2007.11.15
A CASE STUDY ON THE PILE FOUNDATION DAMAGE DURING THE HYOGOKEN-NAMBU（KOBE）EARTHQUAKE(1997)
Madan B.Karkee（GEOTOP）・Hideaki Kishida（Science University of Tokyo）
■掲載誌：EIGHTH INTERNATIONAL CONFERENCE ON SOIL DYNAMICS AND EARTHQUAKE ENGINEERING,p234-p235
■発行所：
■発行：1997/05
The details of the damage to pile foundations due to the January 17, 1995 Hyogoken-Nambu earthquake have continued to emerge as the affected structures are demolished, repaired and upgraded at different stages. From the statistics of the damage to buildings observed in the Hyogoken-Nambu earthquake (Karkee et al, 1997), it is observed that the instances of foundation damage in case of buildings with heavy damage to superstructures is significantly small in comparison to those with slight or no superstructure damage. This trend indicates that the existence of damage to foundation may mean lesser damage to the superstructure, leasing to the difficulty in developing a clear picture of the foundation behavior during extreme earthquake events from visual inspection immediately after the earthquake. In understanding the relationship between the foundation damage and the superstructure damage, it would be logical to see whether the local ground response to the incident earthquake motion is dominated by the ground shaking or the ground failure. Situation where ground failure is likely, such as due to excessive liquefaction and lateral spreading, generally mean the use of relatively long piles taken down to deeper competent layers. In contrast, ground shaking effects tend to be dominant in relatively firmer ground conditions where shorter piles with adequate frictional and end-bearing resistance provide the bearing capacity required in general design practice. This paper presents a case study on a new seven storied condominium building supported by relatively short brecast concrete piles at a fairly firm ground condition. The building seemed to have no structural damage, but derailed investigation revealed severe damage to the piles. This pile foundation damage is discussed in relation to the damage statistics (Karkee et al, 1997) and the interaction analysis of the soil-pile-building system (Karkee and Kishida. 1977)
■発行所：
■発行：1997/05
The details of the damage to pile foundations due to the January 17, 1995 Hyogoken-Nambu earthquake have continued to emerge as the affected structures are demolished, repaired and upgraded at different stages. From the statistics of the damage to buildings observed in the Hyogoken-Nambu earthquake (Karkee et al, 1997), it is observed that the instances of foundation damage in case of buildings with heavy damage to superstructures is significantly small in comparison to those with slight or no superstructure damage. This trend indicates that the existence of damage to foundation may mean lesser damage to the superstructure, leasing to the difficulty in developing a clear picture of the foundation behavior during extreme earthquake events from visual inspection immediately after the earthquake. In understanding the relationship between the foundation damage and the superstructure damage, it would be logical to see whether the local ground response to the incident earthquake motion is dominated by the ground shaking or the ground failure. Situation where ground failure is likely, such as due to excessive liquefaction and lateral spreading, generally mean the use of relatively long piles taken down to deeper competent layers. In contrast, ground shaking effects tend to be dominant in relatively firmer ground conditions where shorter piles with adequate frictional and end-bearing resistance provide the bearing capacity required in general design practice. This paper presents a case study on a new seven storied condominium building supported by relatively short brecast concrete piles at a fairly firm ground condition. The building seemed to have no structural damage, but derailed investigation revealed severe damage to the piles. This pile foundation damage is discussed in relation to the damage statistics (Karkee et al, 1997) and the interaction analysis of the soil-pile-building system (Karkee and Kishida. 1977)
