Hydraulics of Levee Overtopping


Book Description

Earthen levees are extensively used to protect the population and infrastructure from periodic floods and high water due to storm surges. The causes of failure of levees include overtopping, surface erosion, internal erosion, and slope instability. Overtopping may occur during periods of flooding due to insufficient freeboard. The most problematic situation involves the levee being overtopped by both surge and waves when the surge level exceeds the levee crest elevation with accompanying wave overtopping. Overtopping of levees produces fast-flowing, turbulent water velocities on the landward-side slope that can potentially damage the protective grass covering and expose the underlying soil to erosion. If overtopping continues long enough, the erosion may eventually result in loss of levee crest elevation and possibly breaching of the protective structure. Hence, protecting levees from erosion by surge overflow and wave overtopping is necessary to assure a viable and safe levee system. This book presents a cutting-edge approach to understanding overtopping hydraulics under negative free board of earthen levees, and to the study of levee reinforcing methods. Combining soil erosion test, full-scale laboratory overtopping hydraulics test, and numerical modeling for the turbulent overtopping hydraulics. It provides an analysis that integrates the mechanical and hydraulic processes governing levee overtopping occurrences and engineering approaches to reinforce overtopped levees. Topics covered: surge overflow, wave overtopping and their combination, full-scale hydraulic tests, erosion tests, overtopping hydraulics, overtopping discharge, and turbulent analysis. This is an invaluable resource for graduate students and researchers working on levee design, water resource engineering, hydraulic engineering, and coastal engineering, and for professionals in the field of civil and environmental engineering, and natural hazard analysis.




Design and Construction of Levees


Book Description

The purpose of this manual is to present basic principles used in the design and construction of earth levees. The term levee as used herein is defined as an embankment whose primary purpose is to furnish flood protection from seasonal high water and which is therefore subject to water loading for periods of only a few days or weeks a year. Embankments that are subject to water loading for prolonged periods (longer than normal flood protection requirements) or permanently should be designed in accordance with earth dam criteria rather than the levee criteria given herein. Even though levees are similar to small earth dams they differ from earth dams in the following important respects: (a) a levee embankment may become saturated for only a short period of time beyond the limit of capillary saturation, (b) levee alignment is dictated primarily by flood protection requirements, which often results in construction on poor foundations, and (c) borrow is generally obtained from shallow pits or from channels excavated adjacent to the levee, which produce fill material that is often heterogeneous and far from ideal. Selection of the levee section is often based on the properties of the poorest material that must be used.




Dam and Levee Safety and Community Resilience


Book Description

Although advances in engineering can reduce the risk of dam and levee failure, some failures will still occur. Such events cause impacts on social and physical infrastructure that extend far beyond the flood zone. Broadening dam and levee safety programs to consider community- and regional-level priorities in decision making can help reduce the risk of, and increase community resilience to, potential dam and levee failures. Collaboration between dam and levee safety professionals at all levels, persons and property owners at direct risk, members of the wider economy, and the social and environmental networks in a community would allow all stakeholders to understand risks, shared needs, and opportunities, and make more informed decisions related to dam and levee infrastructure and community resilience. Dam and Levee Safety and Community Resilience: A Vision for Future Practice explains that fundamental shifts in safety culture will be necessary to integrate the concepts of resilience into dam and levee safety programs.




Risk Management Series; Design Guide for Improving Critical Facility Safety from Flooding and High Winds


Book Description

On August 29, 2005, Hurricane Katrina caused extensive damage to the coast along the Gulf of Mexico, resulting in an unprecedented relief, recovery, and reconstruction effort. This reconstruction presents a unique opportunity to rebuild the communities and public infrastructure using the latest hazard mitigation techniques proven to be more protective of lives and property. Critical facilities comprise all public and private facilities deemed by a community to be essential for the delivery of vital services, protection of special populations, and the provision of other services of importance for that community. This manual concentrates on a smaller group of facilities that are crucial for protecting the health and safety of the population: health care, educational, and emergency response facilities. The Design Guide for Improving Critical Facility Safety from Flooding and High Winds (FEMA 543) was developed with the support of the Federal Emergency Management Agency (FEMA) Region IV in the aftermath of Hurricane Katrina. This manual recommends incorporating hazard mitigation measures into all stages and at all levels of critical facility planning and design, for both new construction and the reconstruction and rehabilitation of existing facilities. It provides building professionals and decision makers with information and guidelines for implementing a variety of mitigation measures to reduce the vulnerability to damage and disruption of operations during severe flooding and high-wind events. The underlying theme of this manual is that by building more robust critical facilities that will remain operational during and after a major disaster, people's lives and the community's vitality can be better preserved and protected. The poor performance of many critical facilities in the affected areas was not unique to Hurricane Katrina. It was observed in numerous hurricanes dating back more than three decades. Several reasons may explain this kind of performance. In many cases the damaged facilities were quite old and were constructed well before the introduction of modern codes and standards. Some of the older facilities were damaged because building components had deteriorated as a result of inadequate maintenance. Many fa¬cilities occupy unsuitable buildings that were never intended for this type of use. Some newer facilities suffered damage as a result of deficiencies in design and construction or the application of inappropriate design criteria and standards. The primary objective of this manual is to assist the building design community and local officials and decision makers in adopting and implementing sound mitigation measures that will decrease the vulnerability of critical facilities to major disasters. The goals of this manual are to: Present and recommend the use of building design features and building materials and methods that can improve the performance of critical facilities in hazard-prone areas during and after flooding and high-wind events. m Introduce and provide guidelines for implementing flooding and high-wind mitigation best practices into the process of design, construction, and operation and maintenance of critical facilities; and To aid in the reconstruction of the Gulf Coast in the wake of Hurricane Katrina, this manual presents an overview of the principal planning and design considerations for improving the performance of critical facilities during, and in the aftermath of, flooding and high-wind events. It provides design guidance and practical recommendations for protecting critical facilities and their occupants against these natural hazards. It presents incremental approaches that can be implemented over time to decrease the vulnerability of buildings, but emphasizes the importance of incorporating the requirements for mitigation against flooding and high winds into the planning and design of critical facilities from the very beginning of the process.













Basics of Foundation Design


Book Description

The "Red Book" presents a background to conventional foundation analysis and design. The text is not intended to replace the much more comprehensive 'standard' textbooks, but rather to support and augment these in a few important areas, supplying methods applicable to practical cases handled daily by practising engineers and providing the basic soil mechanics background to those methods. It concentrates on the static design for stationary foundation conditions. Although the topic is far from exhaustively treated, it does intend to present most of the basic material needed for a practising engineer involved in routine geotechnical design, as well as provide the tools for an engineering student to approach and solve common geotechnical design problems.




Subdivision Design and Flood Hazard Areas


Book Description

Sustainability, resilience, and climate change are top of mind for planners and floodplain managers. For subdivision design, those ideas haven't hit home. The results? Catastrophic flood damage in communities across the country. This PAS Report is out to end the cycle of build-damage-rebuild and bring subdivision design into line with the best of floodplain planning. Readers will get the tools they need to save lives, protect property, and lay the foundation for a better future.




Earth and Rock-Fill Dams


Book Description

This manual presents fundamental principles underlying the design and construction of earth and rock-fill dams. The general principles presented herein are also applicable to the design and construction of earth levees.