丸太打設による既設戸建て住宅の液状化対策の小型振動実験および数値解析による検討  [in Japanese] SHAKING TABLE TESTS AND NUMERICAL ANALYSIS ON LOG PILING AS A LIQUEFACTION COUNTERMEASURE FOR EXISTING HOUSES  [in Japanese]

Access this Article

Author(s)

Abstract

著者らは,小規模な構造物にも適用できる丸太を用いた液状化対策を開発した.設計法も確立され,適用事例も増えている.その原理は地盤に丸太を打設し,地盤の密度を増大させることである.また,液状化が懸念される地下水位の高い地盤で木材を利用することから,長期間にわたりCO2を固定し,地球温暖化緩和にも効果があることもわかっている.一方で,戸建住宅などの既設小規模構造物の対策については,効果を定量的に検証した工法が適切な価格で提供されてはいないのが現状である.本研究においては,既設構造物の周囲に丸太を打設して液状化の被害を低減する工法を考案した.丸太は既設建物の下への打設は難しく,建物下を改良する場合に比べて効果が限定的となると考えられるが,小型の振動台実験と数値解析によりその有効性を検討した.

 The 2011 Great East Japan Earthquake caused significant soil liquefaction, and many residences were damaged as a result of associated settlement and inclination. This highlighted the importance of seismic countermeasures for small-scale structures. One such measure involves driving logs into the ground to add density. As trees store carbon during growth, logs placed underground below the water table are not prone to deterioration. Based on this characteristic, subterranean log piling represents a dual measure against both global warming and liquefaction. Since log piles can be set only in ground around existing houses rather than directly beneath them, the effect of the resulting densification is limited. However, rigidity added using this approach and the associated partial densification of soil can be expected to have a certain effect in suppressing ground deformation. In this study, shaking table tests were carried out to investigate the effect of log piles placed around existing houses. Also, numerical analysis was conducted to clarify the effects of this technique. As a result, it is found that the settlements and tilts of houses were mitigated by this method.

Journal

  • Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE))

    Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE)) 72(4), I_117-I_128, 2016

    Japan Society of Civil Engineers

Codes

Page Top