Existing Frame Structure By Added And Renovated Stories And Seismic Behavior Analysis

As time is accumulated, the materials of buildings begin to emerge aging naturally, and the performance is of degradation. Especially in the new century, faced with the problem of repairment and reinforcement, a large number of constructions go into a stage of less secure or functional loss. Also with the rapid process of urbanization in recent years, many cities have faced the problem how to deal with the old town in China.The idea of "saving society" tells us to renovate and expand the old town, which is a wise decision. Therefore, the reformation of existing buildings by added and renovated stories will develop greatly in the future.In this paper with the background of practical engineering project, we take measures to measure the structural reliability appraisal of existing buildings, and then adopt the means of the direct increase of the floor to design, at the same time choose more reasonable method of reinforcement to enhance local members. During going on adding storeies, we find a focus on existing buildings by floor reformation that whether the added and old part of the structure can have a reliable anchor or not. In response to this weakness, we begin to further study and get the following conclusions:1,When we design existing buildings by adding stories directly, if the modal parameters does not meet the regulatory requirements, we can increase dimensions of the surrounded members of the structure to improve the stiffness of the buildings, so that it can improve the overall level of lateral force of new buildings after adding stories. In this paper, the project examples by adjusting the corresponding frame beam sections at different locations in different parts of the region to solve this problem.2, When choose methods of the local component reinforcement, we should fully consider the advantages and disadvantages of each method of reinforcement, and take appropriate and reasonable methods for different parts of the components. After structural calculation for this project by added stories, we find it that portion of the beams, plates are short of bearing capacity. Taking into account building is in a state of normal use, we also need to consider to construct efficiently, and decide to adopt a plan of external stick CFRP.3, Using the ABAQUS finite element software to simulate the use of chemically-plantedsteel bar way to connect added frame columns of the old and new concrete joint surface through different depths of anchor, and form different construction environment under normal working conditions. Analysis of different conditions frame column hysteresis curve, as well as skeleton curve and strength degradation of seismic behavior, we can draw conclusions that adequate planted depth(case one) must ensure at the old and new concrete joint surface in order to increase components seismic performance at joint surface. If there is a particularly difficulty of rebar-planting and anchorage in individual area, referred to case three, we should do our best to reach required planted depth in a single component. If some rebars does not reach requied depth, we need to plant another else rebars around the anchorage area to bear force jointly.