In the aftermath of the devastating Great Hanshin Earthquake in 1995, collapsed buildings blocked rescue efforts and disrupted supply transport.

Three decades later, the need for earthquake-resistant structures along major roads remains largely unmet.

The land ministry reported that 4,110 buildings along major emergency transport routes fail to meet seismic safety standards as of April last year. These buildings stand throughout 17 of the nation’s 47 prefectures. 

With the looming threat of the Nankai Trough megaquake and Tokyo inland earthquake, immediate countermeasures are crucial.

In the Great Hanshin Earthquake on Jan. 17, 1995, around 250,000 homes were completely or partially destroyed.

That same year, the government enacted a law promoting seismic retrofitting for buildings constructed before 1981 under old seismic standards. Said buildings do not meet the current criteria for withstanding earthquakes of intensities registering on the upper end of 6 to 7 on Japan’s seismic scale.

The law was further amended in 2013, requiring building owners to conduct seismic assessments on structures located along routes that local governments designated as crucial for evacuation, such as emergency transport roads.

Additionally, it mandated local governments to publicly disclose the results of these assessments.

Targeted buildings are those built under the old seismic standards, which pose a risk of blocking more than half the adjacent road if they collapse.

According to the land ministry, 17 prefectures have published seismic assessment results.

Of the 7,291 buildings targeted, 4,110 are at risk of collapsing in an earthquake with an intensity of upper 6 or higher. 

The other 3,181 are now quake-proof as they have undergone seismic retrofitting, reconstruction or have been demolished.

That translates to only 43.6 percent of the at-risk structures being earthquake prepared.

Within the 17 prefectures, Tokyo had the highest number of buildings with insufficient earthquake resistance, totaling 2,051.

This is followed by Kanagawa Prefecture with 512 buildings and Aichi Prefecture with 379 buildings.

Furthermore, the number of buildings with insufficient seismic resistance is expected to increase.

This is because the 17 prefectures that have already published the results of seismic assessments might designate additional routes where assessments are mandatory. 

More data is also on the way as some of the remaining 30 prefectures are planning to publish their assessment results.

The central government has set a goal to largely alleviate the dangers of buildings with seismic vulnerabilities by 2025.

The goal includes structures along major emergency transport routes; large buildings such as hospitals and schools; and disaster-critical infrastructures, including local government offices and evacuation centers.

However, achieving this goal is expected to be difficult.

STALLED PROJECTS, FINANCIAL BARRIERS

Progress on seismic retrofitting of buildings along major emergency transport routes is slow.

Tokyo, which has the most buildings that do not meet quake resistance standards, established an ordinance in 2011 ahead of the central government that required seismic assessments and mandated the publication of results.

In fiscal 2016, Tokyo authorities conducted individual surveys by visiting the owners of around 1,070 buildings that had undergone seismic assessments but had not yet been retrofitted, rebuilt or demolished.

Among the owners surveyed, 39 percent expressed plans to carry out one of the three solutions, while 54 percent said they had no intention of taking any action.

When asked about the obstacles to carrying out seismic retrofitting, the most common responses were the “high cost burden” and “difficulty in reaching agreements with tenants or unit owners.”

In 2019, Tokyo amended its ordinance to introduce an obligation for residents and other tenants to make efforts to cooperate with building owners in carrying out seismic retrofitting and other improvement works.

In addition to the ordinance, a subsidy program has been established, with central and local governments covering up to 90 percent of retrofitting costs.

However, this has done little to speed up progress.

Osaka Prefecture faces a similar situation.

A 2017 survey of building owners with insufficient seismic resistance found that, as in Tokyo, half had no plans for retrofitting or other improvements. A lack of money was the most common reason.

In fiscal 2020, the Osaka prefectural government launched a program to provide free “seismic producers,” including architects, to advise building owners. These experts offer guidance on carrying out seismic retrofitting and coordinating with tenants.

So far, seven of the 20 buildings that received assistance through the program have undergone seismic retrofitting.

The prefecture is now considering expanding the program to address a wider range of challenges.