Steady flow experiments in saturated clays

Soil Research ◽  
1969 ◽  
Vol 7 (2) ◽  
pp. 91 ◽  
Author(s):  
DE Smiles
Keyword(s):  
Steady Flow ◽  
Flux Density ◽  
Pressure Difference ◽  
Void Ratio ◽  
Water Pressure ◽  
Difference Curve ◽  
Saturated Clay ◽  
Flow Experiments ◽  
Density Of Water ◽  
The Way

When Darcy's law is applied to steady flow of water in saturated clay pastes it is found in general that the flux density of water is not simply proportional to the imposed water pressure difference. This arises because of the dependence of the void ratio of the clay on the pressure difference. In addition, the nature of the flux density/pressure difference curve depends on the way in which the experiment is performed.

Turbocharger-Design Effects on Gasoline-Engine Performance

2005 ◽  
Vol 127 (3) ◽  
pp. 525-530 ◽  
Author(s):  
Theodosios Korakianitis ◽  
T. Sadoi
Keyword(s):  
Steady Flow ◽  
Mass Flow ◽  
Gasoline Engine ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Final Choice ◽  
Design Point ◽  
Theoretical Considerations ◽  
Flow Experiments

Specification of a turbocharger for a given engine involves matching the turbocharger performance characteristics with those of the piston engine. Theoretical considerations of matching turbocharger pressure ratio and mass flow with engine mass flow and power permits designers to approach a series of potential turbochargers suitable for the engine. Ultimately, the final choice among several candidate turbochargers is made by tests. In this paper two types of steady-flow experiments are used to match three different turbochargers to an automotive turbocharged-intercooled gasoline engine. The first set of tests measures the steady-flow performance of the compressors and turbines of the three turbochargers. The second set of tests measures the steady-flow design-point and off-design-point engine performance with each turbocharger. The test results show the design-point and off-design-point performance of the overall thermodynamic cycle, and this is used to identify which turbocharger is suitable for different types of engine duties.

Non-Steady Flow through a Gauze in a Duct

1965 ◽  
Vol 7 (4) ◽  
pp. 449-459 ◽  
Author(s):  
R. S. Benson ◽  
P. C. Baruah
Keyword(s):  
Steady Flow ◽  
Excellent Agreement ◽  
Pressure Loss ◽  
Internal Combustion Engines ◽  
Wave Action ◽  
Combustion Engines ◽  
Flow Through ◽  
Flow Pressure ◽  
Loss Coefficients ◽  
Flow Experiments

By using steady flow relations including pressure loss coefficients a method is developed for calculating wave action in a duct with a gauze. Both steady and non-steady flow experiments for five gauzes are described. The results of the non-steady flow tests showed excellent agreement between the predicted indicator diagrams, using the steady flow pressure loss coefficients, and the measured indicator diagrams. The methods described in the paper may be used by engine designers to predict the effect of gauzes or similar devices on the wave action in exhaust systems of internal combustion engines.

scholarly journals Measurement and Investigation on 1-D Consolidation Permeability of Saturated Clay considering Consolidation Stress Ratio and Stress History

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Le Zhang ◽  
Faning Dang ◽  
Jun Gao ◽  
Jiulong Ding
Keyword(s):  
Model Prediction ◽  
Permeability Coefficient ◽  
Stress Ratio ◽  
Void Ratio ◽  
Stress Difference ◽  
Stress History ◽  
One Dimensional ◽  
Consolidation Pressure ◽  
Saturated Clay ◽  
Stress Ratios

