New Rock bolting technology

(Formatted front inlet tubular)

신기술(NET) 제581호

New Excellent Technology

(주)티에스테크노

Index

1. Summary

2. Problem of existing technology

3. New tubular rock bolting system

4. Product differentiation

against existing technology

5. Patent right and business records

(주)티에스테크노

1-1. Principle and history of rock bolt

- 1 -

ROCK BED NURT

ROCK BOLT

MATERIALS PLATE

History of Rock bolt

▶Shotcrete, Secondary support and Primary support

in NATM

▶Located bolt into the rock bed for resisting collapse

▶Firmly fixed around cutting surface of the ground

Absolutely dependent on ground condition and

installation of supporting process

▶ Apply for a patent by Frölich and Klüpfel (Germany) in 1913 (Delayed due to the First World war)

▶ Resisted patent the first for Rock bolt in 1918(No.302909)

▶ One Point holding support system instead of wooden materials in tunnel

(Wood and cable had used for rock bolting in the initial period)

▶ Most of domestic have taken deformed bar with cement mortar and resin owing to cost

(Adjusting the design by considering ground state → use various types of rock bolts )

(Rock Bolt)

(주)티에스테크노

1-2. Effects of rock bolt and application

Effects of rock bolt

Stampling

Internal pressure

Beam forming

Arch forming Ground forming

Application

Digging

1st S/C

ROCK BOLT

2nd S/C

▶Tunnel

▶Ground digging

▶Reinforcement

- 2 -

(주)티에스테크노

1-3. Rock bolts classification and quality standard

Rock bolt classification

Adaptable for

ground and field

construction condition

▶Material symbol

Deformed bar

Steel pipe

Expansibility steel pipe

Fiber Reinforced Plastic

Cable

▶Way of settled

Front adhesive

Fleet settler

Mixed

Cement mortar

Resin

Friction

Rock bolt quality standard

Diameter(mm)

Material symbolYield strength

(MPa)Tensile strength

(MPa)Ductility rate

(%)

Over Φ25 SD350 Over 350 Over 490 Over 18

- 3 -

(주)티에스테크노

2-1. Increase of accident in tunnel construction

건설현장 사망 사고 속출 비상

Date Place Reasonnumber

of people

9/2HO NAMExpress rail road

Rock bed collapse Dead : 1

9/7Route 36Kwang Bi 1 tunnel

Rock bed collapseDead : 3Injury : 3

9/28Kyung BuExpress

Rail road

Rebar structureCollapse

Dead : 1Injury : 2

▶ Latest accident

3 times of accident in September, 2011

Diversification of design

- considering ground state

Ensure safety

- performing rock bed timbering

Through safety management

Prevention

- 4 -

(주)티에스테크노

2-2. Problem of existing technology (1/2)

Lack of effect of rock bed maintaining

Rock bolt(Φ25)

DesignDiameter(38mm)

Rock blot(Φ25)

RealDiameter(45mm)

To reach perfectly firm up after Rock bolting installation, 7~24 hours need for curing

Difference between design and construct

Construct convenience (Jumbo Drill)

Appearing diameter difference

→Increase of material use : about 1.5 times

- 5 -

InsertingDeformed bar

InsertingIn/output pipe

Bore hole sealing

Injecting Mortar

Complete injecting,Cutting entrance

Assembly nut andDistribution plate

Tighten nut,After curing

(주)티에스테크노

Incongruity Rock bolting Environmental pollution

Loss of adhesion by locating rock bolt

Tough to reach same quality situation

Spilled Ground water

→ loss of materials( mortar, resin)

Environmental pollution by chemicals

Rock Bed

Rock bolt Materials

Rock Bed

Rock bolt Materials

Rock Bed

Rock bolt Materials

■ Congruity Rock bolting

■ Incongruity Rock bolting

■ Loss of materials

■ Environmental pollution

- 6 -

2-2. Problem of existing technology (2/2)

(주)티에스테크노- 7 -

2-3. Swellex Bolt(Imported product)

Swellex Bolt

▶ First invented by Atlas Copco, Sweden (1977∼1980)

▶ Approval constructability and safety in mining and tunnel

: : Easy workability and excellent ability to maintain ground

▶ Limited use in domestic( less than 0.5% )

: High cost item, not competitive

: Mostly use in opened cutting surface for coal and mining

[Principle of frictional force in Rock bed ]

