Mechanical performance and design of

blind-bolted tubular connections

Dr. Fei Xu

Dr. Tak-Ming Chan

Department of Civil and Environmental Engineering

The Hong Kong Polytechnic University

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2

1. Introduction

▪ Component-Based and Full-Scale Connection Investigation

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1. Introduction

Component-based

investigation

Full-scale

investigation

▪ Research Framework

4

▪ Pull-out Behaviour of Modified Bolt in Conf. Concrete: Undergoing

2. Single-Bolt Connection

Specimens

Octagonal hollow

section /mmBolt /mm Con.

GradeB T D0 L Db Lem

D/T

OCT75-3-M16-L60-C30 75 3 181 380 16 60 C30

OCT75-4-M16-L60-C30 # 75 4 181 380 16 60 C30

OCT75-6-M16-L60-C30 75 6 181 380 16 60 C30

Embedded

length

OCT75-4-M16-L0-C30 75 4 181 380 16 0 C30

OCT75-4-M16-L24-C30 75 4 181 380 16 24 C30

OCT75-4-M16-L48-C30 75 4 181 380 16 48 C30

OCT75-4-M16-L75-C30 75 4 181 380 16 75 C30

Bolt size

OCT75-4-M12-L60-C30 75 4 181 380 12 60 C30

OCT75-4-M12-L45-C30 75 4 181 380 12 45 C30

OCT75-4-M20-L75-C30 75 4 181 380 20 75 C30

OCT75-4-M20-L48-C30 75 4 181 380 20 48 C30

concrete

OCT75-4-M16-L60-C20 75 4 181 380 16 60 C20

OCT75-4-M16-L60-C50 75 4 181 380 16 60 C50

OCT75-4-M12-L45-C20 75 4 181 380 12 45 C20

OCT75-4-M12-L45-C50 75 4 181 380 12 45 C50

OCT75-4-M16-L0-C0* 75 4 181 380 16 0 N/A

Extended

blind bolt

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▪ Hollow Octagonal Connection: Experimental Investigation

3. Multi-Bolt Connection

Test SpecimensOctagonal hollow section (mm) End plate (mm) Bolt (mm)

B T D0 L Tp G d dh

OCT150-T4-M16 150 4 362 1600 25 90 16 22

OCT150-T6-M16 150 6 362 1600 25 90 16 22

OCT150-T8-M16 150 8 362 1600 25 90 16 22

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▪ Octagonal Tube-wall Deformation: Experimental Investigation

3. Multi-Bolt Connection

Pre-Tight Test

Blind Blot

Fixed Platform

Measuring Strain

for consecutive 168 hours (7 days)

Bolt Strain Gauge

c. Strain gauge

d. Pre-drilled boltb. Adhesive

a. Syringe

1. Mixing Adhesive

2. Preliminary Heating Mixed b and d

3. Pouring Mixed b into Bolt Hole

4. Inserting Gauge

5. Hot Curing

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3. Multi-Bolt Connection

▪ Octagonal Tube-wall Deformation: Experimental Results

OCT150-T6-M16

Undeformed OCT150-T4-M16

OCT150-T8-M16

3%B

Shear

Fracture

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▪ Bolt-Group & Inclined-Angel Effects of Embd. Bolts: Undergoing

3. Multi-Bolt Connection

Specimens

Octagonal Hollow

Section

/mm

Bolt

/mmCon

.

Gra

de

No. of

Bolts

B T D0 L Db Lem

D/t

OCT150-4-M16-L100-C30-T1 150 4 362 850 16 100 C30

Two

OCT150-6-M16-L100-C30-T1# 150 6 362 850 16 100 C30

OCT150-8-M16-L100-C30-T1 150 8 362 850 16 100 C30

Embd.

Length

OCT150-6-M16-L50-C30-T1 150 6 362 850 16 50 C30

OCT150-6-M16-L130-C30-T1 150 6 362 850 16 130 C30

Con.

Grade

OCT150-6-M16-L0-C0-T1* 150 6 362 850 16 0 0

OCT150-6-M16-L100-C20-T1 150 6 362 850 16 100 C20

OCT150-6-M16-L100-C50-T1 150 6 362 850 16 100 C50

Group

Effects

OCT150-6-M16-L100-C30-F1 150 6 362 950 16 100 C30Four

OCT150-6-M16-L50-C30-F1 150 6 362 950 16 50 C30

Bolt

Dia.

OCT150-6-M12-L100-C30-T1 150 6 362 850 12 100 C30

TwoOCT150-6-M20-L100-C30-T1 150 6 362 850 20 100 C30

Angle OCT150-6-M16-L50-C30-T2 150 6 362 850 16 50 C30

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▪ Tube-Wall Deformation & Split Washer Fracture

4. Finite Element Analysis

V.S