Stability and Construction of Caverns for The Disposal Of Cemented Low-And Medium-Level Wastes

1981 ◽  
Vol 11 ◽  
Author(s):  
W. Raab ◽  
C. Frohn ◽  
M.W. Schmidt

ABSTRACTThe geomechanical and mining-technological aspects of the construction of salt caverns as disposal chambers have been investigated during project phase 2, completed by mid 1981. With a view towards the stability analysis of such a cavern, FEM-estimates have been carried out and evaluated. From these it can be derived that- a rotational ellipsoid would be the most suitable shape- its dimensions should be 82 m (vertical axis) and 42 m (horizontal axis)- the distance (safety pillar) between the neighbouring caverns should be 170 m (vertical) and 180 m (horizontal).For practical engineering purposes the rotational ellipsoid can be modified into a cylinder with conic bottom and top. The numerical model simulated the short term as well as the long term characteristics of the surrounding salt rocks. The short term characteristics were assessed by an elastic approach, the long term characteristics by a rheological model. The input parameters have been determined by means of laboratory tests on ASSE rock salt.In a second step the characteristics of partially and completely filled caverns were simulated. It was shown clearly that deformation of the salt rock comes to a halt when counteracted by the filling.Based upon the results of the stability analysis, investigations were made to find out a suitable mining technique for the construction of the cavern. Solution mining and conventional development by means of drilling and blasting have been studied alternatively. Since both methods have their advantages and disadvantages a decision in favour of the one or the other cannot be made until the actual site has been defined.

2013 ◽  
Vol 353-356 ◽  
pp. 1345-1352
Author(s):  
Ming Zhang ◽  
Qiang Yang

Salt cavern storage is usually in bedded salt rock formation except salt dome, in particular in China. The rocks composing a bedded salt rock formation, e.g., mudstone, rock salt, interlayer, etc., often present viscoelastic-plastic behaviors, which is an important influencing factor of the long-term stability of salt caverns in it. Modelling the rheological behavior with the Druck-Prager creep model, an example of stability analysis of four salt caverns at Jintan Salt Mine of China with the finite element method is elaborated in this paper. The results show that besides the inevitable loss of effective storage room with time due to creep deformation, which decreases evidently with internal pressure but decreases slowly at a certain pressure value, the variation of operating internal pressure in each cavern can cause the change of volumes of other nearby caverns and then affect the stability of all the caverns. The internal pressure difference should be as small as possible during the operation of salt caverns.


2020 ◽  
pp. 18-26
Author(s):  
ZONG GANG ◽  
FU JIAJIA ◽  
WANG YAO

Rainfall is the main cause of landslides, the two are closely related. Based on the theory of saturatedunsaturated seepage and the theory of unsaturated soil shear strength, this paper makes an in-depth comparatve analysis on the infuence of short-term heavy rainfall and long-term weak rainfall on slope stability. The results show: The soil above the slope is more likely to reach saturaton under short-term heavy rainfall, while the infuence of long-term weak rainfall on the slope soil is deeper and the stability is greatly reduced. However, landslides with long periods of weak rainfall are more dangerous. In additon, the method of determining the critcal rainfall of a slope for landslide is obtained, and the safety status of the slope can be directly judged by comparing the actual rainfall with the critcal rainfall, and the classifcaton standard of the safety grade of a specifc slope is further obtained, which can provide reference for landslide preventon and treatment.


