Experimental Research On Anchorage Performance Of Existing Building Isolation Reconstruction

In order to test the reliability of the two anchoring schemes of the existing buildings' seismic isolation reconstruction,three specimens were designed and pseudo-static tested.The specimen? poured concrete twice and installed the isolation bearings by pre-embedded anchor bolts(PEAB),the specimen? used the special inverted cone-shaped chemical anchors(SICCA),and the specimen? installed the isolation bearings with PEAB normally.Besides,the specimen? was reinforced with carbon fiber cloth because the bolt margin did not meet the post-anchor specification requirements.The pillars of the three specimens use the same size(550mm×550mm×650mm),the same concrete model(For simulating the damage of existing building and variables control,the concrete use the C25 model),the same anchor arrangement(8 anchors with the margin of 65mm).And a LRB400 isolated bearing is used in all specimens.All specimens were loaded horizontally with different displacements and frequencies under different vertical loads.The test results show that a little fine cracks appear in the upper bending surface(UBS)of specimen? and ?.No cracks are found on the secondary joint surface(SJS)of the specimen?.No cracks are found on the anchor bolts edges(ABE).The maximum strain of the longitudinal bars,the stirrups,and the concrete on UBS are 317.3,624.2,and 1048.1,which means none of them yielded;the concrete strain at SJS of the specimen? is slightly smaller than the concrete strain at the corresponding location of the specimen?.None of the specimens suffered from anchor failure,and they all can withstand a horizontal load of 250% deformation of the rubber bearing.The specimens consume energy well and they have the same mechanical behaviors as the loads change.As the horizontal loading displacement becomes larger,the secant stiffness decreases slightly,the viscous damping coefficient of the hysteresis curve decreases.As the vertical load increases,the hysteresis curve and the viscous damping coefficient become larger,the energy consumption capacity(ECC)becomes stronger.The ECC of the specimens has an almost linear relationship with the loading frequency,it becomes weaker with the loading frequency increases.Figure 50;Table 17;Reference 55...