Seismic-resistant buildings that were taught by the older generations

Every nation has traditional buildings that withstand earthquake events since people built them through trial and error for hundreds of years. The older generations passed the knowledge to their younger ones on how they meticulously learned the flow of the earthquake forces in the structural elements. Through that, they applied the understanding of structural composition and its connection to ensure the building's integrity. Moreover, the traditional structure is seismic resistant and fulfills cultural appropriateness and acceptance. Hence, we can enjoy robust and beautiful heritage buildings in many countries that blend with nature. I am reflecting on DR. Teddy Boen's teaching when I attended his class more than 30 years ago. 

But, nowadays, constructing traditional houses can be considerably expensive. Cities have become more populated; therefore, people must build vertically so that more than one family can live in the same structure. Limited land forces people to build multistory buildings, a new knowledge for everyone. On the other hand, due to economies of scale, people become familiar with steel and reinforced concrete structures, which materials and builders are available in good numbers in the market.

Due to economic pressure, construction methodologies to build faster are more evolving than the technology to reduce the earthquake impact. For instance, since the early 1990s, it has been common to construct multistory buildings in fast-track. It showed that construction companies can pour the concrete floor every 5-7 days for the upper level. The need for fast construction is understandable since the fixed costs of renting tools and machinery, such as tower cranes and construction team salaries, are expensive. For good projects, they have construction management in which the project manager ensures that construction materials have been installed correctly as quality assurance measures. The problem becomes aggravated if the effort to reduce cost sacrifices the meticulous construction detail. Some builders even go against the law by lowering the quality by reducing cement and reinforcement in the concrete structure.

There is some reflection we can take following the latest earthquake events nowadays. What went wrong with so many casualties due to damage and collapsed structures? In the present times, we have been introduced to new construction technologies and a wide variety of building materials, which is good to some extent. Still, we need to be careful of the paradigm that robust, fast, and economical can always be obtained in constructing a building. It is not due to the methodology but to the builders' capabilities, which relate to their expertise and resources. 

As we might learn from our older generation, they carefully put seismic-resistant features in their buildings. Nowadays, builders need to design, build, and ensure every element is correctly installed following the code, which should be ahead of any measures rather than reducing costs through fast-track or other initiatives to cut costs. Government and aid agencies should emphasize this idea when supporting the post-disaster housing recovery. The government should enforce sanctions on those who violate the codes. Aid agencies need to support self-recovery initiatives by developing the capacities of local actors, including homeowners, to rebuild a robust structure according to their needs.

Arwin Soelaksono

📸 Damaged buildings in Antakya, Hatay, Türkiye.

 

Housing Recovery and Time-frame Dilemma

Housing recovery post-disaster always takes considerable time; hence, instead of rushing to force quick-fix solutions, government and aid agencies should deliver housing assistance according to the pace, capacities, and affected people's preferences.

Major disasters always take time for housing recovery. For instance, following the 2010 earthquake, Haiti took more than ten years. Following the 2011 Great East Japan earthquake, the government planned for ten years of recovery. Nepal took more than six years after the 2015 Gorkha earthquake. But there are some people who are still working on their recovery beyond their government recovery time frame. The problem with massive recovery campaigns is that some people are still struggling to rebuild their housing while their neighbors have already completed the reconstruction.  People in their vulnerability will potentially left behind due to a lack of capacity to acquire resources such as builders, construction materials, and banking systems.  

The affected people surely want to get their lives back to normal, including having their houses rebuilt. From the government's point of view, prolonged housing recovery time will potentially create social and political tension. Hence, in many countries, pressure from political actors for a quick rebuild adds noise to the recovery plan. Aid agencies also facing the same challenges. Due to limited funding, which is also reflected in the limited timeframe, many are tempted to deliver quick assistance but not significantly contribute to the affected people's recovery pathways. Learned from the Asian Tsunami 2004, fishermen in Aceh, Indonesia, who usually live in wooden and timber houses, got housing donations made of brick and reinforced concrete. Since it was a turn-key project, they just received the houses, they have no ability to expand, maintain, or repair. Therefore, many of those houses were broken and unrepaired. The hardest lesson learned was that giving houses will not automatically correlate to improving the earning ability. There are other factors that need to be provided, not merely housing construction per se. 

From the affected people's perspective, they are in shock due to the loss of their family members, their houses, or maybe their livelihood. They need time to digest and comprehend their situation and limitations. Some of them may take refuge in other cities. These situations show that affected households have uniqueness, and we need to be aware of their specific needs. The problems are aggravated if their land is missing due to landslide or tsunami. This includes if they are not allowed to rebuild their houses on their original site due to government regulations that their land is unsafe to rebuild. On the other hand, the construction market those are builders, and construction materials, need time to balance the supply and demand due to massive reconstruction.

Hence, housing recovery needs to be seen as a massive collaboration between recovery actors and the construction market which affected people should be part of it. Both affected people and builders should be trained for proper construction. Government and aid agencies should encourage self-recovery and at the same time, strengthen the initiative with construction market improvement through subsidies, capacity building, and streamlining the policies. Aid agencies with their limitation need to find meaningful contributions that link the house rebuild with their livelihood for sustainability. Shelter or housing organizations should collaborate with other NGOs who are experts in livelihood and land issues since housing recovery is not merely a house rebuild. All of these are taking considerable time since those are processes; in the end, solid collaboration will deliver comprehensive and long-term solutions to the affected people.

