Application And Research Of Performance-based Energy Dissipation Technology In Reinforcement Engineering

There are many earthquakes and serious damages in China.In the new period,the social economy construction develops fast and has set higher demands for the functions and safety degree of building structures,and a large number of existing structures require seismic upgrading.The energy dissipation technology with velocity viscous damper has been widely used because of its clear reinforcement mechanism,significant reinforcement effect,short construction period and low influence to the main structure comparing with the traditional reinforcement method.And introducing conceptual design into seismic retrofit by presenting performance objectives and greatly improving the seismic performance of the buildings can effectively deal with the problems such as strength,deformation and structure that are difficult to solve.At the same time,it can fully display the advantages of energy dissipation and seismic reduction technique,which has great significance to the seismic estimation and hardening design of primary structures.It is also the latest《Seismic Design Code of Building》GB50011-2010(2016Edition)recommended reinforced method.The main works of this paper are as follows :(1)This paper primarily sums up the principle of vibration technique which uses viscous dampers based on the current research achievements,and points out that the damping reinforcement technology has remarkable advantages compared with the traditional strengthening method to enhance the structural resisting power.Then,this paper introduce performance-based design concept and combines it with live standards at home and abroad.the paper also gives a set of performance-based energy dissipation and seismic reduction reinforcement design method by introducing that the main content of it,seismic level,performance level and performance target and so on.At last,integrating the theory with a practical engineering project,this article sets the reinforcement scheme,puts forward the expected performance target,establishes the calculation and analysis model of the original structure and the damping structure,carries out and the nonlinear dynamic analysis under the frequent earthquake and rare earthquake respectively according to the characteristics of the project and the difficulty of reinforcement,The structural force index,displacement index,dynamic response index and energy index before and after damping are comprehensively studied to study how to use performance-based design method in the energy dissipation and damping reinforcement project.(2)Taking a outpatient and inpatient building renovation project in Hefei as an example,this paper explores how to realize dissipation and vibration reduction technology combined with performance-based design in practice.According to the engineering background and reinforcement requirements,it is pointed out that the change of usage makes it have problems in solving the issue that the seismic structural measures such as insufficient anchorage length and small stirrup diameter do not meet the new requirements by using the traditional method of direct reinforcement of structural components.At the same time,only by increasing the section of the component,outsourcing and bonding steel and other methods to strengthen the building has some defects.For example,the quantity of works is large,the period of construction is long,the cost is high,the improving effect is less evident and it will affect the normal operation of the primary building.By introducing the idea of performance-based design,the performance of the energy-dissipated structure can be highly improved,which can meet the requirements of low ductility structure in seismic code,and the seismic structure level is reduced by one degree.(3)Based on the preset damping performance target,the appropriate viscous damper is designed and installed.This paper uses ETABS analysis program to establish two models one represents the original structure and the other is the damping structure,then uses time-history dynamic analysis method under frequent earthquake and rarely occurred earthquake respectively.The changes of storey shearing force,inter-story drift angle,vertex acceleration,velocity and energy dissipation before and after damping are compared to evaluate the damping effect.At the same time,based on the acceptable criterion of hinge,this paper checks the performance of the damping structure under rare earthquake to judge the failure state and performance level of main structural members such as beams,columns,shear walls and energy dissipation substructure.(4)According to the results of force,displacement and energy index under small earthquake,the displacement,static response,energy parameters and structural component performance verification results under large earthquake,this paper concludes that after seismic retrofit,the earthquake resistant behavior of the structure is obviously improved,which can achieve the desired performance targets.Meanwhile it can meet the requirements of low ductility structure with performance 2 in the specification.The anti-seismic structure measures after reinforcement of this project can be reduced by one degree.The introduction of performance design into reinforcement engineering is an essential revolution in the development of strengthening technology.This paper aims to make reference for the further generalization of performance-based energy dissipation and damping reinforcement technology by studying its application way.