HIGH SPEED SINKING BY MECHANIZED SINKING METHOD

GROUP : A-24th SEM

MINING ENGINEERING

The mechanisation of mine development is becoming increasingly important in the mines with increased emphasis on safe and efficient mining. While the process technology of boring machines deployed in mechanical tunneling and their auxiliary equipment have advanced rapidly, the methods used in today's shaft construction are still comparatively conventional.

INTRODUCTION

To achieve high sinking rate in deep underground excavationsDrilling upto higher depth coping with different hydrogeological conditionsReducing cost

OBJECTIVES :-

Factors responsible for the low degree of mechanization

Presence of groundwater

Geology

Depth

Construction lining/blind-enlargement

Area of the cross–section

Types of sinking operations

Sinking Operations

Series system

Parallel system

Simultaneous system

Series system :sinking with non-simultaneous face advancing and erecting of permanent lining.

Parallel system : sinking with simultaneous face advancing and permanent lining erection in certain distances behind the face.

Simultaneous system : advancing the face with simultaneous and erection in the same shaft section.

Sinking operation:

VSM series:

MECHANISED SHAFT SINKING MACHINE

Developed by HERRENKNECHT AG in Kuwait-2003

Best for water bearing soil Generally for shallow shaft( can also be used

for deep shaft) Based on technology of roadheader boom

and cutting drum Machine can also be operated remotely in

water submerged condition

VSM (Vertical Shaft machine)

It comprises of two main structures:- Upper support / thrust frame.

This is made up of six main pieces when fully dismantled, it is normally broken down into two halves which can be transported on a low loader flat black lorry.

Rotary Cutting Unit.This comprises a circular frame which hydraulically clamps to the leading section of the cason, this supports an inner rotary ring which carries the cutting boom. The inner ring is hydraulically rotated through 360 degrees by two high torque slow speed motors. The ground is excavated by a Dosco hydraulic axial boom rated at 110 kW, the boom movements being automatically computer controlled.

Parts of VSM and working

Model specificationsVSM 8000 Can work upto 28 mtr

depth In a rock compressive

strength of 60 MPa Shaft dia. : 6m and 8m

VSM 2500 Can work to a depth of 100 m

In a rock of 85 Mpa strength

VSM 9000 Shaft depth : 23 m Internal dia. : 9 m

VSM 7700 Shaft depth 85 m Internal dia. : 7.7m

VSM 9600 Shaft depth: 160 m For very hard rock

Models of VSM:

VSM

VSM 9000

VSM 9600

VSM 7700

Developed by Herrenknecht AG in collaboration with Rio Tinto

for the mechanised excavation of deep vertical blind shafts

In hard rock conditions (125MPa rock strength)

Can work upto 500 m (experimental)

based on the use of a rotating cutting wheel excavating

SHAFT BORING SYSTEM(SBS)

The excavation process is divided into two steps: • trench excavation to a depth of one stroke

with the cutting wheel rotating around its horizontal axis and being pushed downward in the shaft direction

• excavation of the entire bench (face) area by slewing the rotating cutting wheel 180° around the shaft vertical axis.

SBS excavation process

The cutting wheel has a diameter thatequals the excavation diameter of the shaft (10–12 m). It is equipped with disc cutters at the periphery and the side areas. The frontloading disc cutters have a diameter of 48 cm with a narrow cutter ring design. The cutting paths of the disc cutters are circular.

Working operations in SBS

Mucking is primarily done by two ways : By fore bore hole Hydraulically through pipe lines

The shaft sinking machine has steel ropes attaching it to the sinking unit which is located on the surface.

Mucking

Mechanized mucking

• Time and effort consuming job.• Depends upon the rock fragmentation• Most efficient in medium sized fragmentation. There are several types of muckers like:i. Scrappersii. Overshot loaders on caterpillariii. Cactus grabiv. Cryderman muckers

They can be electrically ,pneumatically or hydraulically driven.

Mucking units

www.herrenknecht.comhttp://www.microtunel.com/71_vsm.htmArticle on “ Shaft sinking equipment” on the

site http://daz24.depdf documents from random sites.

References :-