scholarly journals IMPACT OF VARYING PROPERTIES OF GEOLOGICAL ENVIRONMENT ON THE FORMATION OF LOADS AT SHALLOW-LAYING UNDERGROUND STRUCTURES

2020 ◽  
pp. 13-19
Author(s):  
Natalia Zuievska ◽  
Liubov Shaidetska ◽  
Valentina Gubashova
Keyword(s):  
Urban Development ◽  
Physical And Mechanical Properties ◽  
Strength Characteristics ◽  
Soil Conditions ◽  
Joint Work ◽  
Cement Material ◽  
Future Design ◽  
Soil Cement ◽  
Jet Grouting ◽  
Geological Conditions

Purpose. The purpose of this work is to consider the prospects for the use of jet grouting in urban development. On the example of the considered engineering-geological conditions to show the possibility of wide application of soil-cement elements. Methodology. To consider the main characteristic features of jet grouting, which prevail over traditional geotechnical technologies. To show the possibility of performing soil-cement elements not only in the conditions of strengthening the soil bases, but also in the conditions of anti-filtration elements when performing the protection of ditches. To present the ranges of strength characteristics of soil-cement material for soil conditions of Ukraine. Findings. The type and physical and mechanical properties of soils in which the jet-grouted element is performed will be one of the main factors influencing the geometric size of the elements and the strength of the soil-cement material. Originality. Collected and analyzed strength characteristics of soil-cement material and the presented ranges of their numerical values will allow to use them for future design of jet-routed elements in different soil conditions of Ukraine without the available personal developed practical base. Practical implications. In the progressive rhythm of urban development, the issue of new construction in the immediate vicinity of existing buildings, or the reconstruction of those in disrepair is acute. Due to its features and advantages, the technology of jet cementation allows to solve construction problems where other geotechnologies do not have the opportunity to be applied. Low dynamic impact will allow to perform soil-cement elements at strengthening of buildings and constructions in an emergency condition, low water permeability - to use jet elements as antifiltration, both single, and in joint work with other elements of designs of protection of ditches. Numerical experimental values of the strength of the material obtained by performing jet cementation, will predict the strength characteristics of future soil-cement elements.

scholarly journals Technological solutions for mining of off-balance gypsum reserves in difficult geological conditions

2020 ◽  
Vol 168 ◽  
pp. 00064
Author(s):  
Serhii Skipochka ◽  
Viktor Serhiienko ◽  
Volodymyr Amelin ◽  
Oleh Sytnichenko ◽  
Thibault Faucher
Keyword(s):  
Mechanical Properties ◽  
Quantitative Assessment ◽  
Underground Mining ◽  
Physical And Mechanical Properties ◽  
Strength Characteristics ◽  
Maximum Width ◽  
Geological Conditions ◽  
Selective Mining

Mining technological solutions for underground mining of offbalance gypsum reserves in difficult mining and geological conditions were justified. An analysis of typical geological disturbances of gypsum seams is carried out using the Artemivsk deposit (Ukraine) as an example. Physical and mechanical properties of rocks in disturbed zones are determined. A quantitative assessment of strength characteristics of rocks during their moistening is carried out. The minimum permissible values of the width of the tape pillar and the power of the protective stack above the camera in the presence of a violation in the roof are calculated. The use of selective mining of the lower part of the seam by combines of the “Roadheader” type is recommended. The maximum width and height of the chamber are determined by the type of combine. The technology has been tested and realized at the gypsum mine of the Additional Liability Company “Siniat”.

scholarly journals Geomechanical justification of security measures in the development of the South Khingan deposit of manganese ore

2018 ◽  
Vol 56 ◽  
pp. 02014
Author(s):  
Maksim Rasskazov ◽  
Marina Potapchuk ◽  
Gennady Kursakin ◽  
Denis Tsoy
Keyword(s):  
Physical And Mechanical Properties ◽  
Rock Massif ◽  
Manganese Ore ◽  
Security Measures ◽  
The South ◽  
Rockburst Hazard ◽  
Field Development ◽  
Stage Of Development ◽  
Geological Conditions ◽  
Numerical Simulation Methods

The paper presents the results of geomechanical studies on the assessment of the potential rockburst hazard of the rock massif of the South Khingan deposit of manganese ore at the stage of development. Geodynamic zoning has been performed, mining and technical, mining and geological conditions of field development have been studied, and parameters of physical and mechanical properties of enclosing rocks and ores have been determined. Numerical simulation methods have been used to estimate the stress state of a rock massif at various stages of the deposit development. The tendency of the lower part of the South Khingan deposit to rockburst has been established. The complex of effective organizational and technical security measures has been substantiated in the development of this field.

