Offshore Sea Airport Revetment Structure Foundation Liquefaction Analysis

2013 ◽  
Vol 353-356 ◽  
pp. 2171-2176
Author(s):  
Jie Zhao ◽  
Gao Jie Yun ◽  
Gui Xuan Wang
Keyword(s):  
Dynamic Analysis ◽  
Pore Water ◽  
Effective Stress ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Total Stress ◽  
Treatment Methods ◽  
Ground Treatment ◽  
Over Time ◽  
Liquefaction Analysis

This Earthquake liquefaction analysis of total stress method is often used, but the total stress method does not consider the variation of pore water pressure and the process of development of the liquefaction over time. Using two perspectives which the total stress method and effective stress dynamic analysis given liquefied range of offshore airport foundation under the earthquake , and giving recommendations for ground treatment methods.

Investigation of some controllable factors that impact the stress state in cemented paste backfill

2015 ◽  
Vol 52 (12) ◽  
pp. 1901-1912 ◽  
Author(s):  
James P. Doherty ◽  
Alsidqi Hasan ◽  
Gonzalo H. Suazo ◽  
Andy Fourie
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Cement Content ◽  
Water Pressure ◽  
Cemented Paste Backfill ◽  
Total Stress ◽  
Rest Periods ◽  
Rate Of Increase ◽  
Controllable Factors ◽  
Paste Backfill

This paper presents in-stope measurements of total stress and pore-water pressure at strategic locations within three underground stopes at the Raleigh mine site (Western Australia) that were filled with cemented paste backfill (CPB). The three stopes were very similar in shape. Key differences among the stopes were the filling and resting schedules, the barricade drainage systems used, and the cement content of the CPB. Data from the stopes are compared to determine which controllable factors most significantly influence barricade pressures during and after filling. The most significant factor was the scheduling of rest periods between filling, with even very short pauses in filling dramatically reducing the rate of increase of pore-water pressure and total stress with increasing height of fill.

scholarly journals Implications of the principle of effective stress

2020 ◽  
Author(s):  
Gerd Gudehus
Keyword(s):  
Critical Phenomena ◽  
Pore Water ◽  
Effective Stress ◽  
Critical Points ◽  
Pore Water Pressure ◽  
Numerical Models ◽  
Water Pressure ◽  
Shear Bands ◽  
Triaxial Tests ◽  
Water Saturated

AbstractWhile Terzaghi justified his principle of effective stress for water-saturated soil empirically, it can be derived by means of the neutrality of the mineral with respect to changes of the pore water pressure $$p_w$$ p w . This principle works also with dilating shear bands arising beyond critical points of saturated grain fabrics, and with patterns of shear bands as relics of critical phenomena. The shear strength of over-consolidated clay is explained without effective cohesion, which results also from swelling up to decay, while rapid shearing of water-saturated clay can lead to a cavitation of pore water. The $$p_w$$ p w -neutrality is also confirmed by triaxial tests with sandstone samples, while Biot’s relation with a reduction factor for $$p_w$$ p w is contestable. An effective stress tensor is heuristically legitimate also for soil and rock with relics of critical phenomena, particularly for critical points with a Mohr–Coulomb condition. Therein, the $$p_w$$ p w -neutrality of the solid mineral determines the interaction of solid fabric and pore water, but numerical models are questionable due to fractal features.

Effective stress paths and yielding in soft clays below embankments

1985 ◽  
Vol 22 (3) ◽  
pp. 357-374 ◽  
Author(s):  
D. J. Folkes ◽  
J. H. A. Crooks
Keyword(s):  
Pore Water ◽  
Effective Stress ◽  
Strain Softening ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Clay ◽  
Stress Path ◽  
Excess Pore Water Pressure ◽  
Soft Clays ◽  
Effective Stress Path

Current methods of predicting the response of soft clays to surface loading are often unsuccessful because the assumed constitutive relationships, including effective stress path behaviour, are incorrect. In particular, the transition from small-strain to large-strain behaviour (i.e. yielding) is frequently not taken into account. Recent laboratory testing has demonstrated that the behaviour of soft clays is largely controlled by yielding. The locus of effective stress states causing yield is known as the yield envelope (YE).The effective stress paths (ESP's) in soft clay foundations below the centre of six fills were determined from computed total stresses and measured pore-water pressures. Yield behaviour is clearly indicated by ESP shapes. The yield envelopes inferred from analyses of field data are similar to those obtained from laboratory testing. Effective stress path shapes vary widely, depending on a variety of factors, including imposed stress level, rate of construction, and boundary drainage conditions. This finding contradicts an earlier conclusion that soft clay behaviour can be characterized by a single ESP. Because of the wide range of possible ESP shapes, the parameters [Formula: see text] does not provide an adequate basis for determining the effective stress state in a soft clay.The ESP/YE analyses indicate that yield can occur either during loading or during excess pore-water pressure dissipation following completion of loading. Yield of sensitive soils during loading is usually followed by strain softening. However, in some soils, dilatant behaviour appears to occur. Yield during dissipation of excess pore-water pressure is characterized by a dramatic change in cv and increased compressibility. Key words: soft clay, yield, effective stress paths, field behaviour, strain softening, rate of consolidation.

