scholarly journals The impact of changes in the geological conditions of road bedrock layers while the road was in use

Author(s):  
Stanislav Smugala ◽  
Darja Kubečková ◽  
František Indra

Abstract This article examines the effective road reconstruction technologies applied during construction processes to ensure the required final quality of construction work. The construction quality and especially the overall levelness of roads are influenced by several factors. These factors include high-quality implementation of road structural layers, including active zones, which can be adversely affected by the undisciplined application of technology, insufficient engineering and poor geological surveys. Suitable and effective reconstruction technology provides the required quality of construction work yet does not significantly extend construction time. The authors propose stabilisation using cement or lime during reconstruction. This stabilisation method is used if the structure of the bedrock layers is finely granular. The stabilisation process consists of excavating the unacceptable bedrock layer and mixing it with additives and water. A principally different bedrock stabilisation method consists of completely replacing it with a gravel layer, which is used when individual base layers are diverse and stabilisation using additives would not guarantee the required results, i.e. improved strength characteristics. In some cases, the existing base layers are not suitable for use as road base layers because of their characteristics, such as volumetric instability. For this reason, they must be replaced with more suitable materials. This topic is documented by a practical example.

Author(s):  
Aleksandr N. Kononov ◽  
Anastasia S. Komissarova

Topicality of the study of the attitude to the distance learning format is due to the need to study the impact of such interaction in the “pedagogue-studentˮ system on the quality, motivation and overall satisfaction of students with the learning process. The study involved 120 people from 6 six higher education institutions in Moscow. The use of content analysis allowed us to identify 8 significant contexts (areas) around which the statements of the study participants are grouped: “Roadˮ, “Teachersˮ, “Returnˮ, “Distance learningˮ, “Full-time, full-time attendingˮ, “Training, training formatˮ, “Provided, changedˮ, “Qualityˮ. The results obtained indicate that the main disadvantages of the distance learning format, according to the respondents, are the lack of live communication with teachers, a decrease in the level of motivation and self-organisation, which ultimately has a negative impact on the psychoemotional state of students and the quality of material assimilation. At the same time, among the obvious advantages, there is a reduction in transport and time costs for the road to the place of study, as well as the opportunity to study the material at a convenient time. The results obtained can be used in the development of distance learning programmes for students of higher educational institutions of the Russian Federation.


2019 ◽  
Vol 105 ◽  
pp. 01034
Author(s):  
Svetlana Bakhaeva ◽  
Elena Chernykh

To reduce transportation distance and shipping cost for rock haulage with a single-side development system, it is relevant to build roads on the spoil bank of the open-pit. The article reviews factors affecting stability of the spoil bank and the most common types of deformation. The backward calculation method for obtaining resistance to shear characteristics of the base rocks in contact with a road embankment has been described. Schemes for road constructions on the spoil bank of the open-pit have been considered. Mining and geometric simulation of the road base has been built. Zoning of the road base as per slope angle of the underlying rock and parameters of the haulage berm allow tracing rapidly axis of the technological and engineering roads for actual engineering and geological conditions. Besides, measures to reduce risk factors of landslides during construction of the haulage berm at deposit ledger-wall have been considered.


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 9 ◽  
Author(s):  
Olga Orynycz ◽  
Karol Tucki ◽  
Andrzej Wasiak ◽  
Robert Sobótka ◽  
Arkadiusz Gola

The social cost, as one of the factors determining sustainability of socio-economic development, is strongly dependent upon a number of casualties and mortality in road accidents. The condition of car tires appears to be one of the important factors determining the occurrence of accidents. The vast majority of vehicles are tested every year at vehicle inspection stations. One of the elements affecting the result of the technical condition test and basically the quality of vehicle braking is the technical condition of the tires. Their technical condition is a very important factor responsible for the quality of acceleration, braking, maintaining, or changing the direction of driving. As a consequence, it has a significant impact on road safety. The aim of the study is to examine the impact of tires on the results of tests performed at a vehicle inspection station. The study presents the results of bench measurements of the impact of selected features of tire condition of two vehicles during routine periodic inspections at a vehicle inspection station (VIS). The focus was on an attempt to assess the impact of inflation pressure, age, and tire tread wear on the braking process. The technical studies performed might be a source for legal steps assuring better management of road safety. It can also be expected that the tire choice and condition may affect fuel consumption, and therefore the amount of energy consumed by the road transport.


2020 ◽  
pp. 81-93
Author(s):  
D. V. Shalyapin ◽  
D. L. Bakirov ◽  
M. M. Fattakhov ◽  
A. D. Shalyapina ◽  
A. V. Melekhov ◽  
...  

The article is devoted to the quality of well casing at the Pyakyakhinskoye oil and gas condensate field. The issue of improving the quality of well casing is associated with many problems, for example, a large amount of work on finding the relationship between laboratory studies and actual data from the field; the difficulty of finding logically determined relationships between the parameters and the final quality of well casing. The text gives valuable information on a new approach to assessing the impact of various parameters, based on a mathematical apparatus that excludes subjective expert assessments, which in the future will allow applying this method to deposits with different rock and geological conditions. We propose using the principles of mathematical processing of large data sets applying neural networks trained to predict the characteristics of the quality of well casing (continuity of contact of cement with the rock and with the casing). Taking into account the previously identified factors, we developed solutions to improve the tightness of the well casing and the adhesion of cement to the limiting surfaces.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
D. M. Prieto ◽  
R. Devesa-Rey ◽  
D. A. Rubinos ◽  
F. Díaz-Fierros ◽  
M. T. Barral

