Your project
Technical datanof the project:
Designed in
wind class II and EC3
Dimensions of triangle:
0,5m
Base section:
1m
Tower sections:
6 x 5,5m
Anti-twist section:
3m
Top section:
3m
Total:
1m + 6 x 5,5m + 3m + 3m = 40m
Guyed in three (3 x 120°)
Distance between base section and anchorage guys:
21m
Guys are to be placed under pre-tension, in compliance
with calculation
Accessories:
The tower is designed to be used as a ladder
Fall protection system
Obstruction light
Interface dishes
Steel quality tower:
AE 235
Steel quality guys:
galvanised 1770N/mm²
Tower is galvanised in compliance with norm
Weight:
2000 kg (accessories included, foundation excluded)
Location:
Senegal -
Gandiaye (180km from Dakar)
Mission:
Design, calculation,
manufacturing and installation of a
40m guyed lattice tower at
Gandiaye, to serve as an
expansion of the Sentel
mobile phone network (Dakar -
Kaolack).
Rules for the design of the Lattice tower:
In compliance with the NBN B03-002-1 & 2 wind norms
class II and EC3 for steelworks.
Dimensions of the terrain: 40m x 40m
Guyed 40m lattice tower in triangle with anti-twist system
Antennas on top of tower (2 dishes, 6kN & 7kN
wind
force)
Maximum deflection on top of 0,5°
Accessories:
Cable ladder
Fall protection system
Obstruction light
All calculations, for what the wind is concerned, are to be
made manually in compliance with the NBN norms.
Use of ESA-Prima Win
Advantages:
3D (easy input of geometries)
Physical non-linear conditions (simulation guys and pre-
tension)
2-nd order frame (method Newton raphson)
Fast calculation
Easy output control
Dynamic document
Good graphical presentation
Easy support access and fast feedback
Disadvantages:
Manual calculation of the wind for lattice towers
Characteristics of guys
Pre-tension guys
Maximum deflection in distance (no degrees)
Experiences with esa-prima win:
Started working with ESA-Prima win in April 2000.
The complete 3D design software offers easy input of all
reality elements.
The more specific factors of the design can be discussed in
cooperation
with the support department of ESA-Prima
Win,
which results in a perfect simulation of the project.
The 3D software makes it easier to simulate the 4 wind
directions (N, S, E & W).
Specific input of the characteristics of the guys are based
on my personal experience. The first simulation of the pre-
tension of the guys is based on my own experience. The
final simulation results in a perfect pre-tension in the guys,
which then again results in a perfect dimension of the
guys.
The guyed lattice tower is calculated
with the Newton
Raphson method.
Easy output of the results of the calculation.
Easy control of the pre-tension of the guys.
Good graphical output of the results: The guyed lattice
tower is actually shown on the screen in the way it will
look in reality.
A
major advantage of the program is the dynamic
document:
when changing an input, one click shows the
difference in the document.
However,
working with ESA-Prima Win made me discover
some bugs in the program. These bugs have been
corrected in the new releases.
Modules:
2D-frame
2D-grid
3D-frame
Dynamic document
2-nd order frame
Physical non-linear conditions
27
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