Experimental study on strength of cement stabilized clay

2005 ◽  
Vol 3 (2) ◽  
pp. 116-126 ◽  
Author(s):  
Woo‐Sik Kim ◽  
Nguyen Minh Tam ◽  
Du‐Hwoe Jung
Keyword(s):  
Compressive Strength ◽  
Soil Type ◽  
Unconfined Compressive Strength ◽  
Weight Ratio ◽  
Dry Weight ◽  
Strength Characteristics ◽  
Curing Time ◽  
Compression Tests ◽  
Soil Cement ◽  
Mixing Method

This paper describes the effect of factors on the strength characteristics of cement treated clay from laboratory tests performed on cement mixed clay specimens. It is considered that several factors such as soil type, sample preparing method, quantity of binder, curing time, etc. can have an effect on strength characteristics of cement stabilized clay. A series of unconfined compression tests have been performed on samples prepared with different conditions. The results indicated that soil type, mixing method, curing time, dry weight ratio of cement to clay (Aw), and water‐clay to cement (wc/c) ratio were main factors which can have an influence on unconfined compressive strength, modulus of elasticity, and failure strain of cement stabilized clay. Unconfined compressive strength of soil‐cement samples prepared from dry mixing method was higher than those prepared from wet mixing method.

scholarly journals Influence of nanocellulose on the hydration process of Portland cement and concrete properties

2020 ◽  
Vol 17 (5) ◽  
pp. 155-160
Author(s):  
V. I. Khirkhasova ◽  
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Physical And Mechanical Properties ◽  
Cement Composite ◽  
High Density ◽  
Strength Characteristics ◽  
New Method ◽  
Concrete Properties ◽  
Hardening Process ◽  
Study Results

The paper deals with modification of cement composite and concrete with nanocellulose in low and high density. The author presents the study results of the influence of nanocellulose on the cement composite hardening process, as well as the physical and mechanical properties of heavy concrete. The influence of the used additive on the rheological and strength characteristics of concrete is revealed. A new method is proposed to improve the material performance.

Modification of seismograph records for effects of local soil conditions

1972 ◽  
Vol 62 (6) ◽  
pp. 1649-1664 ◽  
Author(s):  
P. Schnabel ◽  
H. Bolton Seed ◽  
J. Lysmer
Keyword(s):  
San Francisco ◽  
Ground Surface ◽  
Soil Conditions ◽  
Local Soil ◽  
Geological Conditions ◽  
Soil Deposits ◽  
Time Histories ◽  
Seismic Records ◽  
Local Soil Conditions ◽  
Good Agreement

abstract A procedure for modifying the time histories of seismic records for the effect of local soil conditions is presented. The method is based on a conventional one-dimensional wave-propagation approach with equivalent linear soil properties, extended to practical use for transient motions through the Fast Fourier technique. The validity of the approach is tested against the motions recorded at four soil sites and one rock site during the 1957 San Francisco earthquake. The good agreement between the computed and recorded values indicates that rock motions can be computed from motions recorded on soil deposits, and that the computed rock motions in turn can be used to predict the motion that would have been recorded under different soil and geological conditions. The method is also used to evaluate the probable rock motions in the vicinity of El Centro in the earthquake of 1940 and the ground surface motions that could have been developed on various soil conditions in the same general area.

Fire-Retardant Plastering Mortars Based on Exfoliated Vermiculite and Volcanic Ash

2021 ◽  
Vol 1043 ◽  
pp. 133-139
Author(s):  
Tolya Khezhev ◽  
Artur Zhurtov ◽  
Alim Kazharov ◽  
Tamerlan Zrumov ◽  
Asharbek Samgurov
Keyword(s):  
Mechanical Properties ◽  
Volcanic Ash ◽  
Cement Mortar ◽  
Low Cost ◽  
Fire Retardant ◽  
Physical And Mechanical Properties ◽  
Strength Characteristics ◽  
Multifunctional Additive ◽  
Solution Density ◽  
Noticeable Increase

