METHOD OF DAM CONSTRUCTION

A weir has a function, which is to raise the water level of the river and drain portion of existing water flow towards the right bank and left bank of the river to flow into the channel through a decision of the building irrigation networks. Weir can also be defined as the waterworks were built transversely river, so that the water level of the river in the vicinity rises to a certain height, so that river water can flow through the channel divider tapping into the channel and then to the agricultural lands.

A construction of a dam can be made of the land fill, masonry times, and gabion or concrete. A weir construction is made transverse river and its main function is to stem the flow of the river and raise the level or rate of water level upstream.

The terms of dam construction must meet a number of factors, namely

• weir must be stable and able to withstand water pressure at the time of the flood;

• Making the weir should take into account the strength of the carrying capacity of the ground beneath it;

• weir should be able to withstand leakage (seepage) caused by the flow of river water and streams of water that seep into the soil;

• High weir sill must be able to meet the minimum water level required for the entire irrigation area;

• Form peluap must be taken into account, so that water can carry sand, gravel and stones from the upstream and does not cause damage to the body weir.

Dam construction site selection should be based on several factors, namely

• The state of Topography

o In this case all planned irrigated areas can be irrigated, so it must be seen to be the highest elevation diary rice;

o If the highest elevation that will be irrigated rice fields have known the lighthouse weir elevation can be set;

• From both of the above, the location of the dam in terms of topography can be selected.

• The state of Hydrology

In the manufacture of the weir, which is also a factor to be reckoned with - hydrological factors, because it determines the width and length of the dam and weir height depending on discharge plan. Factors - factors that are taken into account, namely the problem of flooding plan, calculation of discharge plans, effective rainfall, rainfall distribution, unit hydrograph, and flooding in the site or weir.

• Topography Conditions

Judging from the location, the dam must consider several aspects, namely

o The height of the weir is not too high.

o Trace trunk is located in a good place.

• Hydraulic conditions and Morphology

o river flow patterns include speed and direction at the time of the flood discharge;

o The depth and width of the water level at the time of the flood discharge;

o The water level in the flood discharge plan;

o Potential sediment transport and distribution.

• Foundations Soil Conditions

Weir must be placed in a location where the soil foundation is good enough so that the building will be stabilized. Another factor that must be considered also the potential for seismic and potential scour due to currents and so on.

• Implementation Costs

The cost of implementation of dam construction has also become a determining factor for the selection of dam construction site. From several alternative locations also in terms of the least expensive in terms of cost and implementation is not too difficult.

Here is a method of making a weir:

1. Preparation of the dam began with the manufacture of diversion channel (channel diversion) built on the right side of the river

2. The work began with the work on the diversion work by digging the soil and manufacture of dykes to divert the river flow. After the diverted river dam site can be drained through the dewatering process.

Pictures river flow diversion

3. Furthermore weir work continued with the excavation work and the results of excavation excavator transported by dump truck to be discharged to the disposal area or kept as stock for embankment material according to soil type and specification.

 Picture excavation work

4. When you encounter the bedrock excavation, rock excavation work done

5. Selected methods of drilling and blasting, which is on the surface of the rock made blasting pattern. Then make a hole with a rock drill (cradler rock driller) or canal drilling

to fill a number of explosives (Dynamit) and detonator as a trigger

Pictures work on hard ground

6. After blasting, excavation proceeds collected by the excavator and dump truck transported to disposal area

7. Excavated rock by blasting (blasting) is usually difficult to form the basis of the neat suit excavation rock excavation existing line in the shop drawing

8. Next use giant breaker mounted on excavators for shaping and smoothing rock excavation

9. Before the foundation of the dam began concrete work, work to be done is finishing rock surface by cleaning up all loose material and seal the surface with a splash grouting.

10. Splash grouting cement is a mixture of sand and water is poured over the surface of the rock

  

Pictures splash grouting work

11. The next stage is concrete work (concrete) for the foundation, the body weir, eddy pool (stilling basin) and the piers and column

12. On the surface friction occurring weir on the river water where it is assumed there are loose rocks, twigs and tree, therefore it needs to be lined with steel fiber concrete

13. In the motion made weir hoist room building that is a driving machine door, mounted in the form of a pulley (hoist) electrically to raise and lower the door

Hoist room weir motion picture

14. After the main part is done, followed by the building and the apron floor stilling basin floor which followed the work of the backfill with selected material (selected embankment)

15. Bridges made a separate ministry for use in the fabrication of precast prestressed concrete, which was launched by launching method trus

16. The main civil works of the most severe is the manufacture and hoist pier deck, because it requires high precision and accuracy in order to interfacing with the work doors (hydro mechanical) not a lot of difficulty

17. In determining the use of formwork scaffolding on the floor hoist room need special handling because at a height of 28 m, should do the job with a load of hundreds of tons of concrete and sizeable deflection

Image sequence weir body work

  

Picture mounting pillars movable weir and king shore hoist insertion deck

18. Implementation of the motion weir and dam remains a critical path. While work apron, stilling basin and Fishway job is not critical but can be implemented in parallel with the work of appropriate capacity to provide concrete dam per day

19. For the manufacture of concrete pier and column used climbing formwork with two types, namely to wear arch and steel formwork for straight used wood and plywood formwork

  

Image-making pier and concrete columns

20. During the implementation phase pengecoranbeton to the pier there are two types of concrete which should be carried out jointly to avoid connection (cold joint) is between ordinary concrete and concrete mixtures tons of steel fiber mix

21. For both types of concrete are not mixed, use chicken wire on hold with iron rods or wire mesh

22. Pengecorannya performed alternately in a relatively the same between steel fiber concrete and ordinary concrete

23. Proceed with casting parts in elevation above and in accordance with the height of climbing formwork

Pictures casting pier and concrete columns weir

24. To hoist room building walls that originally was ordinary concrete, made innovations into the column and beam steel frame with precast prestressed wall panels (hollow core wall) for walls and roof plate.