Learning from Taiwan Building Resilience

Taiwan has made remarkable achievements in construction quality as proven by the recent earthquake. Though the Mw 7.4 (MMI VIII) earthquake took 13 lives, it saved more lives if it is compared to other incidents. For instance, in Cianjur, Indonesia (2022) Mw 5.6 (MMI VIII) earthquake, the total death toll was 635. Stronger earthquake but fewer casualties.  Both Taiwan and Indonesia, are near the 'Ring of Fire' and are prone to earthquakes. From an engineering perspective, at least there are three initiatives we can learn from Taiwan in protecting their people from collapsing buildings under earthquake load. Those are a strict imposition of building codes, continuous construction market improvement, and innovation.

All requirements in the Building Codes are mandatory to obtain building approval. Furthermore, some requirements mandate some deposit of funds into the government account. There will be consequences if the builders or developers fail to fulfill the requirements as stated in the code. The deposited fund will be confestigated. Therefore, any attempt to save costs should not sacrifice the safety factors by delivering sub-standard construction material or workmanship. This regulation becomes effective since there is effective monitoring and a range of sanctions.

To survive in the construction market, builders and construction industries have not only adhered to the code but also successfully improved efficiency. Through years of improvement, Taiwan’s construction industry was found to have higher labor efficiency than mainland China. Along with the labor, their management and technical capacities are increasing.

If the market continuously improves, it will lead to more innovative construction methodologies and technologies. To reduce the impact, we must deliver robust structures and install elements that may dampen or absorb earthquake load. These elements may be pendulums or base isolation. As installed at the Taipei 101 skyscraper, if the building sways, the pendulum can suppress motion by applying forces in opposite directions.

How can this be applied to housing industries in developing countries? It can be applied, but it should not jump to the innovation. It should follow the natural law. Enforcing the code may lead to improvement in the construction market. This means the whole ecosystem must abide by the code, i.e., homeowners, builders, construction material vendors, and government. There should be country-wide education and training for builders. Sending engineers and skilled builders to rural areas to train local builders. Continuous campaign on build-back-safer and seismic retrofitting. Provision of loans for house repair and retrofitting. Along with the market improvement, there will be fair competition to find better ways to increase safety and reduce costs through innovation. At this point, academia should give their input that the innovation is fulfilling the scientific aspects.

Arwin Soelaksono

Screening on seismic vulnerabilities of high-rise urban buildings

The Turkiye earthquake sent an important message to all governments and construction practitioners. Massive damages can happen anywhere at any time to vulnerable buildings due to earthquake hazards. Newer buildings usually are less vulnerable due to improved building codes, particularly in high-rise steel and concrete frame buildings.[i] The key word is abiding by the building code and renewed building code. For a moment, let us keep aside the improvement of building codes as structural engineers and government who, from their studies, have to formulate a new code to follow. This writing is focused on ensuring safe structures where many people already dwell, for which government, construction, shelter, and settlement (S&S) practitioners are responsible.

Are multi-stories building in our areas safe? Were they constructed following the code, and their current usage is according to where it was designed? If the structure would damage or collapses, those affected are not only people who dwell and work in the building. Their neighbor, local livelihood, and public services will also be affected. Hence, the government and building owners have to conduct screening on its safety to minimize the risk and, at the same time to provide proper assistance when the hazard turns into a disaster.

Screening and analyzing risks of high-rise buildings

There are more than 23,000 high-rise buildings above 100 m in height worldwide.[ii] These buildings are exposed to hazards, but their vulnerabilities depend on age, height, use, building quality, subsoil, symmetry, and regularity.[iii] For instance, regular and symmetrical buildings are more robust than irregular structures such as L-shape, which might have additional loads, such as twists, due to earthquakes. On the age part, for instance, on screening 98 high-rise buildings with 8-15 floors in Surabaya, Indonesia. It was found that 21 buildings have fallen into the vulnerable category due to being built before 2002, in which the earthquake regulations have not been applied in Indonesia.[iv]

Since many buildings have to be assessed on their seismic vulnerability, large-scale rapid screening should be conducted. Currently, some tools can be used, such as FEMA P-154 Rapid Visual Screening[vii], there is a web-based[v], and also there is an Android application[vi].  But even if large-scale screening using those tools is launched, the screening quality will depend on the engineers’ capacities and experiences. Those data should be analyzed and interpreted by experienced engineers to identify the vulnerability and, later on, how to strengthen them seismically. Getting the screening recommendations will take considerable time as so many buildings need to be checked.

