Jian Yang

This paper describes an experimental study on the flexural and eccentric compressive behavior of concrete-filled square steel tube (CFSST) beam-columns stiffened with PBL stiffeners. Three types of CFSST beam-columns were fabricated and tested under the flexural moment and eccentric compressive load. Among the three types of columns, the two types of columns were strengthened with the PBL and steel plate stiffeners; the other type of columns was not strengthened. In addition, extensive finite… Show more

This paper describes an experimental study on the flexural and eccentric compressive behavior of concrete-filled square steel tube (CFSST) beam-columns stiffened with PBL stiffeners. Three types of CFSST beam-columns were fabricated and tested under the flexural moment and eccentric compressive load. Among the three types of columns, the two types of columns were strengthened with the PBL and steel plate stiffeners; the other type of columns was not strengthened. In addition, extensive finite element analyses (FEA) were carried out to evaluate the stress distribution. Flexural test results show that failure modes of specimens without stiffeners were different from specimens with the PBL or steel plate stiffeners. The results also demonstrate the distribution of cracks in the concrete was affected by stiffeners and the columns with the PBL stiffeners have the most uniformed crack distributions. The capacity improved by the PBL stiffeners was insignificant. However, the flexural stiffness of the specimen stiffened with the PBL stiffeners was about 20% larger than the unstiffened specimen. Eccentric compressive load test results show the capacity of specimen with the PBL stiffeners was 6.95% larger than the unstiffened specimen. The eccentric compressive capacity decreased with the increase of the eccentricity ratio or slenderness ratio. FEA results show that stiffeners can effectively improve the mechanical behavior of CFSST specimens under bending and eccentric compressive loads. Show less

2015 TRB conference paper

2015 TRB conference paper

This report provides proposed revisions to Section 1.3—Design Philosophy of the AASHTO
LRFD Bridge Design Specifications with detailed examples of the application of the proposed
revisions. The proposed revisions include system factors that can be used during the design
and safety assessment of bridges subjected to distributed lateral load being evaluated using
the displacement-based approach specified in the AASHTO Guide Specifications for LRFD
Seismic Bridge Design or the… Show more

This report provides proposed revisions to Section 1.3—Design Philosophy of the AASHTO
LRFD Bridge Design Specifications with detailed examples of the application of the proposed
revisions. The proposed revisions include system factors that can be used during the design
and safety assessment of bridges subjected to distributed lateral load being evaluated using
the displacement-based approach specified in the AASHTO Guide Specifications for LRFD
Seismic Bridge Design or the traditional force-based approach. Also, the report presents
system factors calibrated for application with bridge systems subjected to vertical vehicular
loads. Show less

2016 TRB conference paper and TRR journal paper