2018 ◽  
pp. 49-68 ◽  
Author(s):  
M. E. Mamonov

Our analysis documents that the existence of hidden “holes” in the capital of not yet failed banks - while creating intertemporal pressure on the actual level of capital - leads to changing of maturity of loans supplied rather than to contracting of their volume. Long-term loans decrease, whereas short-term loans rise - and, what is most remarkably, by approximately the same amounts. Standardly, the higher the maturity of loans the higher the credit risk and, thus, the more loan loss reserves (LLP) banks are forced to create, increasing the pressure on capital. Banks that already hide “holes” in the capital, but have not yet faced with license withdrawal, must possess strong incentives to shorten the maturity of supplied loans. On the one hand, it raises the turnovers of LLP and facilitates the flexibility of capital management; on the other hand, it allows increasing the speed of shifting of attracted deposits to loans to related parties in domestic or foreign jurisdictions. This enlarges the potential size of ex post revealed “hole” in the capital and, therefore, allows us to assume that not every loan might be viewed as a good for the economy: excessive short-term and insufficient long-term loans can produce the source for future losses.


1998 ◽  
Vol 28 (1) ◽  
pp. 29-46
Author(s):  
Jonathan Oberlander

There is growing enthusiasm for transforming Medicare into a voucher system. Advocates claim vouchers would increase the health care choices available to Medicare beneficiaries, reduce the regulatory burden on the federal government, and promote the benefits of fair market competition. In addition, some analysts contend vouchers are the only feasible solution to Medicare's short-term financing problems and the long-term “crisis” of the retirement of the baby-boom generation. The author argues against these claims. Vouchers would not work as advertised by proponents because of the limitations of risk-adjustment methods and unrealistic assumptions about consumer choice. Moreover, the elderly and disabled Medicare population is ill-suited to cope in a competitive insurance system. Implementation of vouchers would therefore pose a threat to both the health of beneficiaries and the stability of the Medicare program. The implications of this analysis for Medicare reform are discussed.


2021 ◽  
Vol 11 (19) ◽  
pp. 8880
Author(s):  
Bowen Guan ◽  
Cunbo Fan ◽  
Ning An ◽  
Ricardo Cesar Podesta ◽  
Dra Ana Pacheco ◽  
...  

As one of the major error sources, satellite signature effect should be reduced or even erased from the distribution of the post-fit residuals to improve the ranging precision. A simulation of satellite signature effect removal process for normal point algorithm is conducted based on a revised model of satellite response, which fully considers the structural and distribution characteristics of retroreflectors. In order to eliminate both long-term and short-term satellite signature effect, a clipping method for SLR data processing is proposed by defining the clipping location as 5.6 mm away from the mean value of the long-term fit residuals to select effective returns for normal points. The results indicate that, compared to normal points algorithm, the RMS per NP of LAGEOS-1 observation data processed by the clipping method is reduced from 62.90 ± 9.9 mm to 56.07 ± 4.69 mm, and the stability of RMS is improved 53%. This study improves the satellite signature effect model and simulates the fluctuation of normal points caused by satellite signature effect for the first time. The new method based on the simulation of satellite signature effect has stronger robustness and applicability, which can further minimize the influence of satellite signature effect on the SLR production and significantly improve the data property.


Author(s):  
K. Al-Durgham ◽  
D. D. Lichti ◽  
I. Detchev ◽  
G. Kuntze ◽  
J. L. Ronsky

A fundamental task in photogrammetry is the temporal stability analysis of a camera/imaging-system’s calibration parameters. This is essential to validate the repeatability of the parameters’ estimation, to detect any behavioural changes in the camera/imaging system and to ensure precise photogrammetric products. Many stability analysis methods exist in the photogrammetric literature; each one has different methodological bases, and advantages and disadvantages. This paper presents a simple and rigorous stability analysis method that can be straightforwardly implemented for a single camera or an imaging system with multiple cameras. The basic collinearity model is used to capture differences between two calibration datasets, and to establish the stability analysis methodology. Geometric simulation is used as a tool to derive image and object space scenarios. Experiments were performed on real calibration datasets from a dual fluoroscopy (DF; X-ray-based) imaging system. The calibration data consisted of hundreds of images and thousands of image observations from six temporal points over a two-day period for a precise evaluation of the DF system stability. The stability of the DF system – for a single camera analysis – was found to be within a range of 0.01 to 0.66 mm in terms of 3D coordinates root-mean-square-error (RMSE), and 0.07 to 0.19 mm for dual cameras analysis. It is to the authors’ best knowledge that this work is the first to address the topic of DF stability analysis.


