WCoE: Mechanisms of Landslides in Over-Consolidated Clays and Flysch and IPL-151 Project: Soil Matrix Suction in Active Landslides in Flysch—The Slano Blato Landslide Case

2014 ◽  
pp. 143-148 ◽  
Author(s):  
Matjaž Mikoš ◽  
Jošt Sodnik ◽  
Ana Petkovšek ◽  
Matej Maček ◽  
Bojan Majes
Keyword(s):  
Soil Matrix ◽  
Matrix Suction

Soil matrix suction: some examples of its measurement and application in geotechnical engineering

Géotechnique ◽  
2003 ◽  
Vol 53 (2) ◽  
pp. 241-253 ◽  
Author(s):  
A. M. Ridley ◽  
K. Dineen ◽  
J. B. Burland ◽  
P. R. Vaughan
Keyword(s):  
Geotechnical Engineering ◽  
Soil Matrix ◽  
Matrix Suction

The Stability Studies of Soil Slope under the Action of Short-Time Heavy Rainfall

2012 ◽  
Vol 170-173 ◽  
pp. 1192-1195
Author(s):  
Zhong Ming He ◽  
Xin Tong Zhao ◽  
Ling Zeng ◽  
Yan Qi Qin
Keyword(s):  
Shear Strength ◽  
Heavy Rainfall ◽  
Soil Slope ◽  
Soil Matrix ◽  
Water Load ◽  
Safety Coefficient ◽  
Rainwater Infiltration ◽  
Matrix Suction ◽  
Short Time ◽  
Slope Safety

Based on the saturated-unsaturated seepage theory and the unsaturated shear strength, the numerical simulations of soil slope seepage field in short-time heavy rainfall was carried out, and on this basis calculated the slope safety coefficient at different rainfall time. The research shows that: the rainfall infiltration will cause the slope soil matrix suction decreased or even disappeared which leads to the slope shear strength reduce; Rainwater infiltration increases the transient water load of infiltration area; and under the dual role of matrix suction reduction and transient water load increasing, the slope safety coefficient has the downward trend obviously.

Factors controlling debris avalanche initiation

1990 ◽  
Vol 27 (5) ◽  
pp. 659-675 ◽  
Author(s):  
P. Buchanan ◽  
K. W. Savigny
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Debris Avalanche ◽  
Soil Matrix ◽  
Debris Avalanches ◽  
Root Cohesion ◽  
Group I ◽  
Whatcom County ◽  
Matrix Suction ◽  
Forest C

Heavy rainfall during a January 1983 storm triggered numerous debris avalanches and associated debris torrents in the Smith Creek basin, western Whatcom County, Washington, United States. Four classes of debris avalanches are recognized: wedges, drainage depressions, logging roads, and discontinuity surfaces. Nine different debris avalanche headscarps that are representative of these four classes are studied in detail. The geometric configuration of each headscarp, the properties of soils comprising the headscarps, and water tables based on numerical models of hillslope hydrology are used in limit equilibrium slope stability analyses to back-calculate root cohesion (Cr) values at failure. The calculated values are consistent with those reported by others. Four groups of Cr values are proposed and correlated with forest vegetation: group I, understory, Cr range from 1.6 to 2.1 kPa; group II, scrub forest, Cr range from 2.1 to 2.5 kPa; group III, mixed forest, Cr range from 2.5 to 3.0 kPa; and group IV, old growth forest, Cr greater than 3.0 kPa. Circular and noncircular failure surfaces are tested to determine the most likely failure configuration. Most computer-generated failure surfaces are consistent with those observed in situ. One debris avalanche is attributed to hydraulic erosion rather than Coulomb shear. Soil matrix suction contributes significantly to slope stability under drained, initial conditions. Loss of soil matrix suction during rainstorms and loss of root cohesion at failure cause a sharp reduction of soil shear strength. The stability of each headscarp is modeled during a moderately severe comparison storm in December 1979. Failure was probable at only two of the nine sites, and field evidence of prior failure is found at one of these. Sites with group I vegetation were also susceptible to failure during this storm. Pore-pressure increases triggered the debris avalanches; however, soil depth, soil density, the presence of smooth bedrock discontinuities, and root cohesion are shown to be important factors controlling initiation locations. The conclusions of this study are based on modeling results, which are only verified by post-failure observations at the avalanche headscarps. Direct field measurement of the hydrologic and shear strength parameters is required before the modeling results and conclusions drawn can be confirmed. Key words: slope stability, debris avalanche, hydrology, root cohesion, forested hillslope, factor of safety, Whatcom County, Washington.

scholarly journals New Progress in the Study of Intergranular Suction and Shear Strength of Unsaturated Soil

2016 ◽  
Vol 20 (1) ◽  
pp. 1-13
Author(s):  
Liansheng Tang ◽  
Haitao Sang ◽  
Liqun Jiang ◽  
Yinlei Sun ◽  
Muhammad Ashraf
Keyword(s):  
Shear Strength ◽  
Effective Stress ◽  
Unsaturated Soil ◽  
Soil Mechanics ◽  
Influence Factors ◽  
Confining Pressure ◽  
Soil Matrix ◽  
Soil Particles ◽  
Quantitative Calculation ◽  
Matrix Suction

