Evaluation of Thermal and Incremental Construction Effects for Monoliths AL-3 andAL-5 of the Melvin Price Locks and Dam

摘要

Two monoliths, a gate monolith and a chamber monolith, from the auxiliary lock atMelvin Price Locks and Dam near Alton, Illinois, are used to explore and evaluate the effects of creep, shrinkage, thermal loads, and construction sequence on massive concrete structures. The material and structural modelling, analysis procedures and software, and results are thoroughly discussed. The nonlinear material subroutines used to model aging modulus, autogenous shrinkage, creep, and smeared crack capabilities are described and discussed with regards to their use in modelling the structure and analyzing structural behavior. These parameters were used to perform a thorough parametric evaluation of their effects on massive concrete structures. The structural models for each monolith and its pile/soil foundation for both the thermal and mechanical analyses are provided. A detailed discussion regarding incremental construction for simulating construction is presented. The incremental analysis procedure was that the lift heights in the gate monolith could be extended in various regions resulting in a minimum savings of $720,000. Each aspect of the modelling and the results are thoroughly discussed and documented through the use of time history plots of critical location temperatures, stresses and strains.