To study the influence of consolidation stress ratio and stress history on 1-D consolidation permeability of saturated clay, one-dimensional consolidation permeability tests were carried out with GDS triaxial device. The results indicated that the permeability coefficient and void ratio of normally and overconsolidated saturated clay decreased with the increase of consolidation stress ratio under different consolidation stress ratios but the same stress history. And the amount of final sample’s compression increased with the increase of the consolidation stress ratio. Under the condition of the same consolidation stress ratio but different stress history, the amount of final compression of the overconsolidated saturated clay was smaller than that of the normally consolidated saturated clay. Besides, the stress difference σdv between consolidation pressure σ and gravity stress σ c z was fitted to the amount of the final sample’s compression, and a good linear relationship between the stress difference σ d v and the amount of the final sample’s compression under each consolidation pressure was obtained. The results showed that it is necessary to consider the influence of consolidation stress ratio and stress history simultaneously on 1-D consolidation permeability of saturated clay. Meanwhile, it can accurately predict the amount of the final sample’s compression after knowing the gravity stress. Moreover, a model prediction analysis was conducted on the saturated clay and recommended to use the modified Kozeny-Carman’s equation to predict the permeability coefficient of Luochuan saturated clay during one-dimensional consolidation.

scholarly journals Dynamics of Biochar-Silty Clay Interaction Using In-House Fabricated Cyclic Loading Apparatus: A Case Study of Coastal Clay and Novel Peach Biochar from the Qingdao Region of China

2020 ◽  
Vol 12 (7) ◽  
pp. 2599 ◽  
Author(s):  
Junwei Liu ◽  
Suriya Prakash Ganesan ◽  
Xin Li ◽  
Ankit Garg ◽  
Aman Singhal ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Shear Modulus ◽  
Dynamic Behavior ◽  
Void Ratio ◽  
Water Pressure ◽  
Damping Ratio ◽  
Cyclic Strength ◽  
Silty Clay ◽  
Amended Soils ◽  
Amended Soil

Biochar has been recently investigated as an eco-friendly material in bio-engineered slopes/landfill covers. A majority of recent studies have focused on analyzing water retention behavior while very few have examined dynamic behavior (i.e., cyclic loading due to earthquake, wind, or wave) of biochar amended soil. As far as the authors are aware, there is no study on the dynamic behavior of biochar amended soils. Considering the above mentioned study as a major objective, field excavated soil was collected and mixed with in-house produced biochar from peach endocarps, at three amendment rates (5%, 10%, and 15%). The un-amended bare soil and biochar amended soil were imposed to a cyclic load in a self-designed apparatus and the corresponding stress-strain parameters were measured. Dynamic parameters such as shear modulus and damping ratio were computed and the results were compared between bare and biochar amended soil. Furthermore, the residual cyclic strength of each soil types were correlated with an estimated void ratio to understand the interrelation between dynamic loading responses and biochar amended soils. The major outcomes of this study show that the addition of biochar decreases the void ratio, thereby increasing the shear modulus and residual cyclic strength. However, the modulus and strength values attenuates after 15 cycles due to an increase in pore water pressure. In contrary, at higher amendment rates, Biochar Amended Soils (BAS) forms clay-carbon complex and decreases both shear modulus and residual cyclic strength.

scholarly journals Evaluation of local friction and pore-water pressure evolution along instrumented probes in saturated clay for large numbers of cycles

2019 ◽  
Vol 56 (12) ◽  
pp. 1953-1967
Author(s):  
Rawaz Dlawar Muhammed ◽  
Jean Canou ◽  
Jean-Claude Dupla ◽  
Alain Tabbagh
Keyword(s):  
Cyclic Loading ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Static Friction ◽  
Good Picture ◽  
Friction Resistance ◽  
Saturated Clay ◽  
Tip Resistance ◽  
Number Of Cycles

To investigate local friction mobilization along piles subjected to cyclic axial loadings, a calibration chamber experiment is presented based on the implementation of instrumented probes in specimens of saturated clay. Typical results obtained with a piezo-probe are presented, allowing not only tip resistance and local friction to be measured, but also the local pore-water pressure developed on the probe shaft. In addition, specific piezometers installed in the clay specimen allow a good picture to be obtained of the pore-water pressure field around the probe during installation and loading. After installation of the probe, a succession of monotonic and cyclic displacement-controlled loading phases is applied. Upon displacement-controlled cyclic loading of the piezo-probe up to a very large number of cycles (105 cycles), an initial degradation of local friction is observed followed by a subsequent reinforcement, which continues until the end of the cyclic sequence. The friction evolution is related to the evolution of the pore-water pressure measured during cyclic loading. In particular, the influence of the cyclic loading sequence on the post-cyclic static friction resistance is evaluated. A comparison is finally made with the results obtained with another type of probe, showing a good consistency between both types of results.

