scholarly journals Base Soil Reinforcement with Vertical Crushed Stone Columns in Cryolithozone

2020 ◽  
Vol 17 (4) ◽  
pp. 68-78
Author(s):  
T. V. Shepitko ◽  
I. A. Artyushenko ◽  
P. G. Dolgov
Keyword(s):  
Strength Properties ◽  
Soil Reinforcement ◽  
Transport Infrastructure ◽  
Strength Characteristics ◽  
Stone Columns ◽  
Crushed Stone ◽  
Use Of Technology ◽  
Permafrost Soils ◽  
Preparatory Stage ◽  
The Stability

Stabilization of permafrost soils of the roadbed base, constructed with assumption of thawing, thanks to improvement of their strength characteristics, requires development and selection of rational structural and technological solutions. The objective of the study was to analyze the effectiveness of use of vertical columns of crushed stone in the permafrost zone and their influence on strength characteristics of the soil base. The study has used general scientific methods, modeling, simulation and comparative analysis. This article proposes a method for improving strength properties of soil of the roadbed base within Obskaya–Salekhard section of the Northern Latitudinal Railway thanks to reinforcement of the roadbed base made with vertical columns of crushed stone, which increases stability of the structure. The proposed basic technological model of construction of the roadbed includes the following main stages: preparatory stage, 1 stage – arrangement of vertical columns of crushed stone and granular subbases, 2 stage – additional compaction with a vibratory roller in case of mismatch of stability of bearing capacity and precipitation of the base to operating standards. The studied object of the transport infrastructure was simulated both without the use of technology for reinforcing it with vertical columns of crushed stone and with its use. The stability coefficient was calculated, and the theoretical surface of embankment collapse was obtained using Midas GTS NX and Plaxis 2D software packages. The stability test of this structure was carried out both in a flat and in a threedimensional setting. The efficiency of using vertical columns of crushed stone to strengthen the embankments constructed on permafrost soils has been shown.

scholarly journals Dependence of physico-mechanical characteristics and safety factor of the soil mass on the spacing of vertical pillars of crushed stone

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Igor Artyushenko
Keyword(s):  
Soil Mass ◽  
Climatic Conditions ◽  
Transport Infrastructure ◽  
Strength Characteristics ◽  
Crushed Stone ◽  
Soil Base ◽  
Railway Line ◽  
The North ◽  
Permafrost Soils ◽  
The Stability

In the design, construction and further operation of communication lines on permafrost soils, the most urgent task is to ensure the reliability of the foundation of the structure. The complexity of construction in the North is due to the presence of permafrost soils in the foundations of buildings, a large number of natural barriers, extreme climatic conditions and lack of infrastructure. In this regard, the choice of structural, technological and organizational solutions for the development of transport infrastructure, including for railways and, first of all, a deformability forecast, measures to ensure the stability of the soil base and the development of rational organizational schemes for their implementation, should be economically feasible, optimal or close to optimal for a particular engineering structure and the region of its location. To ensure stability and sustainability of the soil base of the structure on the Northern Latitudinal Railway section of the new Obskaya-Salekhard railway line, PK 01+50 – PK 06+50, the author proposes a solution to strengthen the base soil with vertical columns of crushed stone. This article shows the effect of vertical columns of crushed stone on the strength characteristics of permafrost soils of the base of the structure. The dependence of the strength characteristics of the soil base on the different steps of the placement of vertical columns of crushed stone is shown. The conclusion is drawn about the most optimal spacing step according to the results of calculations and comparison of various steps of arranging vertical pillars from crushed stone. The results presented in the article are part of the dissertation research I. Artyushenko «Reinforcement of the subgrade base with vertical columns of crushed stone in areas with permafrost soils».

scholarly journals The influence of vertical columns of crushed stone on the cryogenic processes of the soil base of the subgrade

2019 ◽  
Vol 6 (4) ◽  
Author(s):  
Taisiya Shepitko ◽  
Igor Artyushenko
Keyword(s):  
Climatic Conditions ◽  
Oil Fields ◽  
Transport Infrastructure ◽  
Crushed Stone ◽  
Railway Line ◽  
The North ◽  
Permafrost Soils ◽  
The Stability ◽  
Permafrost Thawing ◽  
First Time

