Note: Descriptions are shown in the official language in which they were submitted.
Description
Title: A mechanism of Reinforcing the Solid Round Leg in Existing Telecom
Towers (Guyed & Self-support).
Technical Field: Structural Analysis and Reinforcing of Existing Telecom
Towers with Solid Round Legs.
Background of the Invention: The telecom business is in action every day due
to the fast-growing technologies and the country needs. Telecom companies
have so many towers that were built in the country and it was not designed
for current time requirements, even new towers sometimes the client does not
provide accurate antenna loading due to the lack of information about the
future or no clear prediction of what new technology could be or would need.
So, most of the towers fail in the structural analysis, and require
extraordinarily strong reinforcing to keep it alive.
Leg Reinforcing in telecom towers have long been known and widely used when
the legs become overstressed, and loads are more than its capacity. Engineers
used to weld additional bars beside the solid round legs to increase the
cross-sectional area to avoid any overstressing issues in legs. Later they
used to add additional bars using U-bolts. Using U-bolt is a new way of
adding bars to avoid welding on site. Both types are adding bars direct to
the leg (welded or U-bolted).
Summary of the Invention: Solid round leg comes with splice plates (flange
plates) at top and bottom and bolts to connect. In this invention, reinforcing
is using top and bottom splices, replacing existing bolts with threaded bars,
nuts, and washers, then adding threaded bars, lock nuts & couplers, mounted
to the threaded bars top & bottom. Tightening couplers will split the loads
between solid round leg & threaded bars.
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Date Regue/Date Received 2022-07-04
Brief Description of the Drawings:
RGM is a profile of a guyed tower.
FIGO2 is a profile of a self-support tower.
RGO3 Iis an isometric of a solid round section, showing top splice (TS),
bottom splice (BS), Bracing (BR)& leg (LG).
RGO4 is an isometric of an extracted solid round leg with splice pads, top
& bottom. Section s-s, showing cross section in solid round leg.
RGO5 is an assembly of three solid round sections without reinforcing,
showing existing bolting system (2)& solid round leg (1)
RGO6 is an isometric of an extracted solid round leg (1) showing details of
existing bolting system (bolt 2.1, washer 2.2 & nut 2.3)
FIG117 is an isometric of an extracted solid round leg (1)showing replacement
of an existing bolt with a new threaded bar top(I) & bottom(II) and
intermediate assembly (III) on the side.
RG77A is an isometric of an extracted solid round leg (1)showing replacement
of an existing bolt with a new threaded bar top(I) & bottom(II) and
intermediate assembly (III).
RGOB are an isometric & 2D views of an enlarged detail of assembly (I)
RGO9 are an isometric & 2D views of an enlarged detail of assembly (II)
FIG10 are an isometric & 2D views of an enlarged detail of assembly (III)
RG11 is an elevation of the leg with the lock nut, element 3.4 at a
distance = (Coupler height /2) , [h/2].
RG12 is an elevation of the leg with the intermediate assembly (III) at
initial position.
FIG13 is an elevation of the leg with rotating couplers No. 4.3 to hit
lock nut No. 3.4 at top & bottom.
RaI4 is an elevation of the leg with rotating lock nuts No. 4.2 to
secure the couplers No. 4.3
F1G15 is an elevation of the leg with torquing top coupler No. 4.3 &
secure it with lock nut No. 4.2
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Date Regue/Date Received 2022-07-04
RG16 is an assembly of three solid round sections with reinforcing
Completed.
IRG17 is an enlarged isometric of the joint (from above).
RG113 is an enlarged isometric of the joint (from below).
FIG19 are an isometric & 2D views of three sections with one set of
reinforcing completed.
RG20 is simulating solid round leg as a human without arms.
FIG21 is simulating solid round leg with reinforcing as a human with long
arms.
RG22 is a chart of Compression Capacity of Solid round leg, fy = 43510 psi.
RG23 is a chart of Compression Capacity of Solid round leg, fy = 50760 psi.
RG24 is a chart of Compression Capacity of threaded bar, fy = 80060 psi.
RG25 is a chart of Compression Capacity of threaded bar, fy = 89920 psi.
