隔震技术在既有砌体结构加固中的应用研究

Application and research of seismic isolation technology in strengthening existingmasonry structures

隔震技术可以有效减少输入上部结构的地震力,适用于既有砌体结构的抗震加固。在设计时,首先应根据砌体结构的实际状况,确定隔震目标,选定隔震支座,然后计算出水平向减震系数,对上部结构采用折减后的地震力进行抗震验算,对隔震层按罕遇地震进行承载力计算,下部结构按设防地震进行承载力验算,并按罕遇地震进行抗剪承载力及层间位移角验算。增加隔震层改变了原有砌体结构下部墙体的传力方式,应对隔震层顶面托梁及下部基础进行加固设计。对于无地下室的砌体结构,尚应在正负零增加钢筋混凝土楼盖。在隔震加固施工过程中,应进行施工过程验算,确保竖向力由原墙体传递至隔震垫的过程安全可靠。隔震沟宽度应大于罕遇地震作用下结构最大水平变形的1.2倍,且≥200mm。隔震主体施工完成后,应对周边附属设施及管线做相应柔性连接处理。

The isolation technology can effectively reduce the seismic force input to the superstructure,and is suitable for the seismic reinforcement of existing masonry structures.In the design,firstly,the isolation target shall be determined according to the actual situation of the masonry structure,the isolation bearing shall be selected,and then the horizontal damping coefficient shall be calculated.The reduced seismic force shall be used for the anti-seismic calculation of the upper structure,the bearing capacity of the isolation layer shall be calculated under the rare earthquake,the bearing capacity of the lower structure shall be calculated under the fortification earthquake,and the shear bearing capacity and story drift angle shall be calculated under the rare earthquake.Adding isolation layer has changed the force transmission mode of the lower wall of the original masonry structure.The top joist of the isolation layer and the lower foundation should be strengthened.For masonry structure without basement,reinforced concrete floor shall be added the position where the relative elevation is zero.During the construction of seismic isolation and reinforcement,the construction state shall be checked to ensure the safety and reliability of the process of transferring the vertical force from the original wall to the isolation pad.The width of the isolation trench shall be greater than 1.2 times of the maximum horizontal deformation of the structure under the rare earthquake,and shall not be less than 200mm.After the construction of the isolation layer is completed,the surrounding auxiliary facilities and pipelines shall be subject to corresponding soft connection treatment.