Experimental and numerical investigation of the Saint-Adelphe landslide after the 1988 Saguenay earthquake

2020 ◽  
Vol 57 (12) ◽  
pp. 1936-1952
Author(s):  
Mustapha Abdellaziz ◽  
Mourad Karray ◽  
Mahmoud N. Hussien ◽  
Marie-Christine Delisle ◽  
Catherine Ledoux ◽  
...  
Keyword(s):  
Seismic Analysis ◽  
Pore Water Pressure ◽  
Progressive Failure ◽  
Water Pressure ◽  
Failure Surface ◽  
Crustal Layer ◽  
Softening Behavior ◽  
Initiation And Propagation ◽  
Global Safety Factor

On 25 November 1988, after the Saguenay earthquake, a landslide occurred in the municipality of Saint-Adelphe. The soil profile indicated that the deposit was composed of a stiff clay crustal layer overlying sensitive plastic clay with a soft-to-stiff consistency. A geotechnical investigation was carried out in situ and in the laboratory and included the use of a new seismic simulator to develop a geotechnical model of the Saint-Adelphe clay. The model was incorporated in a finite-difference slope stability analysis before and during the earthquake. The results showed the development of plastic zones and the generation of pore water pressure, but the global safety factor remained above unity. A post-seismic analysis that utilized a strain-softening behavior model showed the initiation and propagation of the plastic zone, as well as the development of a failure surface close to the observed failure surface. Therefore, it is proposed that the Saint-Adelphe landslide could be explained by a progressive failure mechanism.

The Test Study to the Changes of Excess Pore Water Pressure during Precast Pile Construction

2012 ◽  
Vol 193-194 ◽  
pp. 1010-1013
Author(s):  
Shu Qing Zhao
Keyword(s):  
Pore Water ◽  
Clayey Soil ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Excess Pore Pressure ◽  
Soil Pressure ◽  
Excess Pore Water Pressure ◽  
Test Study ◽  
Excess Pore

The construct to precast pile in thick clayey soil can cause the accumulation of excess pore water pressure. The high excess pore pressure can make soil, buildings and pipes surrounded have large deflection, even make them injured. Combining with actual projects, this paper presents an in-situ model test on the changes of excess pore water pressure caused by precast pile construct. It is found that the radius of influence range for single pile driven is about 15m，the excess pore water pressure can reach or even exceed the above effective soil pressure, and there are two relatively stable stages.

scholarly journals Seismic detection of transient changes beneath Black Rapids Glacier, Alaska, U.S.A.: II. Basal morphology and processes

1999 ◽  
Vol 45 (149) ◽  
pp. 132-146 ◽  
Author(s):  
Matt Nolan ◽  
Keith Echelmeyer
Keyword(s):  
Hydraulic System ◽  
Seismic Analysis ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Basal Layer ◽  
Thick Layer ◽  
Reflection Coefficients ◽  
Overburden Pressure ◽  
Arrival Times ◽  
Black Rapids Glacier

AbstractUsing changes observed in daily seismic reflections, we have investigated the basal morphology of Black Rapids Glacier, Alaska, U.S.A. The englacial drainage of ice-marginal lakes caused significant changes in the daily reflections, as well as dramatic increases in basal motion. Changes in reflection arrival times and amplitudes indicate that there is a basal till layer at least 5 m thick at some locations beneath this surge-type glacier. Rapid changes in the observed reflection coefficients during the drainage events indicate that changes in till properties must occur throughout the entire 5 m thick layer, they must last for several days following the lake drainages and they must be completely reversible over as little as 36 min. Our seismic analysis shows that changes in effective pressure of the till are unlikely to cause the required changes in the reflection coefficients, but that a decrease in till saturation is likely. We therefore interpret the cause of the seismic anomalies as being a temporary decrease in saturation as water is input to the subglacial hydraulic system, and propose that such a change may occur quickly and reversibly by a redistribution of overburden pressure. Higher water pressures within the hydraulic system cause that region to support more of the glacier’s weight, leaving the remaining areas to support less. Any till within these areas of decreased normal stress would experience a consequent decrease in pore-water pressure, causing gas to exolve, thus decreasing saturation. This decrease in saturation would cause a change in the strength of the basal layer and may affect basal dynamics.

A Heating Experiment in the Argillites in the Meuse/Haute-Marne Underground Research Laboratory

2007 ◽  
Author(s):  
Yannick Wileveau ◽  
Kun Su ◽  
Mehdi Ghoreychi
Keyword(s):  
Research Laboratory ◽  
Linear Thermal Expansion Coefficient ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Linear Thermal Expansion ◽  
General Description ◽  
In Situ Experiment ◽  
Heating And Cooling ◽  
Underground Research Laboratory

A heating experiment named TER is being conducted with the objectives to identify the thermal properties, as well as to enhance the knowledge on THM processes in the Callovo-Oxfordian clay at the Meuse/Haute Marne Underground Research Laboratory (France). The in situ experiment has being switched on from early 2006. The heater, 3 m length, is designed to inject the power in the undisturbed zone at 6 m from the gallery wall. A heater packer is inflated in a metallic tubing. During the experiment, numerous sensors are emplaced in the surrounding rock and are experienced to monitor the evolution in temperature, pore-water pressure and deformation. The models and numerical codes applied should be validated by comparing the modeling results with the measurements. In parallel, some lab testing have been achieved in order to compare the results given with two different scales (cm up to meter scale). In this paper, we present a general description of the TER experiment with installation of the heater equipment and the surrounding instrumentation. Details of the in situ measurements of temperature, pore-pressure and strain evolutions are given for the several heating and cooling phases. The thermal conductivity and some predominant parameters in THM processes (as linear thermal expansion coefficient and permeability) will be discussed.

