The Large Salcito Landslide Triggered by the 2002 Molise, Italy, Earthquake

2004 ◽  
Vol 20 (1_suppl) ◽  
pp. 95-105 ◽  
Author(s):  
Francesca Bozzano ◽  
Salvatore Martino ◽  
Giuseppe Naso ◽  
Alberto Prestininzi ◽  
Roberto Walter Romeo ◽  
...  
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Ground Level ◽  
Contributing Factors ◽  
Borehole Data ◽  
Clay Shales ◽  
Site Investigations ◽  
Local Seismic Response ◽  
Below Ground ◽  
Scaly Clay

The 2002 Molise, Italy, earthquake triggered a deep planar earthslide about 38 km away from the epicenter, mainly involving scaly clay shales and related weathered material. Based on site investigations and borehole data, the inferred depth of the sliding surface is between 30 and 50 meters below ground level, indicating an involved volume of about 40⋅106 m3. The complex geological setting, the generated excess pore water pressure, and possible local seismic response are thought to have been the primary contributing factors.

High-resolution 3D reflection seismic investigation over a quick-clay landslide scar in southwest Sweden

Geophysics ◽  
2014 ◽  
Vol 79 (2) ◽  
pp. B97-B107 ◽  
Author(s):  
Emil Lundberg ◽  
Alireza Malehmir ◽  
Christopher Juhlin ◽  
Mehrdad Bastani ◽  
Magnus Andersson
Keyword(s):  
Seismic Data ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Geophysical Methods ◽  
Coarse Grained ◽  
Reflection Seismic ◽  
Site Investigations ◽  
Quick Clay ◽  
Triggering Mechanisms ◽  
Landslide Development

Quick-clay landslides often occur in the northern hemisphere in areas that were covered by Pleistocene glaciations. They are particularly common along the shorelines of the Göta River in southwestern Sweden. Characterization of potential landslide areas and identification of features that indicate high risk are necessary to better understand the triggering mechanisms of these events. Therefore, an intensive characterization project was initiated at the Fråstad landslide in Sweden. Part of the characterization program included the acquisition of 3D reflection seismic data to image structures in the normally consolidated sediments, as well as the bedrock topography below the landslide scar. Two seismic horizons within the glacial and postglacial sediments were observed. The shallowest seismic horizon (here, referred to as S1) corresponds to a coarse-grained layer that was previously detected by eight geotechnical boreholes located within the 3D survey area. Discontinuities in S1, mapped by the 3D reflection seismic data, occur across a zone that correlates with the landslide scar boundary, suggesting that this zone may have played a role in triggering and/or in limiting the extension of the landslide. If S1 is truncated by or mixed with clays in this zone, then the outflow of water from the permeable S1 into the clays above may have increased the amount of quick clays above this zone. The increased outflow of water may also have caused a higher pore-water pressure south of the zone, which in turn could have acted as a trigger for the landslide. We evaluated the potential of using the 3D reflection seismic method as a complement to drilling and other geophysical methods when performing landslide site investigations. We also demonstrated the importance of further investigating the relationship between 3D subsurface geometries and landslide development.

scholarly journals The Risk of Liquefaction Associated with Water Head Fluctuation in the Low-lying Area of Tokyo

2019 ◽  
Vol 8 (2) ◽  
pp. 41-47
Author(s):  
Tomohide Takeyama ◽  
Kazuya Honda ◽  
Atsushi Iizuka
Keyword(s):  
Pressure Distribution ◽  
Pore Water ◽  
Seismic Analysis ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Ground Level ◽  
Flood Damage ◽  
Tokyo Bay ◽  
Ground Settlement ◽  
Groundwater Head

 In the wide area of the eastern part of Tokyo, the ground level is less than mean sea level. This area is more vulnerable to disasters than other areas. If large flood damage such as storm surge should occur in this area, the disaster would be a long-term catastrophe. On the coast of Tokyo Bay, countermeasures have been taken by tide embankments and floodgates. However, considering the damage scale when it occurs, an analysis in this area is very important. In this area, ground settlement occurred and groundwater head dropped because groundwater excessively withdrew by the industrial purpose during the period of economic growth. Currently, the groundwater head recovers and the ground settlement has been subsided. However, due to the groundwater head fluctuation, pore water pressure distribution had been different from hydrostatic pressure distribution. Therefore, in the analysis in this area, it is necessary to consider past groundwater head fluctuation. In this research, the ground settlement and the distribution of pore water pressure are simulated from groundwater level fluctuation over the past 100 years. Then, we conducted the seismic analysis by input the distribution of effective stress calculating from the simulated ground water pressure. The sites analyzed in this research are Tokyo Sea Life Park at the mouth of Arakawa River.

scholarly journals Development of Soil Distribution and Liquefaction Potential Maps for Downtown Area in Yangon, Myanmar

2018 ◽  
Vol 4 (3) ◽  
pp. 689 ◽  
Author(s):  
Zar Lee Tint ◽  
Nyan Myint Kyaw ◽  
Kyaw Kyaw
Keyword(s):  
Earthquake Engineering ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Standard Penetration Test ◽  
Soil Liquefaction ◽  
Dry Density ◽  
Borehole Data ◽  
Fine Content ◽  
Liquefaction Potential ◽  
Downtown Area

The problem of soil against liquefaction during earthquakes is devastating geotechnical phenomenon. Soil against liquefaction is generally occurred in loose cohesionless saturated soil when pore water pressure increases suddenly due to earthquakes and shear strength of the soil decreases to zero. Yangon area has been chosen as the study area because it is the most populated and largest city in Myanmar and located in low to medium seismicity region. In this purpose, the liquefaction potential map have been prepared for site planners and decision makers to prevent loss of lives. Geographic Information System (GIS) is very useful in decision making about the area subjected to liquefaction. ArcGIS software is used to develop the liquefaction potential maps of the selected area in Yangon City. To perform in this study, the field borehole data for groundwater table, Standard penetration test (SPT), blow counts, dry density, wet density and fine content, etc. have been collected from the downtown area of this city. Firstly, the safety factor of soil liquefaction is computed by using NCEER (National Center of Earthquake Engineering Research, 1997) Method based on cyclic resistance ratio and cyclic stress ratio and then liquefaction Potential Index (LPI) values are determined using Luna and Frost Method, 1998. Finally, liquefaction potential maps are developed corresponding to the ground motions for annual probability of exceedance equal to 1%, 2% and 10% in 50 years.

