The Research On Controlling Of The Displacement And Engineering Application Of Reinforced-asphalt Seismically Isolated Device

Earthquake is a kind of common and normal natural phenomenon, but due to the complexity of the tectonic and non-intuitive seismogenic area, the causes and mechanisms of its formation has no clear answer. This makes it very difficult to reliably predict when an earthquake occurs, in order to reduce casualties and property losses. According to statistics, casualties and destruction lifeline projects after the earthquake, the vast majority are caused by the collapse of buildings. Therefore, improving the seismic safety of the building structure is the main countermeasures of reducing casualties and property losses after the earthquake. China’s land area is vast, about 80% of the land area located at the seismogenic area, about 50% of the land area located at 7 degrees high seismic intensity. In addition, our country is an agricultural country with relatively backward economy, leading to the lack of seismic measures of the rural construction, and it is easy to appear the phenomena of a huge disaster caused by a small earthquake. To solve the contradiction between high cost of isolation technology and relatively backward economy, our academic team proposed a kind of base isolation device, reinforced asphalt isolation technology, which was put forward. This technology has the characteristics of economy and environment, safety and reliability, simple construction, remarkable isolation effectiveness, very suitable for our country.The basic structure and working principle of the reinforcement-asphalt isolation layer are introduced, the theoretical analysis of the ultimate horizontal displacement of the isolation layer was conducted by using the knowledge of the structural mechanics. The calculation formulae of reinforcement-asphalt isolation layer’ allowable displacement under frequent and severe earthquake and second-order influence coefficient were derived. In addition, the requirements on the slenderness ratio and numbers of the vertical bars were discussed to avoid the second kind of stability in the layer. Through data analysis and curve fitting, calculating formula for the relation between slenderness ratio and numbers of the vertical bars was obtained. To study the displacement of the isolation layer and dynamic characteristics, shaking table tests of specimens were carried out for the cases with different bar diameters and input acceleration amplitudes. The results show that the theoretical analyses agree well with the experimental results, thus, verifying the reliability of the calculation formulae of reinforcement-asphalt isolation layer’ allowable displacement, the second-order influence coefficient, and the relationship between length diameter ratio and its numbers of the vertical reinforcement. According to the formulae is given in this paper to design reinforced asphalt isolation building, which ensures isolation structure doesn’t occur the second kind of stability, and meets the requirements for the deformation of isolation structure.Being based on the existing results of reinforcement-asphalt isolation layer, and considering the results of this study, the design methods of the technology were summarized and comb. Overall, the calculation mainly includes four parts, stability checking, strength checking, displacement checking and damping coefficient. Designing the isolated structure takes into consideration the four parts, to choose the best design. Finally, to facilitate the application of this technology, isolation design is applied to a six-storey building with masonry structure, detailed design process and steps of the technology is given.