CONCLUSIONS 



Mathematical relationships have been derived to describe the failure surfaces in 

 slopes where the assumptions of the infinite slope theory are valid. These relation- 

 ships are general in that they can be applied to conditions of seepage wherein the 

 piezometric level is at any depth below ground surface, provided that seepage is 

 parallel to the slope. The relationships can also be adapted to layered systems, with 

 or without seepage, provided that layering is parallel to the slope. This can most 

 easily be accomplished by treating the material lying above a particular layer as simply 

 a surcharge, or by converting the overlying layers to an equivalent depth of the 

 material for which computations are being made. Use of a digital computer will 

 facilitate computations. 



Applicability of the infinite slope theory to real slopes has been discussed 

 briefly, and it is concluded that no general "rule of thumb" or other criteria can be 

 used to assess its applicability. Each slope must be judged according to its length 

 and according to the soil characteristics and seepage conditions. 



A simplified procedure to account for transition from the active to passive stress 

 states within a long failure mass also has been presented and discussed. It is sug- 

 gested that the simple transition- length idea applied herein to uninterrupted slopes 

 might also be useful in the analysis of some cut slopes. 



General solutions for the failure surfaces in slopes where the assumptions of the 

 infinite slope theory are valid have been derived. The solutions are applicable to 

 layered systems and to any seepage conditions provided that both layering and ground 

 water flow are parallel to ground slope. It is concluded that the infinite slope 

 theory is of limited applicability unless modified. A modification to enable transition 

 from the active to passive stress states is suggested. 



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