Earthquake-induced deformation analyses of the Upper San Fernando Dam under the 1971 San Fernando Earthquake

2001 ◽  
Vol 38 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Guoxi Wu
Keyword(s):  
Finite Element ◽  
Pore Water ◽  
Effective Stress ◽  
Pore Water Pressure ◽  
Ground Deformation ◽  
Water Pressure ◽  
Soil Liquefaction ◽  
Shear Stresses ◽  
Cyclic Shear ◽  
San Fernando

A nonlinear effective stress finite element approach for dynamic analysis of soil structure is described in the paper. Major features of this approach include the use of a third parameter in the two-parameter hyperbolic stress-strain model, a modified expression for unloading–reloading modulus in the Martin–Finn–Seed pore-water pressure model, and an additional pore-water pressure model based on cyclic shear stress. The additional pore-water pressure model uses the equivalent number of uniform cyclic shear stresses for the assessment of pore-water pressure. Dynamic analyses were then conducted to simulate the seismically induced soil liquefaction and ground deformation of the Upper San Fernando Dam under the 1971 San Fernando Earthquake. The analyses were conducted using the finite element computer program VERSAT. The computed zones of liquefaction and deformation are compared with the measured response and with results obtained by others.Key words: effective stress method, finite element analysis, Upper San Fernando Dam, earthquake deformation, VERSAT.

scholarly journals Swelling phenomena and effective stress in compacted expansive clays

2016 ◽  
Vol 53 (1) ◽  
pp. 134-147 ◽  
Author(s):  
David Mašín ◽  
Nasser Khalili
Keyword(s):  
Pore Water ◽  
Effective Stress ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Swelling Pressure ◽  
Constitutive Modelling ◽  
Dry Density ◽  
Expansive Clay ◽  
Experimental Database ◽  
Clay Aggregates

The central aim of this paper is to discuss the applicability of the effective stress principle as defined by Terzaghi (total stress minus pore-water pressure) to predict the behaviour of expansive clay aggregates. Phenomena occurring between individual clay minerals are reviewed first at the molecular level obtained in the colloid science research. In particular, it is noted that, for interparticle distances higher than approximately 1.5 nm, the pore-water pressure in the bulk equilibrium solution forms an additive component of the interparticle disjoining pressure. It is concluded that for these distances Terzaghi’s effective stress principle should be adequate to describe the clay behaviour. To support these developments, an extensive experimental database of nine different sodium and calcium bentonites available in the published literature was analysed. With the aid of double structure constitutive modelling, procedures were developed to extract information about the behaviour of clay aggregates from the experimental measurements. It was then shown that unconfined water retention curves, swelling pressure tests, swelling under constant load tests, and mechanical unloading tests are all uniquely related in terms of the dependency of dry density (or void ratio) of clay aggregate versus mean effective stress. By considering reversibility of aggregate behaviour and full saturation of aggregates, this implies that the effective stress principle is a valid way of predicting expansive clay aggregate volumetric deformation.

scholarly journals Simple 2D Liquefaction analysis of pore water pressure dissipation method for detached house ground

2018 ◽  
Vol 13 (4) ◽  
pp. 393-401
Author(s):  
Hiroshi YOKAWA ◽  
Hideto NONOYAMA ◽  
Atsushi YASHIMA ◽  
Misko CUBRINOVSKI ◽  
Takayasu YOSHIHARA ◽  
...  
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Detached House ◽  
Liquefaction Analysis

THE EFFECTIVE STRESS RESPONSE OF A SATURATED CLAY SOIL TO REPEATED LOADING

1969 ◽  
Vol 6 (3) ◽  
pp. 241-252 ◽  
Author(s):  
D. A. Sangrey ◽  
D. J. Henkel ◽  
M. I. Esrig
Keyword(s):  
Pore Water ◽  
Effective Stress ◽  
Critical Level ◽  
Clay Soil ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Triaxial Tests ◽  
Repeated Loading ◽  
Repeated Stress ◽  
Saturated Clay

The results of a series of tests designed to examine the behavior of saturated clay soil under repeated loading are reported. Triaxial tests, under conditions of axial symmetry, were used and the rates of deformation were chosen so as to permit the accurate measurement of pore water pressure at all stages of the tests.It was found that, for any particular consolidation history, a critical level of repeated stress existed. Below this critical level, a state of nonfailure equilibrium was reached in which the stress-strain curves followed closed hysteresis loops. Above the critical level of repeated stress, effective stress failure occurred; and each cycle of loading produced cumulative increases in deformation.An interesting feature of the test results was that a linear relationship between the magnitude of the applied repeated stress and the increase in pore water pressure was found for stress levels below the critical value.

Destructive Criteria for Highway Thick Filling Area Based on Stress Path Analysis

2014 ◽  
Vol 1021 ◽  
pp. 83-86
Author(s):  
Huai Feng Tong
Keyword(s):  
Path Analysis ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Stress Path ◽  
Total Stress ◽  
Post Process ◽  
Failure State ◽  
Effect Of Treatment ◽  
Path Point

In the course of construction ,the free pore water in the saturation soil of highway foundation is seldom discharged immediately, and the excess pore water pressure comes into being ,which result in the delay of consolidation and time limit for a project, this problem are disposed by post-processing. Based on the variational rule of total stress, pore water pressure and effective stress in the foundation, the stabilization, the occasion and the effect of treatment are determined. So, the key of stress-path method is corresponding relation between failure state and stress-path point. The foundatin of destructive criteria based on stress-path analysis, which offer theoretical gist for the design of post-process and may be used as a reference in similar project.

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