Offshore 1D infinite slope modeling in seismic conditions with OpenSees

2015 ◽  
pp. 993-997
Author(s):  
C Piatti ◽  
L Zuccarino ◽  
O Zanoli
Keyword(s):  
Infinite Slope ◽  
Slope Modeling

Flow Deformation of Liquefied Sand Under Constant Shear Load and Prediction of Flow Slide of Infinite Slope

Geomechanics ◽  
2005 ◽  
Author(s):  
Mitsutoshi Yoshimine ◽  
Hiroto Nishizaki ◽  
Kei Amano ◽  
Yasuyo Hosono
Keyword(s):  
Shear Load ◽  
Infinite Slope ◽  
Flow Slide ◽  
Constant Shear ◽  
Flow Deformation

scholarly journals Shallow Landslides Physically Based Susceptibility Assessment Improvement Using InSAR. Case Study: Carpathian and Subcarpathian Prahova Valley, Romania

2021 ◽  
Vol 13 (12) ◽  
pp. 2385
Author(s):  
Iuliana Armaș ◽  
Mihaela Gheorghe ◽  
George Cătălin Silvaș
Keyword(s):  
Slope Failure ◽  
Surface Displacement ◽  
Unit Weight ◽  
Susceptibility Map ◽  
Case Scenario ◽  
Worst Case ◽  
Infinite Slope ◽  
Actual Surface ◽  
Infinite Slope Stability Model ◽  
Physically Based

A multi-temporal satellite radar interferometry technique is used for deriving the actual surface displacement patterns in a slope environment in Romania, in order to validate and improve a landslide susceptibility map. The probability the occurrence of future events is established using a deterministic approach based on a classical one-dimension infinite slope stability model. The most important geotechnical parameters for slope failure in the proposed study area are cohesion, unit weight and friction angle, and the triggering factor is a rapid rise in groundwater table under wetting conditions. Employing a susceptibility analysis using the physically based model under completely saturated conditions proved to be the most suitable scenario for identifying unstable areas. The kinematic characteristics are assessed by the Small BAseline Subsets (SBAS) interferometry technique applied to C-band synthetic aperture radar (SAR) Sentinel-1 imagery. The analysis was carried out mainly for inhabited areas which present a better backscatter return. The validation revealed that more than 22% of the active landslides identified by InSAR were predicted as unstable areas by the infinite slope model. We propose a refinement of the susceptibility map using the InSAR results for unravelling the danger of the worst-case scenario.

Variability Characterization of SWCC for Clay and Silt and Its Application to Infinite Slope Reliability

2021 ◽  
Vol 33 (8) ◽  
pp. 04021180
Author(s):  
Ammavajjala Sesha Sai Raghuram ◽  
B. Munwar Basha ◽  
K. V. N. S. Raviteja
Keyword(s):  
Infinite Slope

scholarly journals Sigmoidal water retention function with improved behaviour in dry and wet soils

2021 ◽  
Vol 25 (2) ◽  
pp. 983-1007
Author(s):  
Gerrit Huibert de Rooij ◽  
Juliane Mai ◽  
Raneem Madi
Keyword(s):  
Water Retention ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Deep Drainage ◽  
Infinite Slope ◽  
Original Curve ◽  
Dry Conditions ◽  
Conductivity Curve ◽  
Parameter Values

Abstract. A popular parameterized soil water retention curve (SWRC) has a hydraulic conductivity curve associated with it that can have a physically unacceptable infinite slope at saturation. The problem was eliminated before by giving the SWRC a non-zero air entry value. This improved version still has an asymptote at the dry end, which limits its usefulness for dry conditions and causes its integral to diverge for commonly occurring parameter values. We therefore joined the parameterizations' sigmoid midsection to a logarithmic dry section ending at zero water content for a finite matric potential, as was done previously for a power-law-type SWRC. We selected five SWRC parameterizations that had been proven to produce unproblematic near-saturation conductivities and fitted these and our new curve to data from 21 soils. The logarithmic dry branch gave more realistic extrapolations into the dry end of both the retention and the conductivity curves than an asymptotic dry branch. We tested the original curve, its first improvement, and our second improvement by feeding them into a numerical model that calculated evapotranspiration and deep drainage for nine combinations of soils and climates. The new curve was more robust than the other two. The new curve was better able to produce a conductivity curve with a substantial drop during the early stages of drying than the earlier improvement. It therefore generated smaller amounts of more evenly distributed deep drainage compared to the spiked response to rainfall produced by the earlier improvement.

scholarly journals A method for predicting the factor of safety of an infinite slope based on the depth ratio of the wetting front

