Hello, friends in this article I am going to tell you about “Types of Culverts”. Here I have described Slab Culvert, Box Culvert, Pipe Culvert, Arch Culvert with images to make you better understand. So to get full knowledge please read it carefully one by one.
According to NRS 2045, bringing structures of span less than 6m are referred on culverts structure and with span in between 6 to 20 m are referred on the minor bridge.
A culvert is a closed conduit placed under embankment to carry water across the roadway. It is classified as the cross-drainage structure and used extensively in the road drainage system. In fact, more than 75% of the cross-drainage structure are culverts.
Culverts are preferred than a minor bridge because bridge surface forms a part of the carriageway.
Where on top of the culvert is always beneath the carriageway. A culvert does not change the driving condition since there is always some 50 cm thick backfill embankment above it.
At first, I would like to tell you about the different types of materials used for different types of culverts.
The materials used to construct in different types of culverts are given below
4) metals like aluminum, iron
5) Polyethylene having a high density
Culverts are provided according to place and load applied on it, but generally and mostly used culvert is a concrete culvert. So, it may be constructed at the site or maybe pre-casted at the factory.
It is located at the place where the drainage or river passed through the Transportation system like Road.
Types of culverts are given below:-
1) Slab Culvert:- These culverts have masonry abutment with stone over them. In localities where stone patties are not available RCC slabs are used.
RCC slab is designed as simply supported slabs and the span of RCC slab maybe about 3m. where the water opening is less than 15m, and the road crosses the waterway in a relatively high embankment, slab culverts are used.
Multiple slab culverts may be used for the large waterway. These culverts should be located where the road crosses a valley, where there is a stream, watercourse should not move. A minimum freeboard of 0.5m is required in this type of culvert.
Advantages and Disadvantages of Slab Culvert are given below
|1) It is the network acting as a repeater.
|1) It does not have bottom slabs to prevent scouring.
|2) It is very strong.
|2) It require separate foundation to support slab on it.
|3) It can bear the weight of heavy vehicles.
|3) It is expensive than others.
|4) It is easy to design.
|4) Large span slab may affected by heavy vehicles.
2) Box culvert:- These culverts are constructed where the nature of soil below foundation is not suitable for individual footing under piers and abutments.
The size of the rectangular passage should not be less than 60cm X 60cm for easy cleaning of debris. RCC rigid frame box culvert whose height rarely exceeds 3m. These culverts have superior durability due to debris, garter hydraulic efficiency and larger life spans.
Advantages and Disadvantages of Box Culvert are given below
|1)A separate foundation are not required.
|1) Heavy vehicles are not allowed to pass over it.
|2) It is suitable wheree soil is weak.
|2) Not very strong compare to slab culvert.
|3) It is economical.
|3) Challenging part to construct is that dry surface is needed to construct.
3) Pipe Culvert:- When the stream carries low discharge and alignment has high embankment, pipe culvert is considered more suitable.
There should be at least 50 cm cover of soil so that the traffic load transmitted on the pipe is of small intensity and without vibrations.
Single or double barrel precast concrete pipe culvert is commonly used for small opening up to 2X2 m. The minimum diameter of the pipe culvert is limited to 600 mm to facilitate cleaning and avoid blocking.
The standard length of the RCC pipe is fixed at 2.5m, Jointed by color or tongue and groove. Pipes may be made of stoneware, concrete, RCC, etc. The standard size of pipe culvert is 0.5m, 0.75m, 1m, 1.25m, and 2m in diameter.
Advantages and Disadvantages of Pipe Culvert are given below
|1) It can be constructed of any desired thickness and diameter.
|1) It can be harmful due to organic matter, harmful gas inside the pipe.
|2) Precasted concrete or metal pipe can be used to construct soon.
|2) Big and heavy vehicle are rarely allowed to passes over it.
|3) it is strong and durable.
|3) Site clearance is necessary because pipes may jam due to raw materials like plastic and wood.
|4) Crossing of water is under the structure which prevent from scouting soil.
|4) Limited number of pipes can only be constructed.
4) Arch Culvert:- This type of culvert is preferred under the condition where the high filling is involved and there is heavier loading on the culverts.
Arches may be built from brick or stone masonry or plain cement concrete. The span of each arch should not be kept more than 3m.
The selection of culverts to be used is done on the basis of the availability of construction material and economic considerations.
Advantages and Disadvantages of Arch Culvert are given below
|1) It is a greater hydraulic efficiency.
|1) It is hard to design
|2) It is construct to low budget.
|2) It require more concrete materials to construct.
|3) It is durable and strong.
|3) It is Uneconomical
|4) It have stable foundation.
|4) Suitable only for Large space.
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