scholarly journals The Analysis of the Influence of Rock Massif Water Saturation on the Mine Workings Anchoring Design Parameters

2019 ◽  
Vol 105 ◽  
pp. 01027
Author(s):  
Sergey Tsibaev ◽  
Alexey Renev ◽  
Evgenyi Kudrin ◽  
Damir Zaiatdinov

Here in the study results of the sedimentary rocks water saturation effect on the main parameters of anchoring of mine workings: resistance, density and installation step of the support. A series of tests of rock samples with different intervals of their water saturation has been produced. It has been established that water saturation leads to a significant change in the strength properties of sedimentary rocks, depending on their petrographic composition and the period of exposure to moisture. The relation between the degree of water saturation and a decrease in the uniaxial compression strength, between the strength of a dry sample and its tendency to decrease in strength properties under the influence of moisture, between the period of exposure to moisture and decrease in strength properties has been established. The results of the study will allow to more accurately classify the rocks of the roof according to the factors of collapse and stability, which has a significant impact on the calculation of the anchoring parameters of mine workings in water-saturated zones.

Vestnik MGSU ◽  
2021 ◽  
pp. 463-472
Author(s):  
Zaven G. Ter-Martirosyan ◽  
Armen Z. Ter-Martirosyan ◽  
Ahmad Othman

Introduction. In case of brief exposure to static loads or dynamic loads, in conditions of absence of drainage, distribution of total stresses between the skeleton of soil and pore gas-containing water should be taken in account. The situation of the stress-strain state of the base is further complicated when we consider the degree of water-saturation of soil of the foundation (0.8 < Sr ≤ 1). The aim of the study is to pose and solve problem of the stress-strain state of a water-saturated soil massif, Including settlement and bearing capacity of a water-saturated base of a foundation of finite width, depending on the degree of water saturation of soils, taking into account the linear and nonlinear properties of the skeleton of soil and the compressibility of pore gas-containing water. Materials and methods. Henckyʼs system of physical equations are used as a calculation model to describe the relationship between deformation and stresses of soil, which takes into account the influence of the average stress on the deformation and strength properties of the soil. This system allows us to represent the linear deformation of the soil as the sum of the volumetric and shear components of the soil of this deformation. In addition allows us too to determine the deformation of the layer of soil, as part of the compressible thickness of the base of foundation with finite width under conditions of free deformations. Results. Depending on the linear and nonlinear deformation parameters, the settlement can be developed with a damped curve (S – p) and stabilize, and can be developed with a non-damped curve (S – p) and moved to the stage of progressive settlement. Conclusions. Solutions have been made for cases when the water-saturation of the base soils changes in the range of 0.8 to 1.0. It is shown that the settlement and bearing capacity of a water-saturated base significantly depends on the degree of water saturation of soils.


2021 ◽  
Vol 264 ◽  
pp. 02032
Author(s):  
Rashidbek Hudaykulov ◽  
Dilfuza Makhmudova ◽  
Dilshod Kayumov ◽  
Olmos Zafarov

Globally, in arid regions, due to the irrational use of water resources for irrigating plants, salinization of soils occurs, which causes significant damage to the country's economy. In particular, recently in some regions of Uzbekistan, there has been a rise in groundwater and flooding of territories. In these areas, where the soil bases of highways contain such readily soluble salts as: NaCL, Na2SO4·10H2O, MgSO4·7H2O, MgCL2·6H2O, CaCL2·6H2O, NaHCO3, Na2CO3·10H2O, CaCO3 and CaSO4·2H2O, additional suffusion precipitation is often observed which lead to deformations of road surfaces. Additional precipitation is due to the dissolution of salt crystals upon ingress of moisture during filtration leaching. Filtration leaching of soils was carried out in the F-1M device according to the upward flow pattern. To determine the amount of leached salts during the experiment, the infiltrate was taken, its volume and mineralization were recorded. At the end of the tests, the soil was tested according to the general scheme. To assess the influence of the leaching process on the strength indices of the studied soils by the methods of consolidated and fast shear, tests of pre-leached samples were performed. When testing soils, samples were cut, pre-compacted with the same specified load, and leached for a month. In laboratory conditions, the deformation modulus was determined by performing compression experiments. In connection with a sharp change in the modulus of deformation of soils during moistening, the tests were carried out at two values of humidity: at natural and after water saturation without the possibility of swelling. The study results show that the deformation modulus of water-saturated loams satisfactorily correlates with the value of the initial porosity coefficient and decreases as a result of water saturation and leaching. The degree of decrease depends on the value of the initial deformation modulus: the higher it is, the more significant its change. The value of the coefficient of weakening of the soil structure depends on the effective average pressure. The criterion for the permissible salt content in the base of the roadbed of highways should be taken not only the value of the degree of salinity but also the change in the indicators of the mechanical properties of soils used in the design of the construction of the roadway during soaking and leaching.