2018 ◽  
Vol 7 (4) ◽  
pp. 122-126
Author(s):  
Galina Anatolievna Fadeeva ◽  
Elena Evgenievna Boryakova

The fauna of parasitic mites of bats from the karst caves in the region of the Volga Upland was studied in 2004-2005. Six species of bats such as Daubentons water bat, Brandts bat, whiskered bat, pond bat, northern bat and long-eared bat were examined. 18 species of arthropods were detected, among them there are gamasid mites (10 species) and harvest mites (2 species). Leptotrombidium russicum (Oud., 1902) and Myotrombicula sp. were found for the first time in Central Russia. Spinturnix acuminatus (Koch, 1836), Steatonyssus spinosus (Willmann, 1936), Steatonyssus periblepharus (Kolenati, 1858), Macronyssus flavus (Kolenati, 1856) turned out to be the main group of parasites in this study. As for the insects flies of the family Nycteribiidae and fleas of the family Ischnopsyllidae were found. The cluster analysis of ectoparasite fauna has showed that they are more or less evenly distributed among all members of mixed colonies of bats, while there is no violation of specificity in the choice of hosts. Low values of the Berger-Parker index marked a lack of competition between species, which indicates the stability of parasitic communities formed on bats in mixed colonies and in natural habitats. This fact indicates a complex relationship between the parasites in the community on the one hand, and long-term existence of the community on the other hand. This, in its turn, shows that in long-evolving communities competitive relationships between parasites are obliterated, which gives them stability. Herewith the bat colony is used as an integral whole, although some parasitic species prefer certain types of hosts.


2019 ◽  
Vol 7 (3) ◽  
pp. 391-396
Author(s):  
Riki Subagja ◽  
Didit Pradipto

This study aims to analyze the implementation of contract revenue recognition based on PSAK 34. The problem that is often faced by companies that are particularly engaged in the field of construction services in the recognition of income is the method of revenue recognition what should be used or applied, because there are differences in recognition between the one method with others. Especially if a project is done is more than a year or the so-called Long-term project. In addition, the presentation of financial statements of income recognition in each accounting period must be reported in accordance with generally accepted Accounting Standards (PSAK No. 34 concerning Construction Contracts). There is only one method used or applied that is the percentage completion method. The percentage method recognizes income with two approaches, based on physical progress and cost-to-cost. PT X as a construction service company uses the percentage of completion method with a physical progress approach (Physical progress) in the recognition of his opinion for both long-term contract and short-term contract. The results of this study conclude that the accounting treatment of the application of revenue recognition of construction services by using the percentage of completion method with physical progress approach on PT X is in conformity with the accounting standards set in PSAK No. 34. However, when compared to revenue recognition using the percentage of completion method with a cost-to-cost approach the firm can recognize the revenue and expenses more to illustrate or show a more proportional calculation because it corresponds to the costs incurred or poured out.   Keywords: revenue recognition, expense recognition, PSAK no. 34


2013 ◽  
Vol 23 (11) ◽  
pp. 2129-2154 ◽  
Author(s):  
HÉLÈNE BARUCQ ◽  
JULIEN DIAZ ◽  
VÉRONIQUE DUPRAT

This work deals with the stability analysis of a one-parameter family of Absorbing Boundary Conditions (ABC) that have been derived for the acoustic wave equation. We tackle the problem of long-term stability of the wave field both at the continuous and the numerical levels. We first define a function of energy and show that it is decreasing in time. Its discrete form is also decreasing under a Courant–Friedrichs–Lewy (CFL) condition that does not depend on the ABC. Moreover, the decay rate of the continuous energy can be determined: it is exponential if the computational domain is star-shaped and this property can be illustrated numerically.


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