Sasago Tunnel: Ceiling Panels Were Welded Together

Reason unknown.

I thought that at least Japan's civil engineering was still solid. Wrong.

Sankei Shinbun, quoting Kyodo News (12/5/2012):

トンネル天井板は溶接　広範囲崩落の要因か

Ceiling panels of the tunnel were welded together, may have contributed to a large section collapse

９人が死亡、２人が重軽傷を負った山梨県の中央自動車道笹子トンネル崩落事故で、落下した天井板は鉄筋で溶接され、隣接する天井板とつながっていたことが５日、中央道を管理する中日本高速道路への取材で分かった。

9 people died and 2 people suffered injuries in the collapse of [ceiling panels in] Sasago Tunnel on Chuo Expressway in Yamanashi Prefecture. It was revealed on December 5 that the ceiling panels that fell were welded together using rebar.

　崩落は長さ約１３０メートルにわたって起きており、中日本高速はつながっていたことが要因となった可能性を認めている。県警は、現場検証に同行した専門家らの意見を聴き、押収資料を分析するなどして崩落が広範囲にわたった原因を調べる。

The collapsed section is 130 meters long, and Central Nippon Expressway Company is admitting the possibility that the connected ceiling panels contributed to the collapse. The prefectural police will conduct the investigation by taking with the experts who accompanied the inspection of the scene of the accident and analyzing the documents seized from

　中日本高速によると、天井板はコンクリート製で、幅５メートル、奥行き１・２メートル、厚さ８、９センチ。１枚の重さは約１・２トンで、隣接する天井板とはわずかな隙間があるが、それを埋めるように金属で溶接されていた。

According to Central Nippon Expressway, the 5m x 1.2m x 8.9 centimeter ceiling panels are made of concrete, weighing about 1.2 tonne each. There is a small gap in between the ceiling panels, but the gap was filled with metal [rebar] and welded.

　中日本高速は「実際の壊れ方はまだ分からないが、１カ所が落ちてそれに引きずられた可能性も否定できない」としている。

Central Nippon Expressway says, "We still don't know how it actually collapsed, but we cannot deny the possibility that one segment fell, taking the other segments with it."

I thought, "How can you weld a concrete panel?" Looking at the video of FNN News below, the concrete ceiling panels seem to be covered by metal casings.

From FNN News Youtube channel (12/6/2012):

Neither Central Nippon Expressway Company nor the Yamanashi prefectural police has the detailed information or photos or the video regarding this accident available at their websites. I guess they have no intention of learning from the Fukushima nuclear accident when it comes to timely disclosure of information to the general public.

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