Draft

6.2TheCaseStudy 129

6.2.3 CableForces

20 ThethrustH(which is thehorizontalcomponent of thecableforce)is determinedfromEq.

6.8

H =

wL

2

cs

8 h

=

(47)k/ft(3;500)

2

ft

2

(8)(327)ft

= 220 ; 000 k

FromEq.6.12themaximumtensionis

r =

h

Lcs

=

327

3 ; 500

= 0: 0934

Tmax = H

p

1 + 16r

2

= (2;200)k

p

1 + (16)(0:0934)

2

= (2;200)k(1:0675)= 235,000 k

6.2.4 Reactions

21 Cablereactionsareshownin Fig.6.5.

POINTS WITH

REACTIONS TO

CABLES

Figure6.5:Locationof CableReactions

22 Theverticalforcein thecolumnsdueto thecentralspan(cs)is simplythesupportreaction,

6.6

A

POINT OF NO

MOMENT

B

REACTIONS AT

TOP OF TOWER

TOT

L = 3,500 FT

w = 39 + 8 = 47 k/ft

Figure6.6:VerticalReactionsin ColumnsDueto CentralSpanLoad

Vcs=

1

2

wLcs=

1

2

(47)k/ft(3;500)ft= 82; 250 k (6.16)