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| Illustration by Ai |
A comprehensive structural evaluation of the North Minahasa District Government Library Building has confirmed that its reinforced concrete superstructure meets Indonesia's code-based safety and serviceability requirements while identifying one critical structural component that requires close construction quality control. The study was conducted by Josef Arnoldus Johni Sumajouw, Wellem Toad, Mario Marthen Luther Moningka, Novriana Amelia Pangemanan, and Merci Freki Hosang from Politeknik Negeri Manado and published in 2026 in the Jurnal Multidisiplin Madani (MUDIMA). Using ETABS structural analysis software and the latest Indonesian National Standards (SNI), the researchers demonstrated that the building can safely resist gravity and earthquake loads while maintaining structural performance within allowable engineering limits.
As Indonesia continues to expand
public infrastructure, structural safety has become one of the most important
considerations in building design and construction. Public facilities such as
libraries serve thousands of visitors while housing valuable educational
resources, making structural reliability essential not only for protecting
occupants but also for ensuring uninterrupted public services. Because
Indonesia lies within one of the world's most active seismic regions, every
public building must be capable of resisting both everyday structural loads and
significant earthquake forces throughout its service life.
Modern structural engineering no
longer focuses solely on whether a building is "strong enough."
Engineers also evaluate serviceability, which measures how well a
structure performs under normal and seismic loading without excessive
deformation that could affect occupant comfort, functionality, or long-term
durability. One of the most widely used indicators is inter-story drift,
which measures the relative horizontal movement between adjacent floors during
an earthquake. Excessive drift can damage structural and non-structural
components even when total collapse does not occur.
To evaluate the North Minahasa
Government Library Building, the research team adopted a quantitative case
study using actual project documentation combined with advanced numerical
modeling. Primary data consisted of field observations and verification of the
building's structural condition, while secondary data included architectural
drawings, structural plans, reinforcement details, material specifications, and
Indonesian structural design standards. Earthquake loading parameters were
obtained from the official 2021 PUPR Response Spectrum for the North
Minahasa region.
The researchers developed a
detailed three-dimensional structural model using ETABS, one of the
world's leading structural analysis platforms. The reinforced concrete building
was modeled according to Indonesian standards, including SNI 1726:2019
for earthquake-resistant design, SNI 1727:2020 for structural loading, SNI
2847:2019 for reinforced concrete design, and SNI 8900:2020 for
simplified reinforced concrete guidance. The analytical workflow included load
classification, seismic modeling, internal force analysis, inter-story drift
evaluation, reinforcement verification, and demand-capacity assessment for
beams, columns, and slabs.
The study assessed both strength
and serviceability performance. Structural strength was evaluated by
comparing the forces acting on structural members with their available
capacities, while serviceability focused on limiting building deformation
during earthquake loading. The researchers interpreted the results using Demand-Capacity
Ratios (DCR), where values below 1.00 indicate acceptable
performance, while values approaching 1.00 identify structural elements
requiring closer quality control.
The analysis produced several
important findings that demonstrate the overall reliability of the library
building.
Among the most significant
results were:
- The maximum inter-story drift utilization
reached 40.56% of the allowable limit in the X-direction,
leaving nearly 60% additional serviceability reserve.
- The maximum drift utilization in the Y-direction
reached 41.45%, also remaining comfortably below the code limit.
- Beam B1 achieved a flexural demand-capacity
ratio of 0.63 and a shear ratio of 0.41, indicating
satisfactory structural performance.
- Beam BK1 performed even more efficiently,
recording flexural and shear ratios of 0.45 and 0.26,
respectively.
- Column K1 recorded a shear demand-capacity
ratio of 0.74, remaining safely within acceptable engineering
limits.
- Column K2 reached a ratio of exactly 1.00,
meaning it satisfies the minimum design requirement but possesses no
additional shear reserve beyond the calculated design capacity.
- The reinforcement provided for both X-direction
and Y-direction slabs substantially exceeded the minimum reinforcement
area required by design calculations, providing an additional structural
safety margin.
One of the study's most important
contributions is its emphasis on interpreting safety margins rather than
simply declaring that a building is safe. Instead of reporting reinforcement
dimensions alone, the researchers quantified how much reserve capacity remained
within each structural component. This approach provides engineers with a
clearer understanding of which elements perform comfortably below their limits
and which components deserve greater attention during construction and future
maintenance.
The identification of Column
K2 as the governing structural member illustrates this approach. Although
the column satisfies Indonesian design requirements, its demand-capacity ratio
indicates that it operates at its minimum allowable shear capacity. The
researchers therefore recommend particularly strict supervision of
reinforcement placement, concrete quality, workmanship, and inspection
procedures during construction to ensure that actual field conditions match the
design assumptions.
Beyond this individual project,
the findings have broader implications for Indonesia's rapidly expanding public
infrastructure sector.
For government agencies,
the study demonstrates how integrated structural evaluations can improve
accountability and ensure public buildings comply with modern engineering
standards before entering service.
For structural engineers,
the research provides a practical workflow that combines ETABS numerical
modeling with code-based demand-capacity interpretation, producing more
informative evaluations than conventional reinforcement calculations alone.
For construction contractors,
the results highlight the importance of maintaining high construction quality,
particularly for structural members operating near their design limits.
For building owners and
facility managers, the research emphasizes the value of periodic structural
assessment, especially for buildings located in earthquake-prone regions where
long-term safety depends on continued monitoring and maintenance.
According to the researchers from
Politeknik Negeri Manado, the North Minahasa Government Library Building
satisfies the evaluated strength and serviceability requirements under the
modeling assumptions adopted in the study. However, they also emphasize that
future evaluations should incorporate nonlinear seismic analysis, material
testing, as-built verification, soil-structure interaction,
and Building Information Modeling (BIM) integration to provide an even
more comprehensive understanding of structural performance throughout the
building's lifecycle.
The study demonstrates that
combining advanced structural modeling with detailed engineering interpretation
allows public buildings to be evaluated more transparently and comprehensively.
As Indonesia continues investing in resilient infrastructure, performance-based
structural assessment will play an increasingly important role in protecting
public safety while ensuring that government facilities remain reliable for
decades to come.
Author Profile
Josef Arnoldus Johni Sumajouw
is a researcher and lecturer at Politeknik Negeri Manado specializing in
structural engineering, reinforced concrete design, seismic analysis, and
computational structural modeling. He served as the corresponding author of
this study.
Wellem Toad, Mario
Marthen Luther Moningka, Novriana Amelia Pangemanan, and Merci
Freki Hosang are researchers from Politeknik Negeri Manado whose
expertise includes civil engineering, structural design, reinforced concrete
structures, and infrastructure performance evaluation.
Source
Article Title: Code-Based
Superstructure Safety Evaluation and Serviceability Margin Assessment of the
North Minahasa District Government Library Construction Project
Journal: Jurnal
Multidisiplin Madani (MUDIMA)
Publication Year: 2026
Volume & Pages: Vol.
6, No. 6, June 2026, pp. 766–774
DOI: https://doi.org/10.55927/mudima.v6i6.65
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