Research On Practical Design Method Of Rigid Sliding Isolation Bearings

Due to the limitation of friction coefficient,frictional sliding isolation technology was mainly applied to some brick masonry structures with small aspect ratio and low height in the early stage,but the research on frame structure is less.At the same time,because the energy dissipation mode of this technology is only friction energy dissipation,excessive displacement in earthquake will cause damage to the limit device and need to set a reset mechanism separately,which makes the construction difficult.At present,rubber bearings,which are widely used in isolation buildings,also have their shortcomings,such as incomplete vulcanization of rubber,easy aging,small vertical pressure and so on.In order to overcome the shortcomings of the above-mentioned isolation technology,a new rigid sliding plate isolation bearing is proposed in this paper.The bearing integrates the sliding system and the reset rubber shear spring.It has the advantages of simple structure,low cost,easy transportation and construction,and is suitable for multistory and high-rise buildings.Based on this isolation bearing,the following main research work has been done in this paper:(1)Based on the properties of traditional rubber materials,the stiffness theory of rubber isolation bearings and the friction force model of friction sliding bearings,the theoretical stiffness of sliding system and reset rubber shear spring group in rigid sliding plate isolation bearings are compared and analyzed,and the hysteretic curves of each part and the whole bearing are established.(2)The mechanical properties of a new rigid sliding plate isolation bearing were tested with a 1500-ton compression-shear tester.The friction coefficient and force-displacement curves of the bearing under different vertical loads and different friction materials(pure PTFE and modified PTFE)were investigated.The test results show that the mechanical properties of the new rigid sliding plate isolation bearing are very stable,the friction coefficient of the friction material is small(0.02~0.04),and the vertical bearing capacity of the bearing is high,so it is an ideal isolation bearing.(3)Based on the experimental results of rigid sliding plate isolation bearings,according to the relevant design standards and codes at home and abroad,as well as the theoretical analysis and experimental research results of predecessors,using SAP2000 finite element software and taking a one-story steel structure model as an example,the design methods suitable for rigid sliding plate isolation bearings at present stage are summarized and discussed,and the detailed design process is given.It includes seismic wave input and parameters setting of isolation bearing,which provides a reference for future generations in isolation design and helps to promote the use of the rigid sliding plate isolation bearing in practical engineering.(4)Through practical engineering design cases,the traditional rubber isolation technology and rigid sliding plate isolation technology are adopted to isolate the vibration.The inter-story displacement,inter-story shear force and top acceleration of the above frame model structures are compared and analyzed.The isolation effect of the two kinds of isolation bearings is evaluated and compared with the seismic response of the superstructure before and after isolation.The results show that the new rigid sliding plate isolation bearing developed in this paper can completely compare with the traditional rubber isolation bearing in isolation effect.(5)In order to study the specific performance of the bearing body in seismic response,the residual displacement and hysteretic energy dissipation of the rigid sliding plate bearing itself are analyzed.The results show that the rigid sliding plate isolation bearing can basically return to its initial position after adding the reset shear rubber spring group;the energy dissipation effect is good,and it can consume seismic energy in the earthquake;the hysteresis curve is consistent with the theoretical test results,and the simulation method and parameter setting method are correct.The new rigid sliding plate isolation device developed in this paper has the functions of friction slip system and automatic reset.It has simple structure,strong applicability and simple construction,and can be applied to practical engineering.It has important scientific and theoretical value,practical significance and application prospects.