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Technical Letters

ETL 1110-3-506 Engineering and Design Aviation Complex Planning and Design Criteria for Army Unmanned Aircraft Systems UAS – Historical Copy Expired

This ETL provides guidance and criteria for planning and design of runways and ancillary movement areas that support operations of Army wheeled UAS that are presently fielded. Download: 29/ETL 1110-3-506 Aviation Complex Planning and Design Criteria for Army Unmanned Aircraft Systems UAS.pdf Size: 1.25 MB

ETL 1110-2-576 Engineering and Design Ice-Affected Stage Frequency

This ETL provides guidance on the development of ice-affected stage frequency (SF) relationships and includes a literature review of advances made in the last two decades, as well as case studies illustrating the various methods.

ETL 1110-2-575 Engineering and Design Evaluation of I-Walls

This ETL provides updated technical criteria and guidance for evaluation of existing I-walls. General guidance for performing I-wall evaluation is provided along with detailed updates to existing guidance that focus on three I-wall performance items: the flood-side gap that was discovered at I-walls in New Orleans after Hurricane Katrina; the rotational stability failure mode found to be the critical failure mode for most I-walls evaluated nationwide in the Phase II evaluation; and criteria for consideration Read more

ETL 1110-2-573 Engineering and Design Construction Cost Estimating Guide for Civil Works – Historical Copy Expired

This engineer technical letter establishes uniform guidance to describe methods, procedures, and formats for the preparation of construction cost estimates and construction contract modification estimates and total project costs.

ETL 1110-2-571 Guidelines for Landscape Planting and Vegetation Management at Levees, Floodwalls, Embankment, Dams, and Appurtenant Structures

This ETL provides guidelines to assure that landscape planting and vegetation management provide aesthetic and environmental benefits without compromising the reliability of levees, floodwalls, embankment dams, and appurtenant structures. It is important to note that all minimum guidelines presented herein are just that—minimums. The dimensions of the vegetation-free and root-free zones defined in this document provide the minimum acceptable buffer between vegetation and flood damage reduction Read more

ETL 1110-2-568 Seismic Evalluation Procedures for Existing Civil Works Powerhouses

The purpose of this guidance is to provide an evaluation procedure to be followed to properly assess the seismic performance of existing USACE civil works powerhouses. This evaluation procedure is needed to identify those powerhouse superstructures that may need remediation to assure that they can continue to provide electrical generation critical to post-earthquake on-site emergency response and to the post-earthquake recovery of communities.

ETL 1110-2-566 Advanced Reliability Analysis of Fatigue Cracking in Horizontally Framed Miter Gates

A series of navigational locks and dams along the nation’s inland waterways provide the ability to transport large tonnages of materials and goods efficiently over long distances.  These facilities are operated and maintained by the U.S. Army Corps of Engineers and form a vital part of the transportation economy of this country.  The lock miter gates, which are large steel structures that open and close to allow passage of vessels while maintaining required water pools at the dams, are critical Read more

ETL 1110-2-565 Foundation Engineering: In-the-Wet Design and Construction of Civil Works Project

This ETL will furnish guidance for the planning, design, and construction of foundations constructed in-the-wet for civil works structures. This document covers foundation types, subgrade preparation methods, test programs, positioning systems, installation techniques, quality control procedures, tolerances, case histories, and lessons learned. Traditionally, marine structures have been constructed in-the-dry within a cofferdam using a dewatering system. An alternative method, with potential cost Read more