American Journal of Environmental Engineering and Science 2014; 1(5): 104-109

Published online November 30, 2014 (http://www.openscienceonline.com/journal/ajees)

Initial tension forces in guys of steel industrial chimneys at adjustment phase

Bernard Wichtowski, Janusz Hołowaty

Faculty of Civil Engineering and Architecture, West Pomeranian University of Technology Szczecin, Szczecin, Poland

Email address

Janusz.Holowaty@zut.edu.pl (J. Hołowaty)

To cite this article Bernard Wichtowski, Janusz Hołowaty. Initial Tension Forces in Guys of Steel Industrial Chimneys at Adjustment Phase. American Journal

of Environmental Engineering and Science. Vol. 1, No. 5, 2014, pp. 104-109.

Abstract

The free standing and guyed industrial chimneys are the most typical steel chimney structures. Structural system of guyed

chimneys is very similar to masts, in particular, to tube masts. Sometimes steel chimneys with too loose guys are in risk to

collapse. In the paper, the presented results relate to initial tension force adjustments in 10 steel chimneys. The chimneys range

is from 25,0 to 60,5 m of height. Two ways of determining the initial tension forces are described. The measured values of

initial tension forces are presented. Analyses of performance in service conditions are also carried out. All the presented

chimneys required adjustments because they had deviations from verticality and their guys were hanging loosely. The initial

forces in guys at adjustment stages were calibrated to receive adequate horizontal rigidity of the chimney shaft in order to

avoid high normal force in the shaft and to prevent guy vibration. The method of initial tension force regulation in chimney

guys can be adopted for the assessments and adjustments of technical condition in similar structures.

Keywords

Chimneys, Guys, Tension Forces, Adjustment Phase

1. Introduction

The most popular types of steel chimneys are free-standing

chimneys and those with guys. As to the structural scheme and

forms of structure, a guyed chimney corresponds, to a

significant extent, to calculation requirements defined for

masts, in particular, with reference to masts with a tabular

shaft [1-3]. Sometimes guys insufficiently tensioned are the

reason of steel chimney collapses.

Usually initial tension forces in guyed chimneys are

selected so as to:

• obtain a proper initial horizontal rigidity of the shaft

elastic support,

• avoid of too large axial forces in the shaft, resulted from

vertical components of the tension forces,

• avoid vibration of guys.

In the paper, based on the example of the structure of ten

guyed steel chimneys in which adjustments were made, the

results of measurement of initial tension values in guy ropes

are presented. The analyses of the initial guys tension forces

may be useful when evaluating the technical condition of

similar structures and at their adjustment [4, 5].

2. Characteristics of Chimneys and

Guy Ropes Examined

General construction data of the discussed ten steel

chimneys with guys are presented in Fig. 1 and in Table 1. The

chimneys have single flue pipes without thermal insulation of

differentiated construction and height, ranging from 25,0 to

60,5 m. In seven cases, they are rigidly attached constructions

on a foundation with one level of guys, however, three

chimneys with two levels of guys and the height of 46,2 and

2×41,0 m („b”, „d1” and „d2” chimneys) based in an

articulated way on brick pedestals („b”), 7,1 m and 6,0 m high

reinforced concrete pedestals („d1” and „d2”). All chimneys

have single-flue pipe welded of structural carbon steels St3SY

and St3S of diameters ranging from 720 to 1520 mm. Former

Polish steel grades (St3SY and St3S) are similar to European

steel grade S235.

105 Bernard Wichtowski and Janusz Hołowaty: Initial Tension Forces in Guys of Steel Industrial Chimneys at Adjustment Phase

Chimneys were used in a continued way or in season. Each

of them served an independent boiler, using fine coal and the

boilers were not operating simultaneously but in turns. This

had it that each chimney was turned off and cooled in turns.

Chimneys marked with letter and number were of identical

structure.

