Book Description

A broken-back culvert is defined as a culvert in which one or more breaks occur in the culvert profile. An analysis model called Broken-Back Culvert Analysis Program (BCAP) was developed to evaluate the hydraulic performance of such culverts. BCAP uses design inputs of discharge, culvert shape, size, material, and inlet type, culvert profile and tailwater conditions to predict the headwater depth, water surface profile and outlet velocity of a broken-back culvert. Using this information, the user can determine if the culvert is operating satisfactorily or if it needs to be modified by either altering the culvert design or adding an energy dissipator to the culvert. An important feature of BCAP is the ability to predict the occurrence, location, and length of hydraulic jumps inside broken-back culverts. Model results compared favorably to those from tests completed in the Hydraulics Laboratory at the University of Nebraska-Lincoln and to compatible tests from the Federal Highway Administration computer program HY8.