The tunnel engineering is one among the foremost interesting disciplines in engineering. The work is complex and difficult throughout its course, but interesting. The operations and therefore the constructions with Tunnel equipment are administered underground without disturbing the bottom surface.
In most of the cases tunnel construction is dear but it saves time and provides comfort. Large excavation of soil or rock etc. is important for a tunnel construction. With the supplyof recent equipment, tunnel excavation and backfilling has become easier. therefore the required Equipment for tunnel construction are :
Boom type Roadheader is a piece of excavating equipment consisting of a boom-mounted cutting head, A loading device having conveyor-belt, And a crawler travelling track to move the machine forward into the rock face. The cutting head consists of rotating drum mounted in line or perpendicular to the boom having spikes, Compression fracture micro-wheel heads like TBM (tunnel boring machine) used to cut the rock.
Roadheader basically used in uniform kind of rock. Nowadays, Such roadheader is available which can cut the rock having 120 MPA of compressive strength and is generally operated electrically.
Drilling Jumbo (Tam Rock) :
A drilling Jumbo consists of one, two or three rock drill carriages and platform for loading the holes with explosives.After Shotcrete machine, Tam rock is another important equipment in tunnel work use for multiple purposes. The main function of this equipment is rock bolt installation, drilling of rock holes and grouting work. Modern jumbos usually fitted with rubber tyres and diesel-powered, there are also exist variants with steel wheels, to ride on rails and are electrically operated while working.
Air Ventilator :
The tunnels with a length above some hundred meters, mechanical ventilation is unavoidable, therefore the working area becomes very suffocated. It requires proper air to breath; therefore,
the design of a tunnel ventilation system is important. During design of the ventilator system of tunnel we need to consider losses due to leakages, bends, diversions, gradient and length of the tunnel to provide the adequate amount of oxygen into the working area.
The crawler Haggloader is also called as Tyre Belt Haggloader. This is used for the mucking work after the blast is done. The efficiency of the machine varies from 30-80 cum/hr depends upon the type and capacity of the equipment. Haggloader is available in two types depend upon the requirement and purpose of the work.
For Big slopes (<32°) :- Used in Coal-mining and Roadway tunnel etc.
For Level Surface (15°):- Used in Railway tunnel especially.
A loader is a heavy machine used in construction to move load materials such as muck. There are many types of loader, which, depending on design and application, are called by various names as per attachment including bucket loader, front loader, front-end loader, payloader, scoop, shovel, skip loader, wheel loader. The loading capacity of wheel loader varies from 120-160 cum/hr depend upon the size of the bucket and frequency of dumpers.
Dumper is used in tunnel work for shifting muck from tunnel to the dumping yard. The capacity of the dumper used in tunnels is 25 ton. The size of the equipment or vehicle is also depending upon the diameter of tunnel.
Rock breaker is a powerful percussion hammer fitted to an excavator / Backhoe for demolishing rock or concrete structure. Rock breaker powered by an auxiliary hydraulic system , which is fitted with a foot-operated valve for this purpose. The only disadvantage of this machine is that It cannot be moved to distant places due to its crawling action.
Bucket lifter is another important Tunnel equipment used in tunnelling project. It has two major attachments i.e. bucket type or fork lift type. Bucket type is mainly used in grouting work at the top side of tunnel and fork lifter is used for the lattice girder erection work. It is boom mounted machine and having around 11-13 metre of boom with a capacity of 200 kg at the time of full extension of boom.
Concrete Batching Plant may be a device where numerous ingredients like cement, sand, water and other additives is been combined so as to make concrete. Batching is that the process of weighing and introducing the ingredients into the mixer for developing a batch of concrete. so as to know the working rule of a concrete batching plant, it’s important to understandthe various components of the plant. Calibration is another important part in batching plant having frequency 15-30 days depends upon production quantity or client requirement. The capacity of batching plant varies from 30cum/hr- 180cum/hr depend on the need of the location.
Aggregate feeder unit (divided into 4 parts)
Silos (may be of cement, fly ash, microsilica etc.)
Cement Feeder unit
JS1000 Mixer (Capacity varies from 0.5-3.0 cum)
Concrete prepared from batching plant are now transported to the site by the means of special trucks named as Transit Mixer. With this process the material has already been mixed prior to the loading. The concrete mixing transport truck maintains the material’s liquid state through agitation or by the rotation of the drum. The interior of the drum on a concrete mixing truck is fitted with spiral blade. In one rotational direction, the concrete is pushed deeper into the drum and vice-versa. This is known as “charging” the mixer. When the drum rotates in the other direction, the concrete comes out of the drum. The capacity of transit mixers varies from 6-9 cum.
Shotcrete Machine is used to spray concrete under pneumatic pressure having compressor mounted at the top of the machine. This machine is electrically operated while spraying shotcrete. Shotcrete Machine consists of boom, air-compressor, concrete-hopper, electric cable wheel and accelerator tank and is operated with remote control by skilled operator. Calibration of accelerator unit is recommended to meet up the optimum dosage of accelerator in respect to the cement. The capacity of the machine depends upon the size of hose pipe and generally it is kept between 30-40 cum/hr.
MAI pump is very essential tool in respect to the grouting work. It is an automated machine in which we can fix the ingredients like cement, water and anti-shrinkage compound. Before using this machine, calibration becomes very important so that fixed amount of ingredients, are to be added. It is very easy to transport, very compacted and is very useful aspect in grouting purpose.
A crawler excavator may be a self-propelled vehicle designed to dig or grade, or move earth and enormous objects and is assessed by its mode of its operation. the various sorts of excavators include wheeled, walker, towed and rail excavators. associated with tracked tanks widely employed by armies, these crawlers move upon an equivalent rotating wheel systems, but even have the power to dig, pick and transport excavated materials as they proceed. In tunnels it’s widely utilized in face cutting, drainage work or slop cutting works etc
A total station is an electronic/optical instrument used for profile marking, marking of blast holes and erection of lattice girder. Traverse Survey is also done to check the alignment of the tunnel by Total station. It is a electronic transit theodolite integrated with electronic distance measurement (EDM) to measure both vertical and horizontal angles and the slope distance from the instrument to a particular point. Again, the calibration of total station is also important to check any error in the machine.
Crusher plant is a unit of different components which are having different work from screening of the boulder to the crushing and washing of aggregates. plant may be fixed or mobile. It is divided into six components i.e. vibration feeder, crusher, vibrating screen, belt conveyor, central electronic control system, washing unit. Basically, crusher plants are of four types:
Mr. Ankit Ranaut
Mr. Ankit is a Civil Engineer who worked as a Assistant manager in larsen and toubro (L&T) and has rich experience ( 6+) in tunnel projects. He is an Author, Editor and Partner at constructionblogs.in