Currently, the development of communications in the North is becoming increasingly important for the economy of the Russian Federation. According to the strategy for the development of railway transport until 2030, the construction of the Northern latitudinal passage railway will allow unloading the Trans-Siberian Railway, get transport approaches to the gas and oil fields of the Yamalo-Nenets Autonomous District, and later the Krasnoyarsk Territory, and provide communication with the ports of the Northern Sea Route. The complexity of construction in these regions is due to several reasons: the presence of weak soils in the foundations of structures, the unpredictability of the behavior of frozen soils during freezing-thawing, difficult climatic conditions, and the lack of transport infrastructure. To ensure the stability and sustainability of the subgrade on the Northern latitudinal passage section of the new Obskaya-Salekhard railway line PK 01+50 – PK 06+50, the authors proposed a decision to reinforce the foundation soils with vertical columns of crushed stone. This improvement technology is used in the North for the first time, but it has proven itself in areas with weak foundations. The Northern latitudinal passage section of the new Obskaya-Salekhard railway line PK 01+50 – PK 06+50 is carried out according to the II design principle with the assumption of permafrost thawing. This article has performed and analyzed the modeling of thermophysical processes both with the use of this technology and without it. Conclusions are drawn on the appropriateness of using this technology in the permafrost zone. The results presented in the article are part of the dissertation research I. Artyushenko «Reinforcement of the subgrade base with vertical columns of crushed stone in areas with permafrost soils».

scholarly journals The study of the soil of the base of the Krasnoyarsk territory and the method of strengthening

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Andrey Zaitsev ◽  
Igor Artyushenko
Keyword(s):  
National Economy ◽  
Climatic Conditions ◽  
Transport Infrastructure ◽  
Crushed Stone ◽  
Main Stage ◽  
Economic Relations ◽  
Geographical Society ◽  
The North ◽  
Crushed Granite ◽  
Permafrost Soils

Railways in Russia rightfully occupy one of the key places in the national economy in connection with the geographical conditions, technological features of the economy and the possibility of maximizing the use of the country's transit potential. The problem of modernizing the transport system of Russia, its adaptation to the requirements of the functioning of the national economy and foreign economic relations is becoming increasingly relevant for the regions of the North. As part of the main stage of the expedition “Transpolar Highway”, conducted by the Russian Geographical Society (RGS) together with the Russian University of Transport (RUT) from September 19 2019 to October 15 2019, specialists from the Russian University of Transport examined the territory of the Krasnoyarsk Territory to assess the possibility of designing and building tracks messages in these regions. The lack of transport infrastructure, the unpredictability of the behavior of frozen soils during freezing-thawing, the presence of weak soils in the foundations of structures, difficult climatic conditions, all these factors determine the complexity of construction in these regions. This article describes the determination of the strength characteristics of soils using a dynamic Panda penetrometer-density meter in the field. Conclusions are made about the appropriateness of using these soils in the foundations of structures. Due to the lack of quarries for the production of crushed granite in the Norilsk region and the difficulty of transporting this material, the use of Norilsk metallurgy waste as a replacement for crushed stone was analyzed. The results presented in the article are part of the dissertation research I. Artyushenko "Reinforcement of the subgrade base with vertical columns of crushed stone in areas with permafrost soils"

General concept of determining the parameters of non-mining walls of ultra-deep diamond deposits development open pits

2021 ◽  
pp. 48-53
Author(s):  
I. V. Zyryanov ◽  
A. N. Akishev ◽  
I. B. Bokiy ◽  
N. M. Sherstyuk
Keyword(s):  
Rock Mass ◽  
Structural Relaxation ◽  
Slope Angle ◽  
Field Tests ◽  
Friction Angle ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Open Pit ◽  
Open Pit Mining ◽  
Relaxation Coefficient

