Performance Transition
Analysis of Mono-Lattice Tower At 100ft, 150ft and 200ft Under Wind and Seismic
Loading
Ajij Farid Shaikh1*, Vishwajeet
Ashok Kadlag2
1 Student, M.E. Structures, Akluj, Maharashtra
theajijshaikh@gmail.com
2 Assistant Professor, Ajeenkya DY Patil School of
Engineering, Lohegaon, Pune, Maharashtra
Abstract: Aesthetically pleasing and structurally sound
tower systems that can withstand high winds and earthquakes are in high demand because
to the fast growth of the telecommunications industry. The effect of wind and seismic
loads on the performance transition of 100-foot, 150-foot, and 200-foot Mono-Lattice
towers is compared. The Mono-Lattice tower is a combination of lattice towers and
monopole towers, which combines the advantages of small footprint and beautiful
appearance of monopole tower with that of higher rigidity and load-bearing capacity
of lattice tower. Conforming to the requirements of IS 1893 (Part 1):2016, TIA-222-H,
& IS 875 (Part 3):2015, Non-linear P-Delta analysis and Finite Element Analysis
(FEA) have been carried out in the software tnxTower. One of several structural
criteria that were tested was the height of the tower. These included base shear,
bending moment and maximum horizontal deflection. The results showed that the wind
exposure of the Mono-Lattice tower is lower than that of the full lattice tower
and the wind induced deflection & bending moments are less than those of the
traditional monopole tower. The Mono-Lattice's rigidity and serviceability improved
at 100 ft height, having a deflection of only 0.536 in. in a wind. Additionally,
compared to lattice and monopole towers, wind-induced bending moments was much lower,
suggesting better structural efficiency and less need for foundations. The seismic
base shear values were comparatively higher in the case of the Mono-Lattice tower
making the foundation design considerations more critical. The general conclusions
of the analysis will indicate that for medium to high rise telecom applications
the Mono-Lattice layout will be the best combination of aesthetics, structural performance,
wind rejections, and a low base cost.
Keywords: Mono-Lattice Tower, Telecom Tower, Wind Loading, Seismic
Loading, P-Delta Analysis, Finite Element Analysis, Deflection, Base Shear, Bending
Moment, Structural Efficiency
INTRODUCTION
With
the fast expansion of Telecom network and the increasing demand of high-speed wireless
communication technologies such as 4G & 5G, Telecom towers must be economically
viable, aesthetically appealing and structurally efficient. Due to the excellent
appearance and small footprint, monopole tower is used widely in the urban region;
due to the excellent rigidity and load-carrying capacity, lattice tower is widely
used. The two tower shapes are used in the telecom industry. Monopole towers at
higher elevations experience the issue of bending moments and deflections that are
greater than the lattice counterparts, and also require more space to install, and
are exposed to more wind.
To overcome
these deficiencies, a new hybrid structural solution (Mono-Lattice) has emerged,
that incorporates some of the best attributes of monopole and lattice towers. The
Mono-Lattice tower is a result of the combination of monopoles' slim profile and
reduced land space requirements, and lattice systems' improved stiffness, structural
stability. Such a hybrid solution is particularly suitable for medium to tall telecom
towers because of its structural properties and flexibility in the urban context.
In this
research, the strength of the structure of Mono-Lattice towers with heights of 100',
150' and 200' is studied under wind loading and seismic loading. The primary software
used in this research is tnxTower, which is a Finite Element Analysis (FEA) and
Non-linear P-Delta analysis tool to determine the critical structural parameters
such as base shear, bending moment and maximum horizontal deflection. The study
was performed under the TIA-222-H, IS 1893 (Part 1):2016 and IS 875 (Part 3):2015
considering the geology of Pune area and base wind speed of 39 m/s.
This
is the motivation for this undertaking, which is basically to discover how the structural
effectiveness & performance of Mono-Lattice towers vary with their height. The
performance of monopole towers is satisfactory at low levels, but they can be very
fragile at high (overturning) levels, and prone to excessive swaying. The lateral
stiffness and the reduction of wind-induced reaction should be achieved by Mono-Lattice
arrangement and mitigate these impacts. The research also aims to evaluate the effect
of base shear & bending moments due to wind & seismic loads on the foundation
requirements, with the help of measurement.
The
results of the study will provide insight into the performance of the Mono-Lattice
towers at different heights and demonstrate its suitability for modern telecommunication
applications which seek optimal structural performance, minimised site footprint
and enhanced serviceability.
OBJECTIVES
·
To assess the Mono-Lattice towers' structural
performance at 100, 150, and 200 feet when subjected to seismic and wind loads.
