拼装虚托对装配式顶拱结构的力学影响

在装配式双构件顶拱结构的实际拼装过程中，因托拱千斤顶行程不同步，易导致千斤顶虚托现象发生。基于三维数值计算，分析不同虚托条件下装配式双构件顶拱结构的力学性能，并依据最大主应力失效准则，完成不同虚托状态下装配式顶拱结构的力学性能评价。研究分析发现：上部承托平台虚托时，结构内部最大主应力向压应力趋势发展；下部承托平台虚托时，结构内部的最大主应力向拉应力趋势发展；仅上部承托平台虚托时，装配式双构件顶拱结构主体均满足最大主应力抗拉设计限值；出现任一下部承托平台虚托时，装配式双构件顶拱结构局部区域不满足最大主应力抗拉设计限值。

Mechanical Influences of Empty Support on Prefabricated Arch Structures

In the assembly of a prefabricated double-member arch structure, a jack empty support phenomenon is easily caused by stroke asynchronism. Based on a three-dimensional numerical calculation, this study investigated the different empty supports fabricated under the condition of a double-component top arch structure and their mechanical properties, and on the basis of maximum principal stress failure criterion, analyzed the different empty mechanical properties of a fabricated under-roof arch structure. Evaluation, research, and analysis found that: (1) when the upper supporting platform is in empty support, the maximum principal stress in the structure is compressive stress; (2) when the lower supporting platform is in empty support, the maximum principal stress in the structure is tensile stress; (3) when only the upper supporting platform is in empty support, the main body of the prefabricated double-member top arch structure meets the maximum principal stress tensile design limit; and (4) when there is an empty support in the lower supporting platform, the partial area of the prefabricated double-member top arch structure does not meet the maximum principal stress tensile design limit.