Author(s):  
D.V Babets ◽  
O.S Kovrov ◽  
S.K Moldabayev ◽  
R.M Tereschuk ◽  
D.O Sosna

2019 ◽  
Vol 41 (4) ◽  
pp. 223-230
Author(s):  
Mirosława Bukowska ◽  
Anna Smolorz

AbstractThis article presents the results of tests on the energy properties of sedimentary rocks in the Upper Silesian Coal Basin. The rocks were tested both in an air-dry state and in a water saturation state. Samples of sedimentary rocks were collected from boreholes drilled in the underground workings of coal mines located within the area of the city of Jastrzębie, in the areas of the Chwałowice Trough and Rybnik Trough (south-western part of the Upper Silesian Coal Basin) and in the Main Trough. Influence of saturation condition on the values of the tested energy parameters was observed. The values of elastic energy and dissipated energy obtained for the samples tested in water saturation were lower compared to the values obtained for samples tested in air-dry state. As observed, an increase in the values of the given types of specific energy corresponds to an increase in the uniaxial compression strength in air-dry state and in water saturation state. Results of the tests are original and they can be applied while analysing the possibility of the occurrence of some dynamic phenomena and hazards in mine workings in Carboniferous rock mass in the Upper Silesian Coal Basin, caused by mining operations.


TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 631-638
Author(s):  
FREDERIC KREPLIN ◽  
HANS-JOACHIM PUTZ ◽  
SAMUEL SCHABEL

Paper for recycling is an important fiber source for the production of corrugated base paper. The change in production capacity toward more and more packaging papers affects the composition of paper for recycling and influences the paper quality. This research project investigated the influence of the multiple recycling of five different corrugated base papers (kraftliner, neutral sulfite semichemical [NSSC] fluting, corrugating medium, testliner 2, and testliner 3) on suspension and strength properties under laboratory conditions. The corrugated board base papers were repulped in a low consistency pulper and processed into Rapid-Köthen laboratory sheets. The sheets were then recycled up to 15 times in the same process. In each cycle, the suspension and the paper properties were recorded. In particular, the focus was on corrugated board-specific parameters, such as short-span compression test, ring crush test, corrugating medium test, and burst. The study results indicate how multiple recycling under laboratory conditions affects fiber and paper properties.


1987 ◽  
Vol 67 (4) ◽  
pp. 825-834 ◽  
Author(s):  
M. S. AULAKH ◽  
D. A. RENNIE

The effects of wheat straw incorporation on denitrification, immobilization of N, and C mineralization were investigated at H2O contents of 60, 90 and 120% saturation. Incorporation of increasing levels of straw consistently increased the rate of denitrification for the first 4–8 d, followed by negligible N losses thereafter. In a total period of 96 d, the addition of 1.0% straw increased N losses from 2.5 to 10.1, and from 61.6 to 83.9 μg g−1 in the 60 and 120% water saturation treatments, respectively. The pattern of CO2-C evolved was practically identical to that of the denitrification rate for the initial period when sufficient [Formula: see text] was present. This study has confirmed that in flooded soils, high rates of denitrification will persist only when C is supplied by native or applied organic C sources, provided adequate [Formula: see text] is present. When [Formula: see text] was low, denitrification rates rapidly decreased, even with a sufficient supply of C. Immobilization of fertilizer N (50 μg N g−1 as K15NO3) was very rapid. Around 90% of the total immobilization of applied N occurred within 4 d. Incorporation of 1.0% straw increased the immobilization of fertilizer N from 8.4 to 42.8, and from 1.0 to 7.6% in the 60 and 120% water-saturated treatments, respectively. Remineralization of recently immobilized fertilizer N was observed after 32 d in the 60% saturation treatments only. Key words: Denitrification, wheat straw, mineralization of N


