273. In the LWT experiments, as a bar approached equilibrium, its 

 shoreward face appeared to approach the angle of initial yield, followed at 

 later profile survey times by intermediate lower values. This alternating 

 behavior in bar angle supports the concept of a continuous steepening of the 



Q. 

 O 



cx 



2x10 



2x10 



(i?tc/Lo)m 



Figure 24. Comparison of measured and predicted nondimensional 

 horizontal distance between break point and trough bottom 



shoreward slope to a limiting angle followed by avalanching which adjusts the 

 slope to a lower value. Figure 25 shows the behavior of the average shoreward 

 slope of a bar Pj with time for Cases 401 and 501, increasing at first and 

 then having smaller values after a certain initial maximum slope was reached. 

 However, the number of profile surveys is too small to obtain reliable 

 information about the avalanching process apart from circumstantial evidence 

 that it appeared to occur. 



101 