Arwin Soelaksono

Photo from Carl Courts Getty Images Photo Journalist https://twitter.com/GettyImagesNews/status/1702063191914668088

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 

Return home, recovery pathway difficult to measure

Today (May 6), we mark three months of the Türkiye and Syrian earthquake, and it is reported that about 20 percent[i] of those affected by the earthquake who migrated to the cities they used as refuge have returned. For instance, only in Hatay province, Türkiye, 92,000 out of 565,000 who have taken refuge in areas outside Hatay have returned.[ii] The number is expected to rise since more people are having trouble paying rent due to increased house rent prices. Turkish Housing Sector Group reported that house rents in Türkiye increased by 16 percent on average following the earthquakes.[iii] On the other hand, authorities believe 65-70% of families in tents are from homes that are low or have minor damage[iv], so there is a possibility they might be returning to their homes. So the number of returnees will be around 1 million since about 1.8 million people are currently in tents.[v]

Influencing factors on the scale of return and its challenges

In every affected people, there is always the desire to return home. There are external factors that can influence their decision.  The most influential is their confidence due to the aftershocks diminishing. When they overcome the trauma, they will think about their assets and livelihood back home. Their children need to be back in the classroom. If those living in the refuge share this idea, one family can be a pioneer and create a bandwagon effect[vi]. Then there will be a massive home returning.

But some challenges can impede the smoothness of this process. Unprepared utilities in their home areas will put them in tents or refuges longer. Water can be an issue, such as debit and the quality due to the pipe needing repair. Repairing of pipes needs to wait until rubble removal can be completed. Electricity also needs to be well functioned as they need to run their appliances moreover the coming summer they need for the refrigerator. They might also consider repairing their houses, but more than hardware vendors and builders will be required in the current market.

Preparing massive return

It is essential to understand the uniqueness of recovery pathways. People must be able to choose which recovery process they should follow. But they can be assisted by preparing the market. As inflation of construction material and labor costs is inevitable, strengthening the local market can reduce the impact of inflation. If cement, steel rebar, and other materials can be available with sufficient amounts and stable prices during recovery, the risk of interruption of the recovery process can be minimized. All of these need government policy and local economic development strategy. It is always challenging to link the housing recovery with sustainable economic growth if extensive umbrella to maintain the market is unavailable.

Other market actors are the builders. As this disaster could be the biggest in decades, skilled or qualified builders are less than needed. Therefore adding new builders or even training the homeowners to repair their houses will be crucial. There should be messaging and training in their home areas to ensure they can repair their houses properly. Otherwise, people just put plaster and paint, such as cosmetics but overlook to ensure that weakened parts need to be repaired.

Lastly, the decision to return home or stay in the tents or refuge solely depends on each household. It cannot be predicted when or how big, but it can be anticipated. Government and humanitarian agencies have an essential role in anticipating the return and preparing the ecosystem so that self-recovery can naturally happen and robust house can be achieved.

Gaziantep May 6, 2023. 

Arwin Soelaksono

Photo: Twitter @StepHaiselden[vii]

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[i] Support to Life. Emergency Situation Report 26 April 2023

[ii] OCHA. 2023 Earthquakes Situation Report No. 11 As of 23 March 2023

[iii] Support to Life. Emergency Situation Report 26 April 2023

[iv] Temporary Settlement Support Sector Turkey EQ Response Sector Briefing 27 April 2023

[v] Shelter Sector Türkiye. Information brief Shelter Sector No. 1 – 28 April 2023

[vi] The tendency for people to adopt certain behaviors, styles, or attitudes simply because others are doing so.

[vii] https://twitter.com/StepHaiselden

Earthquake engineering is for everyone

 

Earthquake engineering is not only for the elite but for everyone. The consequences of not abiding by the building code will never differentiate engineers or ordinary people. Understanding the earthquake’s impact only needs common sense, but many people intentionally ignore it since the occurrence is rare. The good news is that for more than four decades, the sophisticated earthquake engineering code gradually translated into guidance and regulation. The engineered and non-engineering buildings have the direction to design and build with the help of various guidance available.  Building Code enforcement is embedded in the building permit when people want to build their houses or other buildings.  

Then, why are so much devastation due to earthquakes in many countries? For instance, from 1998-2017, 747,234 deaths and USD 661 billion loss were recorded worldwide due to earthquakes[i]. As people know that earthquakes are unpredictable, many questions exist regarding whether the risk can be minimized. Following the Padang, Indonesia earthquake (2009) and the Haiti earthquake (2011), the campaign on “Earthquakes don’t kill people, collapsed buildings do” was started. This initiative is to put enforcing the building codes and standards more seriously, as it has been reported that They have significantly reduced deaths in Japan and the United States.[ii]

Then, there must be links between the campaign of enforcing the code and poor construction and the use of the building after construction is completed.

