On the 10th of August 2013 the beautiful town of Tõrva (Estonia) hosted it's yearly spell casting festival Tõrva Loits. This is the sixth time Tõrva Loits is held, bringing to the audience great performances, leading musicians and exciting spectacle in a lovely natural setting.
- a technical report with 29 self-explanatory Figures -
PEHD Manhole and Chamber design stipulates various manufacturing configurations dependent upon actual site conditions. A number of factors including water table height, depth of cover and backfilling materials have significant impact on base configurations.
Where PEHD Manholes and chambers will be installed in areas with high ground water levels, a double bottom construction is recommended, which has to be filled with liquid concrete at the job site. In the case of the double bottom type there are two openings in the upper bottom one is for the filling of the liquid concrete and one is for the venting during the filling process. These openings need to be closed after filling and hardening of the concrete with covers. When installing the manholes up to 1200 mm diameter in ground water, for lift-retention reasons, a backfilling width of at least 50 cm is to be maintained outside and a concrete filling of the benching may be necessary.