Feature of Swellex Bolt

▶ Despite of huge modify, no collapsed just sliding

▶ Strong pressure around rock bed by expansion

: getting combined stress when the bolt push and pull

▶ In purely shear, stay their form without any changed

: flexibility (highly expansibility materials)

(주)티에스테크노- 8 -

2-3. Problem of Swellex Bolt (1/1)

Location and type of fluid inlet

▶ Injecting through small inlet

: 3~4min for expansion (4m)

: after expansion, still stay fluid in tube

: possibility of corrosion by incomplete

drainage system

Non economic efficiency

▶ Limited use in local tunnel

: incomparable due to high price

: problem in purchasing and application

: some of mining use in domestic

Description Unit price Remark

Mn16(Φ54mm, t＝2mm) KRW 72,000

4m Mn24

(Φ54mm, t＝3mm) KRW 100,000

Swellex Bolt(Imported)

Deformed bar(Normal

rock bolt)

KRW 72,000 ~

KRW 35,800(Including materials)

(주)티에스테크노

3-1. Summary of technology development

Principle of technology development

Tubular steel pipe rock bolt : Injecting fluid into the pipe in

high pressure (250~300 bar) for expanding and strongly fixed in

rock bed

- Mechanical gearing and frictional force

- Ground reinforcement technology for quick firm up

[Tubular steel pipe rock bolt]

[Comparing expanded or not]

[All completing Rock bolt]

BeforeAfter

① Inserting Rock bolt

② Expanding ③ Holing in rock bed

※ Sharing same principle but improved shape of inlet, producing

process, cost and so on.

- 9 -

(주)티에스테크노

3-2. New technology performance

Properties of material

▶Carbon steel for machine structural use for good ductility

▶Implementing agency : SGS Construction laboratory

Division Unit Measure Result (max)

Chemicalproperty

C %

KS D 1652 - `07

0.20Si % 0.02

Mn % 0.44P % 0.10S % 0.003

Division Unit Measure Result

Mechanical

property

Yield strength

MPa

KS B 0802 - `03

431 (over 350 )

Tensile strength

MPa 529 (over 490 )

Ductility % 30 (over 18)

A Type B Type C Type

t = 2.0mm t = 2.3mm t = 2.3mm (zinc galvanizing)

Type of product

- 10 -

(주)티에스테크노

3-3. Method of manufacture

- 11 -

Circle steel pipe

Attach Cap and Injecting inlet

Processing

Internally fold the pipe

Attach adhesive member

(주)티에스테크노

3-4. Component and feature

Top Body Bottom

1. Top

2. Body

3. Bottom

▶ Top (Fluid inlet)

- to inject fluid into the body, connected steel pipe

- Front inlet : smoothly injecting and drainage

▶ Body (Folded steel tube type)- part of expanding by hydraulic pressure: shape of folded steel tube

: Diameter : normal : 34mm → after expanding : 48mm

▶ Bottom- perfectly sealed to protect leaking water when the body expanding

- 12 -

(주)티에스테크노

3-5. Effect

Quick firmed up

Efficiency

Adaptable

Eco-friendly

Easy workability

Expand tubular pipe, strongly settled on rock bed

Mechanical gearing and frictional force between rock

bed and Rock bolt

Lightweight product, improved the operation speed

Identical quality using hydraulic system

Not include cement mortar and resin

Harmlessness in human and nature(underground water)

Crushed zone : strong frictional force in crushed rock

radial expanding

Water zone : construct without fixedness materials

Localization and systematization of mass production

Cost efficiency and importing substitution effect

- 13 -

(주)티에스테크노

3-6. Construct procedure

① Preparing Rock bolt and pump ② Drilling for rock bolting③ Insert Rock bolt around

drilled area

⑥ Result conformation④ Rock bolting (pipe expanding) ⑤ Done (within 2 min)

Tubular steel pipe rock bolt

Pump

Hydraulic pressure machine

Connecting

hose

- 14 -

(주)티에스테크노

4-1. Product differentiation against existing rock bolting

Improved safety Excellent in !!!

▶ Exhibit frictional force immediately on rock bolting area

▶ Prevent the accident which is able to happen in tunneling such as rock falling

Division Tubular pipe Rock bolt Existing Rock bolt (Deformed bar)

Method High pressureCement mortar

Resin and so on

Time ofFirmed up

Immediately after

installation

Curing period

(7~ 24hours)

Feature

■ Quickly fixed

rock bolt

■ Prevention of

rock falling and

displacement spread

from relaxation

■ Early strength

insufficiency

■ Possibility of

rock falling

during their curing

- 15 -

Insert deformed bar

Insert In/Out pipe

Seal the bore hole

Injecting mortar

Bending the inlet

Install the nut and distribution plate

Tighten nut

Done

strongly stick with rock bed

High pressure expanding

Insert Rock bolt

(주)티에스테크노

①

②

4-1. Product differentiation against deformed bar

Efficient in time and space Great work in air compression !!!

