scholarly journals SLIDING STABILITY OF LANDWARD SLOPE CLAY COVER LAYERS OF SEA DIKES SUBJECT TO WAVE OVERTOPPING

2011 ◽  
Vol 1 (32) ◽  
pp. 5
Author(s):  
Andre Van Hoven ◽  
Bianca Hardeman ◽  
Jentsje W. Van der Meer ◽  
Gosse Jan Steendam
Keyword(s):  
Pore Pressure ◽  
Field Measurements ◽  
Storm Event ◽  
Infiltration Capacity ◽  
Wave Overtopping ◽  
Cover Layer ◽  
Sliding Stability ◽  
Clay Cover ◽  
Pore Pressure Build Up ◽  
Sea Dikes

Sea dikes with landward slopes covered by grass and clay cover layers, subject to wave overtopping, can become unstable and slide. Sliding stability of the cover layer is caused by a decrease in shear strength due to an increase in pore pressure in and underneath the clay cover layer. This holds for both clay dikes and sand dikes with a clay cover layer. A method is presented to determine the potential pore pressure build up due to a storm event with wave overtopping. The method combines of the shelf knowledge and is supported by laboratory measurements and field measurements during prototype scale wave overtopping tests and sliding test on Dutch sea dikes. The method contains three steps: 1) determine the infiltration time, depending on the storm duration and the sea state; 2) determine the infiltration capacity of the dike slope, either by choosing a safe value or field measurement and 3) determine the potential pore pressure build up, determined by step 1) and 2) and the dike structure and geometry. The potential pore pressure build up can be used in the standard stability analyses tools published in Dutch guidelines on dike design and dike safety assessment.

Pore Pressure Build-up of Silt Soft Clay under Dynamic Loading at Zhoushan Islands

2012 ◽  
Vol 594-597 ◽  
pp. 460-464
Author(s):  
Qian Shi ◽  
Kui Zhou ◽  
Qiang Li
Keyword(s):  
Pore Pressure ◽  
Dynamic Loading ◽  
Dynamic Load ◽  
Soft Clay ◽  
Test System ◽  
Dynamic Responses ◽  
Minor Effect ◽  
Consolidation Pressure ◽  
Anisotropic Consolidation ◽  
Pore Pressure Build Up

The mechanism of dynamic tri-axial test is introduced in this paper and the dynamic responses of silt soft clay at Zhoushan are studied using a dynamic tri-axial test system. The laws of pore pressure build-up of the silt clay are obtained which are affected by the consolidation pressure and dynamic load. The greater the consolidation pressure and the dynamic loading is, the more the build-up of pore pressure is. However, the dynamic load has minor effect on pore pressure build-up under the anisotropic consolidation.

WAVE OVERTOPPING AT OSTIA YACHT HARBOUR BREAKWATER: COMPARISON BETWEEN FIELD MEASUREMENTS AND MODEL TESTS IN 2D AND 3D

2005 ◽  
Author(s):  
JIMMY GEERAERTS ◽  
PETER TROCH ◽  
JULIEN DE ROUCK ◽  
MARC WILLEMS ◽  
LEOPOLDO FRANCO ◽  
...  
Keyword(s):  
Field Measurements ◽  
Model Tests ◽  
Wave Overtopping ◽  
2D And 3D

Influence of the groundwater on the stability of a clay bank in Baie James, Québec

1985 ◽  
Vol 22 (3) ◽  
pp. 409-413
Author(s):  
Peter Rosenberg ◽  
Jacques Provençal ◽  
Guy Lefebvre ◽  
J.-Jacques Paré
Keyword(s):  
Pore Pressure ◽  
Factor Of Safety ◽  
Field Measurements ◽  
Failure Surface ◽  
Surface Failure ◽  
Failure Morphology ◽  
Critical Failure Surface ◽  
Groundwater Regime ◽  
The Stability ◽  
River Banks

The Rivière Broadback in northern Québec flows westward almost parallel to latitude 51 °N to discharge into Baie James at its southern end. Near the estuary the river banks are in clay. Surveys of the landsliding activity showed that many of the slides are superficial, with depths seldom greater than about 2 m, and are usually in the clay crust.Instrumentation revealed regional groundwater pattern close to the river banks that showed areas varying from those with significant underdrainage to those with hydrostatic pressure conditions. The stability of 26 m high river slopes inclined at 27° in an area of underdrainage was investigated.Triaxial testing on undisturbed tube samples was used to obtain the postpeak parameters. Stability analyses gave a factor of safety close to one for shallow failure surfaces. With underdrainage, the factor of safety for deep failure surfaces is appreciably higher. When hydrostatic pore pressure conditions are assumed, analysis gave a factor of safety for deep failure that was reduced by about 30%.The results of the analyses emphasize the relation between the morphology of the landslide activity and the groundwater regime. With underdrainage, effective stresses increase much faster with depth and the critical failure surface is always close to the surface, as confirmed by field observations. Key words: natural slope, clay, pore pressure, field measurements, stability failure surface, failure morphology.

