Full-scale test and strut-and-tie model of thick plate multiple block anchorage zone

In order to provide the design method for the TPMB (thick plate multiple block) anchorage zone, the full-scale test of the TPMB anchorage zone of the longest cantilever beam was conducted against the backdrop of the cantilever staircase of Shanghai Grand Opera House . The FEM (finite element model) was established and the parameters were analyzed. The stress development of the rebars and concrete at each tension stress concentration position was obtained. The force flow distribution and the local effect forces of the anchorage zone under different influencing factors were investigated. The results indicate that the local bending force in TPMB anchorage zone was minimal. Only the last block experienced the tie-back tension force. As the plate became thinner and the block was positioned farther from the front end of the plate, the local bending force increased. The bursting force was mainly distributed from the anchor to the half of the block length . The single STM (strut-and-tie model) is developed incorporating the bifurcation of the tie-back tension force and the plate thickness. A series-parallel method for calculating local effect forces and reinforcement design in TPMB anchorage zone is proposed. The specification JTG3362–2018 is unsuitable for TPMB anchorage zone, due to the insufficient safety margin of the block stirrups, and excessive use of plate bottom rebars , resulting in the waste of steel. The specifications CEB-FIP and AASHTO are applicable, but the reinforcement are conservative, resulting in low strength utilization rate of reinforcement. The single STM and series-parallel method proposed in this paper are suitable for the TPMB anchorage zone, ensuring structural safety while maximizing the strength utilization rate of the rebars. This study can offer a theoretical foundation for relevant specifications and can serve as a reference for practical engineering applications of the TPMB anchorage zone. • The TPMB (thick plate mutiple block) anchorage zone was firstly studied. • A single STM (strut-and-tie model) is established. • Series and parallel method is proposed for the TPMB anchorage zone. • Specification JTG3362–2018 is not suitable for TPMB anchorage zone. • Specifications CEB-FIP and AASHTO are conservative.