Experimental Research On The Seismic Performance Of Self-insulating Inner-framed Structural Wall With Opening

In China,the masonry structure will remain a kind of structural form that has been extended in the field of village and township construction for a considerable period,but the seismic performance of the masonry houses is generally relatively inferior,the proportion of energy-saving and load-bearing structure system's use is not high and the building energy consumption is large,so it is an urgent need for building construction to promote the integration of seismic performance and energy conservation.My research group developed a series of energy-saving bearing blocks and self-insulating inner-framed structural wall,the insulation performance and mechanical performance of the wall were enhanced,the force performance can achieve the parallel effect of building energy conservation,which is benefit for the development of village houses.Because of the building function's requirements,the openings are common on the wall,but the results of the earthquakes show that the wall is weakened by the openings,piers and breasts are weak links in the earthquake.Therefore,to obtain seismic performance and the seismic design method of self-insulating inner-framed structural wall with opening has become an urgent problem to be solved.In this paper,through the pseudo-static test of the two full-size self-insulating innerframed structural walls with opening and the analysis of the various seismic performance indexes,the seismic performance and failure mechanism of the walls are revealed,the weakening effect of different opening rate on the overall performance of wall is compared.The test results show that:(1)The larger the hole,the more obvious the weakening of the capacity and stiffness.The larger the opening rate,the lower the cracking load,the maximum load and the ultimate load.However,the decrease degree of maximum bearing capacity is less than that of the wall sectional area.The overall trend of stiffness degradation is about similar of the two specimens,the deterioration of stiffness tends to be faster in the initial stage and the deterioration of stiffness tends to be moderate with the increase of displacement.(2)The ductility coefficients of specimen W-1 and specimen W-2 are 3.034 and 4.085 respectively,which have all-right ductility.(3)The deformation of the wall along the height during the elastic stage is generally curved or linear type,when enters the failure stage,the deformation of the wall along the height shows shear type.(4)The energy dissipation capacity of the wall decreases with the increase of opening rate after the wall cracks.(5)The core column's and horizontal strip's reinforcements are both involved in bearing load,restrain and delay the development of inclined cracks,and have played a better role in improving the deformation ability and ductility of the wall.It is an effective measure to improve the seismic performance of the wall with reinforced concrete core columns and horizontal strips around the opening and wall.According to experimental research and theoretical analysis,this paper divides the failure process of the wall into elastic stage,elastic-plastic stage and the failure stage,and adopts corresponding mechanical models to describe the full process force characteristics of the wall under horizontal and vertical loads.(1)In the elastic stage,the wall is regarded as an equivalent elastic slab model of composite material with energy-saving bearing blocks as the body,concrete of core columns and horizontal strips as reinforcing fibers.(2)In the elasticplastic stage,the wall is regarded as a shear resistance mechanism composed of concrete equivalent baroclinic struts,horizontal bars,and vertical bars.(3)In the failure stage,the wall degenerates into a "weak frame" system formed by the inner-frame.Based on the equivalent elastic slab model and the shear resistance mechanism system,this paper presents the correction calculation formula for the cracking load and the maximum bearing capacity calculation method of the self-insulating inner-framed structural wall with opening.After comparison,the theoretical calculations and experimental results of the two stages agree well.Both calculation methods have a certain theoretical basis and practical value,meet the needs of the actual engineering calculation,and can be used for the promotion and popularization of energy-saving bearing blocks and self-insulating inner-framed structural wall,and promote the integration of seismic performance and energy conservation.