The Design and Construction of Ocean Outfall Diffuser for Samut Prakarn Wastewater Management

摘要

The Ocean Outfall Diffuser system is a mechanism for transmitting and dispersing of treatedrnwastewater from the shore to the ocean through a submarine pipeline. The original conceptrnenvisaged a gravity flow pipeline to be installed below the seabed. Among several constructionrnalternatives proposed, the inverted tunnel siphon constructed by a tunnelling technique is preferred.rnThe inverted tunnel diffuser system comprises (1) an onshore shaft and an offshore shaft, locatedrn2,620 m apart; (2) a segmental tunnel with an inside diameter of 2.6 m, connecting the two shafts atrnthe elevations of -26.0 and -23.0 m MSL, respectively; (3) a submarine pipeline (diffuser header);rnand (4) 100 risers spaced equally on top of the diffuser header, extending 0.7 m above the seabedrnfor dispersing the treated wastewater to the ocean. The design, analysis and the constructionrnprocedures of the onshore and offshore shafts, submarine pipeline, and temporary structures forrnlaunching the onshore and offshore shafts are presented in this paper.