| Coupling beam is an important component of coupled shear wall structure and a critical path to transmit loads between shear walls. Under the seismic action, reinforced concrete coupling beams are more vulnerable, which lead to harmful influence on seismic performance of the whole structure. To improve the seismic performance of coupling beam, a new type of coupling beam which is encased with steel truss on the basis of ordinary reinforced concrete coupling beam is presented. Tests and theoretical researches are done on seismic performance of the reinforced concrete coupling beam encased steel truss are discussed in this paper. The key points are showed as follows:(1) Aseismic low reversed cyclic loading tests were conducted on eight reinforced concrete coupling beams encased steel truss,considering the effect of steel ratio, span-to-depth ratio etc. to investigating the seismic performance of energy dissipation and failure patterns etc. It shows that the ductility coefficient of the reinforced concrete coupling beams encased steel truss are all higher than 3.0, which indicates a good seismic resistance. Raising steel ratio can significantly improve the seismic performance of coupling beam, while lower span-to-depth ratio has the same effect when other conditions remain the same. Cutting flange plate on reinforced concrete coupling beam encased steel truss is beneficial to concrete pouring and damage section control, but harmful to the seismic performance with lower seismic indicators, specifically, ultimate bearing capacity was reduced by 25.7%.(2) On the basis of test results, restoring force model and calculation method of shear bearing capacity are established. In addition, anti-seismic design suggestion and methods of the reinforced concrete coupling beam encased steel truss are proposed.The research results of this thesis can provide the reference and basis for further research and anti-seismic design of the reinforced concrete coupling beam encased steel truss. |
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