Tunnel Lighting & Their Types

Different tunneling work and activities can not be completed effectively and acceptably if there is deficient light in the tunnel.

It is recommended that light with a power of 260 lumens for each m2 in the working zone is adequate for appropriate viability of tunneling work.

Following are the circumstance and areas which request satisfactory light in tunnel:

1. Obstructions in the tunnel.
2. In drilling and mucking zones.
3. At the base of shafts.
4. At pumping stations.
5. At underground fix shafts.

Significant Points

In the entire tunnel, adequate lights ought to be introduced in order to decrease the power of the obscurity just as to expand the perceivability of tunnel clients.

The dispersing of lights relies upon various factors, for example, tunnel size, size of the brilliant source, rock surface, and so forth.

The arrangement of risky dull spots during disappointment of the light bulb can be maintained a strategic distance from by giving a bigger number of lights of little wattage as opposed to barely any lights of bigger wattage.

The electrical lighting circuit in the tunnel ought to be isolated into a few free circuits with independent protectors and breaker boxes. Such a game plan would make fixing work simpler. Just the influenced bit can be killed and the remainder of the associations won't be disturbed.

Types of tunnel lights

Following are the four kinds of lights normally utilized in tunneling work:

Lanterns and lamp burning oil

These are utilized during study work. These are taken by hand where required and burning gasoline is utilized to get light from them.

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Published By
Rajib Dey
www.constructioncost.co
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Methods of Repairing Cracks in Concrete

It is generally determined that concrete structures face cracking hassle in the course of its lifestyles. This crack ought to be given extreme and careful attention and repair on proper time. Repairing cracked concrete involves quite a few time and value constraints.

There are several techniques of concrete crack restore. Choosing the ideal technique of concrete crack repair will let you save a whole lot of time, cash and power and might deliver long-lasting results. It is vital to understand the kind and nature of cracks that have appeared inside the construction to have the ability to pick out the most suitable and price-effective technique of restore. It is also vital to recognize the cause of cracks so that it is able to be corrected to preserve the cracks from recurring.

The following are the methods of repairing cracks in concrete:

Epoxy Injections: Epoxy injection technique of concrete crack repair can be used to bond the cracks having greater than or same to 0.05mm opening. This technique is not appropriate for crack is energetic and if the cracks are large in number, or whilst the water leakage can't be controlled.

In this approach, the cracks on uncovered concrete surfaces are sealed through injecting epoxy under the concrete crack. But, it's essential to find and connect the major motive of cracks before injecting the epoxy into the cracks otherwise the cracks will keep on emerging once more and again.

Problems which include leakages and silt contamination harm the efficiency of epoxy, therefore it is recommended to fix these problems earlier than injecting the epoxy to make it remaining longer. The Epoxy injection approach of crack repair requires quite a few discipline and skillful execution so that you need to make sure that the person executing the repairs knows his work.

Epoxy resin loses power while exposed to fireplace or sustained elevated temperatures and fireproofing safety is required for such structural maintenance.


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Published By
Rajib Dey
www.constructioncost.co
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Boring methods of exploration

The boring methods are applied when direct methods can’t work for exploration at deeper depths. On the basis of the method of boring, there are both disturbed and undisturbed samples. While choosing the boring method for a specific job, the following points should be taken into consideration:

a. The materials to be received and the relevant efficiency of the different boring methods in such materials.
b. The accessible facility and the precision with which modifications in the soil and ground water conditions can be set.
c. Feasible disruption of the material to be sampled.

Given below, several types of boring methods:

DISPLACEMENT BORING: It belongs to a combined method of sampling & boring operation. Closed bottom sampler, slit cup, or piston type is pushed into the ground up to the required depth. Then the sampler is removed from soil underneath it, by rotating the piston, & finally the piston is unleashed or withdrawn.

The sampler is then again pushed further down & sample is acquired. After extraction of sampler as well as sample from sampler, the sampler is retained in closed condition & again utilized for another depth.

Features:

a. Simple and inexpensive method if extreme caving is not happened. It can’t be applied for loose sand.
b. Significant modifications of soil character are identified with penetration resistance.
c. They are 25mm to 75mm holes.
d. Fairly continuous sampling in firm and dense soil, either to safeguard the sampler from damage or to get rid of unpleasantly heavy construction pit.

WASH BORING: This method is mostly recognized since limited equipments are employed. Consequently, low-cost and easy portable handling and drilling equipments can be utilized. Initially, an open hole is created on the ground to facilitate the soil sampling or rock drilling operation underneath the hole. The hole is expanded by chopping and twisting action of the light bit. Cutting is performed with forced water and water jet under pressure via the rods working inside the hole.

AUGER BORING: This method is rapid and inexpensive with simple, light, flexible and low-cost instruments for large to small holes. It is very suitable for soft to stiff cohesive soils and also can be used to determine ground water table. Soil detached with this is distressed but it is superior as compared to wash boring, percussion or rotary drilling. This method should not be applied for very hard or cemented soils, very soft soils, since there is possibility for entering the flow into the hole. This method is not recommended for fully saturated cohesionless soil.

ROTARY DRILLING: Rotary drilling method of boring is suitable for extremely resistant strata. It is relevant to determine the rock strata as well as access the quality of rocks from cracks, fissures and joints. It can also be applied in sands and silts also. Here, the depth of the bore holes is extended with rotary percussion method. A heavy string of the drill rod is utilized for choking action. The broken rock or soil fragments are detached with circulating water or drilling mud pumped via the drill rods and bit up via the bore hole from which it is compiled in a settling tank for recirculation. If the depth is small and the soil is stable, water alone can be applied. The drilling fluids play an important role since as they help in stabilizing the bore hole.

PERCUSSION DRILLING: For hard soils or soft rock, auger boring or wash boring are not recommended. For such strata, percussion drilling is mostly used. Here, the hole is expanded by alternatively lifting and dropping a heavy drilling bit which is connected with the lower end of the drilling bit and it is connected with the cable. Once the soil attains it’s bearing strength, churn bit and the slurry are detached with bailers and sand pumps. Modification in soil character is recognized with the composition of the outgoing slurry.

CONTINUOUS SAMPLING: The sampling operation progresses the borehole and the boring is done completely by obtaining samples constantly. To resist the caving in soils, the casing is applied. This method is useful to obtain trustworthy and detail information on soil condition as compared to the other methods. So, it is frequently utilized in detailed and special foundation exploration for vital structures.

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Published By
Rajib Dey
www.constructioncost.co
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