采用UHPC加固的钢筋混凝土框架结构抗震性能研究

Study on seismic behavior of reinforced concrete frame structures strengthened with UHPC

为提升老旧钢筋混凝土框架结构的抗震性能,降低增大截面加固法对建筑空间的占有率,提出了基于UHPC(超高性能混凝土)的增大截面加固法,对钢筋混凝土框架柱进行加固。以某需要加固改造的钢筋混凝土框架结构为例,对采用UHPC加固后的整体结构进行了多遇地震下的反应谱分析和罕遇地震下的动力弹塑性分析,并与采用传统增大截面法加固后结构的抗震性能进行对比。分析结果表明,UHPC加固法与传统增大截面法对结构地震响应的影响规律一致,加固后结构的抗侧刚度增大,层间位移角显著降低,罕遇地震下结构构件的损伤状态得到了有效控制。相比传统增大截面的加固法,在保证整体结构具有相同抗震性能的前提下,UHPC加固法可降低本项目中框架柱截面尺寸30%以上,减小构件加固对使用空间的占有率,并提升现场施工效率。

In order to improve the seismic performance of old reinforced concrete frame structures and reduce the share of architectural space due to enlarging section method,the enlarging section method based on UHPC(Ultra High performance concrete)is proposed to strengthen reinforced concrete frame columns.A reinforced concrete frame structure which needs strengthening and reconstruction is chosen.And the frame columns are strengthened with UHPC.The response spectrum analysis under frequent earthquakes and dynamic elastic-plastic analysis of the whole structure under rare earthquakes are carried out.The seismic performance of the structure strengthened by UHPC is compared with the structure strengthened by traditional enlarging section method.The results show that the influence of the UHPC strengthening method is consistent with that of the traditional enlarging section method on the seismic response of the structure.As the increasing of frame column sections,the lateral stiffness of the structure is increased,the inter-story displacement angle is significantly decreased,and the damage state of structural members under rare earthquake is effectively controlled.Compared with the traditional enlarging section method,on the premise of ensuring that the whole structure has the same seismic performance,UHPC strengthening method could reduce the cross-section size of frame columns by more than 30%for the structure in this paper.The share of architectural space due to enlarging section method is also reduced,and the efficiency of on-site construction is effectively improved.