The research results on the development of fire-retardant composite cement mortar mixtures on exfoliated vermiculite and volcanic ash with the use of a multifunctional additive are presented D-5. Compositions of fire-retardant composite mortars, which make it possible to significantly improve the physical and mechanical properties of mortar mixtures and mortars, are proposed. Introduction of a multifunctional supplement D-5 in mortar mixtures makes it possible to improve the composite mortar mixtures properties and improve the solution characteristics. Replacement of finely dispersed fraction of exfoliated vermiculite d<0,63 mm volcanic ash by volume in mortar mixtures does not cause a noticeable increase in the solution density, while their strength characteristics increase. The developed composite mortar mixtures meet the requirements of GOST 28013–98 and have a low-cost price due to volcanic ash use.

scholarly journals Influence of various additives on properties of concrete

2020 ◽  
Vol 164 ◽  
pp. 14007
Author(s):  
Zalina Tuskaeva ◽  
Soslan Karyaev
Keyword(s):  
Mechanical Properties ◽  
Water Resistance ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Air Entrainment ◽  
Strength Characteristics ◽  
Chemical Additives ◽  
Construction Time ◽  
Design Strength ◽  
Multifunctional Additive

A comparative analysis of concrete samples without chemical additives and three concrete samples with additives was carried out The first sample contains the liquid additive, the other two contain the powder additive. The article aims at finding out the effectiveness of additives influence on the physical and mechanical properties of concrete and the basis for the application areas of modified types of concrete. By means of laboratory tests, the physical and mechanical properties of concrete mixtures are determined. To determine the strength characteristics of concrete samples, the IM-1250M testing machine was used. The tests were carried out under the same temperature and humidity conditions. According to the results of the experiments, the samples with the multifunctional additive "D-5" showed the best characteristics of concrete, and the samples with the dolomite flour additive were the cheapest. As a result of the experimental analysis, the effects of three additives on the strength characteristics of concrete and water resistance were determined. Cemplast and D-5 additives are highly effective modifiers of concrete and mortar. They can increase the strength by 20-40% at the age of 28 days at dosages of 1.6-6% with a decrease in water-cement ratio and a decrease of cement amount by 20%. Additives highly increase the workability of the mixture, air entrainment and water resistance. While using the chemical additives an early set of the concrete design strength is observed for the construction time reducing in 7 days.

scholarly journals Temperature monitoring of surface layers of the earth in Perm

2019 ◽  
Vol 265 ◽  
pp. 04004
Author(s):  
Andrey Ponomaryov ◽  
Aleksandr Zakharov
Keyword(s):  
Urban Development ◽  
Temperature Change ◽  
Temperature Fluctuations ◽  
Temperature Monitoring ◽  
Clay Soils ◽  
Seasonal Temperature ◽  
Surface Layers ◽  
The Earth ◽  
Geological Conditions ◽  
The City

The article presents the results of monitoring the temperature of the surface layers of the earth. Monitoring was carried out at two sites with engineering-geological conditions typical for Perm. The geological conditions of the first site are clay soils, the second site is sandy. The first site is located in a dense urban development, the second in an unfinished part of the city of Perm. The depth of the soil massif on which the temperature was monitored was: for the first site - 19 m, for the second site - 37 m. Based on monitoring results, a picture of the temperature change in the soil massif in time for both sites was obtained. In the article, the average monthly temperatures of the soil massif are plotted on both sites. The zone of fluctuations in the temperature of the soil massif is revealed depending on the temperature of the outside air. The depth of the zone of seasonal temperature fluctuations was 10m. Monitoring determined that the temperature of the ground mass is below 10m: for the first site + 12 ° C with a decrease in temperature to 10°C to a depth of 19m, for the second site - a constant + 6-7°C to a depth of 37m.

Experimental Study on the Engineering Characteristics of Improved Soil

2010 ◽  
Vol 168-170 ◽  
pp. 1426-1431
Author(s):  
Zhi Qing Li ◽  
Zhen Dong Cui ◽  
Yan Ping Wang ◽  
Li Chao Wang ◽  
Duo Zhong
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Fly Ash ◽  
Physical And Mechanical Properties ◽  
Hybrid Structure ◽  
Strength Characteristics ◽  
Shanxi Province ◽  
Hydration Reaction ◽  
Test Results ◽  
Shearing Strength

According to the typical loess in Shuozhou in Shanxi province, tests involved in compaction characteristics, shearing strength characteristics and disintegration are carried out by using loess and three kinds of improved loess, namely lime and fly-ash, lime and cement, cement and fly-ash. The best improved soil method is selected. The test results indicate that the compact hybrid structure is formed by fly ash and loess. The activity of fly ash is activated as a result of the lime mixing. A series of hydration reaction prompt the intensity of modified loess. And the physical and mechanical properties of improved loess are improved noticeably.

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