预应力在我国大跨度结构中的应用研究综述

Review of the application of prestressing in long span structures in China

为了提高大跨度结构的正常使用性能,通常在混凝土结构中施加预应力.结果表明,预应力混凝土结构具有更好的使用性、耐久性和大跨度适用性,其中预应力混凝土空心板结构在不显著降低承载力和刚度的前提下明显减小结构自重,预应力型钢混凝土梁(板)结构采用较小的截面尺寸即可满足承载力和刚度的需求.开发城市地下空间是解决城市用地紧张的有效手段,我国地下大跨空间常用的结构形式主要包括密排框架(肋梁)结构、折板或拱形结构、变截面(加腋)板结构、预应力混凝土结构、型钢-混凝土组合结构和Y形柱结构6种形式,相比之下,跨度较大时宜采用预应力结构.

To improve the normal performance of large-span structures,prestressing is usually applied in concrete structures.The results indicate that prestressed concrete structures have better usability,durability,and large-span applicability.Among them,prestressed concrete hollow slab structures significantly reduce the weight of the structure without significantly reducing the bearing capacity and stiffness.The prestressed steel reinforced concrete beam(slab)structure can meet the requirements of bearing capacity and stiffness using smaller cross-sectional dimensions.Developing urban underground space is an effective means to solve the shortage of urban land.The commonly used structural forms of underground large-span spaces in China mainly include six forms:densified frame(ribbed beam)structure,folded plate or arched structure,variable section(haunched)plate structure,prestressed concrete structure,steel-concrete composite structure,and Y-shaped column structure.In contrast,prestressed structure is preferred when the span is large.