OBSERVATION OF THE SEISMIC BEHAVIOR OF GRAVITY TYPE QUAY WALL AND DEVELOPMENT OF ITS EARTHQUAKE RESISTANT DESIGN.

本研究旨在解释地震引起岸墙失稳的机理，阐明液化对沉箱与回填土相互作用的显着影响。通过对1995年兵库县南部地震等日本数次强震造成的重力式码头墙破坏的仔细调查，发现其破坏程度与回填土液化的发生密切相关。经过抗液化处理的码头墙可以在强烈地震中幸存下来，几乎没有损坏，这与未经处理的码头墙经常出现的严重损坏形成鲜明对比。然后，我们对模型码头墙进行了一系列模型振动台试验，重点关注回填地中液化的影响。研究发现，根据回填土是否发生液化，沉箱的运动有很大不同。当不发生液化时，沉箱上波动的土压力抑制了沉箱的运动。另一方面，当回填土发生液化时，由于土压力脉动分量与惯性力相位角一致，沉箱滑动加剧。模型振动试验中还仔细观察了液化过程中作用于沉箱后壁的脉动土压力。这表明沉箱的稳定性判据不应以液化开始为依据，而应以突然的相变为依据。我们还在日本北海道钏路港进行了全尺寸试验重力式岸墙在地震过程中动力行为的现场观测，旨在证实液化对岸墙破坏的决定性影响，为评价挡土结构地震土压力和发展重力式合理抗震设计方法提供依据。码头墙。 2003年十胜大地震中，试验码头墙发生震动，地震烈度为Ⅴ级。对测试码头壁观察到的动态行为的分析显示了液化对测试码头壁变形的影响。较少的

This research project was conducted aiming to explain the mechanism of the instability of quay wall induced by earthquake, and clarify the significant influence of liquefaction on the interaction between the caisson and the backfill ground. The close investigation of the damage to gravity type of quay walls caused in several strong earthquakes in Japan including the 1995 Hyogoken-nambu Earthquake, clarified that the degree of damage was strongly related to the occurrence of liquefaction in the backfill ground. The treated quay walls against liquefaction could survive the strong earthquakes with little or no damage, in marked contrast to the severe damage frequently seen in untreated quay walls.Then, we conducted some series of model shaking table tests on model quay walls focusing on the effect of liquefaction in the backfill ground. The movement of the caisson was found to be quite different depending on whether liquefaction occurred in the backfill ground or not. The fluctuating eart … More h pressure on the caisson suppressed the movement of the caisson when liquefaction did not occur. On the other hand, sliding of the caisson was enhanced since the fluctuating component of earth pressure and the inertial force coincide in phase angle, when liquefaction occurred in the backfill ground. The fluctuating earth pressure acting on the back wall of the caisson in the process to liquefaction was also carefully observed in the model shaking tests. This suggested that stability criteria of the caisson should be developed not by the onset of the liquefaction but by the sudden phase change.We also conducted a field observation of dynamic behavior of full-scaled test gravity type of quay wall during earthquakes in the Port of Kushiro, Hokkaido, Japan, aiming to confirm the decisive effect of the liquefaction on the damage to quay wall, and provide information for the evaluation of seismic earth pressure on retaining structure and the development of rational earthquake resistant design method for gravity type quay wall. In the 2003 Tokachi-oki Earthquake, the test quay wall was shook with the seismic intensity of rank V+. The analysis of the observed dynamic behavior the test quay wall showed the effect of the liquefaction on the deformation of the test quay wall. Less