▶ Reduce Rock bolting time and immediately confirm the stats

▶ Able to manage identical quality

Division Tubular pipe Rock bolt Existing Rock bolt(Deformed bar)

Operation Hour Within 2 minutes

More than 10 minutes

(7~24hr for curing )

Workers 1∼2 people 2∼3 people

Around Water Available Depends on the site

Confirm Immediately Takes longer

[Step for deformed bar]

[Step for tubular pipe]

- 16 -

(주)티에스테크노

4-1. Product differentiation against deformed bar

Eco-friendly No pollutant!!

▶ Harmlessness in human and nature

▶ Available in groundwater flow sector

DivisionTubular steel pipe

Rock boltDeformed bar

overview

FeatureHarmlessness in human

and enviroment 無

Harmful for human and

(use industrial materials)

[Example of environment pollution]

[Loss of material in existing Rock bolt]

[Cement mortar]

[resin]

- 17 -

(주)티에스테크노

4-2. Product difference against Swellex Bolt

시공효율 향상

▶ Inject fluid through the wide Top part

▶ Faster (10∼20 seconds per 4M for expanding time)

Division Tubular pipe Rock bolt Swellex Bolt

Outline

time Within 2 minutes 4 ~ 5 minutes

Feature■ Expanding by hydraulic pressure

■ Wide injecting area

■Expanding by hydraulic pressure

■Narrow injecting area

- 18 -

Shorter construction time!!!

Injecting areaInjecting area

(주)티에스테크노- 19 -

5-1. Industrial property and achievement

Industrial property

Advertisement

▶ NETA No.581 : Wide injecting area in Top part

▶ Patent registration No. 10-0972357 : Expandable tubular Rock bolt

▶ Patent registration No.10-1038472 : Rock bolt and supporting method

▶ Patent registration No.10-1038476 :Rock bolt and supporting method

▶ Patent application No. 2010-0106891 : Rock bolt, hydraulic pressure and

other six difference applications.

NETA 1time, Patent registration 3 time, Patent application 7times

▶ Best thesis award at Korean Society of Civil

Engineers (KSCE) 2011

▶ Hold a 30th Anniversary symposium for Korean

Society for Rock Mechanics (KSRM) 2011

▶ Hold a conference for Korean Society for Railway

▶ Report to Korean Tunneling Association

“ Applicability of tubular pipe Rock bolt ”

(주)티에스테크노- 20 -

5-2. Site test(1-1)

Site outline

Test of expanding

숏크리트

[Before the expanding] [After the expanding]

▶ Location : In-cheon subway 212 sector (T/K)

▶ Rock bolt testing during the ventilating opening

excavation work(Depth=26m, Type: Banded gneiss)

▶ 3times of testing (L=4m)

(주)티에스테크노- 21 -

Construction sequence

Endure in 18tons loading (Reference : SGS Korea Co,Ltd)

① Drilling for Rock bolt ② Insert the Rock bolt ③ Rock bolting (pipe expanding)

④ Done ⑤ Pull out test

5-2. Site test(1-2)

(주)티에스테크노- 22 -

5-2. Site test(2-1)

Site outline

Site situation

▶ Location : Busan subway Line No.1 and 4 Sector(T/K)

▶ Horizontal and vertical drilling mostly Sedimentary rock around

▶ 3 times of testing (L=3m, 4m)

[Situation of underground ] [Rock bolting plan]

(주)티에스테크노

Construction sequence

Endure in 18tons loading (Reference : SGS Korea Co.Ltd)

① Inspection ② Testing Rock bolt ③ Insert Rock bolt

④ Rock bolting (pipe expanding) ⑤ Pull out test

5-2. Site test(2-2)

- 23 -

(주)티에스테크노

Address : 7F 190-15 Bangi Dong Songpa Gu Seoul Korea

Mobile : +82-10-3792-0411 / Kyle Lee ( Director )

Tel : +82-2-3432-0411 Fax : +82-2-3432-0413

E-mail : kyle@blkorea.com