scholarly journals Sagging-collapse sinkholes: simulation modelling

2020 ◽  
Vol 164 ◽  
pp. 02028
Author(s):  
Victor Khomenko
Keyword(s):  
Experimental Study ◽  
Simulation Modelling ◽  
Laboratory Simulation ◽  
Groundwater Levels ◽  
Complex Process ◽  
Saturated Sands ◽  
Geological Phenomenon

In the paper a kind of sinkholes is considered, which is typical for areas where soluble rocks are covered by clay’s layer overlapped by saturated sands. The presence in soluble rocks of non-filled cavity contacting with covering clays is necessary to the sinkhole formation, however it can be provoked not only by cavity’s enlarging but else by changes of groundwater levels. The mechanism of this complex process has been researched by its in-laboratory simulation modelling, and its results can possibility to the author to name this phenomenon as “sagging-collapse sinkholes”, because it includes sagging and collapse of clays accompanied by downward moving of sands and sometimes by their liquefaction. Modelling technology is given in the paper in detail and the conception of investigated process is offered. Except experimental study of sagging-sinkhole formation the purposes of the work was quantitative forecasting of this geological phenomenon. Forecasts have been developed that allow calculating the diameter of the expected sinkhole, particularly. An assessment of their reliability is given.

Experimental Investigation of Contact Stresses Between a U.S. Locomotive Wheel and Rail

1983 ◽  
Vol 105 (2) ◽  
pp. 64-70 ◽  
Author(s):  
S. Kumar ◽  
Y. S. Adenwala ◽  
B. R. Rajkumar
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Experimental Investigation ◽  
Contact Stress ◽  
Contact Stresses ◽  
Laboratory Simulation ◽  
Poor Agreement ◽  
Real Contact ◽  
Freight Car ◽  
Locomotive Wheels

An experimental study of the real contact stresses for U.S. locomotives and rails including the effects of plasticity and wear has been performed under laboratory Hertzian simulation using the IIT-GMEMD wheel-rail simulation facility. Experiments were performed under both traction and braking conditions to account for differences observed earlier in the two modes. Wheel/rail tests were conducted using adhesion coefficients of 0.02, 0.15, and 0.25. Average contact stresses for various stages of wear were determined by measuring the contact areas. A synthesis of all the data generated showed that for operation of purely tractive wheels of a typical U.S. locomotive on a rail, the stabilized average contact stress ranges from approximately 100 to 25 ksi as the continuous operating adhesion coefficient ranges from 0 to 0.25. In order to determine the contact stresses for locomotives under field conditions, measurements of contact stresses were made on three different locomotives with wheels of different degrees of wear. Contact stresses for locomotives were found to be higher than stabilized contact stresses established by laboratory simulation tests. The locomotive wheel contact stresses were found to be closer to freight car wheel stabilized contact stresses established in an earlier study than for the laboratory locomotive simulation. It is suggested that this is due to the fact that 20 to 50 times as many cars operate on the same rails as do locomotives. On the basis of these experiments it is recommended that for U.S. locomotive wheels an average stabilized contact stress of approximately 65 ksi rather than the current 138 ksi would be quite stable. Profile and dynamic stability should be achieved simultaneously in such an approach. Currently available 2-D theories have been used to compare the experimental data showing poor agreement and reasons for discrepancy.

How Do Individuals Judge Organizational Legitimacy? Effects of Attributed Motives and Credibility on Organizational Legitimacy

2017 ◽  
Vol 59 (3) ◽  
pp. 545-576 ◽  
Author(s):  
Johannes Jahn ◽  
Melanie Eichhorn ◽  
Rolf Brühl
Keyword(s):  
Experimental Study ◽  
Organizational Legitimacy ◽  
Social Benefits ◽  
Vignette Study ◽  
Corporate Activity ◽  
Corporate Credibility ◽  
Complex Process ◽  
Social Cause ◽  
The Relationship

This experimental study examines individuals’ legitimacy judgments. We develop a model that demonstrates the role of attributed motives and corporate credibility for the evaluation of organizational legitimacy and test this model with an experimental vignette study. Our results show that when a corporate activity creates benefits for the firm—in addition to social benefits—individuals attribute more extrinsic motives. Extrinsic motives are ascribed when a corporation is perceived as being driven by external rewards as opposed to an altruistic commitment to a social cause. Extrinsic motives negatively affect corporate credibility and organizational legitimacy judgments. This article contributes to a better understanding of the complex process of organizational legitimacy judgment by shedding light on the individual’s perspective and expounding the relationship between attributed motives, corporate credibility, and organizational legitimacy.

Experimental Study on the Effects of Fault Movement on the Engineered Barrier System

2008 ◽  
Author(s):  
Morimasa Naito ◽  
Yuya Saito ◽  
Kenji Tanai ◽  
Mikazu Yui
Keyword(s):  
Experimental Study ◽  
Experimental Approach ◽  
Test Equipment ◽  
Laboratory Simulation ◽  
Deep Geological Repository ◽  
Simulation Test ◽  
Fault Movement ◽  
Bentonite Buffer ◽  
Geological Repository ◽  
Engineered Barriers

An experimental approach is introduced for understanding how the engineered barriers of a deep geological repository system are affected by fault movement. The experiments are conducted using laboratory simulation test equipment. So far, the experiments indicate that the metal overpack is rotated within the bentonite buffer due to its plasticity, but not breached. Numerical analyses are also carried out to supplement the range of the experiments, which is limited by the capability of the test equipment.

A laboratory simulation of toluene cleanup by air sparging of water-saturated sands

2000 ◽  
Vol 72 (2-3) ◽  
pp. 167-178 ◽  
Author(s):  
Jonathan W. Peterson ◽  
Matthew J. DeBoer ◽  
Kimberly L. Lake
Keyword(s):  
Laboratory Simulation ◽  
Air Sparging ◽  
Saturated Sands ◽  
Water Saturated

Duplicate Confluence Precipitation Technology Processing Desulphurization Dust Removal Actual Waste Water Experimental Study

2014 ◽  
Vol 986-987 ◽  
pp. 709-712
Author(s):  
Yun Xia Gao ◽  
Xue Min Dai ◽  
Li Yao ◽  
Guo Ying Nan
Keyword(s):  
Waste Water ◽  
Experimental Study ◽  
Water Treatment ◽  
Field Test ◽  
Laboratory Simulation ◽  
Surface Load ◽  
Treatment Efficiency ◽  
Treatment Performance ◽  
Hydraulic Load ◽  
Load Impact

In order to discuss the treatment performance of wastewater from desulphurization precipitator by settling technique of compound flow, the field test rendered the effluents of integrated desulfurization precipitator as the handing objects. The results show that the critical load of the sediment separator is 4mm/s. When the surface load is less than or equal to 4 mm / s, the turbidity of effluent is less then 10 degrees and the maximum is less then 18.2 degrees. The effect of hydraulic load impact on the water treatment system is greater than that of pH and SS of inlet. The treatment efficiency of field test is equivalent that of laboratory simulation.

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