详情

原文传递 Composite Action during Construction of Steel Trapezoidal Box Girder Bridges.

题名：	Composite Action during Construction of Steel Trapezoidal Box Girder Bridges.
作者：	topkaya, c. yura, j. a. williamson, e. b. frank, k. h.
关键词：	shear studs, bracing forces, strength, performance evaluation, loads(forces), specifications, concretes
摘要：	In steel trapezoidal box girder bridge systems, the U-shaped steel girder is designed to act compositely with the concrete deck to form a closed box for live loading. During the construction stage, however, the behavior is not well understood. The usual practice of assuming the system to be non-composite during construction requires substantial top flange bracing to form a quasi-closed box section. Field studies have Composite box girders with live loading, and girders during construction, have to be evaluated during the design of curved steel trapezoidal box girder bridges. Considering both cases, the design for construction loading is the least understood and is the most important. Stresses due to construction loading can reach up to 60-70 percent of the total design stress for a given cross section. A three-phase study was undertaken to investigate the behavior of curved trapezoidal box girders during construction. In the first phase, laboratory tests were performed to investigate the shear transfer between the concrete deck and steel girder at early concrete ages (hours, not weeks). In the second phase, an easy-to-use finite element program, UTrAp, was developed for the analysis of these systems under construction loads and is documented in CTR Report 1898-3 (October 2002). The program has the capability of modeling the effects of semi-cured concrete. The third phase focused on the monitoring of two curved trapezoidal box bridges during construction. The measured forces and stresses in the field were compared with the analyses using the developed software. Findings from laboratory and field tests revealed that composite action develops at very early concrete ages. The developed software provides good correlation between measured field data and computed results. / NOTE: Research rept. (9/1/2001-8/31/2002). / Supplementary Notes: Sponsored by Texas Dept. of Transportation, Austin. Research and Technology Implementation Office. and Federal Highway Administration, Austin, TX. Texas Div. / Availability Note: Order this product from NTIS by: phone at 1-800-553-NTIS (U.S. customers); (703)605-6000 (other countries); fax at (703)605-6900; and email at orders@ntis.gov. NTIS is located at 5285 Port Royal Road, Springfield, VA, 22161, USA.
总页数：	u0718；54p
报告类型：	科技报告