Analysis Of The Influence Of Uneven Base Settlement On Seismic Performance Of RC Framework Structure

Underground space development will inevitably lead to the displacement of thesurrounding soil, which results in buildings near the base to generate internal forces andadditional deformation, causes uneven subsidence damage to the buildings, and has animpact on the seismic performance of the structure. In order to solve this problem, thepaper makes subsidence and earthquakes effect on structures together and uses thedynamic elastic-plastic time history analysis method to study the destructive process ofsettlement buildings under the earthquake action.Firstly, SAP2000Software is used to establish a framework structure model,reinforcement property of each structure section is calculated by structure design, andplastic hinge, used to show the elastic-plastic performance of structure under earthquake,is defined on structural beams and columns in accordance with the requirement ofAmerica FEMA-356seismic assessment methods. Secondly, based on the limit-valuerequirements on framework structure settlement of Code for Design of BuildingFoundation (GB50007-2011), various types of settlement conditions are designed, andsettlement is applied to structure basis by displacement load, the internal forces changeof structure under the sedimentation is calculated. Thirdly, EL-Centro seismic waveinput structure model is selected to simulate the destructive process of structure underseven-degree rare earthquake action.The analysis shows:(1) Uneven settlement will cause violent changes of structureinternal forces at special places, different types of settlement act great different impacton structure internal forces, compared with overall tilt, part settlement is more easily tocause localized changes in the structure;(2) under earthquake action, drift angle ofsettlement structure increases with decrease of height, the effect of column-end fixedconstraint slightly reduces at the bottom level, all drift angle do not exceed the toleranceof1/50.(3) Under the action of earthquakes, the development process of plastic hinge ofsettlement structure is still dominated by beam-hinge failure mode. Under the effect ofbottom hinge, it is an ideal failure mode of structure to act a rigid body rotation of asingle degree of freedom around the bottom;(4) under earthquake action, thedeformation near the unilateral settlement structure constraint column is larger thanother places, central locations of the internal settlement structure and the top of structurehave a larger deformation, serious damages happen in these areas that have low bearingcapacity reserves and prone to be damaged. The study results have certain significance to the seismic hardening of framework structure occurring settlement damage.