新三亚火车站混凝土空腹网架结构温变效应研究

Thermal effect analysis of concrete open-web grid structure of New Sanya Railway Station

对三亚火车站站房多点支承钢筋混凝土空腹网架结构进行了温变效应原位测试试验,研究温变作用下结构的挠度、应变特点及其分布规律.同时,利用有限元软件ANSYS对结构做了相应的理论分析.研究表明,挠度梯度随位置变化呈线性变化,挠度分布与结构的实际工作特点相符.温变作用下,上弦杆的应变值及应变梯度均略低于下弦杆,表明楼板参与上弦工作,但约束作用不强;结构温变应变梯度约为9με/℃,即温度增加1℃,应力值增加约0.29MPa,可知温变较大时,所产生的次生应力较大,设计时应充分考虑温变效应的影响.挠度及应变的实测值与理论值之间有一定误差,但二者所反映的分布规律及特点较吻合.

The concrete open-web grid structure supported by column of Sanya railway station is researched through in-situ test. The characteristic and distribution law of displacement and strain under thermal effect is investigated by finite element software ANSYS. Research shows displacement grad linearly changes with position, and these characteristics conform to structure＇s working characters. Under thermal effect, strain and thermal strain grad of upper chord is lower than those of lower chord, which show slab worked with upper chord but the constraint capacity of slab is limited. The thermal strain grad of structure is about 9με/℃, i. e. if the temperature increase 1degree, structural strain will increase 0.29 MPa, and the secondary stress which caused by temperature change is large. The influence of thermal effect should be considered in design. Although there are some errors between results of in-situ test and theoretical study, they can reflect the same characteristic and distribution law.