Design of a Stream Diversion Channel for Bridge Pier Protection Structure Construction

This paper presents the design and hydraulic analysis of a stream diversion channel over the lower Santa Ana River in Riverside County, California, which is used to divert stream in the main channel of the river and create space for constructing the pier nose extension structures for the BNSF railroad bridge over the river. The hydraulic characteristics of the river at construction site are obtained from on field observations and the flow information at nearby National Water Information station of the USGS, and they are used to design the diversion channel. The advanced hydraulic (open channel) analyses, using HEC-RAS River Analysis System, are performed to verify the satisfaction of diversion channel to the project specifications and criteria. In addition, the design of stream diversion system also requires the stability assessments of its several components, including temporary diversion dam, channel bank slope, and bridge sheet pile abutment wall in front of the channel. With thorough evaluations of theses design aspects, the diversion channel is designed successfully and functions well as expected.