ANALYSIS OF CULVERT APPROACHES WITH PILES OF VARYING LENGTH

Abstract

For the construction of culverts and their approaches on soft and highly compressible  soils,  an innovative  approach  is  to provide  piles with  length decreasing  with distance  from  the culvert.  The  equivalent  stiffness  of  the piled  strip  as  a function  of  the relative length of the piles estimated  from Brown and Wiesner (1976), is bounded by Linear and exponential variations  with distance.  An extended  Pasternak type model is  proposed for the culvert approaches with piles of varying length. The response of the system is shown to be governed by the relative stiffnesses of the granular bed, the culvert foundation, the approaches at the near and far ends and the relative pile length to diameter ratio. The settlement profiles are presented  for the  typical values  of  the above  parameters.  The  relative  stiffness  of  the granular pad has a significant effect on settlements and on the loads transferred to the culvert foundations.