RG26 is a chart of Compression Capacity of threaded bar, fy = 100080 psi.
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Date Regue/Date Received 2022-07-04
Detailed Description:
Telecom towers are two types, Guyed 011300 & Self-Support Tower 011304.
Engineers
use Solid Round(Circular)legs (HGM) in both types because of its good
sectional area properties being of a symmetrical shape and high torsional
resistance. These towers are designed to support antennas, equipment and
feeding cables and to resist wind pressure and ice. The telecom industry is
growing so fast and requires changing antennas and their associated equipment
frequently. These changes require structural engineers to check the structure
to ensure the tower works within the allowable stress limits. In many cases
some towers have issues with the legs. The main issue is being the compression
resistance less than the compression load. The compression resistance is the
compression value that the leg can resist safely, it is defined by leg cross
sectional area, unsupported length and strength of material used. The
compression load is the load going on leg due to dead load of structure
(equipment, antennas, cables, mounts) and live load (wind & ice).
All weld guyed or all weld self-support towers consists of welded sections
(AGO. Each section is about (10 to 20) feet high (H) (Re&01,02,03,040). The
three
Legs (LG) are connected by bracing system, (diagonals & horizontals). Bracing
pattern(BR) could be one of these common shapes X, W, S, IS or K system.
Sections are connected through splice connections (splice pads and bolts).
Splice pads are welded to the leg at top (TS) & bottom (BS). Bolts connect
sections through its splice pads to form the tower assembly. Each tower is
assembly of welded sections (HG 05).
By-law a structural engineer is required to analyze the tower structurally
for any loading changes, dead load, or live load (Canadian Standard
Association - S37), when the legs are getting highly stressed over the limit
then reinforcing the leg is mandatory.
When the structural analysis identifies which section is overstressed then
this mechanism (invention) of reinforcing is required.
The idea behind this invention is demonstrated in (FIC620&21). Solid round leg
is simulated as a human without arms and loads reach the ground through the
human legs. When the solid round leg is loaded with heavy load and it requires
reinforcing, the threaded bars are simulated as adding arms to the human body
and these arms are long and reaching the ground. Applying torque on couplers
is like pushing the ground using hands to transfer part of the loading to
the ground through the arms. By this way, heavy load is split between solid
round leg and threaded bars.
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Date Regue/Date Received 2022-07-04
The assembly of this reinforcing mechanism (invention)consists of three
assemblies (I, II & III) (RGSO1&7A:
1. Assembly I consists of (RG08):
= (1)Threaded bar No. 3.1
= (3)Nuts No. 3.2
= (2)Washers No. 3.3
= (1)Lock nut No. 3.4
2. Assembly II consists of (RG09):
= (1)Threaded bar No. 3.1
= (3)Nuts No. 3.2
= (2)Washers No. 3.3
= (1)Lock nut No. 3.4
3. Assembly III consists of (R0610,17&18):
= (1)Threaded bar No. 4.1
= (2)Lock nuts No. 4.2
= (2)Couplers No. 4.3
= (4) x n*, Plates No. 5.1
= (4) x n*, bolts No. 5.2
= (4) x n*, Nuts No. 5.3
= (1) x n*, Clamp No. 5.4
= (4) x n*, Washers No. 5.5
= (4) x n*, Nuts No. 5.6
n* = number of required joints to define the unsupported length(Lu) (RG16).
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Date Regue/Date Received 2022-07-04
In the three sections assembly (RG05), assuming mid-section(B)is
overstressed, and it requires reinforcing. The procedure of this invention
is as follows:
1. Replace splice bolts at top, bolting system 2 011300, one at a time with
the new threaded bar, assembly (I) (11136070i.
2. Replace splice bolts at bottom, bolting system 2 (RG(16), one at a time
with the new threaded bar, assembly (II) (RGS07&09).
3. Repeat the previous steps to replace all the existing bolts (RG6)with
the new threaded bars , assembly I & II (H08&09).
4. Prepare the intermediate assembly (III) (ROSMITI), adding the number of
plates No. 5.1 & nuts No. 5.3 (RGS17&18) to have the required unsupported
length (Lu) (RG16)of the reinforcing system.
