Somewhere between 3% and 5% of Japan s industry is located in the area of strong ground shaking in and around Kobe. This includes most types of industry from light manufacturing to high-technology and heavy industry. As in most of Japan, and particularly Tokyo, much of the industry is concentrated near the port on landfill or very recent, soft soils. Due to strong ground motion amplification on soft soils and the extensive ground failures (caused by settlement and liquefaction) in these areas, damage to industry in the Kobe area was severe. Observed failures included extensive damage to large building foundations; all types of industrial buildings, equipment, and equipment systems; fire protection systems; racks; and inventory. The reduced ability to transport raw materials and finished goods to, from, and within the region will also greatly impact industry in the Kobe area. Industries affected include shipbuilding, steel plants, breweries, pharmaceutical firms, computer component manufacturing plants, and consumer goods production facilities.
Structural Damage
Access to industrial facilities in the region was very limited. The EQE team did have access to the facilities of some U.S. and European multinational companies, of which there is a large percentage in Kobe. In those facilities, structural damage was generally minor. Other damage, however, was not.
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Damage to unanchored laboratory equipment
The most severe structural damage, as well as associated damage to exterior storage areas and tank farms, occurred to industrial structures immediately adjacent to wharves and other retaining structures at navigable watercourses and other coastal facilities. Severe damage to industrial structures along shorelines was observed from Nishinomiya to western Kobe. Numerous structures settled more than 2 or 3 meters and were partially or fully submerged in water. Other structures partially collapsed or tilted severely because of foundation failures. Most tilted structures were probably buildings on mat foundations (usually pre-1980s vintage) without supporting piles.
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A heavily damaged steel plant in the Nishinomiya Port area. The most apparent damage was caused when the top third of the concrete stack sheared off. The top portion of the stack plummeted into a neighboring portion of the facility.
Wherever there was lateral spreading of soils and retaining structures along the shoreline, extensive damage was observed to tank farms (tank tilting), silos (tilting and collapses), cranes, stacks, and other such structures. Several tall, industrial, reinforced concrete stacks were leaning, and at least one collapsed. The collapsed stack was observed at a steel facility along the waterfront in Nishinomiya. The upper one-third of the stack broke off and embedded into the adjacent building.
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Left: These unanchored tanks fell off their supports.
Right:: Rocking and displacement of the quay wall was caused by lateral spreading of reclaimed land. This area, on the Nishinomiya Port, was flat before the earthquake.
Away from the shoreline, structural collapse of industrial facilities was relatively rare compared to the collapses in the housing, transportation, and commercial sectors. However, ground settlement caused extensive damage to the interiors of buildings, as well as to the infrastructure that is routed into the buildings. One case involved a pile-supported industrial building with a floating floor slab (or slab-on-grade). Although the peripheral piles successfully supported the structure, the floor slab failed when the underlying soil settled; this failure pulled down the columns that had supported the roof and caused it to collapse. Loading platforms, roads, storage and parking areas, various utilities, and other appurtenant structures were often observed to be severely damaged. Such damage was particularly severe on the numerous recently engineered islands in Osaka Bay. Many square kilometers of such land were observed to be affected.
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Severe damage to piers and warehousing along damaged quay walls. The quay walls have rotated toward the water, pulling the structures with them. The partially collapsed Hanshin Expressway can be seen in the background.
Steel manufacturers in the Kobe area were severely affected by the earthquake. One steel company Japan s fifth largest estimated that it would take months to resume full operations in its Kobe plant, while another steel company was unable a week after the earthquake to provide an estimate of restoration time. Both firms Kobe headquarters buildings were declared unsafe structures and could not be occupied. It was reported that four buildings at the first steel company collapsed, and the company was considering closing its Kobe industrial facilities and shifting operations north to its Kakogawa plant.
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A damaged concrete plant on reclaimed land east of Rokko Island. The conveyors are severely damaged, and several tanks have toppled.
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Left: Silos and port facilities on reclaimed land next to Rokko Island. Tanks in the foreground are leaning. The silos in the background are severely damaged.
Right:: Damage along the Port of Kobe shore. The severe rotation, lateral spreading, and settlement of the quay walls and fill material are typical of almost the entire developed border of the port. The building in the foreground has split into two parts.
Very large, multistory, reinforced concrete shear wall warehouses on Rokko Island and in central Kobe had very little damage. These buildings appeared to have superior lateral strength and were evidently designed considering the contribution of heavy storage to the design earthquake loads. The observed damage to contents resulted primarily from toppling of stacked goods or unanchored storage racks.
