Mulshi dam, situated about 40 km from Pune, is a storage dam for Bhira hydro power station of Tata Power Company Limited. The dam constructed across the rivers Mula & Nila near village Mulshi during the years 1921-26 is a gravity dam constructed in rubble masonry.
When constructed, the dam was not designed for earthquake forces and uplift pressures. In view of the seismic activity in this region, the dam has been recently strengthened to cater to earthquake forces as well as uplift pressures. Strengthening has been carried out by construction of buttresses in colgrout masonry at the downstream face of this dam. The buttresses 35 in number are 15 m thick and 20 m wide. Under the scheme of strengthening, the Full Reservoir Level (FRL) of Mulshi reservoir has been raised by 1 m to obtain an additional storage capacity of 40 Mm³ and the buttresses have been designed to enable the dam to sustain this additional water load.
The spillway capacity of the dam was designed on the basis of the empirical flood formulae. As required by current design standards the spillway capacity has been doubled to cater to PMF by constructing a new spillway, downstream of the old spillway. The new spillway, constructed in the tail channel of the old spillway, is provided with 7 radial gates each of size 6.5 m x 12 m. installation of Seismograph system and instrumentation system for Remote Operation of Spillway Gates at Mulshi Dam.
TCE Scope of Work
1. Checking structural stability of the existing dam for raised FRL and seismic forces.
2. Engineering for field investigation and tests.
3. Planning and detailed design of buttresses.
4. Flood estimation and flood routing to assess hydrological safety.
5. Hydraulic and structural design of new overflow section and energy dissipation arrangement
6. Technical assistance in obtaining approval of the proposed modifications from statutory agencies.
7. Preparation of Tender Document; enquiry specifications and Bill of quantities for civil works.
8. Strengthening measures like grouting, pointing, shotcrete, guniting, etc., of dam for reducing the seepage/permeability.
9. Detailed construction drawings for modifications to existing Non-overflow section, buttresses, modifications to overflow section.
10. Construction supervision of rehabilitation & strengthening works
11. Inspection of fabrication of automatic tilting gates (36 numbers, each of size 12 m wide x 1.87 m height) & radial gates and inspection of installation works at site.
12. Design, preparation of detailed drawings, procurement support, inspection & expediting services and commissioning assistance for installation of Seismograph system and instrumentation system for Remote Operation of Spillway Gates at Mulshi Dam.