·
To determine the most effective telecom tower
layout by analyzing and contrasting deflection, base shear, & bending moment
responses.
RESEARCH METHODOLOGY
In this
study, the structural performance of 100-, 150-, and 200-foot Mono-Lattice telecom
towers subjected to wind and seismic loading is evaluated. Critical structural parameters
including deflection, bending moment, and base shear were studied using Finite Element
Analysis (FEA) in tnxTower software, and the analysis was conducted in accordance
with IS 875 (Part 3):2015, IS 1893 (Part 1):2016, & TIA-222-H standards. In
order to examine crucial structural characteristics as base shear, bending moment,
and deflection, tnxTower software was used for Finite Element Analysis (FEA) and
non-linear P-Delta analysis. Standards such as TIA-222-H, IS 1893 (Part 1):2016,
& IS 875 (Part 3):2015 were followed in conducting the analysis.
Non-linear P-Delta Analysis Method
The
second-order effects caused by axial loads acting on distorted forms are captured
by the extra moments created by the Non-linear P-Delta analysis. Because it takes
into consideration the geometric non-linearity, which has a major impact on the
performance and stability of tall, thin structures like telecom towers, this study
approach is vital. The P-Delta effect is especially noticeable in monopoles, which
are single continuous cantilevered structures. For precise Deflection and Base Bending
Moment values in a comparative examination of 100ft, 150ft, & 200ft Monopole,
Full Lattice, MonoLattice models & the P-Delta effect is crucial. The mono-lattice
is an improvement over the monopole in terms of lateral displacement reduction because
to its braced lattice construction. P-Delta analysis will determine the precise
amount by which the secondary moment is reduced by the lattice's extra stiffness.
The main argument in favor of the Mono-Lattice as a structurally better option than
the Monopole at 150 and 200 feet in height is based on this comparison.
Numerical Method
Finite Element Analysis (FEA): The
tnxTower program is a potent tool for making nonlinear behavior predictions and
modeling complicated loading situations. Finite element analysis (FEA) models may
account for geometric defects, non-linearities in the material, and specific loading
circumstances. The program tnxTower was used for this. The non-linearities of the
material, geometric flaws, and specific loading circumstances may all be included
in FEA models.
Table 1: Topography Details
|
Type |
Values |
|
Region |
Pune |
|
Wind Speed |
39 m/sec (88 mph) |
|
Terrain Category |
3 |
|
Importance Factor |
1 |
|
Risk Coefficient |
1 |
|
Topography Factor |
1 |
|
Relevant Codes |
IS 875 (Part 3): 2015, IS 1893 (Part 1): 2016, TIA-222-H |
Table 2: Section properties for Monopole Tower
|
Sr. No. |
Parameter |
100 ft (30 m) |
150 ft (45 m) |
200 ft (60 m) |
|
1 |
Base Diameter |
3.57 ft |
3.57 ft |
3.57 ft |
|
2 |
Top Diameter |
1.38 ft |
1.38 ft |
1.38 ft |
|
3 |
Number of Flats |
18 |
18 |
18 |
|
4 |
Grade of Steel |
A607-60 |
A607-60 |
A607-60 |
Table 3: Section
properties for Mono-Lattice Tower
|
Sr. No. |
Parameter |
100 ft (30 m) |
150 ft (45 m) |
200 ft (60 m) |
|
1 |
Lattice + Monopole Height |
50 ft + 50 ft |
80 ft + 70 ft |
120 ft + 80 ft |
|
2 |
Base Face Width |
15 ft |
18 ft |
24 ft |
|
3 |
Top Base Width |
5 ft |
6 ft |
6 ft |
|
4 |
Height of Section × Number |
25 ft × 2 |
20 ft × 4 |
20 ft × 6 |
|
5 |
Number of Legs |
4 |
4 |
4 |
|
6 |
Grade of Legs |
A582-70 |
A582-70 |
A582-70 |
|
7 |
Leg Size Dia. × Thickness |
ROHN 4” X-STR, ROHN 3” STD |
ROHN 4” X-STR, ROHN 3” STD |
ROHN 4” X-STR, ROHN 3” STD |
|
8 |
Base Diameter |
1.5 ft |
2 ft |
2 ft |
|
9 |
Top Diameter |
1 ft |
1 ft |
1 ft |
|
10 |
Number of Flats |
18 |
18 |
18 |
|
11 |
Monopole Grade |
A572-65 |
A572-65 |
A572-65 |
Load Combinations
According
to IS 875 Part 3:2015, IS 1893 Part-I:2016, or TIA-222-H, the towers were subjected
to 37 different load combinations that covered both the Ultimate Limit State (ULS)
and the Serviceability Limit State (SLS). The ULS combinations included factored
dead or wind loads (1.2D + 1.0W and 0.9D + 1.0W) utilized at twelve different wind
directions ranging from 0° to 330° in increments of 30°, for a total of 25 strength-level
cases. In a total of twelve serviceability instances, SLS combinations include unfactored
dead load (D + W) in all twelve directions. Included as well was a dead-load-only
enclosure. The wind speed was 39 m/s, which is in line with the terrain of the Pune
area (Terrain Category 3), and no ice loading was applied.