Differentiated types of ropes were used for guys in the

discussed chimneys. They are steel ropes from tinned wire of

identical diameter of six strands with double or three layer

construction of strands T6×19 („b”, „g1”, „g2”) and T6×37

(„a”, „c”) with organic chord A and ropes W-S6×36+A („d1”,

„d2”, „e”, f”, „h”). The parameters of these ropes, according to

the Polish standards are given in Table 2. In all chimneys,

three guys were applied on every level, placed every 120°.

The angles of inclination from the horizontal level of the guy

chords υ were differentiated and fluctuated from 31,95° to

77,20° (Fig. 1).

At the bottom, the guys were attached in reinforced

concrete anchorage blocks through bolts (Fig. 2) put into the

ropes. Only in the ropes of „a” chimney near the anchorage

block were the tensioning devices assembled which were

adjusted to the connection of a dynamometer. In „b”, „d1” and

„d2” chimneys, the guys of two levels were anchored in one

block (Fig. 2).

In the analyzed ten chimneys, the overhanging sag of guys’

ropes was clearly visible and in some chimneys, deflection of

the shaft axis from the vertical (Fig. 3). For example, the

deflection of „d1” and „d2” chimneys’ tops amounted to 510

and 528 mm, or else was 4,4 and 4,5 times larger than

admitted standard assembling deflection δ = H/300, where H

constitutes the height of the chimney over the foundation.

The occurring rope sag was the proof of a too small value of

initial tension forces in the guys. This was confirmed by

executed field measurements. For example, in the ropes of „c”

chimney, the values of initial tension forces amounted to

2×5,83 and 14,11 kN. This means that the stresses in ropes had

only the values of 25,5; 25,5 and 61,6 MPa.

Table 1. Technical data of the chimney structures

Chimney

(Fig. 1)

Height

[m]

Level of guys

[m]

Shaft parameters Length of rope chord [m]

Diameter[mm] Plate thickness [mm]

1 2 3 4 5 6

„a” 60,50 47,50 1520 7,9÷16,3 56,35

„b” 46,20 38,50; 21,90 720 6,1÷9,8 45,67; 25,97

„c” 45,00 35,00 1016 7,8÷9,6 43,01

„d1”, „d2” 41,00 36,00; 26,00 800 9,1÷9,4; 9,0÷9,4 39,31÷55,07; 30,42÷49,13

„e” 40,00 25,20 920 9,1÷10,02 35,18; 35,60; 18,55 1)

„f” 31,00 22,30 1000 6,7÷7,4 22,86; 25,59; 30,54

„g1”, „g2” 30,00 19,70 820 5,1÷11,8

5,0÷12,1

24,32; 27,02; 25,60 1)

23,85; 24,00; 24,14

„h” 25,00 16,30 820; 1250 8,7÷9,2; 7,4÷7,8 22,50

1) – guys attached on the roof of a boiler house

Fig. 1. General construction data for ten steel chimneys

American Journal of Environmental Engineering and Science 2014;

Chimney

(Fig. 1)

Height

[m] Number of

levels Type

1 2 3 4

„a” 60,50 1 T6×37+A

„b” 46,20 2 T6×19+A

„c” 45,00 1 T6×37+A

„d1” 41,00 2 W-S6

„d2” 41,00 2 W-S6

„e” 40,00 1 W-S6

„f” 31,00 1 W-S6

„g1” 30,00 1 T6×19+A

„g2” 30,00 1 T6×19+A

„h” 25,00 1 W-S6

Chimney Level

(Fig. 1)

Height

[m]

1 2 3

„a” 1 47,5

„b” 2

1

38,5

21,9

„c” 1 35,0

„d1” 2

1

36,0

26,0

„d2” 2

1

36,0

26,0

„e” 1 25,2

„f” 1 22,3

„g1” 1 19,7

„g2” 1 19,7

„h” 1 16,3

a)

Fig. 2. Guy anchorage

American Journal of Environmental Engineering and Science 2014; 1(5): 104-

Table 2. Technical parameters of guy ropes

Guy ropes

φφφφ

[mm]

