1. Robert L. Parker, Sr. Centennial Professor of Engineering, Ferguson Structural Engineering Laboratory, Univ. of Texas, 10100 Burnet Rd., Building 177, Austin, TX 78758 (corresponding author).
2. Warren S. Bellows Centennial Professor of Civil Engineering, Ferguson Structural Engineering Laboratory, Univ. of Texas, 10100 Burnet Rd., Building 177, Austin, TX 78758.