DUGLAS ALLIANCE LTD., General Contractor of the Sendje HPP construction realized the Wele river closure on September 12, 2015.
The definition of time of river closure was a crucial issue for the whole construction process as it is connected with weather peculiarities of the construction district, in particular wet and dry seasons following each other. In accordance with the developed scheme of passage of diversion flow, a feeding reinforced concrete structure which forms a part of gravitation concrete dam has been constructed for derivation of water flow while river Wele closure on the left bank. The ed time period of river closure corresponds to the termination of one of dry seasons when the water flow in the river is close to minimum – 95 – 100 m3/s. This decision gave us the possibility to achieve the minimal costs of the works of river closure and we managed to complete the closure in the dry season of 2015.
The works on closure started already prepared areas on the right bank. In advance we have planned the pilings of rock and loamy soil as well as of oversized materials for final closure of closing gap which have been continuously transported for formation of the cofferdams body closing the river. We used 2000 m3 of soil for river closure, the total volume of cofferdams piling equals to 66 000 m3. Due to well-coordinated work of construction subdivision, the river Wele closure has been fulfilled within two days.