<p>The suction between soil particles is the basis and core problem in the study of unsaturated soil. However, is the suction between soil particles just the matrix suction, which has been widely used since the discipline of unsaturated soil mechanics was established. In fact, the concept of matrix suction is from soil science and reflects the water- absorbing capacity of the soil. Matrix suction characterizes the interaction between soil particles and pore water rather than the interactions between soil particles, which are not in conformity with the principle of the effective stress of soils. The suction of unsaturated soil, in essence, is the intergranular suction composed of absorbed suction and structural suction. In this paper, first, the basic concepts of absorbed suction and structural suction were briefly introduced. Then, with soil mechanics, powder science, crystal chemistry, granular material mechanics and other related disciplines of knowledge for reference, the quantitative calculation formulas were theoretically deduced for the absorbed suction for equal-sized and unequal-sized unsaturated soil particles with arbitrary packing and the variable structural suction for equal-sized unsaturated soil particles with arbitrary packing and unequal-sized unsaturated soil particles with close tetrahedral packing. The factors that influence these equations were discussed. Then, the shear strength theory of unsaturated soil was established based on the theory of intergranular suction through the analysis of the effective stress principle of unsaturated soil. This study demonstrates that the shear strength of unsaturated soil consists of three parts: the effective, cohesive force, the additional strength caused by external loads and the strength caused by intergranular suction. The contribution of the three parts to the shear strength of unsaturated soil depends on the following influence factors: soil type, confining pressure, water content and density. Therefore, these factors must be comprehensively considered when determining the strength of unsaturated soil.</p>

Overview of Measurements of Unsaturated Soil Matrix Suction

2014 ◽  
Vol 955-959 ◽  
pp. 3615-3619
Author(s):  
Yan Hui Liu ◽  
Hong Zhang ◽  
Chao Guo
Keyword(s):  
Field Test ◽  
Unsaturated Soil ◽  
Measurement Range ◽  
Test Method ◽  
Soil Matrix ◽  
Matrix Suction ◽  
Physical Principles ◽  
Field Test Method

Matrix suction is very important in researching the properties of unsaturated soil. At present, there have been a lot of measurements of matrix suction. Basing on the physical principles of each kind of measurements, this paper divides them into indoor test method and field test method and evaluates them by equipment needed, operation steps, measurement range and matters needing attention.

INFLUENCE OF SOIL MATRIX ON SOIL-WATER RETENTION CURVE AND HYDRAULIC CHARACTERISTICS

2017 ◽  
Vol 16 (4) ◽  
pp. 869-877
Author(s):  
Vasile Lucian Pavel ◽  
Florian Statescu ◽  
Dorin Cotiu.ca-Zauca ◽  
Gabriela Biali ◽  
Paula Cojocaru
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Water Retention Curve ◽  
Hydraulic Characteristics ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Soil Matrix ◽  
Retention Curve

scholarly journals Effects of preferential flow on snowmelt partitioning and groundwater recharge in frozen soils

2019 ◽  
Vol 23 (12) ◽  
pp. 5017-5031 ◽  
Author(s):  
Aaron A. Mohammed ◽  
Igor Pavlovskii ◽  
Edwin E. Cey ◽  
Masaki Hayashi
Keyword(s):  
Soil Moisture ◽  
Groundwater Recharge ◽  
Preferential Flow ◽  
Frozen Soil ◽  
Time Lags ◽  
Runoff Generation ◽  
Frozen Ground ◽  
Soil Matrix ◽  
Frozen Soils ◽  
Flow Through

Abstract. Snowmelt is a major source of groundwater recharge in cold regions. Throughout many landscapes snowmelt occurs when the ground is still frozen; thus frozen soil processes play an important role in snowmelt routing, and, by extension, the timing and magnitude of recharge. This study investigated the vadose zone dynamics governing snowmelt infiltration and groundwater recharge at three grassland sites in the Canadian Prairies over the winter and spring of 2017. The region is characterized by numerous topographic depressions where the ponding of snowmelt runoff results in focused infiltration and recharge. Water balance estimates showed infiltration was the dominant sink (35 %–85 %) of snowmelt under uplands (i.e. areas outside of depressions), even when the ground was frozen, with soil moisture responses indicating flow through the frozen layer. The refreezing of infiltrated meltwater during winter melt events enhanced runoff generation in subsequent melt events. At one site, time lags of up to 3 d between snow cover depletion on uplands and ponding in depressions demonstrated the role of a shallow subsurface transmission pathway or interflow through frozen soil in routing snowmelt from uplands to depressions. At all sites, depression-focused infiltration and recharge began before complete ground thaw and a significant portion (45 %–100 %) occurred while the ground was partially frozen. Relatively rapid infiltration rates and non-sequential soil moisture and groundwater responses, observed prior to ground thaw, indicated preferential flow through frozen soils. The preferential flow dynamics are attributed to macropore networks within the grassland soils, which allow infiltrated meltwater to bypass portions of the frozen soil matrix and facilitate both the lateral transport of meltwater between topographic positions and groundwater recharge through frozen ground. Both of these flow paths may facilitate preferential mass transport to groundwater.

Dermal Uptake of Organic Chemicals from a Soil Matrix

Risk Analysis ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 407-419 ◽  
Author(s):  
Thomas E. McKone
Keyword(s):  
Organic Chemicals ◽  
Soil Matrix ◽  
Dermal Uptake
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