Am

[mm2]

Weight

[kg]

Rm

[MPa]

Inclination

[o]

5 6 7 8 9

37+A 28 294 2,78 1600 υ = 57,45

19+A 20 151 1,43 1800 υg =61,05

37+A 25 229 2,18 1600 υ = 54,46

S6×36+A 20 170 1,61 1600 υg =56,91

S6×36+A 20 170 1,61 1600 υg =66,31

S6×36+A 22 196 1,86 1600 υ = 45,74

S6×36+A 22 196 1,86 1600 υ = 77,20

19+A 14 72 0,69 1400 υ = 54,09

19+A 14 72 0,69 1400 υ = 55,69

S6×36+A 20 170 1,61 1600 υ = 46,42

Table 3. Values of introduced forces in guys

Tension force of rope [kN]

guy I guy II guy III average value

4 5 6 7

36,7 56,7 59,6 51,0 (50,34)

23,6

24,4

23,6

24,4

23,6

24,4

23,6

24,4

21,0 30,2 43,0 31,4

14,3

18,0

20,0

17,0

23,1

27,4

19,1

20,8

15,5

15,1

16,8

17,6

20,9

21,9

17,7

18,2

16,4 20,6 22,8 19,9

14,7 20,2 31,3 22,1

7,8 9,3 10,9 9,3

8,9 11,1 12,1 10,7

18,9 19,4 20,5 19,6 (19,47)

b)

anchorage systems: a) chimney „a”, b) chimney „b”, c) chimney „c”

-109 106

Inclination angle υυυυ

57,45

=61,05 υd =45,78

54,46

=56,91 ÷41,14 υd =47,85÷32,26

=66,31 ÷40,82 υd =58,71÷31,95

45,74÷41,74

77,20÷46,90

54,09÷35,38

55,69÷54,68

46,42

Stress

[MPa] average value

8

51,0 (50,34) 173,5

156,3

161,3

137,1

112,4

122,4

104,1

107,0

101,7

112,7

128,3

147,6

19,6 (19,47) 115,3

c)

107 Bernard Wichtowski and Janusz Hołowaty: Initial Tension Forces in Guys of Steel Industrial Chimneys at Adjustment Phase

a)

Fig. 3. Guy ropes of chimney „b”: a) before adjustment, b) after tension adjustment

3. Initial Tension Forces of

Guys in the place of connection with chimney

up elastic supports in the horizontal direction.

of such a support depends upon the

inclination angle of the guy, its modulus of

number of guys at a given level and, first of

tension. The forces of the initial tension of

correspondingly to the required horizontal

the elastic support whose calculation has been

6].

The range of initial stress in guy ropes

may be assumed in values recommended for

with a pipe shaft, i.e. ranging from 100

values in Table 3 relate to forces and initial

were introduced in the ropes during shaft

analysed chimneys.

In all 39 guys of ten chimneys, the introduced

tension of ropes of a given level, when

causes in them a stress of values larger than

value recommended in the literature

Corresponding values of forces in guys were

rope tension caused by the shortening of tensioning

the anchorage blocks. For example, in „c”

was shortened by a value of 50, 80 and a 100

very small range of bolts regulation in seven

same time, there was a necessity to shorten

shifting the foundation thimbles.

4. Analysis of Initial Tension

In seven chimneys, the value of initial tension

determined by the dynamic method by counting

vibration amplitudes in a defined time. By

the rope near its connection with anchoring,

was caused and the amplitude of vibrations

deflection) N in time t = 10 or 15 s. The rope

half of its spread is calculated according

obtained from the transformation of the formula,

circular frequency of vibrations [5, 7-9]:

Bernard Wichtowski and Janusz Hołowaty: Initial Tension Forces in Guys of Steel Industrial Chimneys at Adjustment Phase

b)