As humanitarian shelter and settlement practitioners, what contribution can we make to minimize the risks? There are many, but in this writing, I am proposing just two of them.

To begin with builder training. In non-engineered house construction, people must know that there is Building Code. This mainly happens in developing countries and many of which are rural. The builders need more knowledge and skills. The unavailability of appropriate construction materials aggravates this situation. For instance, there is no deformed steel rebar, cement is too expensive due to transportation costs, and sand is contaminated with saline or contains silt. Therefore, builders need to be trained. They need to know how to fix the rebar and properly install building elements from the foundation to the roof.

Lastly, a campaign on how to use the building properly. There were incidents due to the removal of columns since the homeowner wanted to use their house as the shop. Other cases found that homeowners added more stories since their families were growing. It is their house; they can do anything according to their needs, but it should be community messaging; the houses need seismic strengthening due to functional changes. If their houses collapse, it might affect homeowners and their neighbors. And the trained builder can work with this seismic strengthening.

Arwin Soelaksono

Gaziantep, Turkiye. April 9, 2023.

Photo: personal archive. Palu, 2019.

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[I] Economic Losses, Poverty and Disasters 1998-2017, The Centre for Research on the Epidemiology of Disasters (CRED), The UN Office for Disaster Risk Reduction (UNISDR).

[ii] Reliefweb. https://reliefweb.int/report/world/earthquakes-don%E2%80%99t-kill-people-collapsed-buildings-do

Big push to accelerate reconstruction post-disaster

Everyone feels that housing recovery post-disaster is always awfully slow. Hence, governments, social societies, and affected people are considering accelerating the process. But people need to remember the nature of the genuine recovery and construction process.

There are two options for accelerating the rebuilding process, i.e., from external and internal. Both impact the process but have different results and long-term benefits. External push can speed up the reconstruction but have problems both in sustainability and inclusivity. Two examples of external push i.e., using contractor companies and imposing deadlines. This article was written based on reflections on the experience of the housing recovery in Indonesia and Nepal. 

In some housing recovery, the government may give construction work to construction companies. Those companies with experience in the construction of real estate houses could work faster than the houses the homeowners built. But there is a limitation. Contractor companies are primarily interested in modular structures, and the houses, such as apartments and compound housing, are not scattered. For construction companies, building private houses with various designs and various building materials in scattered locations will add operation costs. Also, it reduces the profit obtained from discounts if they use the same building materials for the whole house. In these landed houses, turnkey projects mean homeowners who have not participated in the construction process will have problems when they want to upgrade or work on maintenance. Hence, sustainability has become one of the issues.

Government or aid agencies might impose deadlines for the reconstruction program in which exceptional conditions or assistance might be ended at a specific time. Understandably, post-disaster reconstruction phases will be finished. But expecting that imposing the deadline will accelerate the process will only be partially effective. Only those with adequate capacities to rebuild can catch up with deadlines. Those with internal challenges such as poverty, areas with poor infrastructures, and people unreached by government and aid organizations will be left behind. 

For instance, the Nepal government imposed a deadline on housing recovery following the 2015 earthquake. Homeowners who could not finish the construction work at a particular milestone will not be eligible for the subsequent cash assistance. For some people, the milestone deadlines triggered their best effort to finish their houses. Since the recovery was owner-driven, not all homeowners can complete their houses to meet the deadlines. The most vulnerable people and those living in areas with difficult access to construction materials and technical support missed the deadline. 

Therefore, applying external push speeds up the recovery process, but it will not be a genuine rebuild since it does not solve the root of the cause of vulnerability. Hence, the effort should mainly strengthen the market systems and actors. These initiatives are to create an internal push to the recovery process.

At the peak of recovery, there will be inflation due to the scarcity of construction materials and the shortage of skilled laborers. Even if it is inevitable, the severe condition that can hamper the reconstruction process can still be anticipated. The supply chain should be managed so the construction material is not limited to a specific material. During the peak of Aceh’s post-tsunami recovery (2006), the price of red brick tripled. The construction was almost stopped since almost everyone could not afford to buy them. Therefore, architects and engineers should provide various housing designs with various building materials. Moreover, there should also be a massive campaign to reuse the salvaged material to reduce the need to purchase new materials.  From the government side, the policy of easing taxes related to construction materials should be applied. Furthermore, the government should ensure all infrastructures can support transporting construction materials to whole affected areas. Strengthening the market system should also cover reliable financial service providers (FSP). There should be a strategy and policy to support the most vulnerable people to access banks or other FSPs.

The market actors' capacities, architects, engineers, builders, and even homeowners should be strengthened. Post-disaster rebuild is not business as usual. The work volume is larger than the regular construction work and should also change the practices. Hence, there should be training on construction and oversight during the process. Advocacy to homeowners to build their knowledge and ability to construct their houses by themself if they own a landed house. If they live in a multi-story apartment, they know which apartment was built by following the code. 

All of these should be carried out as earliest as possible. It will take months and even a year or two before the effect can be realized. The market system and market actors can be continuously strengthened then the homeowners and other market actors can benefit from working toward the deadline.

Arwin Soelaksono

Photo: Women participating in building a house at Thulogaun, Nepal. From the personal archive.