Study On Seismic Performance Of Masonry Structure With Sliding Isolation Ring Beam

In recent years, the occurrence of earthquake is frequent, and earthquake frequency presents a increasing trend. When earthquake coming, distant rural areas suffer the most serious disaster. Mainly because the damage of rural buildings leads to the personnel and economic losses of residents. Therefore, the need of studying on seismic and isolation technology of low-rise rural buildings is more and more urgent. And what’s more, regarding as the main structural form in rural areas, the low-rise masonry structure buildings should become the main study object, at the same time,its research should meet the rural situation of low level both in economy and construction.A isolation technology with sliding isolation ring beams that suitable in rural areas is put forward, which is made up with sliding isolation ring beams as the measure of preventing freezing and bloating, Bound rubber beam as the measure of displacement limiting and recovery, and low-grade modified mortar as the sliding materials. In order to improve the seismic performance of low-rise masonry structure buildings in rural areas. Experimental study was done on the isolation technology with sliding isolation ring beams, the main processes of the study and the drawn conclusions are presented as follows:(1)The basic mechanical property of the limiting device and the main materials of isolation layer in the isolation technology with sliding isolation ring beams was tested. Through the shear test of bound rubber beam, the shear strength under different working conditions, such as different materials, temperatures, and amounts of stirrup, was studied, and the making craft of bound rubber beam was summarized. The result shows that, the shear strength of bound junked tire is much higher than the bound rubber beam’s, low temperature can make the stiffness of the bound rubber beam increased, and the amount of the stirrup has no obvious effect on the shear strength of bound rubber beam. Through the mortar strength compression test, the proper mix ratio of modified mortar of isolation layer, and the effect rules on mortar compression strength after mixing different ratios of talcum powder and graphite powder. The result shows that,the compressive strength of modified mortar is increased firstly and then decreased with the ratio of admixture increasing.(2)In order to explore the modified mortar that according with the designed requirement that not cracking under minor earthquake and cracking under medium and large earthquakes, Through pressure-shear test and the friction coefficient test of modified mortar isolation layer, the shear bearing capacity, the friction coefficient as well as the variation law of modified mortar isolation layer were studied under 39 conditions. The result shows that, the modified mortar layer(the dosage of 5% talc powder for M2.5 mortar) can reflect the double functions of " control of sliding start " and " consuming energy by sliding " comprehensively.(3) Though the pseudo-static test on one ordinary masonry wall and two isolation walls, the isolation performance of the isolation technology with sliding isolation ring beams was studied. The result shows that, the isolation walls with modified mortar isolation layer and steel ball-modified mortar isolation layer is in the elastic state with no cracks in all test process, and the hysteretic curves is relatively full, both of them have good ductility, stiffness degradation slower and favorable energy dissipation capacity, it can consume the earthquake energy and improve the seismic performance of low-rise masonry structure effectively.(4)The applicable seismic intensity and economical efficiency of modified mortar isolation layer and steel ball- modified mortar isolation layer were analyzed. The result shows that, the two isolation layers can be used in high earthquake-intensity area, but the cost increases marginally.