Cantilever failure investigations for cohesive riverbanks

As a cantilever failure involves rapid channel widening and delivers a large volume of sediment into the channel, it is important to understand this mechanism from the river engineering point of view. Different types of riverbank failures have been investigated in several previous studies, but these works have limitations in understanding the complex mechanisms of cantilever failure regarding the coupling of fluvial erosion with that failure. Experiments were thus carried out to assess the underlying mechanisms of cantilever failure using three types of cohesive materials classified on the basis of their percentages of silt–clay content. The experiments showed that fluvial erosion of the lower part of cohesive riverbanks progressively undermines the upper part during the initial stage of a cantilever failure. Tension cracks then develop at the upper surface of the cohesive riverbanks and beam failure occurs thereafter. A mathematical model of cantilever failure was also developed. The model uses a triple-...

[1]  A. M. Osman,et al.  RIVERBANK STABILITY ANALYSIS. I: THEORY , 1988 .

[2]  Athanasios N. Papanicolaou,et al.  Stability Analysis of Semicohesive Streambanks with CONCEPTS : Coupling Field and Laboratory Investigations to Quantify the Onset of Fluvial Erosion and Mass Failure , 2014 .

[3]  Shoji Fukuoka,et al.  Study of Cohesive Riverbank Erosion Mechanism through Analysis of Flow Fields Near and Inside Eroded Bank , 2002 .

[4]  Stephen E. Darby,et al.  An analytical method to estimate failure plane angle and tension crack depth for use in riverbank stability analyses , 2010 .

[5]  Nicola Casagli,et al.  Mechanisms of riverbank failure along the Arno River, central Italy , 2003 .

[6]  A. B. Hald,et al.  Hydromorphological and biological factors influencing sediment and phosphorus loss via bank erosion in small lowland rural streams in Denmark , 2003 .

[7]  C. Thorne,et al.  Analysis of riverbank instability due to toe scour and lateral erosion , 1993 .

[8]  Masanori Michiue,et al.  STUDY ON HYDRAULIC RESISTANCE AND BED-LOAD TRANSPORT RATE IN ALLUVIAL STREAMS , 1972 .

[9]  Takashi Hosoda,et al.  NUMERICAL ANALYSIS OF RIVER CHANNEL PROCESSES WITH BANK EROSION , 2000 .

[10]  Stephen E. Darby,et al.  Experimental and numerical investigation of the stability of overhanging riverbanks , 2013 .

[11]  Shoji Fukuoka,et al.  EROSION EXPANSION MECHANISM OF COHESIVE (SILT) BANK BY THE STREAM FLOW , 1999 .

[12]  J. Hooke.  Magnitude and distribution of rates of river bank erosion , 1980 .

[13]  C. Thorne,et al.  Stability of composite river banks , 1981 .

[14]  J. Best,et al.  Meander-Bend Evolution, Alluvial Architecture, and the Role of Cohesion in Sinuous River Channels: A Flume Study , 2007 .

[15]  T.K.S. Abam.  Genesis of channel bank overhangs in the Niger Delta and analysis of mechanisms of failure , 1997 .

[16]  Laura Nardi,et al.  Modeling Interactions between Riverbank Hydrology and Mass Failures , 2013 .

[17]  Stephen E. Darby,et al.  Identifying the effects of parameter uncertainty on the reliability of modeling the stability of overhanging, multi-layered, river banks , 2011 .

[18]  Kensuke Kobayashi,et al.  Numerical computation of free meandering channels with the application of slump blocks on the outer bends , 2010 .

[19]  Pierre Y. Julien,et al.  River mechanics: Frontmatter , 2002 .

[20]  S. Darby,et al.  Coupled simulations of fluvial erosion and mass wasting for cohesive river banks , 2007 .

[21]  Jennifer G. Duan,et al.  Analytical Approach to Calculate Rate of Bank Erosion , 2005 .

[22]  Yuichi Iwagaki,et al.  I) HYDRODYNAMICAL STUDY ON CRITICAL TRACTIVE FORCE , 1956 .

[23]  Laura Nardi,et al.  An experimental investigation on mass failures occurring in a riverbank composed of sandy gravel , 2012 .

[24]  P. Julien,et al.  Numerical simulation of meandering evolution , 2005 .

[25]  Yasuyuki Shimizu,et al.  Numerical Simulation of Relatively Wide, Shallow Channels with Erodible Banks , 2005 .

[26]  J. Lewin.  Initiation of bed forms and meanders in coarse-grained sediment , 1976 .

[27]  B. Mech.,et al.  River width adjustment. I : Processes and mechanisms , 1998 .

[28]  Raymond Torres,et al.  Hydraulic erosion of cohesive riverbanks , 2006 .

[29]  Yasuyuki Shimizu,et al.  Experimental simulation of meandering in clay mixed sediments , 2010 .

[30]  P. Couper,et al.  Effects of silt–clay content on the susceptibility of river banks to subaerial erosion , 2003 .