kinyume na matarajio ya awali kwamba bwawa hilo litatumia miaka 2 kujaa lakini sasa limetumia mwezi mmoja tu kujaa na sasa maji yanalazimika kupunguzwa
Maswali ni mengi ambayo hayajajibiwa kitaalamu na watu wa Mradi wa JNHPP
TOKA MAKTABA:
JNHPP halijaanza uzalishaji umeme wowote kwa kuwa ujenzi wake unaendelea chini ya changamoto kubwa
Maelezo ya mhandisi katika mradi wa bwawa la umeme la JNHPP Rufiji kwa mh. Naibu Waziri Mkuu, jinsi ya kuimarisha mwamba ambao ndiyo msingi wa ukuta na tuta la bwawa la JNHPP Rufiji kitaalamu zoezi linaitwa grout curtain.
Hivyo kwa sasa maji yanafunguliwa kwa wingi yasijaze bwawa maana linaweza kubomoka kutokana na michoro ya ramani ilivyotaka haikufuatwa.
ZIARA YA NAIBU WAZIRI MKUU BWAWA LA JNHPP TAREHE 18 September 2023
Mhandisi wa mradi anafafanua kwa naibu waziri mkuu aliye pia waziri wa nishati Mh. Dotto Biteko juu umuhimu wa kufanya
grout curtain kuimarisha msingi wa bwawa kuzuia maji kupenya ktk msingi / foundation kuzuia hatari kubwa ya dhahiri :
View: https://m.youtube.com/watch?v=Y8CkZ4Za7Gw
A vertical section through a concrete dam is shown here. The stored water is on the left and the grout curtain is shown in black, with the drainage curtain downstream of it also in black.
An exaggerated example is shown at a concrete gravity dam where wide cracks in a foundation permit seepage to pass under the dam and emerge downstream.
downwards, counteracts against the water pressure to stop the dam overturning about the downstream toe.
3. If there is no grouting under the dam seepage can potentially pass along open cracks at its base and exert pressure upwards. This acts to reduce the effect of the dam's weight and therefore reduces its safety.
The illustration shows a dam tilting about its downstream toe because the dam has insufficient weight to withstand the combined effect of storage pressure and uplift pressure.
4. However, if a grout curtain intercepts the seepage and thereby cuts off most of the uplift pressure, the dam's stability is improved.
This dam failed because of foundation problems.
Blocks of it tilted around the downstream toe and were then washed downstream by the suddenly released water. One of them remained and can be seen lying on its back beyond the two blocks which did not fail.
CHANGAMOTO :
Injinia akielezea changamoto iliyowakuta wakandarasi mainjinia bwawa la Aswan Dam nchini Misri na anafafanua njia ya kukabiliana na uwezekano wa bwawa kuvunjika kwa kutumia utaalamu wa kiuhandisi kuzuia hatari hivyo kwa mbinu ya ziada kuimarisha msingi na tuta kwa kufanya
grout curtain kuziba nyufa zinazoweza kupenyeze / kuvuja maji chini ya msingi / foundation.
Grout curtain :
THE CONSTRUCTION CHALLENGES ASWAN HIGH DAM, EGYPT
View: https://m.youtube.com/watch?v=0VaCxQnrAFYThe designing of the Aswan High Dam faced many difficulties, for it has to be constructed on a pervious foundation in the lake of the existing Aswan Dam.
The whole extent of the main dam foundation will be covered with a layer of compacted dune sand about 82 feet deep.
The rockfill above this layer will have a clay core made of Nile silt. The dam will be protected against seepage by two lines of defence, a horizontal impervious blanket in the upstream part and a vertical grout curtain descending in the pervious bed of the river to a depth of 690 feet until it strikes natural bed rock.
This grout curtain will plug the voids in the layers of sedimentary materials underneath the dam.