Natural geological conditions together with the impact of human activities could produce environmental problems due to high As concentrations. The aim of this study was to assess the role of epipsammic biofilm-sediment systems onto As (V) sorption and to evaluate the effect of the presence of equimolar P concentrations on As retention. A natural biofilm was grown on sediment samples in the laboratory, using river water as nutrient supplier. Sorption experiments with initial As concentrations 0, 5, 25, 50, 100, 250, and 500 μg L−1were performed. The average percentage of As sorbed was78.9±3.5and96.9±6.6% for the sediment and biofilm-sediment systems, respectively. Phosphate decreased by 25% the As sorption capactity in the sediment devoid of biofilm, whereas no significant effect was observed in the systems with biofilm. Freundlich, Sips, and Toth models were the best to describe experimental data. The maximum As sorption capacity of the sediment and biofilm-sediment systems was, respectively, 6.6 and 6.8 μg g−1and 4.5 and 7.8 μg g−1in the presence of P. In conclusion, epipsammic biofilms play an important role in the environmental quality of river systems, increasing As retention by the system, especially in environments where both As and P occur simultaneously.


Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2493 ◽  
Author(s):  
Huawen Yan ◽  
Weigong Zhang ◽  
Dong Wang

Automobile proving ground is important for the research of vehicles which are used for vehicle dynamics, durability testing, braking testing, etc. However, the road in automobile proving grounds will inevitably be damaged with the extension of the service life. In most previous research, equipment similar to a laser profilometer was used to detect the quality of the road, the principle of which is to reflect the quality of the road by measuring the roughness of the pavement. This method ignores the elastic deformation of the road itself when the vehicle is traveling and it is difficult to compensate for the error. Therefore, this paper presents a new method based on a force sensor to reduce the impact of elastic deformation, such as tire deformation, pavement deformation, and wheel rim deformation. In this study, force sensors mounted on the wheels collect the three-dimensional dynamic force of the wheel. The presented method has been tested with two sets of cobblestone road loads, and the result shows that the load intensities imposed by the test vehicle on the target road are 88.3%, 91.0%, and 92.05% of the intensity of the load imposed by the test vehicle on a standard road in three respective dimensions. It is clear that the proposed method has strong potential effectiveness to be applied for wear detection and analysis of a special road.


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Zhijun Sha ◽  
Xiang Long ◽  
Jiahui Feng ◽  
Haibo Jiang ◽  
Tianlong Wang

AbstractTo widen bridges, a usual method is to cast joint connections between new and old bridge decks without traffic interruption. The traffic vibrations have negative influence on the quality of joint connections. Shortening the construction time can alleviate the impact on the traffics, a fast-hardening retarding high-early-strength concrete (FRHC) for the connections is in need. In this study, low-alkalinity sulphoaluminate cement (LASC) concrete was modified to gain these characteristics. Based on FRHC concrete, four slab specimens including a monolithic concrete slab and three joint FRHC slabs were cast to investigate their flexural behaviors. With proper splicing details in joint connections, the joint FRHC specimens behaved approximately similar to the monolithic specimen. Combing the laboratory tests and engineering practice, the newly developed FRHC mixture succeeded in fast-hardening, retarding and high-early strength and the joint connections filled with FRHC have a good flexural performance.


2021 ◽  
Vol 334 ◽  
pp. 01027
Author(s):  
Valentina Yadykina ◽  
Rashid Sharapov ◽  
Christina Pashkova ◽  
Anatoly Gridchin ◽  
Anna Trautvain

Based on literature data, the paper analyzed the impact of transport operational indicators related to the quality of road surface coverage on road safety. It presented the results of experimental studies on the effect of the road adhesion cationic thermostable additive on the properties of bitumen and asphalt concrete. The authors identified that the introduction of this additive leads to an increase in the viscosity and softening temperature of bitumen, its adhesion to mineral materials, which has a positive effect on strength, water resistance, shear stability, crack resistance, fatigue durability of asphalt concrete. The conclusion was made about the regularity of improving road safety, related to the improvement of the quality of the pavement, arranged from asphalt concrete with the application of the tested additive.


Author(s):  
Andrei Mikhailovich Sal'va

The object of this research is the ice wedge casts and concomitant polygonal microrelief. The subject of this research is the delineation of ice wedge casts on the margin of southern exposure of the Lake Churapcha in Central Yakutia. It is a known fact that in permafrost areas, a pronounced polygonal microrelief is a sign of the presence of ice wedge casts. In geology, “delineation” is the outlining of contours and delimitation of boundaries of the deposits, minerals, and zones with different quality of mineral raw materials and mining-geological conditions, according to the data of geological study for rational development. Ice wedge casts and there is such deposit. The article summarizes the results of field engineering and geological surveys conducted in 1995 on the shore slope of southern exposure the lake that contains ice wedge casts. The author also examines the data from modern satellite images for detecting the activation of polygonal microrelief. The surveys of 1995 confirmed the widespread occurrence of ice wedge casts in the indicated district. According to geological section, the ice wedge casts were identified and delineated. The results of section of the bottom of lake-reservoir demonstrate that it is located in the “thawing bowl”. The presence of ice wedge casts is also indicated by a pronounced polygonal microrelief, which is confirmed by satellite images. As a result of climate warming, the upper limit of ice wedge casts may also change, approximately to 0.3 m, which depends on the air temperature, amount of precipitation and depth of seasonal thawing.


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