原文传递
METHODS TO REDUCE BUILT-IN RESIDUAL STRESSES
IN STEEL BRIDGE DIAPHRAGMS (Phase I)
| 题名： | METHODS TO REDUCE BUILT-IN RESIDUAL STRESSES IN STEEL BRIDGE DIAPHRAGMS (Phase I) |
| 作者： | Jeffrey M. South, PE and Christopher Hahin, PE |
| 关键词： | Bridges; Built-In Stresses; Residual Stresses; Diaphragms; Bascule Bridges; Multi-Plate Girder Steel Bridges; Strain Gages; Strain Relief; Aluminum Alloys; Rubbers |
| 摘要： | EXECUTIVE SUMMARY This investigation determined the magnitude and origin of residual stresses in plate girders, diaphragms and stiffeners built-in during construction. Residual stresses can contribute to crack formation. Three different steel bridges were studied: (1) a multi-girder bridge anchored at the abutments with no center pier; (2) a 4-span continuous multi-girder bridge with piers; (3) a movable, double-leaf bascule bridge. Bridges were instrumented with strain gages at the fabricator. Changes in reference strains were monitored: (a) after steel erection and bolt-up; (b) after deck placement; and (c) after parapet placement. Built-in stresses varied widely. Mean tensile stress was 35 MPa [5.1 ksi], with a standard deviation (SD) of 40 MPa [5.8 ksi]. Mean compressive stress was -51 MPa [-7.4 ksi] with an SD of 39 MPa [-5.7 ksi]. Highest tensile stress measured was 146 MPa [21 ksi]. Methods to attenuate the effects of built-in strain were proposed, including: (1) lower-modulus aluminum and zinc alloys for diaphragm components; (2) synthetic rubber used in shear connectors; (3) new designs which accommodate misalignment, distortion and deflection; and (4) retrofit attachments to X and K-brace diaphragms. The study recommends Phase II resting of proposed modifications which could improve constructibility and durability in actual bridges. |
| 报告类型： | 科技报告 |
相关文献
- Methods to Reduce Built-in Residual Stresses in Steel Bridge Diaphragms (Phase I); Physical research rept. (Final) Mar 94-Dec 99
- EFFECTS OF REMOVING DIAPHRAGMS FROM STEEL GIRDER BRIDGE.
- FATIGUE OF DIAPHRAGM-GIRDER CONNECTIONS.
- Continuity Diaphragm for Skewed Continuous Span Precast Prestressed Concrete Girder Bridges.
- Guidelines for Analyzing Curved and Skewed Bridge and Designing Them for Construction. Final rept.
- Reliability-Based Performance Assessment of Damaged Ships. Final rept.
检索历史
应用推荐
