Impact of spatial variability in undrained shear strength on active lateral force in clay

2015 ◽  
Vol 52 ◽  
pp. 121-131 ◽  
Author(s):  
Yu-Gang Hu ◽  
Jianye Ching
Keyword(s):  
Shear Strength ◽  
Spatial Variability ◽  
Lateral Force ◽  
Undrained Shear Strength ◽  
Undrained Shear

Stochastic stability analysis of a test excavation involving spatially variable subsoil

2006 ◽  
Vol 43 (10) ◽  
pp. 1074-1087 ◽  
Author(s):  
Yu-Jie Wang ◽  
Paul Chiasson
Keyword(s):  
Shear Strength ◽  
Stability Analysis ◽  
Slope Stability ◽  
Spatial Variability ◽  
Progressive Failure ◽  
Soft Clay ◽  
Stochastic Modelling ◽  
Undrained Shear Strength ◽  
Slope Stability Analysis ◽  
Undrained Shear

A stochastic slope stability analysis method is proposed to investigate the short-term stability of unsupported excavation works in a soft clay deposit having spatially variable properties. Spatial variability of undrained shear strength is modelled by a stochastic model that is the sum of a trend component and a fluctuation component. The undrained shear strength trend, which is also spatially variable, is modelled by kriging or a random function. Slope stability analyses are performed on the stochastic soft clay model to investigate the contribution of spatial variability of undrained shear strength to a disagreement among high factors of safety computed from deterministic methods for slopes that have failed. Probabilities of failure as computed from the stochastic analyses give a better assessment of failure potential. Probability of failure values also correlate with time delay before failure. This phenomenon may be related to progressive failure or creep and to pore pressure dissipation with time.Key words: slope stability analysis, failure probability, spatial variability, stochastic modelling, geostatistics, vane tests, sensitive clay.

A New Procedure for Simulating Active Lateral Force in Spatially Variable Clay Modeled by Anisotropic Random Field

2015 ◽  
Vol 31 (4) ◽  
pp. 381-390
Author(s):  
Y.-G. Hu ◽  
J. Ching
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shear Strength ◽  
Random Field ◽  
Retaining Wall ◽  
Lateral Force ◽  
Undrained Shear Strength ◽  
Undrained Shear ◽  
Element Method

AbstractA new procedure for simulating the active lateral force (Pa) is proposed for clays with anisotropic spatially variable undrained shear strength (su). With the proposed procedure, the Pa samples can be simulated without the use of the random field finite element method (RFEM). It requires only simple algebraic calculations and chart checking. Two retaining wall examples with isotropic or anisotropic random field are used to demonstrate the effectiveness of the proposed procedure.

scholarly journals Simple Equations for Considering Spatial Variability on the Bearing Capacity of Clay

2019 ◽  
Vol 5 (1) ◽  
pp. 93
Author(s):  
Davood Azan ◽  
Abdolhossein Haddad
Keyword(s):  
Shear Strength ◽  
Spatial Variability ◽  
Bearing Capacity ◽  
Variable Parameter ◽  
Undrained Shear Strength ◽  
Strip Footing ◽  
Random Field Theory ◽  
Monte Carlo Simulation Technique ◽  
Simple Equations ◽  
Undrained Shear

In the present paper, the effect of spatial variability of undrained shear strength on the bearing capacity of shallow strip footing on clay was investigated and two new and simple equations were introduced for incorporating the effect of soil variability parameters on the undrained bearing capacity of strip footing on clay. For investigating the spatial variability of clay, undrained shear strength was assumed as a spatial variable parameter with the use of random field theory. The Monte Carlo simulation technique was used to obtain the probability distribution of the bearing capacity of footing on nonhomogeneous clay. The spatial variability of the undrained shear strength was investigated using three controlling parameters: coefficient of variation (COV) of the undrained shear strength as well as the scales of fluctuation of the shear strength in horizontal and vertical directions. The Mohr-Coulomb failure criterion and finite difference method were used to model the plastic behaviour of soil and calculate the bearing capacity of the footing. The results show that by increasing the COV of the undrained shear strength, the average bearing capacity decreases while the COV of the bearing capacity increases. Moreover, the average bearing capacity of footing has an approximate increasing trend with increasing the scales of fluctuation.

Modelling spatial variability of soil parameters

1990 ◽  
Vol 27 (5) ◽  
pp. 617-630 ◽  
Author(s):  
M. Soulié ◽  
P. Montes ◽  
V. Silvestri
Keyword(s):  
Shear Strength ◽  
Spatial Variability ◽  
Undrained Shear Strength ◽  
Geostatistical Analysis ◽  
Earth Dam ◽  
Soil Parameters ◽  
Bay Area ◽  
Measurements Errors ◽  
Weak Zones ◽  
Undrained Shear

The purpose of this study is to show that geostatistics can help in finding the structure of the spatial variability of the undrained shear strength within a clay deposit. The site under study, B-6, owes its name to the earth dam that will be constructed on it; the site is located on the shore of the Broadback River in the James Bay area of Quebec. The geostatistical analysis is carried out on the unaltered zone of the B-6 clay; it shows an anisotropic structure for the spatial variability. The knowledge of the structure (variogram) of the undrained shear strength is used in the kriging theory to compute estimations at points of the deposit where experimental measurements are not available. Kriging is also used to identify weak zones within the B-6 clay. The geostatistical analysis of the B-6 clay gives the opportunity to test the capability of the method. Even if the errors of measurements were small, the variogram has permitted detection and correction of a bias that affected a certain number of vane profiles. Key words: clay, geostatistics, undrained shear strength, variogram, measurements errors, kriging.

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