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|Title:||Thermal stress analysis of Mississippi River Lock and Dam 26(R)|
|Authors:||United States. Army. Corps of Engineers. St. Louis District.|
Information Technology Laboratory (U.S.)
Bombich, Anthony A.
Norman, C. Dean.
Jones, H. Wayne.
Finite element method
Melvin Price Locks and Dam
|Publisher:||Structures Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Technical report (U.S. Army Engineer Waterways Experiment Station) ; SL-87-21.|
Abstract: This report describes an investigation to analyze selected monoliths of Mississippi River Lock and Dam 26 (Replacement) (L&D 26(R)) for thermal and construction induced stresses using three-dimensional (3-D) finite element methods (FEM). The St. Louis District recommended that one of several commercially available general purpose FEM codes be used to perform the analysis. The guidelines to accomplish the goals of the study were developed into evolutionary four-phase plan. The first phase was to evaluate and select a code from the recommended candidates best capable of modeling the problem. Evaluation criteria included the capability to simulate incremental construction, materials aging, time-stepping, inclusion of a comprehensive element library with capability to easily implement user-defined material models, the ability to model large numbers of reinforcing bars, and have efficient numerical solutions with flexible means for selecting time steps. The program was also required to be user-oriented, be well supported by the developer, and have a high potential for remaining at the state-of-the- art level. After evaluation, a review committee selected the ABAQUS program as the code best suited to solution of the problem. During the second phase, a solution/method verification was performed based on test case problems. Simple problems with known solutions were tested to verify that the ABAQUS program would give exact or reasonable results as appropriate. In phase three a series of two-dimensional (2-D) solutions of L&D 26(R) monoliths L-13 and L-17 were conducted using both ABAQUS and the WES2DT programs. The WES2DT program had been verified during previous projects where 2-D approximations were appropriate. The 2-D solutions ranged from single-step, gravity-only loading through staged, incremental construction thermal stress analyses that included some or all of the effects of temperature, gravity, pile elasticity and creep. The WES2DT program employed a simple creep model. An aging-creep model developed for a related project was used with ABAQUS. Phase four provided for 3-D FEM solutions of the two monoliths. All work was completed for the 3-D FEM analyses except for actually conducting the computer runs. Computer costs and limitations on computer resources prohibited execution of planned computer runs except for one gravity turn-on analysis of L-13. Although the computer runs were not made, complete documentation of the 3-D problem solution up to the actual execution of the computer runs are included in this report. Even though the 3-D analyses, as planned, could not be completed, it was felt that the objectives relating to the conduct of incremental construction thermal analyses of mass concrete utilizing a modern, general purpose FEM code were realized. These included successful 2-D incremental thermal analyses in which all construction, environmental, and thermal properties aspects were adequately handled by ABAQUS. Most of the important aspects of 2-D incremental thermal analyses were also acceptable except for modeling early-age materials properties. Reliable early-age materials properties data did not exist for L&D 26(R) concrete at the time of the study; consequently, aging modulus, creep, and shrinkage data were taken from other test results. This led to calculation of excessive thermal stresses and creep relaxation at early time. Results indicated that concrete stresses and the distribution of pile loads beneath the monoliths are significantly affected by the assumptions made in the analysis such as single-stage gravity turn-on versus staged, incremental construction with temperature effects, and also aging, creep, and shrinkage. Analyses such as described in this report are an effective means for establishing the bases for mass concrete construction temperature control plans. More research is required to fully develop incremental construction FEM analyses in this construction support role as well as to delineate the extent to which incremental construction analyses should be incorporated into structural design. NOTE: This file is large. Allow your browser several minutes to download the file.
|Rights:||Approved for public release; distribution is unlimited.|
|Appears in Collections:||Technical Report|
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