程土建成本中占比居高不下。在合适部位采用高强钢筋,针对顶板结构布置进行选型分析,可有效减少地下室顶板造价。梳理了地下室顶板人防设计荷载与覆土厚度及板短边跨度的关系,分别从理论公式计算取值与规范查表法得到了人防荷载的大致规律。采用加腋大板、单向次梁、十字梁3种布置方案对人防地下室顶板进行了柱跨度、覆土厚度、人防荷载等的参数化分析。综合地下室净高、用钢量等因素,分析表明加腋大板布置方案最优。基于8.7m×8.7m柱跨的加腋大板方案,研究了梁、板采用高强钢筋的经济性及用钢量占比,分析表明人防荷载越大,主要受力构件采用高强钢筋等级越高越经济。

The top plate of the civil air defense basement has a high proportion in the civil engineering cost of civil air defense engineering due to its large design load and high reinforcement ratio of the beam and slab sections.Adopting high-strength steel bars at appropriate locations and conducting selection analysis for the layout of the roof structure can effectively reduce the cost of the basement roof.The relationship between the design load of civil air defense on the basement roof and the thickness of the soil cover and the span of the short side of the slab was sorted out,and the approximate law of civil air defense load was obtained from theoretical formula calculation and standard table lookup method.Parameterized analysis of column span,soil cover thickness,and civil air defense load was conducted on the top plate of the civil air defense basement using three layout schemes:haunched large plate,one-way secondary beam,and cross beam;Based on factors such as the net height of the basement and the amount of steel used,the analysis shows that the layout plan of the haunched large plate is the best.Based on the haunched slab scheme with a column span of 8.7m,the economy and steel consumption ratio of using high-strength steel bars in beams and slabs were studied.The analysis showed that the higher the civil air defense load,the more economical the use of high-strength steel bars in load-bearing components.