2007 ◽  
Vol 10 (06) ◽  
pp. 711-729 ◽  
Author(s):  
Paul Francis Worthington

Summary A user-friendly type chart has been constructed as an aid to the evaluation of water saturation from well logs. It provides a basis for the inter-reservoir comparison of electrical character in terms of adherence to, or departures from, Archie conditions in the presence of significant shaliness and/or low formation-water salinity. Therefore, it constitutes an analog facility. The deliverables include reservoir classification to guide well-log analysis, a protocol for optimizing the acquisition of special core data in support of log analysis, and reservoir characterization in terms of an (analog) porosity exponent and saturation exponent. The type chart describes a continuum of electrical behavior for both water and hydrocarbon zones. This is important because some reservoir rocks can conform to Archie conditions in the fully water-saturated state, but show pronounced departures from Archie conditions in the partially water-saturated state. In this respect, the chart is an extension of earlier approaches that were restricted to the water zone. This extension is achieved by adopting a generalized geometric factor—the ratio of water conductivity to formation conductivity—regardless of the degree of hydrocarbon saturation. The type chart relates a normalized form of this geometric factor to formation-water conductivity, a "shale" conductivity term, and (irreducible) water saturation. The chart has been validated using core data from comprehensively studied reservoirs. A workflow details the application of the type chart to core and/or log data. The analog role of the chart is illustrated for reservoir units that show different levels of non-Archie effects. The application of the method should take rock types, scale effects, the degree of core sampling, and net reservoir criteria into account. The principal benefit is a reduced uncertainty in the choice of a procedure for the petrophysical evaluation of water saturation, especially at an early stage in the appraisal/development process, when adequate characterizing data may not be available. Introduction One of the ever-present problems in petrophysics is how to carry out a meaningful evaluation of well logs in situations where characterizing information from quality-assured core analysis is either unavailable or is insufficient to satisfactorily support the log interpretation. This problem is especially pertinent at an early stage in the life of a field, when reservoir data are relatively sparse. Data shortfalls could be mitigated if there was a means of identifying petrophysical analogs of reservoir character, so that the broader experience of the hydrocarbon industry could be utilized in constructing reservoir models and thence be brought to bear on current appraisal and development decisions. Here, a principal requirement calls for type charts of petrophysical character, on which data from different reservoirs can be plotted and compared, as a basis for aligning approaches to future data acquisition and interpretation. This need manifests itself strongly in the petrophysical evaluation of water saturation, a process that traditionally uses the electrical properties of a reservoir rock to deliver key building blocks for an integrated reservoir model. The solution to this problem calls for an analog facility through which the electrical character of a subject reservoir can be compared with others that have been more comprehensively studied. In this way, the degree of confidence in log-derived water saturation might be reinforced. At the limit, the log analyst needs a reference basis for recourse to capillary pressure data in cases where the well-log evaluation of water saturation turns out to be prohibitively uncertain.


2018 ◽  
Vol 212 ◽  
pp. 01013
Author(s):  
Vadim Balabanov ◽  
Victor Baryshok ◽  
Nikita Epishkin

The sharply continental climate of the Irkutsk region is characterized by wide temperature intervals throughout the year. The repeated cyclicity of freezing and thawing of building materials in the water-saturated state influences the change in technical characteristics and the durability of concrete products and structures. The concrete products’ features in such climatic conditions create the need for the production of concretes with improved indicators of physical and mechanical properties. The effect of modifying additives on the technological characteristics of sulfur concrete is established. The effect of all elements of sulfur concrete on its strength and frost resistance. The composition of sulfuric concrete is obtained, which meets all the requirements and also has high strength and increased frost resistance. Formulations with a certain ratio of structural sulfuric concrete mixtures were developed. As a result of the use of technical sulfur in the composition of concrete products, the problem of utilizing annually accumulating reserves of technical sulfur is partially solved. The strength properties of sulfuric concretes easily compete with high-quality brands of concrete, special types of concretes that have in their composition additives.


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