2015 ◽  
Vol 3 (1) ◽  
pp. 791-836 ◽  
Author(s):  
B.-G. Chae ◽  
J.-H. Lee ◽  
H.-J. Park ◽  
J. Choi
Keyword(s):  
Steady State ◽  
Slope Stability ◽  
Unsaturated Soil ◽  
Landslide Susceptibility ◽  
Shallow Landslides ◽  
Rainfall Infiltration ◽  
Wetting Front ◽  
Operating Characteristics ◽  
Infinite Slope ◽  
Depth Ratio

Abstract. Most landslides in Korea are classified as shallow landslides with an average depth of less than 2 m. These shallow landslides are associated with the advance of a wetting front in the unsaturated soil due to rainfall infiltration, which results in an increase in water content and a reduction in the matric suction in the soil. Therefore, this study presents a modified equation of infinite slope stability analysis based on the concept of the saturation depth ratio to analyze the slope stability change associated with the rainfall on a slope. A rainfall infiltration test in unsaturated soil was performed using a column to develop an understanding of the effect of the saturation depth ratio following rainfall infiltration. The results indicated that the rainfall infiltration velocity due to the increase in rainfall in the soil layer was faster when the rainfall intensity increased. In addition, the rainfall infiltration velocity tends to decrease with increases in the unit weight of soil. The proposed model was applied to assess its feasibility and to develop a regional landslide susceptibility map using a Geographic Information System (GIS). For that purpose, the spatial databases for input parameters were constructed and landslide locations were obtained. In order to validate the proposed approach, the results of the proposed approach were compared with the landslide inventory using ROC (Receiver Operating Characteristics) graph. In addition, the results of the proposed approach were compared with the previous approach used steady state hydrological model. Consequently, the approach proposed in this study displayed satisfactory performance in classifying landslide susceptibility and showed better performance than the steady state approach.

scholarly journals Landslide and debris flow susceptibility zonation using TRIGRS for the 2011 Seoul landslide event

2013 ◽  
Vol 1 (3) ◽  
pp. 2547-2587 ◽  
Author(s):  
D. W. Park ◽  
N. V. Nikhil ◽  
S. R. Lee
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Debris Flow ◽  
Slope Stability Analysis ◽  
Flow Paths ◽  
Infinite Slope ◽  
Erosion Rates ◽  
Landslide Event ◽  
Physically Based ◽  
Pore Pressure Response

Abstract. This paper presents the results from application of a regional, physically-based stability model: Transient Rainfall Infiltration and Grid-based Regional Slope-stability analysis (TRIGRS) for a catchment on Woomyeon Mountain, Seoul, Korea. This model couples an infinite-slope stability analysis with a one-dimensional analytical solution to predict the transient pore pressure response to the infiltration of rainfall. TRIGRS also adopts the Geographic Information Systems (GIS) framework for determining the whole behaviour of a slope. In this paper, we suggest an index for evaluating the results produced by the model. Particular attention is devoted to the prediction of routes of debris flow, using a runoff module. In this context, the paper compares observed landslide and debris flow events with those predicted by the TRIGRS model. The TRIGRS model, originally developed to predict shallow landslides, has been extended in this study for application to debris flows. The results predicted by the TRIGRS model are presented as safety factor (FS) maps corresponding to transient rainfall events, and in terms of debris flow paths using methods proposed by several researchers in hydrology. In order to quantify the accuracy of the model, we proposed an index called LRclass (landslide ratio for each predicted FS class). The LRclass index is mainly applied in regions where the landslide scar area is not well defined (or is unknown), in order to avoid over-estimation of the model results. The use of the TRIGRS routing module was proposed to predict the paths of debris flow, especially in areas where the rheological properties and erosion rates of the materials are difficult to obtain. Although an improvement in accuracy is needed, this module is very useful for preliminary spatiotemporal assessment over wide areas. In summary, the TRIGRS model is a powerful tool of use to decision makers for susceptibility mapping, particularly when linked with various advanced applications using GIS spatial functions.

Polynomial Families for Flat-Faced Underwater Bodies and Wall-Sided Ship Sections

1979 ◽  
Vol 23 (04) ◽  
pp. 297-300
Author(s):  
Paul S. Granville
Keyword(s):  
Cube Root ◽  
Infinite Slope ◽  
Zero Curvature ◽  
Inflection Points ◽  
Wide Range ◽  
Root Term

Polynomial families that contain a cube-root term are developed to satisfy requirements of infinite slope and zero curvature. Adjustable parameters are used to provide a wide range of curves without inflection points. Applications are to flat-faced underwater bodies and wall-sided ship sections.

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