City prototype dolos static response with FEM models using geometrically 

 identical boundary conditions. The FEM stresses, which were due only to self- 

 weight loads, were 10 to 20 percent of the prototype stresses, indicating that 

 the bulk of the prototype static stress is due to the wedging loads. The 

 wedging loads are a function of the dolos weight, dolos slenderness or waist 

 ratio, unit-to-unit friction, and several other secondary variables. Scaling 

 the unit surface friction correctly is therefore critical, but difficult, 

 because it increases with time due to nesting and progressive exposure of 

 aggregate at the spalled contact surfaces. Because the unit-to-unit friction 

 is difficult to model in the small-scale units and little is known about the 

 long-term changes of the surface friction coefficient, current design guidance 

 must rely on prototype level static measurements. 



Final Dolos Design 



90. In the final design phase, illustrated in Figure 10, the 

 individual EPFs from the physical model study will be combined into a single 

 design EPF using the methods outlined in Part II. The maximum likely stress 



Maximum Principal Stress 

 Exceedance Probability 



Figure 10. Dolos final design 



40 