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Tanks in the port area. The ground shows signs of massive liquefaction and settlement. The tanks appear to be on pile-supported foundations.
Small- and medium-sized manufacturing firms were heavily damaged. Structural, fire, or contents damage affected more than 40% of the local knitted goods manufacturers and more than 90% of the synthetic leather shoe manufacturing facilities. City officials worry that production will now be moved to low-wage countries like China.
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Damage to facilities on reclaimed land, Nishinomiya Port. The quay walls have rotated and displaced, with the full surface dropping as much as 3 meters in some areas. In the background is a badly damaged bridge.
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These sake tanks appear to have survived the complete collapse of the traditional wood-frame building that housed them.
Heavy damage to the numerous liquor (sake) production facilities also occurred in the area stretching over Kobe s Higashi Nada and Nada wards and Nishinomiya. About one-third of the country s entire liquor production takes place in Kobe. Traditional wooden plants and storehouses collapsed, and some reinforced concrete structures had severe damage. At many of the major facilities, modern reinforced concrete buildings appeared to be undamaged. High-technology equipment housed in these structures, however, may have been severely damaged or destroyed, compounding business interruption losses.
Nonstructural Damage
Differential settlement and tilting of ground-supported slabs within buildings damaged equipment. In one case, the slab-on-grade in a pile-supported structure settled differentially between the pile caps. While not structurally significant, this resulted in extensive misalignment of manufacturing equipment. Re-leveling of the machinery was expected to take several weeks.
The shaking itself also caused damage to more sensitive equipment and equipment that was not properly anchored. For some plants, short-term fixes to equipment that had been affected by settlement involved jacking up machinery as much as 30 centimeters in order to achieve proper alignment. This procedure often caused significant delays in resuming production.
Breakage and leakage of fire sprinkler lines in manufacturing facilities were observed from Akashi to Osaka, resulting in extensive damage to manufactured goods, stock, and machinery. Virtually all of the leakage can be attributed to the failure of unbraced or inadequately braced piping. Fortunately, there were no fires reported at these facilities. Had proper bracing been in place, considerable damage and business interruption could have been avoided. It should be noted that it was not sufficient to simply clean up the water damage to resume operations. Repairs to the fire suppression systems also had to be completed.
One research facility located about 20 kilometers northeast of central Kobe had only minor structural damage to most of its buildings, and breakage of water and wastewater lines caused by minor ground settlement. Extensive damage to the contents, however, was noted. Unanchored lab hoods shifted, bookshelves and cabinets toppled onto desks, and computer equipment fell to the floor. There was extensive breakage of glass jars containing a variety of chemicals. Most of this damage could have been easily prevented with simple anchorage.
Other Causes of Business Interruption
Many of the industries affected by the earthquake are suppliers of parts for industries outside the affected area. Since much of Japanese industry relies on just-in-time delivery, damage to industry located in Kobe and the breakdown of the transportation system in the area are causing business interruptions to a variety of industries not directly affected by the earthquake. Business interruption insurance is typically not available in Japan, which will add significantly to the overall industrial losses.
One report stated that by January 21, at least four major electronics plants, six steel or heavy industrial plants, and three beverage plants had been shut down because of the earthquake. In some cases, facilities were closed because employees were unable to get to work, rather than because of severe physical damage to the facility itself. By Monday, January 23, nearly one week after the earthquake, many of these plants had reportedly resumed at least partial production. In some cases, the availability of water, gas, and power determined whether or not a business reopened.
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: Damage along the Port of Kobe shore. The severe rotation, lateral spreading, and settlement of the quay walls and fill material are typical of almost the entire developed border of the port. The building in the foreground has split into two parts
A reduction in work force availability is an important factor in industrial operations. Personal tragedy, loss of housing, and the debilitation of mass transit meant that many employees were unable to work right after the earthquake. This, in turn, means that many businesses will be unable to recover from the disaster in a timely manner, which may bankrupt some industrial concerns.
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The January 17, 1995 Kobe Earthquake
An EQE Summary Report, April 1995
Transportation
One of the most far-reaching and disturbing aspects of the earthquake was the severe and extensive damage to the transportation system. Kobe sits astride the principal transportation corridor between the central and southwestern parts of Japan s main island, Honshu. The corridor is less than 5 kilometers wide between Osaka Bay and the mountainous terrain on the north side of Kobe. Earthquake damage to highways, bridges, and rail systems left Kobe s city streets as the only land access along this corridor, resulting in major congestion and greatly impeded relief efforts. Many of these surface streets were also unusable, blocked by debris from collapsed structures and damaged by ground settlement. Use of alternative road or rail lines added hours to normally short