ABSTRACT
ABSTRACT: All types of collisions of pipelines with water race are frequently solved by elaborating sewer trap constructions. Such constructions are often encountered in sewerage systems when it is necessary to overcome an obstacle and for this reason by main collectors of large dimensions are used. Channels located in close neighborhood to surface water should be constantly monitored, since every damage or failure of the under-river pipeline or channel leading surface water may cause very serious consequences. Municipal and industrial wastes, when in contact with surface water may quickly result in contamination and ecological catastrophe. Surface water disturb water and sewerage balance and in extreme cases, with high pressures applied to the sewer trap construction, they may produce a very quick propagation of the damage and finally, construction disaster. Due to a very specific construction of a sewage trap (most frequently located under watercourses of Rother fix hindrances) it is impossible to repair or replace a pipeline network that is created by sewage trap in a traditional, dig technology. Owing to the development of civil engineering and the use of trenchless technologies, restoring the original condition of pipelines and assuring their safe exploitation are highly feasible. In the paper, examples of sewer traps will be provided and finished projects of sewerage systems rehabilitation, shown. The first structure to comment on will be a waste trap on the main drain of DN1200 located in the region of Pulawy (southeast of Poland) under Kurowka River. The sewer trap is composed of three steel pipeline networks of DN600. Rehabilitation works consisted in making short relining with PEHD modules. The second example will be a steel sewer trap of DN2200 located under discharge water of Thermal-electric power station in Konin (central Poland). Regeneration was made in Maxi-Trolining technology. The aim of this paper is to present trenchless methods of sewer trap structures rehabilitation and explain in detail all technological process as well as by-pass methods and materials solutions applied in pipelines and sewer traps entrance chambers.
