混凝土夹芯拱形屋盖力学承载性能研究

Study on mechanical bearing performance of concrete sandwich arch roof

为研究混凝土夹芯拱形屋盖的承载性能,探究结构力学承载机制,通过对混凝土夹芯拱板进行压弯受力分析,推导建立了混凝土上、下拱板独立作用和联合作用下的开裂内力及极限内力判据公式,借助有限元模拟分析了两铰椭圆拱形夹芯屋盖的内力分布规律及变形特点,结合屋盖破坏特征探究了开裂内力和极限内力判据公式的适用性。结果表明:竖向荷载下夹芯拱形屋盖承载力与夹芯板的压弯内力密切相关;混凝土夹芯拱板的开裂及压碎一般发生在距拱脚l/20处,拱顶内力状态及应力水平相对较低;夹芯椭圆拱形屋盖的开裂内力宜采用联合作用判据公式,而极限内力计算则推荐采用独立作用判据公式。

In order to study the bearing performance of concrete sandwich arch roof and explore the bearing mechanism of structural mechanics,through the analysis of compression and bending force of concrete sandwich arch plate,the criterion formulas of cracking internal force and ultimate internal force under independent and combined action of concrete upper and lower arch slabs are derived,and the internal force distribution and deformation characteristics of two-hinged elliptical arch sandwich roof are analyzed by means of finite element simulation.Combined with the failure characteristics of roof,the applicability of the criterion formula of cracking internal force and ultimate internal force is explored.The results show that the bearing capacity of the sandwich arch roof under vertical load is closely related to the compression-bending internal force of the sandwich plate,and the cracking and crushing of the concrete sandwich arch plate generally occur at l/20 away from the arch foot,and the internal force state and stress level of the vault are relatively low.The cracking internal force formula of sandwich elliptical arch roof should be adopted,while the independent action criterion formula is recommended for the calculation of ultimate internal force.