Study On Out-of-plane Stability Of Infilled Walls With Horizontal Slip Layer Under In-plane And Out-of-plane Coupling

China is an earthquake-prone country,every earthquake will have an impact on production and life.When an earthquake occurs,the destruction of the infilled wall poses a considerable threat to the escape of personnel.Under earthquake,the infilled wall may be coupled by the inertial force caused by the in-plane displacement and the external velocity at the same time,so it is of great significance to study the performance of the packed wall under the in-plane and out-of-plane coupling effect.This paper is aimed at infilled wall with horizontal slip layer,and studies the coupling effect of the infilled wall by numerical simulation.The main research contents are as follows:1)According to the division of failure stages in the in-plane of the infilled wall,the limits of the story drift ratio under each stage are summarized.Based on the out-of-plane analysis of the infilled wall,the out-of-plane damage mechanism is summarized.Based on the influence of the in-plane and out-of-plane coupling,the formula of the reduction coefficient of the outof-plane bearing capacity of the infilled wall is summarized.2)Based on the existing test data of the infilled wall,the finite element model of the infilled wall was established by using the numerical analysis method,and the rationality of the parameters of the finite element model was verified.On this basis,the differences in the outof-plane stability mechanical properties of the infilled wall with horizontal slip layer and the ordinary infilled wall are analyzed without considering the in-plane and out-of-plane coupling.The results show that the slip layer in the infilled wall destroys the integrity of the wall,weakens the constraint of the surrounding frame,and reduces the "arch" bearing effect.Under the same out-of-plane action,the out-of-plane failure degree of the infilled wall with horizontal slip layer is different from the ordinary infilled wall,the former is greater than the latter,and the out-of-plane stiffness of the former is smaller than the latter,and the peak load of the former is 22.2% lower than the latter.The out-of-plane bearing capacity of the infilled wall with horizontal slip layer is greater than that required by the code,which meets the design requirements of the code.The out-of-plane bearing capacity of the filled wall with horizontal slip layer is safe.3)The differences in the out-of-plane stability mechanical properties of the infilled wall with horizontal slip layer and the ordinary infilled wall are analyzed with considering the inplane and out-of-plane coupling,and compared with those without considering the in-plane and out-of-plane coupling of the surface.The results show that with the increase of the story drift ratio,the damage degree of the infilled wall increases,the out-of-plane stiffness decreases,the "arch" bearing effect decreases,and the in-plane and out-of-plane coupling reduces the out-of-plane bearing capacity of the filled wall obviously.When the story drift ratio is 0.125%,the peak load of the infilled wall with horizontal slip layer increases by 3.57% compared with that without coupling,and the peak load of the ordinary infilled wall decreases by 8.84%compared with that without coupling.When the story drift ratio is 0.25%,0.5%,0.75% and1.0%,the peak load of the infilled wall with horizontal slip layer decreases 21.43%,59.52%,76.19% and 87.5%,respectively,compared with that without coupling.The peak load of ordinary infilled wall is reduced by 35.58%,54.19%,73.72% and 79.07%,respectively,compared with that without coupling.When the story drift ratio is 0.75%,the infilled wall with horizontal slip layer under the rare earthquake of 9 degrees and the story drift ratio is1.0%,the infilled wall with horizontal slip layer under the rare earthquake of 7 degrees(0.15g),8 degrees(0.3g)and 9 degrees do not meet the requirements of the code,and the out-of-plane bearing capacity of the infilled wall with horizontal slip layer in other cases is greater than the requirements of the code,which meets the requirements.When the story drift ratio is 1.0%,the ordinary infilled wall under the rare earthquake of 9 degrees does not meet the requirements of the code,and the out-of-plane bearing capacity of the ordinary infilled wall in other cases is greater than the requirements of the code,which meets the requirements.4)For the infilled wall with horizontal slip layer,a fitting formula for the reduction coefficient of out-of-plane bearing capacity is obtained.The rationality of the formula is verified by comparing the calculated value with the simulated value.