大型建筑超长无缝设计的结构裂缝控制技术

Technique of Structural Crack Control for Overlong Jointless Structure of Large Scale Building

根据钢筋混凝土高层建筑超长结构无缝设计的特点,对其主要技术难点进行了系统分析,提出了一维非稳态温度场的分析模型和数值计算方法,并对河南信息广场工程的屋盖和墙面温度场进行了数值计算分析。计算结果表明,超长结构在温度荷载作用下最危险期是在结构施工后期,即结构形成整体但屋面和墙面还没有进行保温材料施工这一阶段,使用阶段建筑物结构构件表面的温度场数值是很小的;性能可靠的保温隔热材料的合理使用和其它建筑物裂缝控制综合集成技术措施的正确实施,超长无缝设计的结构裂缝问题是可以得到有效控制的。

The significance and the technical key points are analyzed,according to the distinguishing feature of the overlong jointless structural design for the RC high rise building,analytical model for one-dimension non steady-state temperature field is put forward,and the numerical analysis of temperature field for the practical project of Henan Informarion Plaza is carried out.The calculated results indicated that the most dangerous period for the temperature actions is at the later stage of construction phase,in which the several segments of the sub-structure are formed to an integrated structure,but the thermal insulation material both for the roof and filled walls are not constructed.In fact,the numerical values of the temperature field for the surfaces of structural elements in the service phase are very small.The structural crack problems could be controlled effectively for the overlong jointless structure of high rise building,through the reasonable usage of high performances materials both preservating heat and insulting against heat,and the implementation of the technical measures of crack controlling such as to set the last-cast joints in the building,to exert the prestressed bar on the ground floor slab and the roof slab,to cover the main structural elements using prefabricated external walls and to enhance the usual practice of materials preservaring heat and insulting against heat on roof.