Guy ropes of chimney „b”: a) before adjustment, b) after tension adjustment

of Ropes

chimney shaft make

direction. The flexibility

diameter, length,

of elasticity, on the

of all, the initial rope

of guys are selected

rigidity (kN/m) of

been given in [1-3,

of steel chimneys

for ropes of masts

to 350 MPa. The

initial stresses which

adjustment of the

introduced average

they are attached,

than the minimum

σo = 100 MPa.

were introduced by

tensioning bolts with

„c” chimney, the bolt

100 mm. Following a

seven chimneys, at the

shorten the rope by

Tension Forces

tension forces was

counting the number of

a sharp jerking of

anchoring, a vertical wave

vibrations counted (full

rope initial tension at a

according to the Eq. (1)

formula, defining the

0.4077GF =

where

FG rope tension in kN,

G total rope weight in kN,

l rope length in m,

N number of amplitudes in time

t time of measuring N vibration

The initial tension force determined

is a force in the centre of guy spread

is determined according to the Eq.

sin cos

2 2A G

G GF F

υ υ = − +

where

υ is the declination angle from

chord.

The difference in the value of

and (2) is insignificant and depends

the rope. For example, for guys

difference amounts to 1,3 and 0,7%

3, col. 7).

The initial tension forces determined

guys of a cold chimney and

assembling temperature T0 = +10°C.

force in another temperature, its

which takes into account the current

following dependence:

G T mF T E Aα υ∆ = − ∆

where

αT coefficient of linear

12⋅10-6

/°C,

∆T difference between the

temperature, is equal Ta – T0,

E0 = 125 (145) elastic modulus

core (metal core) in GPa,

Am metallic area of guy wires

Bernard Wichtowski and Janusz Hołowaty: Initial Tension Forces in Guys of Steel Industrial Chimneys at Adjustment Phase

Guy ropes of chimney „b”: a) before adjustment, b) after tension adjustment

2

2

0.4077 G l N

t (1)

time t,

vibration amplitudes in s.

determined according to the Eq. (1)

spread and its value at FA anchor

Eq. (2):

2 2sin cos

2 2

G Gυ υ = − +

(2)

from the horizontal plane of guy

of forces according to the Eq. (1)

depends mainly on the weight of

guys of „a” and „h” chimney, this

0,7% (FG and FA forces in Table

determined in Table 3 relate to

are referred to the standard

+10°C. For the adjustment of the

its correction ∆FG is introduced,

current temperature Ta, from the

0

2cosG T m

F T E Aα υ∆ = − ∆ (3)

thermal expansion, is equal

the current and assembling

modulus for ropes with non-metal

wires in cm2.

American Journal of Environmental Engineering and Science 2014;

In three chimneys „d1”, „d2” and „e”, the

was adjusted by a direct method of measurement,

the value of forces with the use of the dynamometer

parallel into the rope. The measurement of

out with dynamometers of bow type of 30

dynamometers were assembled in special

member devices, specially prepared for

chimneys „d1” and „d2” these devices were

the ropes of a given fixing level only

measurement (Fig. 4a), and in „e” chimney they

permanently in guy ropes (Fig. 4b). The guy

level took place at the same time in a continued

permanent land survey control of chimney shaft

The permanent fixing of measuring

chimney rope allowed to conduct the measurement

forces occurring in various operating conditions.

analyses was conducted for a chimney out of

and in operation (warm) at external temperatures

and –4°C [8, 9]. The measured values of

ranged from 12 to 29% of the value of

average 22,5% at Text = +19°C and 23,5% at

Theoretically, the operating forces in gu

from the following dependence:

a)

Fig. 4. Guy sections close to the foundation with measuring

5. Conclusions

• All chimneys required an adjustment

simultaneous adjustment of rope initial

standard value because of significant deflection

vertical and a significant sag of ropes.

• As results from the analyses of the guys

section 4, it is not always necessary

tension, according to the Eq. (2). This

particular to guys of a small weight.

