Estimation of the occurrence of a volcanic mud flow based on the theory of liquefaction of a volcanic ash layer caused by vibration of an earth quake or impact force of a slope failure

基于地震振动或边坡破坏冲击力引起的火山灰层液化理论估计火山泥流的发生

• 批准号: 01560171
• 负责人: 谷口 義信
• 金额: $ 1.6万
• 依托单位: Miyazaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01560171/
• 关键词: volcanic mud flow; volcanic ash; fluidization; vibration; dilatancy; shearing resistance force; 液状化

In this study, first it was tried to make clear the mechanism of the fluidization of volcanic ash layer by the vibration of an earth quake or impact force of a slope failure. This volcanic ash layer lain between volcanic accumulations is made by falling ash in an area of active volcano, next it was to predict the occurrence of a volcanic mud flow based on the theory of liquefaction of the mass of volcanic ash caused by the action of vibration or impact force stated above. As a result, the followings could be clarified.Judging from the result of the rheological test of a slurry consisted of volcanic ash and water, it can be defined as an entirely volcanic mud flow when the volumetric concentration of it is over 15%. When the vibration with low frequency acts on a slurry with the concentration of over 48.5% which consists of the only volcanic ash, the effect of dilatancy presents conspicuously itself, and the shearing resistance force of it increases in accordance with the number of vibr … More ation. When the concentration of it gets to about 66%, it presents entirely plasticity and the nobility of it decreases greatly. But the effect of dilatancy is prevented and the mobility of it increases when small gravels are mixed into that slurry, because the particle sizes in the slurry are not so homogenious as those in the slurry consisted of the only volcanic ash. The mobility of it gets the highest at the mixing ratio of about 40%. The mass of volcanic ash is easily fluidized in only few seconds by the vibration with low frequency of 5 cycle/sec and the amplitude of lcm- 2cm in the concentration below 66%.When a volcanic ash layer suffers from the vibration with high frequency like an earth quake, the critical angle for the occurrence of the movement of it decreases by 20ﾟ - 30ﾟ in comparison with that in the usual state when any vibration dose not act on it. The apparent internal friction angle of a slurry with high concentration falls much lower than that with low concentration. This means that liquefaction of volcanic ash layer would be easily caused by the vibration like an earth quake or impact force of a slope failure in an area of active volcano even if in a little rain fall. Less

在这项研究中，首先试图通过斜坡故障的地质或冲击力的振动来清除火山灰层流动性的机理。火山堆积之间的这种火山灰层是通过在活火山区域中掉落的灰分制成的，其次是根据上述振动或影响力引起的质量质量的火山灰质量的理论来预测火山泥流量的发生。结果，可以阐明以下因素。从泥浆的流变测试的结果判断，由火山灰和水组成，可以将其定义为当体积浓度超过15％时，它可以完全定义为完全火山泥流量。当低频的振动作用于浓度以上超过48.5％的泥浆上时，由唯一的火山灰组成，膨胀的效果显着，其剪切阻力会随着振动的数量而增加。当它的浓度达到约66％时，它完全表现出可塑性，而贵族的贵重性会大大减少。但是，当小图被混合到泥浆中时，它可以防止扩张的效果，并且它的迁移率会增加，因为浆料中的粒径并不像浆料中的粒度那样均匀。它的流动性在混合率约为40％时获得最高。火山灰的质量在仅几秒钟内就可以在几秒钟内被5个周期/sec的病毒轻易流动，并且在低于66％的浓度下，LCM -2 cm的放大器。当火山灰层以高频（例如地球地质的频率）降低的情况下，该病毒的频率很高时，与任何情况相比，当时均与30°的行为相比，这是一个关键的角度。在上面。高浓度的浆料的明显内摩擦角降低了低浓度的较低量。这意味着火山灰层的液化很容易由振动引起，例如在活跃火山区域中斜坡故障的地质或冲击力，即使在小雨下降也是如此。较少的

项目成果

Taniguhi,Y.Hirano,M.Hikida,M.: "Study on the Volcanic Mud Flow of Ichinomiya on 2 July in 1990,Japan-U.S.Workshop Abstracts" Snow Avalanche,Landslide,Debris flow Prediction and Control. 19-19 (1991)

Taniguhi,Y.Hirano,M.Hikida,M.：“1990年7月2日一宫火山泥流研究，日美研讨会摘要”雪崩、滑坡、泥石流预测与控制。

Taniguchi,Y.,Hirano,M.,Hikida,M.: "Study on the Volcanic Mud Flow of Ichinomiya on 2 July in 1990,JapanーU.S.Workshop Abstracts" Snow Avalanche,Landslide,Debris Flow Prediction and Control. 19-19 (1991)

Taniguchi, Y., Hirano, M., Hikida, M.：“1990年7月2日一宫火山泥流研究，日美研讨会摘要”雪崩、滑坡、泥石流预测与控制19-19。 (1991)

Taniguchi, Y: "Hirano, M. and Hikida, M. : Study on the Volcanic Mud Flow of Ichinomiya on 2 July in 1990" Snow Avalanche, Landslide, Debris Flow Prediction and Control, Japan- U. S. Workshop Abstracts.

Taniguchi, Y：“平野 M. 和 Hikida, M.：1990 年 7 月 2 日一宫火山泥流研究”雪崩、滑坡、泥石流预测与控制，日美研讨会摘要。

谷口 義信: "桜島火山泥流の流れの特性" 砂防学会ワ-クショップ. 21-29 (1990)

谷口义信：“樱岛火山泥流的流动特征”萨博学会研讨会21-29（1990）。

谷口 義信: "桜島火山泥流の流れの特性" 砂防学会ワ-クショップ荒廃渓流における地形変化と堆積土砂の制御. 21-29 (1990)

谷口义信：《樱岛火山泥流的流动特征》侵蚀控制学会研讨会地形变化与退化山溪中的沉积物沉积控制21-29（1990）。