In Situ Study on Soil Disturbance Induced by Shield Tunneling in Tianjin

2013 ◽  
Vol 368-370 ◽  
pp. 1674-1677
Author(s):  
Yong Hua Cao ◽  
Xiao Qiang Kou
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soil Disturbance ◽  
Ground Settlement ◽  
Soil Pressure ◽  
Shield Tunneling ◽  
Tunnel Face ◽  
Tunneling Process

In urban environment, the soil disturbance induced by shield tunneling can be sensitive because it can cause deformation of the ground and damage the near structure. To study this disturbance in the construction process of Tianjin metro line No.3, in-situ monitoring of pore water pressure, soil pressure and ground settlement were conducted. The pore water pressure was monitored for the soil around the tunnel. The soil pressure was monitored for the soil around the tunnel and on the tunnel face. It was revealed that the pore water pressure and soil pressure changed twice in the tunneling process and these changes were induced by cutting face and grouting at the shield tail. The soil pressure on the tunnel face reached its maximal value when the distance between the cutting face and the sensor elements was around the diameter of the tunnel. Ground settlement developed in the tunneling process. The shape of ultimate settlement trough is closed to the one obtained by Pecks method.

scholarly journals Numerical modeling of progressive failure and its implications for spreads in sensitive clays

2013 ◽  
Vol 50 (9) ◽  
pp. 961-978 ◽  
Author(s):  
Ariane Locat ◽  
Hans Petter Jostad ◽  
Serge Leroueil
Keyword(s):  
Progressive Failure ◽  
Limit Equilibrium ◽  
Pressure Ratio ◽  
Earth Pressure ◽  
High Sensitivity ◽  
Failure Surface ◽  
Soil Mass ◽  
Initiation And Propagation ◽  
Failure Propagation ◽  
Steep Slopes

Spreads are a type of large landslide occurring in sensitive clays. Stability analyses using the limit equilibrium method give factors of safety that are too large and are therefore not applicable to this type of landslide. The progressive failure mechanism is believed to explain the initiation and propagation of the failure surface and the dislocation of the soil mass in horsts and grabens, typical of spreads. A numerical method is presented to identify the parameters influencing progressive failure and to validate the application of this mechanism to spreads. The method evaluates the stresses acting in the slope before failure and models the initiation and propagation of the progressive failure. It is demonstrated that high, steep slopes, with a large earth pressure ratio at rest, are more susceptible to progressive failure and the failure surface propagates over a large distance. Failure is more likely to occur when soil with high brittleness is involved. Soil with low strength at large deformation induces failure propagation over a larger distance. Eastern Canadian clays can exhibit high sensitivity and large brittleness during shear and are susceptible to progressive failure, which explains the occurrence of spreads in these soils.

scholarly journals In situ measurements of till deformation and water pressure

2006 ◽  
Vol 52 (177) ◽  
pp. 175-182 ◽  
Author(s):  
Martin Truffer ◽  
William D. Harrison
Keyword(s):  
Pore Water ◽  
Pressure Transducer ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Spatial Homogeneity ◽  
Early Season ◽  
Surface Motion ◽  
Speed Up ◽  
Tilt Sensor

AbstractA newly developed hammer was used to insert two autonomous probes 0.8 m and 2.1 m into clast-rich subglacial till under Black Rapids Glacier, Alaska, USA. Both probes were instrumented with a dual-axis tilt sensor and a pore-water pressure transducer. The data are compared to a 75 day record of surface velocities. Till deformation at depth was found to be highly seasonal: it is significant during an early-season speed-up event, but during long periods thereafter measured till deformation rates are negligible. Both tilt records show rotation around the probe axis, which indicates a change in tilt direction of about 30°. The tilt records are very similar, suggesting spatial homogeneity on the scale of the probe separation (4 m horizontal and 3.3 m vertical). There is evidence that during much of the year sliding of ice over till or deformation of a thin till layer (<20 cm) accounts for at least two-thirds of total basal motion. Basal motion accounts for 50–70% of the total surface motion. The inferred amount of ice–till sliding is larger than that found at the same location in a previous study, when surface velocities were about 10% lower. We suggest that variations in ice–till coupling account for the observed variations in mean annual speed.

Further Study on the Application of Self-Boring Pressuremeter Test in Clays

2011 ◽  
Vol 243-249 ◽  
pp. 2752-2758
Author(s):  
Quan Cao ◽  
Hong Chen
Keyword(s):  
Experimental Investigation ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Small Strain ◽  
Linear Analysis ◽  
The Self ◽  
Geotechnical Investigation ◽  
Pressuremeter Test ◽  
In Situ Method

The self-boring pressuremeter test has potential advantages over the conventional in situ method in the geotechnical investigation. It not only provides fundamental soil properties for the designer, but also plays more important role in the geotechnical analysis. With help of Cambridge self-boring model pressuremeter tests, some new application are studied in this paper as following: (1) Analysis of stress paths in clays adjacent to the cavity wall during self-boring pressuremeter test; (2) Experimental investigation on stiffness of soils at small strain under non-linear analysis; and (3) Study on magnitude of the changes in pore-water pressure of clays, which will help to enlarge the application of self-boring pressuremeter test in geotechnical engineering.

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.

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