Seismic behavior of lap lengths for precast concrete shear walls assembled with improved grouting-anchor connections

An improved grouting-anchor connection method of precast concrete shear walls (PCSWs) is proposed. The connection was composed of filling grouting material in metal corrugated pipe, used to effective the overlap of steel bars between walls, as well as surrounded spiral stirrups complete valid constrain. This paper focuses on the influence of the lap length of the connecting steel bar on improved connection for precast concrete shear wall in order to explore the seismic performance based previous research results. Four precast concrete shear walls with improved grouting anchorage connection with lap length of 0.7la (25d) and 0.9la (32d) (la as the anchorage length of tensile steel bar, d as diameter of steel bar) and two precast concrete shear walls with traditional grouting anchorage (TGA) connection with lap length of 0.9la experiments under cyclic loading were carried out. Experimental findings indicated that a lap length of 0.7la offers seismic performance comparable to that of 0.9la, accompanied by only slight reductions in ductility, stiffness, and energy dissipation. Therefore, 0.7la is recommended for enhancing construction efficiency while maintaining an acceptable performance trade-off, whereas 0.9la is more suitable for conservative design. Further seismic behaviors analysis of different lap lengths, 0.7la (25d) to1.6la (56d), as well as traditional direct anchoring connections were studied by ABAQUS. Finally, a new shear calculation formula on the lap lengths of these improved connection has been proposed and verified as well.