火灾高温下装配式竖井结构热力耦合响应研究OA

Prefabricated shaft structures can efficiently utilize urban spatial resources and have developed rapidly in recent years.However,there is still a gap between their fire resistance research and actual engineering needs.In this study,the thermo-mechanical coupling response mechanism of prefabricated shaft structures under high-temperature fire conditions was investigated through scaled heating tests and numerical simulations,and the temperature distribution,damage evolution and structural deformation behavior were revealed.In the model test,micro-concrete was used to simulate the shaft lining structure,a high-temperature heating device was adopted to simulate the fire environment,multi-circumferential and multi-depth thermocouples were arranged to monitor the temperature field.The test results show that the internal temperature distribution of the shaft is significantly affected by the chimney effect,with the maximum temperature in the middle region reaching 659℃.The concrete lining exhibits an obvious thermal hysteresis effect,and the maximum temperature difference between the inner and outer walls is 303℃.Under high-temperature fire conditions,the structural damage is mainly characterized by bottom slab spalling,extrusion and cracking at joints,and stress concentration around bolt holes.Further numerical parametric analysis indicates that the deformation mode of the shaft structure is jointly affected by fire duration and fire location.Local deformation is the most significant when the top is exposed to fire,while overall deformation is more severe under unilateral fire exposure.