TIME TO THE END OF PRIMARY CONSOLIDATION (EOP) OF SOFT CLAYEY SOILS: CONCERNING THE EFFECT OF ATTERBERG’S LIMIT AND CYCLIC LOADING HISTORY

2019 ◽  
Vol 128 (2B) ◽  
pp. 29-41
Author(s):  
Trần Thanh Nhàn
Keyword(s):  
Cyclic Loading ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Clayey Soils ◽  
Loading History ◽  
Cyclic Shear ◽  
Wide Range ◽  
Primary Consolidation ◽  
Time Required

In order to observe the end of primary consolidation (EOP) of cohesive soils with and without subjecting to cyclic loading, reconstituted specimens of clayey soils at various Atterberg’s limits were used for oedometer test at different loading increments and undrained cyclic shear test followed by drainage with various cyclic shear directions and a wide range of shear strain amplitudes. The pore water pressure and settlement of the soils were measured with time and the time to EOP was then determined by different methods. It is shown from observed results that the time to EOP determined by 3-t method agrees well with the time required for full dissipation of the pore water pressure and being considerably larger than those determined by Log Time method. These observations were then further evaluated in connection with effects of the Atterberg’s limit and the cyclic loading history.

Conjectures, Hypotheses, and Theories of Drumlin Formation (In memory of Stanislaw Baranowski)

1981 ◽  
Vol 27 (97) ◽  
pp. 503-505 ◽  
Author(s):  
Ian J. Smalley
Keyword(s):  
Shear Strength ◽  
Pore Water ◽  
Stress Level ◽  
Critical Stress ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Glacial Till ◽  
Forming Process ◽  
Stress Levels

AbstractRecent investigations have shown that various factors may affect the shear strength of glacial till and that these factors may be involved in the drumlin-forming process. The presence of frozen till in the deforming zone, variation in pore-water pressure in the till, and the occurrence of random patches of dense stony-till texture have been considered. The occurrence of dense stony till may relate to the dilatancy hypothesis and can be considered a likely drumlin-forming factor within the region of critical stress levels. The up-glacier stress level now appears to be the more important, and to provide a sharper division between drumlin-forming and non-drumlin-forming conditions.

The temperature and pore water pressure in soil subjected to dynamic load

2018 ◽  
Vol 35 (2) ◽  
pp. 111
Author(s):  
Kun ZHANG ◽  
Ze ZHANG ◽  
Xiangyang SHI ◽  
Sihai LI ◽  
Donghui XIAO
Keyword(s):  
Pore Water ◽  
Dynamic Load ◽  
Pore Water Pressure ◽  
Water Pressure

Development of Experimental P-Y Curves from Centrifuge Tests for Piles Subjected to Static Loading and Liquefaction-Induced Lateral Spreading

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Milad Souri
Keyword(s):  
Static Loading ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Pressure Ratio ◽  
Lateral Spreading ◽  
American Petroleum Institute ◽  
Unique Contribution ◽  
Pile Groups ◽  
Centrifuge Tests ◽  
Centrifuge Models

The results of five centrifuge models were used to evaluate the response of pile-supported wharves subjected to inertial and liquefaction-induced lateral spreading loads. The centrifuge models contained pile groups that were embedded in rockfill dikes over layers of loose to dense sand and were shaken by a series of ground motions. The p-y curves were back-calculated for both dynamic and static loading from centrifuge data and were compared against commonly used American Petroleum Institute p-y relationships. It was found that liquefaction in loose sand resulted in a significant reduction in ultimate soil resistance. It was also found that incorporating p-multipliers that are proportional to the pore water pressure ratio in granular materials is adequate for estimating pile demands in pseudo-static analysis. The unique contribution of this study is that the piles in these tests were subjected to combined effects of inertial loads from the superstructure and kinematic loads from liquefaction-induced lateral spreading.

scholarly journals The Hydromechanical Interplay in the Simplified Three-Dimensional Limit Equilibrium Analyses of Unsaturated Slope Stability

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 73
Author(s):  
Panagiotis Sitarenios ◽  
Francesca Casini
Keyword(s):  
Analytical Solution ◽  
Slope Stability ◽  
Slope Failure ◽  
Failure Modes ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Three Dimensional ◽  
Stability Limit ◽  
Smooth Transition

This paper presents a three-dimensional slope stability limit equilibrium solution for translational planar failure modes. The proposed solution uses Bishop’s average skeleton stress combined with the Mohr–Coulomb failure criterion to describe soil strength evolution under unsaturated conditions while its formulation ensures a natural and smooth transition from the unsaturated to the saturated regime and vice versa. The proposed analytical solution is evaluated by comparing its predictions with the results of the Ruedlingen slope failure experiment. The comparison suggests that, despite its relative simplicity, the analytical solution can capture the experimentally observed behaviour well and highlights the importance of considering lateral resistance together with a realistic interplay between mechanical parameters (cohesion) and hydraulic (pore water pressure) conditions.

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