5. Adjust the lock nut No. 3.4 at top (RGH) to be away from the end of
threaded bar No. 3.1, assembly(I) by (coupler height)/2 [h/2].
6. Adjust the lock nut No. 3.4 at bottom (FIGII) to be away from the end of
threaded bar No. 3.1, assembly(II) by (coupler height)/2 [h/2].
7. Place the intermediate assembly(III) in between top (I) & bottom (II)
threaded bars (RG12).
8. Rotate the coupler No. 4.3 at top, assembly (III) (RG13) to hit the lock
nut No. 3.4 in assembly (I).
9. Rotate the coupler No. 4.3 at bottom, assembly (III) (RG13) to hit the
lock nut No. 3.4 in assembly (II).
10. Repeat the previous steps for the rest of intermediate assembly (III)to
have all threaded bars installed (RG13).
11. Connect the plates No. 5.1, using bolts No. 5.2, washers No. 5.5 & nuts
No. 5.6, in intermediate assembly (III) around the solid round leg (RGS17
&18).
12. Add the clamp No. 5.4 above the assembly of plates No. 5.1 in previous
step and tighten it (RC617&18).
13. Tighten all the bolts No. 5.2 with nuts 5.6 connecting the plates No.
. 1 (RGS17&18).
14. Rotate the lock nut No. 4.2 in intermediate assembly (III) at top to
secure the coupler No. 4.3 (RG14).
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Date Regue/Date Received 2022-07-04
15. Rotate the lock nut No. 4.2 in intermediate assembly (III) at bottom to
secure the coupler No. 4.3 (RG14).
16. Apply the required torque on top coupler No. 4.3 (RG15), using wrench by
rotating up towards the top splice and at the same time rotate the lock
nut No. 4.2 (RG15) to secure the coupler at final position.
17. By applying the required torque on all the intermediate threaded bars
(III), one after another, an axial load has been created in the
reinforcing mechanism and part of the load on the solid round leg has
been transferred (RG16).
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Date Regue/Date Received 2022-07-04
Definitions:
fy Yield stress of steel 0136 72,23,24 25,26)
Lu Unsupported length, also called buckling length (ROS1419)
SR Solid Round (FIGS 22, 23, 24 25, 26)
LG Leg (RG 03)
TS Top splice (RG03)
BS Bottom Splice (FIG 03)
BR Bracing (FIG03)
H Height of solid round section 1 Oft - 2 Oft (RGS01,02,03,0411)
L = H - (length of element 3.1) (FIG 11)
A 1st section in three sections assembly (RG05)
B 2nd section in three sections assembly (RG05)
C 3rd section in three sections assembly (RG05)
I Top assembly (first assembly) (FI1S07,07A08)
II Bottom assembly (second assembly) (RCS 07,01A09)
III Intermediate assembly (third assembly) (R1.E07,07A10)
1 Leg (RGS 05, 06, 07, 07A 08, 09, 11, 12 13, 14 15, 17, 18)
2 Existing bolting system assembly (FIGS 05, 06, 07)
2.1 Existing Bolt (FIGS 06)
2.2 Existing washer (FIG&06)
2.3 Existing Nut (RCS 06)
3.1 Threaded bar (RGS 07A OR 09, 11, 12 13,14, 15)
3.2 Nut (RGS 07A 08, 09,11, 12 13,14 15)
3.3 Washer (RGS 07A Oa 09,11,12,13,1415)
3.4 Lock nut (RCS 07A 08, 09,11, 12 13,14 15)
4.1 Threaded bar (FIGS 07A10,11,12,13,14 15)
4.2 Lock nut (FIGS 07A 10,11,12,13, 1415)
4.3 Coupler (FIGS07A 10,11,1213,1415)
5.1 Plate (RGS 17,18)
5.2 Bolt (FIGS 17,18)
5.3 Nut (Res 17,10
5.4 Clamp (R17,18)
5.5 Washer (RGS 17, 111)
5.6 Nut (RGS 17, 1E0
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Date Regue/Date Received 2022-07-04
