11 Dec 2024

Adaptive Hydraulics (AdH) Version 4.7.1 Sediment Transport User’s Manual: A 2D Modeling System Developed by the Coastal and Hydraulics Laboratory

Abstract: Guidelines are presented for using the US Army Corps of Engineers (USACE) Adaptive Hydraulics (AdH) modeling software to model 2D shallow water problems with sediment transport (i.e., AdH linked to the Sediment Transport Library [SEDLIB]). This manual describes the inputs necessary to use the SEDLIB sediment transport library from within AdH, to perform coupled hydrodynamic, sediment, and morphological computations. The SEDLIB sediment transport library is intended to be of general use and, as such, examples are given for basic sediment transport of cohesive, noncohesive, and mixed suspended sediment loads and bedload.

2 Dec 2024

Adaptive Hydraulics 2D Shallow Water (AdH-SW2D) User’s Manual (Version 4.7.1): Guidelines for Solving 2D Shallow Water Problems with the Adaptive Hydraulics Modeling System

Abstract: Guidelines are presented for using the US Army Corps of Engineers Adaptive Hydraulics modeling software to model 2D shallow water problems. Constituent (nonsediment) transport is also included in this document. Sediment transport instructions are contained in a supplemental user’s guide.

29 May 2024

Finite Element, Petrographic, and Mechanical Analyses of Field-Cored Concrete Fairlead Beam Anchor Rods from Luke Air Force Base

Abstract: The fairlead beam is used to accomplish installation of the Barrier Arresting Kit 12 energy absorber for setback aircraft arresting system (AAS) installations at permanent operating facilities. Typical fairlead beams are affixed to a Portland cement concrete (PCC) foundation pad by a series of anchor assemblies made up of steel anchor rods set in grout inside galvanized pipe sleeves. US Air Force Civil Engineering Center (AFCEC) subject matter experts have identified a pattern of premature failures in these steel anchor assemblies when they are nondestructively inspected during AAS overhauls. The US Army Engineer Research and Development Center was tasked by AFCEC to investigate potential reasons for these premature failures. This report outlines methods and results of a finite element analysis of the anchorage, a visual and petrographic analysis of field-cored PCC anchor rods from Luke Air Force Base, and a mechanical analysis of specimens taken from the anchor rods within the PCC cores. Multiple modes of PCC distress were observed, and corrosion was evident in and around the anchor assemblies. Mechanical testing of specimens from the anchor rods indicated that an inferior grade of steel was used to fabricate these particular assemblies. Finally, observed deviations from design intention are discussed.

11 Jan 2024

Simulated Barge Impacts on Fiber-Reinforced Polymers (FRP) Composite Sandwich Panels: Dynamic Finite Element Analysis (FEA) to Develop Force Time Histories to Be Used on Experimental Testing

Abstract: The purpose of this study is to evaluate the dynamic response of fiber-reinforced polymer (FRP) composite sandwich panels subjected to typical barge impact masses and velocities to develop force time histories that can be used in controlled experimental testing. Dynamic analyses were performed on FRP composite sandwich panels using the finite element method software Abaqus/Explicit. The “traction-separation” law in the Abaqus software is used to define the cohesive surface interaction properties to evaluate the damage between FRP composite laminate layers as well as the core separation within the sandwich panels. Numerical models were developed to better under-stand the damage caused by barge impacts and the effects of impacts on the dynamic response of composite structures. Force, displacement, and velocity time histories were obtained with finite element modeling for several mass and velocity cases to develop experimental testing procedures for these types of structures.

3 Jun 2021

Finite element analysis of quoin block deterioration and load transfer mechanisms in miter gates: pintle and pintle connections

Abstract: The U.S. Army Corps of Engineers (USACE) currently operates and maintains approximately 193 commercially active lock sites with 239 locks and dams spanning nearly 12,000 miles. These networks of water channels are used to transport 600 million tons of domestic cargo, generating $405 billion in revenue annually. Nearly 60% of these structures in operation are over 50 years old and have reached design life. A failure of the miter gates could result in a major negative impact on the economy and on the ability to maintain flood control. Administrators need recommendations to better prioritize maintenance and repair of the USACE miter gates. This work investigated the influence of miter gate’s quoin block degradation on load transfer to the pintle and/or pintle connections. Results of finite element analysis are reported for the quoin block degradation simulated levels of 0%, 25%, 50%, and 75%. The parametric study shows the overstressed regions are the pintle neck and bolt-hole regions. To improve pintle designs so they may better mitigate detrimental environmental based deterioration effects, this work recommends (1) increasing the thickness of the bolt-hole connection region and (2) adding ribbing reinforcement around the neck area of the pintle.

12 May 2021

Development of CORPS-STIF 1.0 with Application to Ultra-High Performance Concrete (UHPC)

Abstract: This report introduces the first release of CORPS-STIF (Concrete Observations Repository and Predictive Software – Structural and Thermodynamical Integrated Framework). CORPS-STIF is envisioned to be used as a tool to optimize material constituents and geometries of mass concrete placements specifically for ultra-high performance concretes (UHPCs). An observations repository (OR) containing results of 649 mechanical property tests and 10 thermodynamical tests were recorded to be used as inputs for current and future releases. A thermodynamical integrated framework (TIF) was developed where the heat transfer coefficient was a function of temperature and determined at each time step. A structural integrated framework (SIF) modeled strength development in cylinders that underwent isothermal curing. CORPS-STIF represents a step toward understanding and predicting strength gain of UHPC for full-scale structures and specifically in mass concrete.

25 Jun 2020

PUBLICATION NOTICE: A Generalized Approach for Modeling Creep of Snow Foundations

ABSTRACT:  When an external load is applied, snow will continue to deform in time, or creep, until the load is removed. When using snow as a foundation material, one must consider the time-dependent nature of snow mechanics to understand its long-term structural performance. In this work, we develop a general approach for predicting the creep behavior of snow. This new approach spans the primary (nonlinear) to secondary (linear) creep regimes. Our method is based on a uniaxial rheological Burgers model and is extended to three dimensions. We parameterize the model with density- and temperature-dependent constants that we calculate from experimental snow creep data. A finite element implementation of the multiaxial snow creep model is derived, and its inclusion in an ABAQUS user material model is discussed. We verified the user material model against our analytical snow creep model and validated our model against additional experimental data sets. The results show that the model captures the creep behavior of snow over various time scales, temperatures, densities, and external loads. By furthering our ability to more accurately predict snow foundation movement, we can help prevent unexpected failures and extend the useful lifespan of structures that are constructed on snow.

17 Jun 2020

PUBLICATION NOTICE: Theory, Formulation, and Implementation of The Cartesian and Spherical Coordinate Two-Dimensional Depth-Averaged Module of the Adaptive Hydraulics (AdH) Finite Element Numerical Code

Abstract: The US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, has undertaken the development of the multi-module Adaptive Hydraulics (AdH) hydrodynamic, sediment, water quality, and transport numerical code. This report documents the mathematical formulation and numerical implementation of the two-dimensional depth-averaged module of AdH.