A unified approach to densification and liquefaction of cohesionless sand in cyclic shearing

1979 ◽  
Vol 16 (4) ◽  
pp. 659-678 ◽  
Author(s):  
S. Nemat-Nasser ◽  
A. Shokooh
Keyword(s):  
Experimental Data ◽  
Void Ratio ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Unified Theory ◽  
Saturated Sand ◽  
Unified Approach ◽  
Homogeneous Sample ◽  
Excess Pore Water Pressure ◽  
Excess Pore

When submitted to cyclic shearing, loose dry sand densifies, and undrained saturated sand may liquefy. Based on energy considerations, a unified theory for densification and liquefaction of a homogeneous sample of cohesionless sand is proposed. It is observed that these phenomena involve rearrangement of grains in microscale, requiring an expenditure of a certain amount of energy, which increases as the void ratio approaches its minimum value and decreases as the excess pore water pressure increases. On the basis of rough estimates, explicit relations are developed for both the densification and liquefaction phenomena, and the results are applied to predict relevant available experimental data.

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.

An Introduction to Vacuum Sewerage System and its Applications in China

2012 ◽  
Vol 610-613 ◽  
pp. 2467-2471
Author(s):  
Jing Tang ◽  
Min Li ◽  
Bao Zhen Wang
Keyword(s):  
Negative Pressure ◽  
Pressure Difference ◽  
Collection System ◽  
Sewerage System ◽  
Key Technologies ◽  
The Way ◽  
Wastewater Collection

Vacuum sewerage system (VSS) is an ecological wastewater collection system in which negative pressure difference in pipelines is used to transport sewage gradually to vacuum station for centralized treatment. Classification and application areas of VSSs were reviewed. Various vacuum generators in vacuum stations were compared. Types and key technologies of user terminals in VSSs were presented. Conveying mechanism of vacuum pipelines was illustrated. The way to discharge sewage from VSSs was introduced.

scholarly journals Undrained Shear and Pore Space Characteristics of Treated Loose Sands with Lime-Activated Zeolite in Saturated Settings

2020 ◽  
Vol 30 (2) ◽  
pp. 105-132
Author(s):  
Babak Jamhiri ◽  
Mohammad Siroos Pakbaz
Keyword(s):  
Shear Strength ◽  
Pore Water ◽  
Void Ratio ◽  
Pore Space ◽  
Water Pressure ◽  
Undrained Shear Strength ◽  
Alkali Activation ◽  
Unconfined Compression ◽  
Overburden Pressure ◽  
Undrained Shear

AbstractThis research investigates the mechanical behavior of artificially cemented sandy soils formed by lime alkali activation of natural zeolite under saturation settings. In order to verify the bar capability of cemented sands with this new method, an analysis of the undrained shear strength of the soil with pore water pressure ratio measurements was performed from the interpretation of the results of unconfined compression tests. The effect of zeolite-lime blend on treated sands was also visualized by scanning electron microscopy. For the studied soils, it was concluded from the unconfined compression stress values that the soil is fully capable of withstanding compressions due to overburden pressure. Additionally, this study seeks to evaluate the effect of the void ratio on the pore space and undrained shear strength. The results showed that pore water B-ratio increases with the decrease of the void ratio. Moreover, with the increase of zeolite content, confining pressure, and curing age, the peak failure strength increases. The results indicated a promising consistency of treated samples with lime and zeolite under various values of undrained shearing and B-ratios, making this method an ideal treatment for loose sand deposits.

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