Full-scale Destructive Tests Research Articles

Finite element failure analysis of reinforced concrete T-girder bridges

Failure behaviors of in-situ deteriorated reinforced concrete T-girder bridges under cyclic loading is experimentally observed and a finite element modeling technique to predict the behaviors is developed. In this study, full-scale destructive tests of in-situ bridges are performed by applying cyclic loads up to failure, and modeling techniques for the non-linear finite element analysis of in-situ deteriorated reinforced concrete T-girder bridge are presented. Two in-situ reinforced concrete T-girder bridges were selected for the failure tests and the analysis, one a symmetrically loaded bridge and the other a non-symmetrically loaded bridge. Path-dependent in-plane constitutive laws of cracked reinforced concrete were utilized for material modeling of the analysis. An RC zoning method was applied to two-dimensional finite element modeling of the symmetrically loaded bridge and a combination of frame elements utilizing the fiber technique and layered shell elements were used for three-dimensional modeling of the non-symmetrically loaded bridge. Experimental results indicate that significant load carrying capacity is retained in old reinforced concrete bridges and analysis results show that the manner of modeling of degraded support conditions significantly affects the predicted responses of the capacity as well as the stiffness of the bridges. This significant effect of support conditions of the deteriorated RC bridges is verified and a simple modeling technique for the support condition is proposed to consider the degradation of supports. By applying the proposed modeling to the boundary condition of the bridges, a finite element failure analysis is carried out for the bridges subjected to cyclic loading. Then, the analytical results are compared with full-scale failure test results. The comparison shows that the finite element analysis technique along with the proposed boundary condition can be effectively applied to the failure analysis of in-situ reinforced concrete T-girder bridges subjected to cyclic loading.

Analyzing the Ultimate Capacity of a Precast Segmental Box Girder Bridge

The second State Expressway System (SES) in Bangkok, Thailand includes about 32km of elevated roadway. The precast concrete segmental part of this roadway consists of about 1130 box girder spans of lengths 24.9m to 48.8m. Because of the large investment involved, it was cost-effective to produce a prototype test span, to confirm the adequacy of the design. This paper compares the full-scale destructive test of the span with an analytical analysis of its performance. The test span was designed according to the 1983 AASHTO Standard Specifications and the 1989 AASHTO Guide Specifications for Segmental Bridges. A live load was used, with an overload provision of 27.8t trucks at 11.15m spacing occupying one lane. The span corresponded to the SES standard two-lane ramp; it was 45.25m long, with a 14-segment 10.2m wide deck. Its longitudinal tendons were external, and deviated at three locations within the span. Steel billets were used to induce test loading. Before the test span's ultimate loading, a computer program was run to estimate the span's ultimate behaviour. The paper describes the girder behaviour and the flexural strength analysis. The unbonded computer model adequately predicted the test span's ultimate capacity, and made various other predictions about the span's failure.

VERIFYING THE PERFORMANCE OF STANDARD DUCTILE CONNECTIONS FOR SEMI-CONTINUOUS STEEL FRAMES.

Keywords ABERTAY UNIVERSITY DUNDEE, OVE ARUP, STEEL CONSTRUCTION INSTITUTE STEEL, FRAMES, DUCTILE, STANDARD, CONNECTIONS, SEMI CONTINUOUS, PERFORMANCE, VERIFICATION, DESIGN, DESTRUCTIVE, TESTS, TESTING, DUCTILITY, WEBS, BUCKLING, MOMENTS, ROTATION, CURVES, STRENGTH, RESISTANCE, MODES, FAILURES, RIGID, RIGIDITY, ROTATIONAL, STIFFNESS, PREDICTION, BEAMS, DEPTH... Show All