Seismic Performance of Precast Shear Wall Systems and Connection Details for Underground Structures

Connection details are critical for both seismic performance and constructability of underground precast concrete (PC) shear wall systems. Current traditional wall-to-wall shear connection details present considerable constructability issues. To address this issue, application of cast-in-place (CIP) connecting beams (i.e., cap and waling beams) at the top and midheight of a precast shear wall system was studied. Under the capacity design concept specified in current standards, three test specimens were designed and tested under the reversed cyclic loadings. Of the three, two employed CIP connecting beams. The third, which served as the reference specimen, adopted the traditional ductile connection detail of embedded wire loops. In addition, numerical simulations and corresponding reverse analyses were conducted to identify the effect of wall-to-wall shear connection details on seismic performance of the precast shear wall systems. Although excellent seismic performance can be achieved by using traditional shear connection, satisfactory seismic performance may also be achieved with proper integration of only CIP beams.