Study and Numerical Analysis on Seismic Performance of Concrete U-Shaped Shear Wall

Table 3

Experimental phenomena of URC-X.

	Observed results
kN	No obvious cracking of specimens
kN	Horizontal cracks appear at the interface between the web and the wall limb, tending to develop downward-inclined cracks, and the shear wall is in the cracking stage
kN	Wall limb 2 steel bars yield first under tension, and the specimen enters the yield stage
Δ = 10∼30 mm	The horizontal cracks between the web and the wall limb gradually develop into oblique cracks with an inclination angle of 20°–60°.
Δ = 30∼40 mm	The concrete at the bottom of wall limb 2 was slightly exfoliated, and the cracks at the bottom formed “V” and “X” shapes, and the crack width gradually increased. The distribution of cracks at the wall limb was dense at the abdomen and sparse at the end
Δ = 40∼50 mm	Steel bar buckling at the junction of wall limb 1 and web, outward expansion, spalling of the external concrete protective layer, concrete crushing of the three-sided wall, a sharp drop of horizontal load, and specimen failure