• A significant reduction in stresses found

guys causes an increase in the natural

American Journal of Environmental Engineering and Science 2014; 1(5): 104-

the guy initial tension

measurement, related to

dynamometer connected

forces was carried

30 kN range. The

special lock-tension

this purpose. In

were assembled into

only for the time of

they were installed

guy tension of a given

continued manner with a

shaft tilt.

devices into „e”

measurement of real

conditions. Such an

of operation (cold)

temperatures Text = +19

„operating forces”

initial tension (on

at Text = –4°C).

guys are determined

sina p init

e T m

T h T lF E A

l

υ∆ + ∆ =

where

Fe difference in the value

warm chimney,

∆Ta change in the temperature

(measured or calculated) in relation

initial tension, is equal Ta – Tinit

∆Tinit change in the temperature

initial tension temperature, is equal

hp length of a „working”

(distance between the top of inlet

fixed).

The equation (4) was used for

tension forces in „b” chimney guys.

in ropes was carried at Text =

temperatures of the shell for the

guys: h1 = 14,8 m – Tinit = 60°C

(compare Fig. 1).

b)

Guy sections close to the foundation with measuring device: a) chimney „d1” and „d2”, b) chimney „e”

of shafts with the

initial tension to the

deflection from the

ropes.

guys initial tension in

necessary to determine the

This note relates in

found out in chimney

natural period and in the

coefficient of wind operating

increase in the value of bending

• The assumption of the

stresses of a value σ >100

distribution of horizontal load,

side also take part.

References

[1] The CICIND Chimney Book.or Steel, CICIND, Zurich, 2005.

[2] Smith, BW, CommunicationLondon, 2007.

-109 108

0

sina p init

e T m

T h T lF E A

lα

∆ + ∆

(4)

of forces in guys at cold and

temperature of chimney shell

relation to the temperature at

init,

temperature of guys in relation to the

equal Ta – Text,

section of chimney shaft

inlet and the level where guys are

for the determination of initial

guys. The adjustment of forces

+3°C and measured average

the individual sections under the

60°C i h2 = 31,4 m – Tinit = 45°C

device: a) chimney „d1” and „d2”, b) chimney „e”

operating and in consequence an

bending moments [10].

guys initial tension causing

>100 MPa has it that in the

load, the guys from the leeward

Book. Industrial Chimneys of Concrete 2005.

Communication Structures, Thomas Telford,

109 Bernard Wichtowski and Janusz Hołowaty: Initial Tension Forces in Guys of Steel Industrial Chimneys at Adjustment Phase

[3] Rykaluk, K, Steel Structures. Chimneys, Towers and Masts, OWPW, Wrocław (in Polish), 2005.

[4] Włodarczyk, W, “On failures and desinging of steel chimneys”, Inżynieria i Budownictwo, No. 10, pp. 535-539 (in Polish), 1998.

[5] Wichtowski, B, “Adjustment of steel chimneys with be-level guyed”, Inżynieria i Budownictwo, No. 5, pp. 240-243 (in Polish), 2013.

[6] Pałkowski, Sz, Steel Structures, Selected Problems and Design, PWN, Warszawa (in Polish), 2001.

[7] Instruction ER-01, Operation of towers and masts, TP SA, Warszawa (in Polish), 1995.

[8] Wichtowski, B, “Forces in guys according thermal analysis of structural shell of a 40 m high steel chimney”, Przegląd Budowlany, No. 8-9, pp. 32-35 (in Polish), 1994.

[9] Wichtowski, B, Hołowaty, J, “Steel chimneys at adjustment phase. Initial tension forces in guys”, EUROSTEEL 2011, 6th European Conference on Steel and Composite Structures: Research – Design – Construction, Budapest 2011, pp. 2499-2504.

[10] Kozłowski, A, Baran R, “Variablility of loads on a guyed chimney in service”, Inżynieria i Budownictwo, No. 10, pp. 392-394 (in Polish), 1992.