Report on Properties Affected by the Great East Japan Earthquake

Report on Properties Affected by the Great East Japan Earthquake

Property Report: Comparison Between Conventional Methods and the TNF Method — Great East Japan Earthquake

“Seismic Intensity 6−”: Liquefaction Effectively Suppressed

  1. The upper soil layer at this site consists of a silt layer deposited to a depth of approximately 19 m.
  2. The minimal impact observed from the earthquake is believed to be due to the building responding integrally with the full-area improved ground layer, which reduced seismic motion input between the bottom of the improved layer and the underlying ground.
  3. The confinement (“enclosure”) effect provided by the full-area improved layer clearly demonstrates that the occurrence of liquefaction was effectively suppressed.
  4. Even if liquefaction were to occur locally, the full-area improved layer resists it integrally.
Property Name Construction Period Improved Area (m2) Improvement Volume (m3) Scale Structure Type
Home Improvement Store (name withheld) Apr. 2009 8,989 17,618 Single-story Steel structure
Retail Store (name withheld) Apr. 2009 2,485 5,322 Single-story Steel structure
Retail Store (name withheld) Apr. 2009 2,630 6,602 Single-story Steel structure
Location: Namegata City, Ibaraki Prefecture / Photo taken: March 17, 2011

TNF Method

Continued operations with no interior or exterior damage
Continued operations with no interior or exterior damage
No level differences or cracking observed
No level differences or cracking observed
No floor cracking observed
No floor cracking observed

Nearby Conventional Construction

Nearby Store A: Liquefaction observed at multiple locations
Nearby Store A: Liquefaction observed at multiple locations
Nearby Store A: Undulating pavement (top); gap formed between building and pavement (bottom)
Nearby Store A: Undulating pavement (top)
Gap formed between building and pavement (bottom)
Nearby Store B: Entrance glass damaged and business suspended; large cracks in parking area
Nearby Store B: Entrance glass damaged and business suspended (top)
Large cracks observed in the parking area (bottom)

“Seismic Intensity 6+”: No Uplift or Structural Failure Observed

  1. The upper ground layer at this site consists of loam deposited to a depth exceeding 10 m.
  2. While strong shaking acts directly on buildings supported by piles, buildings with foundations constructed using the TNF Method are considered to experience reduced seismic intensity.
  3. Even in the event of ground settlement, no uplift-related or similar structural issues were observed.