RESULT AND DISCUSSION
The
structural behavior of 100-, 150-, and 200-foot Mono-Lattice towers subjected to
wind and seismic loads was assessed using the findings derived from Finite Element
Analysis (FEA) and Non-linear P-Delta analysis. In order to comprehend the towers'
stability, stiffness, or structural efficiency, crucial structural measures like
base shear, maximum horizontal deflection, and bending moment were used to evaluate
their performance.
Figure 1: 100ft Mono-Lattice Tower
Figure 2: 150ft Mono-Lattice Tower
Figure 3: 200ft Mono-Lattice Tower
Table 4: Maximum Horizontal Deflection
|
Type of Tower |
Height (ft) |
Seismic Induced Displacement (in) |
Wind Induced Displacement (in) |
|
Mono-Lattice |
100 ft |
1.896 |
0.536 |
|
Mono-Lattice |
150 ft |
1.932 |
1.932 |
|
Mono-Lattice |
200 ft |
7.965 |
7.965 |
When
compared to the Monopole (4.231 in) and the Mono-Lattice (0.536 in) at 100 ft, the
former provides a considerable decrease in seismic-induced deflection (e.g., 1.896
in) and a large reduction in wind-induced deflection (4.231 in). This proves that
the lattice integration successfully stiffened the tower, especially when it came
to lower-level wind stresses.
Figure 4: Maximum
Horizontal Deflection
Table 5: Maximum Bending Moment Mono-Lattice
|
Height |
Seismic BM (kN.mm) |
Wind BM (kN.mm) |
|
Mono-Lattice 100ft |
50,174 |
1,72,218 |
|
Mono-Lattice 150ft |
1,01,705 |
3,13,266 |
|
Mono-Lattice 200ft |
2,48,155 |
5,45,335 |
Due
to its strong wind base shear and considerable wind exposure, the Lattice tower
receives the largest wind-induced BM, for example, 2,046,140 kNmm at 200 ft. With
a wind BM of 545,335 kNmm compared to 1,127,084 kNmm at 200 ft for the monopole
and 545,335 kNmm for the lattice tower, the mono-lattice design is clearly the most
efficient structural form in wind resistance.
Figure 5: Maximum
Bending Moment Mono-Lattice
Table 6: Base Shear
|
Type of Tower |
Height (ft) |
Seismic Induced Base Shear (kN) |
Wind Induced Base Shear (kN) |
|
Mono-Lattice |
100 ft |
8.4516 |
13.345 |
|
Mono-Lattice |
150 ft |
8.4516 |
31.137 |
|
Mono-Lattice |
200 ft |
10.586 |
66.723 |
The
Mono-Lattice tower, on the other hand, reports a much larger seismic base shear
(for example, 10.586 kN at 200 feet), which indicates that it has a bigger mass
or a basic period that draws more seismic force. When designing the foundation,
this is a vital factor to take into mind. Mono-Lattice towers exhibit much reduced
wind base shear, which is to be anticipated given the relatively lower wind-exposed
surface area as compared to other tower technologies.
Figure 6: Base
Shear
The
Mono-Lattice tower is an effective solution that bridge the gap between the Lattice
tower, which has a high degree of rigidity but a low level of aesthetic appeal,
and the Monopole tower, which has a high degree of flexibility but a high level
of aesthetic appeal.
Table 7: Mono-Lattice Performance
|
Performance Metric |
Mono-Lattice Performance |
Findings |
|
Deflection |
Significantly lower than Monopole (especially wind deflection
at 100 ft), but higher than Lattice. |
Improved Serviceability: Provides better stiffness than
Monopole. |
|
Wind BM |
Significantly lower than both Lattice and Monopole. |
Structural Efficiency: Requires smaller foundational elements
and base plate due to reduced overturning moment. |
|
Wind Base Shear |
Similar to Monopole and much lower than Lattice. |
Reduced Wind Load: Lower aerodynamic profile is confirmed. |
|
Seismic Base Shear |
Highest among all tower types. |
Foundation Consideration: Requires a more robust foundation
to resist higher seismic lateral forces. |
While
the Mono-Lattice design maintains the look of the Monopole and has a lower wind
loading profile in comparison to the Lattice, it displays higher performance in
reducing wind-induced bending moments and delivers better stiffness (lower deflection)
in comparison to the Monopole design. The increased seismic base shear is the most
significant constraint, and it is imperative that the foundation design take this
into consideration.