Violent Wave Overtopping: CLASH Field Measurements at Samphire Hoe

2004 ◽  
Author(s):  
Tim Pullen ◽  
William Allsop ◽  
Tom Bruce ◽  
Jimmy Geeraerts
Keyword(s):  
Field Measurements ◽  
Wave Overtopping

Back-calculation of consolidation parameters from field measurements at a reclamation site

2001 ◽  
Vol 38 (4) ◽  
pp. 755-769 ◽  
Author(s):  
Lai Fa Cao ◽  
Ming-Fang Chang ◽  
Cee Ing Teh ◽  
Yung Mook Na
Keyword(s):  
Pore Pressure ◽  
Land Reclamation ◽  
Ground Improvement ◽  
Field Measurements ◽  
Coefficient Of Consolidation ◽  
Vertical Drains ◽  
Undisturbed Samples ◽  
Back Calculation ◽  
Reclamation Project ◽  
Consolidation Parameters

A pilot test was carried out at a land reclamation project site to study the effect of vertical drains on the rate of consolidation of a marine clay deposit in Singapore. Theoretical and numerical analyses were conducted to interpret the field measurements of pore pressure and settlement, and consolidation parameters were back-calculated. The back-calculated preconsolidation pressure is similar to that obtained from the laboratory consolidation test on undisturbed samples, but the field-deduced compression index is generally larger than that measured in the laboratory. The coefficient of consolidation back-calculated from the settlement measurement is larger than that from the pore-pressure measurement. The coefficient of consolidation for horizontal flow obtained from the Rowe cell test, which is comparable to that back-calculated from the field settlement measurement, is recommended for the preliminary design of vertical drains without the need of considering the smear effect.Key words: clays, consolidation, ground improvement, numerical modelling and analysis, permeability, vertical drains.

Finite element analysis of the stability of a vertical cut using an anisotropic soil model

1988 ◽  
Vol 25 (1) ◽  
pp. 119-127 ◽  
Author(s):  
P. K. Banerjee ◽  
A. S. Kumbhojkar ◽  
N. B. Yousif
Keyword(s):  
Finite Element ◽  
Pore Pressure ◽  
Factor Of Safety ◽  
Constitutive Relations ◽  
Field Measurements ◽  
Failure Surface ◽  
Time To Failure ◽  
Soil Behavior ◽  
Element Analysis ◽  
Anisotropic Soil

A finite element (FE) analysis of the field test excavation in Welland Clay is performed using an anisotropic soil behavior model. This paper describes the model, FE formulation, and transient effective stress stability analysis, and compares FE results with the field measurements. The analysis reflects the postexcavation decrease in the factor of safety with time and predicts the failure of the slope along the observed failure surface. The parametric study shows that the time to failure is a function of the pore pressure boundary conditions at the excavation surface and affects the transient factor of safety. Key words: constitutive relations, excavations, finite element, plasticity models, pore pressure, soil anisotropy, stability.

scholarly journals Evaluating three commonly used infiltration methods for permeable surfaces in urban areas using the SWMM and STORM

2021 ◽  
Author(s):  
Frida E. Å. Parnas ◽  
Elhadi M. H. Abdalla ◽  
Tone M. Muthanna
Keyword(s):  
Urban Areas ◽  
Sandy Soils ◽  
High Sensitivity ◽  
Field Measurements ◽  
Infiltration Rate ◽  
Infiltration Capacity ◽  
Infiltration Process ◽  
Sewer Systems ◽  
Combined Sewer

Abstract Climate change and urbanization increase the pressure on combined sewer systems in urban areas resulting in elevated combined sewer overflows, degraded water quality in receiving waters, and changing stream flows. Permeable surfaces offer infiltration potential, which can contribute to alleviate the runoff to combined sewer systems. The variation in urban soil characteristics and the initial moisture conditions before a rainfall event are important factors affecting the infiltration process and consequently runoff characteristics. In this study, the urban hydrological models SWMM and STORM are used to evaluate the Green-Ampt, Horton, and Holtan infiltration methods for three urban sandy soils. A sensitivity analysis was carried out on a set of key parameter values. In addition, long-term simulations were conducted to evaluate the ability to account for initial soil moisture content. The results showed that the Holtan method's ability to account for both available storage capacity and maximum infiltration rate, as well as evapotranspiration in the regeneration of infiltration capacity, gave the best result with regards to runoff behaviour, especially for long-term simulations. Furthermore, the results from the urban sandy soils with different infiltration rate at saturation, together with a high sensitivity to the degree of sensitivity for maximum infiltration rate under dry conditions and minimum infiltration rate under wet conditions, indicate that field measurements of infiltration rate should be carried out at saturation for these soils.

Sign in / Sign up

Export Citation Format

Share Document