A Literature Review on the Sediment Transport Process in Shallow-Grade Culverts and Storm Sewers

Sedimentation of fine muddy material in culverts and storm sewers becomes an important issue in Texas coastal plain shallow-grade drain systems. It leads to a reduction inflow capacity with time and an associated high cost of cleaning. It may not be possible to maintain the required 2 feet per second along sewer in time. The objective of study is to conduct an extensive literature review, and field survey to implement physical experiment for quantifying the sediment transport process in shallow grade culverts and storm sewers. The previous studies indicate that culverts or sewers should be designed to transport fine grains as a suspended load and transport granular sediments as a bed load, and to erode the sediment deposition with high flow velocity to achieve self-cleaning. The suspended load, bed load and bed erosion sediment transport equations have been developed as the function of the sediment grain size, the sediment concentration, the slope of the culverts or sewers, the bed roughness. To quantify the sediment characteristics, three samples were collected from the culvert, the ditch and the sewer located in Orange County of southeast Texas. The sieve analysis indicates that d50 are greater than 0.5mm and d65 are greater than 1mm for all the samples. However, more fine particles are included in the sewer sump and ditch than that in the culvert. The ongoing study is to set up a physical model based on the key variables in the previous transport equation to study the transport process in shallow grade culverts and storm sewers.