The Study On Seismic Strengthening Of Infilled Frame Structure With Passive Control

Earthquake is a kind of disaster that human beings can’t control, only bythe prevention of an earthquake can decrease the loss. The damage and collapseof the buildings during the earthquake are the main reasons to the seismicdisasters and losses. Seismic reinforcement is an effective method to enhancethe seismic capacity of the built structures and decrease the earthquakedisasters. Based on these ideas, a passive control method is adopted in theanalysis and research of seismic reinforcement to the infill wall in framestructures. The major contents are as follows:1. First of all, the relevant literatures of home and abroad are read in detail,and the method of seismic check and reinforcement of structures is summarizedbriefly. The seismic performance levels, seismic performance goals andquantitative indexes of them are also summarized, so that the quantitativeindexes of seismic performance goals, the limit value of inter-storydisplacement angle and damage condition of the filler wall, to the reinforcedconcrete infill wall in frame structures of the hospital are put forward. Besides,the modified model of filler wall proposed by Hashemi and Mosalam， whichhas taken the interactions between the in-plane and out-plane of the filler wallinto consideration, is described in detail..2. Seismic check of the reinforced concrete infilled frame structures basedon the performance state is figured out in the paper. Based on OpenSees, afinite element model of four-layer hospital frame structure with reinforcedconcrete infilled wall is set up. Three ground motions, that is, EI Centro,Parkfield and San Fenando, are selected to carry out the seismic check on thelevel of rare earthquake. Based on the quantitative indexes of seismicperformance goals to the reinforced concrete infilled frame structures of thehospital, the limit value of inter-story displacement angle and damagecondition of the filler wall, a judgment can be made to confirm that thefour-layer structure does not meet the requirements of seismic performancegoals, and reinforcement should be taken into considerations.3. Passivecontrol seismic reinforcement to the reinforced concrete infilledframe structures based on the performance state is discussed in this paper.According to the seismic check of the four-layer reinforced concrete infilled frame structure, passivecontrol seismic reinforcement is adopted by usingadditional damper. By use of three ground motions such as El Centro,Parkfield and San Fenando, comparative analysis of the four-layer structurebefore and after seismic reinforcement is carried out, including distribution anddegree of plastic hinge, damage condition of the filler walls and changes of theinter-story displacement angle.After that, based on the response of thefour-layer structure with seismic reinforcement using additional damper underrare earthquake, whether the structure meets the requirement of the quantitativeindexes of seismic performance goals to the reinforced concrete reinforcedconcrete infilled frame structures of the hospital is discussed. Results shownthat, under rare earthquake, the inter-story displacement angle of each floor arealmost smaller than1/200and none of the filler walls collapse, whichdemonstrate that the results meet the functional requirements after modification.