CONCLUSION
This
research used Non-linear P-Delta and Finite Element Analysis to examine the structural
behavior of 100-, 150-, and 200-foot Mono-Lattice telecom towers subjected to wind
and seismic loads. A combination of the structural benefits of lattice towers alongside
the compact & visually beautiful features of monopole towers is achieved by
the Mono-Lattice structure, as shown by the results. Lower wind-induced deflection
& bending moments were observed in the Mono-Lattice tower in comparison to the
traditional monopole tower, suggesting that the former is more rigid and efficient
structurally. With less wind-induced bending moment, there is less chance of overturning
and less foundation needs, which means the approach is good for communications infrastructure
financially. The Mono-Lattice design was also shown to be aerodynamically efficient
due to the reduced wind base shear. The research did find the fact that Mono-Lattice
tower has a larger seismic base shear than other tower types, particularly at higher
heights, thus it's important to be cautious when designing the foundation and anchorages.
Although this is a drawback, the Mono-Lattice tower outperformed other medium &
tall telecom structures in terms of space efficiency, strength, stiffness, and wind
resistance. In urban areas, when land availability, aesthetics, & structural
performance are paramount, the Mono-Lattice tower offers an optimal solution for
contemporary telecom applications.
References
1.
Kumar, M. P., Raju, P. M., Navya, M., & Naidu,
G. T. (2017). Effect of wind speed on structural behaviour of monopole and self-support
telecommunication tower. Asian Journal of Civil Engineering (BHRC), 18(6).
2.
Joseph, R., & Varghese, J. (2015). Analysis
of monopole communication tower. IJESTA, 1(11).
3.
Ravishankar, P., Arun, L., & Sudha, G. C.
(2018). Analysis of four legged steel telecommunication tower–Equivalent static
approach. International Research Journal of Engineering and Technology (IRJET),
5(8).
4.
Balaji, K. V. G. D., Ramesh, B., Kumar, S. B.,
Jnanchand, S., & Patnaikuni, C. K. (2018). Effect of cyclonic load factor on
monopole towers. International Journal of Engineering and Technology (IJET),
7(4.17), 75–84.
5.
Shetty, S. M. R., Anusha, M., Ashwini, A., &
Rajiv, T. (2019). Dynamic analysis of 4-legged steel telecommunication tower. International
Journal of Civil Engineering and Technology (IJCIET), 10(1).
6.
Jain, A. K., Shivanshi, & Pinaki. (2016).
Comparative analysis of telecommunication tower. International Journal of Innovative
Research in Electrical and Electronics Engineering (IJIERE), 3(5).
7.
Kaveh, A., Mahdavi, V. R., & Kamalinejad,
M. (2017). Optimal design of the monopole structures using the CBO and ECBO algorithms.
Periodica Polytechnica Civil Engineering, 61(1), 110–116.
8.
Sharma, K. K. (2025). Comparative analysis of
steel telecommunication tower subjected to seismic & wind loading. Civil
Engineering and Urban Planning: An International Journal (CiVEJ).
9.
Kasera, S. C. (2025). Structural analysis of telecommunications
towers: Report content and its importance to the industry and public. World Journal
of Advanced Engineering Technology and Sciences.
10.
Gayatri, G. (2023). Comparative study of wind
and ice loads on telecommunication towers in hilly terrain. ICGEST.
11.
Tanuku, S. (2020). Comparative study on analysis
of telecom tower using Indian and American standards. In Proceedings of the International
Conference on Emerging Trends in Engineering and Technology.
12.
Balamurugan, M. (2018). Comparative analysis of
steel telecommunication tower. International Journal of Advanced Research Trends
in Engineering and Technology (IJARTET).
13.
Barelikar, S. M., & Goral, S. S. (2017). Review
on wind and non-linear dynamic analysis of self-supporting telecommunication tower.
Journal of Constructional Steel Research.
14.
Tah, A. M., Alsilevanai, K. M., & Ozakca,
M. (2016). Comparison of various bracing systems for self-supporting steel lattice
structure towers. American Journal of Civil Engineering.
15.
Rajasekharan, J., & Vijaya, S. (2014). Comparative
analysis of steel telecommunication tower subjected to seismic and wind loading.
Journal of Constructional Steel Research.
16.
Siddesha, H. (2010). Wind analysis of microwave
antenna towers. International Journal of Applied Engineering Research, 1(3).