A specific feature of open pit mining of diamond deposits in Western Yakutia is the construction of the open pits in the zone of negative ambient temperatures, which includes thick permafrost rock mass, and which is at the same time complicated by the influence of cryogenic processes on deformation of pit wall benches. The paper presents the comparative analysis of strength characteristics in frozen and thawed rocks, stability of benches during mining, the general geomechanical approach to the determination of parameters of non-mining walls of the ultra-deep open pit diamond mines, and the parameters of nonmining walls and benches. Optimization of open pit wall configuration should primarily be based on the maximum utilization of the strength properties of frozen rocks in combination with the development of new approaches, calculation schemes and methods for assessing stability of open pit walls and benches of unconventional design, including the non-mining vertical benches. The main design characteristic that determines the parameters of open pit walls is the structural tectonic relaxation coefficient, which specifies the calculated value of cohesion in rock mass. For the diamond deposits, the values of the structural relaxation coefficient were obtained in a series of field tests and back calculations. Full-scale tests were carried out both during exploration operations in underground mines and in open pits. The accuracy of determining the values of the structural relaxation coefficient in the range of 0.085–0.11 is confirmed by the parameters of non-mining walls in an open pit mine 385–640 m deep, with overall slope angles of 38–55° and a steeper H 0.35–0.5 lower part having the slope angle of up to 70° with average strength characteristics of 7.85–11.84 MPa and the internal friction angle of 28.1–37.4°. Using the natural load-bearing capacity of rock mass to the full advantage, which the values of the structural relaxation coefficient of deposits show, allows optimization of open pit wall slope design and minimization of stripping operations.

Weldability: Effect of Alloying Element Sc, Mn, and Zr on Alloys of the Al-Mg-Sc-Mn-Zr System

2019 ◽  
Author(s):  
V. I. Lukin
Keyword(s):  
Aluminum Alloys ◽  
Practical Importance ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Mg Alloy ◽  
Alloying Element ◽  
Processing Properties ◽  
Alloys Of The Al ◽  
Effect Of Alloying

Scandium in aluminum alloys behaves as the most efficient modifier of the structure of the material and as an agent suppressing recrystallization. This unique behavior of scandium in alloys of the Al-Mg system greatly increases the strength characteristics, whilst retaining on a higher level the ductility and processing properties of deformed semi-finished products. This article describes the effect of complex alloying the Al-6.3% Mg alloy with scandium, manganese and zirconium on the weldability and strength properties of the material is of considerable scientific and practical importance.Investigations.

scholarly journals THE INFLUENCE OF THE STORAGE CONDITIONS OF RAW MATERIALS ON THE PRESERVATION OF THE PROPERTIES OF THE FUR SEMI-FINISHED PRODUCT

2021 ◽  
Vol 53 (3) ◽  
pp. 52-58
Author(s):  
Natalya P. Bodryakova
Keyword(s):  
Elevated Temperature ◽  
Relative Humidity ◽  
Raw Materials ◽  
Storage Conditions ◽  
Strength Properties ◽  
Biological Factor ◽  
Point Scale ◽  
Complex Characteristic ◽  
Characteristic Features ◽  
The Stability

This article deals with the problem of preserving the properties of a semi-finished fur product under the influence of a biological factor during the storage of raw materials. The characteristic features of the biodegradation of untreated rabbit skins during storage at elevated temperature and relative humidity are identified and described. A complex characteristic of a semi-finished fur product developed from raw materials of various degrees of microbiological spoilage is given. The author offers a point scale of assessment dynamics of the processes of destruction of fur raw materials and a point assessment of the organoleptic indicators of the semi-finished product was developed. As a result of comprehensive studies, it was found that the degree of damage to the fur raw materials being processed affects the decrease in the stability of the structure and strength properties of the finished semi-finished product.

