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.
Table of Contents
Preface
Chapter 1 INTRODUCTION
1.1 Background
1.2 Contents of This Book
Chapter 2 SURGE OVERFLOW, WAVE OVERTOPPING AND COMBINATION
2.1 Surge Overflow
2.2 Wave Overtopping
2.3 Combined Wave and Surge Overtopping
2.4 Turbulent Overtopping
Chapter 3 THREE STRENGTHENING SYSTEMS
3.1 Background
3.2 Three Innovative Levee Overtopping Protection Methods
3.3 Material Properties of the Three Strengthening Systems
Chapter 4 FULL-SCALE PHYSICAL MODEL TESTING OF LEVEE OVERTOPPING
4.1 Full-scale Test Model Setup
4.2 Installation of Levee Strengthening Layers
4.3 Instrumentation and Data Collection
4.4 Testing Procedure
4.5 Erosion Check Method
4.6 Scale, Model, and Measurement Effects
Chapter 5 TESTING OF EROSION FUNCTION APPARATUS
5.1 Erosion Function Apparatus (EFA)
5.2 EFA Tests
5.3 Test Results
Chapter 6 HYDRAULIC PARAMETERS OF COMBINED WAVE AND SURGE OVERTOPPING
6.1 Distribution of Incident Wave
6.2 Wave Overtopping Patterns
6.3 Hydraulic Parameters of Surge-only Overflow
6.4 Combined Wave and Surge Overtopping Discharge
6.5 Hydraulic Parameters of Landward-side Slope
6.6 Standardized Analysis of Hydraulic Parameters of Combined and Surge Overtopping
6.7 Shear Stress
Chapter 7 TURBULENT ANALYSIS
7.1 Measurement Setup
7.2 Overtopping Discharge
7.3 Turbulent Intensity of Overtopping Flow
7.4 Turbulent Shear Stress
Chapter 8 HYDRAULIC EROSION ON LANDWARD-SIDE SLOPE OF LEVEES AND CONCEPTUAL MODEL OF SOIL LOSS FROM LEVEE SURFACE
8.1 Hydraulic Erosion on Landward-side Slope of Levees
8.2 Conceptual Model of Soil Loss from Levee Surface
Chapter 9 NUMERICAL STUDY OF COMBINED WAVE OVERTOPPING AND STORM SURGE OVERFLOW OF STRENGTHENED LEVEE
9.1 POM Method
9.2 SPH Method
Chapter 10 NUMERICAL STUDY OF TURBULENCE OVERTOPPING AND EROSION
10.1 Numerical Methodology
10.2 Model Calibration
10.3 Storm surge overflow erosion
10.4 Combined wave/surge overtopping shear stress, turbulence and erosion
10.5 Erodibility and failure of HPTRM-strengthened levee under different overtopping conditions
References
