The Use of Shaft in the Construction of Tunneling

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  • Topic: RAISE, Soil, Georgia Institute of Technology
  • Pages : 6 (1421 words )
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  • Published : October 2, 2012
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A
TERM PAPER
ON
THE USE OF SHAFT IN THE CONSTRUCTION OF TUNNELING

PREPARED BY
OJUBOLAMO OYELAYO OMOLAYO
FPA/QS/10/3 – 0040
LEVEL: HND II

SUBMITTED TO
THE DEPARTMENT OF QUANTITY SURVEYING
SCHOOL OF ENVIRONMENTAL STUDIES
THE FEDERAL POLYTECHNIC, ADO – EKITI
EKITI STATE

LECTURER IN CHARGE
BLD. OLADIPO
SEPTEMBER, 2012 
THE USE OF SHAFT IN THE CONSTRUCTION OF TUNNELING
Shaft construction describes the building of vertical openings such as Raises and shafts. Shafts are vertical openings used for supplying equipment, personnel and support systems in the horizontal tunnel where the pipeline is installed. DEFINITIONS, APPLICATIONS, SHAPES.

RAISINGS
Raisings are driven in the upward direction. They can be vertical or steeply inclined. During raising, gravity assists in drilling and mucking thereby making the process faster and heaper (R.Tatia, 2005) SHAFTS

Shafts are vertical openings which are driven downward. Decisions about the size shape and positioning of shafts and raisings are taken based on the purpose they are intended to serve. Usually circular shafts are preferred in almost all situations because they are very stable. Also, when strata should be built, we can use the advantages or rectangular or elliptical shafts and use their cross sectional areas (R. Tatia, 2005). APPLICATIONS

According to (R. Tatia, 2005) applications of raises and shafts are listed below. (1)Hydro – Electric projects
Surge chamber
Ventilation shaft
Elevator shaft
Pressure shaft
Cable shaft
(2)Water supply
Access or service shaft
Ventilation
Supply riser
Uptake or down – take shaft
(3)Waste water shafts
Drop shafts
Tunnel projects
Ventilation
Accelerators housing
Access
RAISE DRIVING TECHNIQUES
One classification for the raises is based on the application of explosives that is to say with and without explosives while driving. The line diagram below show a classification of raising techniques. Conventional methods

The open rising techniques is used in driving shaft raises which are less than 10meters. Compartment method.
Raising by mechanical climbers; Alimark raise climber.
Alimark Company introduced this technique in 1957, and even today it is often used in driving blind raises which have long lengths. The Alimark raise climber is designed to drive raises up to 100m long or more. There are several kinds of climbers available: pneumatic, electric and diesel. The following are important features of this technique.

It make it possible to drive very long raises, vertical or inclined, straight or curved and mostly rectangular shape. The raise climber can be driven into in safe position using backward guardrails. Because of it features for blowing air and water at the face after blasting, risks of fuel gases are eliminated, and the time required for ventilation is reduced. An additional extension piece can be connected to the platform. Blast hole techniques

Long hole raising
Drop rising
“Drop rising” technique is the advanced version of the “long hole raising” technique. This technique is based on the vertical carter retreat concept. The crater has five holes, one of the holes is at the center and the other four are at the corners, in the method drills, drill parallel holes in the raise direction. After that holes are blasted in stages. Raises of longer lengths, up to 150m can be drilled using this method. Raising by application of raise borers.

The technique can be used to drive a raise between 2 levels in the ground using this technique Raises have been drilled successfully even in poor ground where the soil condition is not very good. A circular shape is obtained from this technique, the machine is set up at the top and drills a hole of 225 to 250m in diameter, to get to the lower level. After that a large reamer bit is put on at the bottom of the drill rod and them it reams up the raise we can execute the reverse procedure by the machine, however,...
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