Exposure of urban infrastructure because of climate change-induced flood: lesson from municipal level planning in Bangladesh

2020 ◽  
Vol 1 (3) ◽  
pp. 107-125
Author(s):  
Md. Mostafizur Rahman ◽  
Ishrat Islam
Keyword(s):  
Climate Change ◽  
Transport Infrastructure ◽  
Future Climate Change ◽  
Master Plan ◽  
Content Type ◽  
Exposure Analysis ◽  
Socioeconomic System ◽  
Flood Exposure ◽  
The Stability ◽  
Municipal Level

Purpose Bangladesh is one of the most flood-prone countries in the world. A number of research works have identified that the flood scenario will be aggravated with climate change context in Bangladesh. In 2014, Bangladesh had prepared municipal level master plan for 222 municipalities with a view to planned urban development. But climate change-induced flood has not been considered in master plan, which poses a question toward the sustainability of the plan. Ullapara Municipality of Sirajganj district has been selected to conduct the research. This study aims to evaluate how infrastructure in proposed master plan will be exposed to climate change-induced flood. Design/methodology/approach The methodology of this study follows geographic information system (GIS)-based flood exposure analysis of selected infrastructure. These infrastructures include transport infrastructure, educational infrastructure, health infrastructure and other urban facilities. Climate change-induced flood for the year 2040 has been used for flood exposure analysis. Findings It is evident from the flood exposure analysis that about 33.99% roads will be exposed to 1.5 m–2 m inundation level; seven primary school, six secondary school and four colleges would be highly exposed to 2.0 m–2.50 m inundation level; four health facilities would be exposed to 1.0 m–2.0 m inundation level because of future climate change. This inundation scenario for long duration will lead to dysfunction of concerned infrastructure and, in turn, undermine the stability of a socioeconomic system of Ullapara Municipality. Originality/value As the master plan is not fully implemented till now, there is scope for intervention for considering climate change-induced flood to make the plan sustainable.

scholarly journals Shrinkage and Strength Properties of Coal Gangue Ceramsite Lightweight Aggregate Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yunsen Wang ◽  
Jingping Qiu ◽  
Chao Zeng
Keyword(s):  
Waste Treatment ◽  
Concrete Strength ◽  
Lightweight Aggregate ◽  
Strength Properties ◽  
Coal Gangue ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Concrete Shrinkage ◽  
Strength Tests ◽  
The Stability

It is a promising and effective method for waste treatment by using coal gangue to make lightweight aggregate concrete. However, lightweight aggregate concrete with low-density coal gangue ceramsite is prone to cracking during volume shrinkage, which limits its application in the construction industry. In an attempt to resolve the problem of cracking in shrinkage, this study investigated the effect of prewetting time and shrinkage reducing agents on shrinkage volume and concrete strength through a series of concrete shrinkage and strength tests. The experimental results show that shrinkage volume reduced at a prewetting time of 12 hrs or with a 2% addition of D-230 polyether amine reductant. With the optimal conditions of 12 hrs prewetting time and 2% addition of the reductant, the concrete shrinkage volume significantly decreased with a negligible impact on its strength. Appropriate amount of shrinkage reducing agent and adjustment of prewetting time of coal gangue ceramsite are necessary to reduce the shrinkage rate and improve the stability of the specimen. This is of great significance to wide application of lightweight aggregate concrete with coal gangue ceramsite.

Influence Study of Plasticizer Compatibility on Strength Properties of Ethylene-Vinyl Acetate

2018 ◽  
Vol 935 ◽  
pp. 79-83
Author(s):  
A.N. Volotskoy ◽  
Yuriy V. Yurkin ◽  
V.V. Avdonin
Keyword(s):  
Mechanical Properties ◽  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Dynamic Mechanical Properties ◽  
Strength Properties ◽  
Polymer Materials ◽  
Strength Characteristics ◽  
Actual Problem ◽  
Urgent Task ◽  
Wide Range

This research is devoted to the actual problem of the development of damping polymer materials which are effective in a wide range of temperatures and having satisfactory strength characteristics. There are many works devoted to the study of dynamic mechanical properties of filled composites, but most do not take into account the influence of plasticizer on the strength properties of the polymer, as they change its characteristics for the worse. In this respect, the study and comparison of the mechanical properties of the polymer base with the introduction of different types and concentrations of plasticizers is an urgent task. According to the received regularities it was possible to define the type, concentration and boundaries of the polarity of the plasticizer, which reduces the strength characteristics of ethylene-vinyl acetate to a lesser degree.

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