Even if the recommendation reaches the building owners, there is no guarantee they will immediately strengthen it even if they know their building is vulnerable to earthquake. Seismic strengthening, even if it is more economical rather than building a new one after a disaster, many people still need to find this initiative as an investment. It is increasingly costly if there are many vulnerable parts in the building. On the other hand, there is no enforcement for the building owner to retrofit their buildings seismically. Also, there is no incentive for building owners to apply retrofitting. Hence, there should be regulations and incentives that every building owner can be responsible for the safety of their buildings, whether it is an apartment or an office building.

Risk reduction measures and preparing the response in the urban context

The data and analysis are valuable information for the government and S&S practitioners. The risk and its magnitude can be mapped for contingency planning. For instance, how many buildings, local businesses, and public services would be affected if an earthquake happened in a particular magnitude? There should be sufficient local capacities to respond to the disaster at desirable times.

The developed local capacities should be able to support affected people who lost their dwellings according to their circumstances and recovery pathways. The support also should not diminish the affected people’s capacities to self-recover. On the other hand, government and S&S practitioners should strengthen the self-recover initiatives with sound technical guidance. This is to ensure a safer rebuild in more sustainable ways.

As other sectors should also be involved in recovery, local government and the S&S community should support the market’s reopening through shelter assistance. The assistance should trigger a multiplier effect through the construction job market and building material market, which is massively needed during rebuilding. In many parts of the world, the construction sector in high-rise buildings is widely known as the prime mover of economic activities. They will draw other businesses to participate, such as transportation that brings construction materials, restaurants, communications, etc. The government should have a strategy to maintain market stability; otherwise, at some point, there will be a scarcity of construction materials or the job market. This instability would lead to inflation which might hamper the reconstruction process.

S&S practitioners might provide training for builders to improve construction practices and help them obtain builder certificates, which also need to work on. These builders with particular skills can work in middle or high-rise building construction since workers must show their credentials before being hired.

All of these are to improve responder capacity on the whole level, from the beginning, which is preparedness measures to the reconstruction phases. On the other hand, if the building owners follow the recommendation from the screening, many buildings can be seismically strengthened, then the level of damage will not be massive.

Arwin Soelaksono

Photo taken by: Hazal Güverçinci

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[i] Cochrane S.W., Schaad, W.H. Assessment of Earthquake vulnerability of buildings. 1992

[ii] https://www.integralrisk.global/how-many-high-rise-buildings-are-there-in-the-world/

[iii] Cochrane S.W., Schaad, W.H. Assessment of Earthquake vulnerability of buildings. 1992

[iv] Wahyu Riyanto et al 2020 IOP Conf. Ser.: Mater. Sci. Eng. 739 012040` Earthquake Vulnerability Assessment of High-Rise Buildings in Surabaya using RViSITS Android Application

[v] Kassem. M.M, et. al. Assessment of Seismic Building Vulnerability Using Rapid Visual Screening Method through Web-Based Application for Malaysia. 2021

[vi] Wahyu Riyanto et al 2020 IOP Conf. Ser.: Mater. Sci. Eng. 739 012040` Earthquake Vulnerability Assessment of High-Rise Buildings in Surabaya using RViSITS Android Application

[vii] Rapid Visual Screening of Buildings for Potential Seismic Hazards: A Handbook Third Edition FEMA P-154 / January 2015