scholarly journals SOIL LAYER CUT OFF BY THE AGGREGATE FOR REMOVING THE TOPSOIL FROM THE ROAD SUBLAYER: DETERMINATION OF THE CHAIN SPEED AND SIZES

2020 ◽  
Vol 17 (1) ◽  
pp. 32-43 ◽  
Author(s):  
V. A. Nikolaev

Introduction. For the durable road at the minimum necessary cost of its construction the topsoil should be removed without affecting the ground. The problem of cheaper road construction without reducing the quality can be solved by creating an aggregate for the sublayer’s formation. The aggregate removes the topsoil from half of the road sublayer and one of the ditch. The buckets of the moving aggregate cut off the soil layer from below and from one side. Therefore, each bucket is mounted by the bottom blade, the right blade and the console blade, partially cutting the topsoil from below for the passage of the next bucket. The blade of the lower knife with the 10 degrees’ angle to the plank of the bucket; the blade of the right knife and the blade of the console knife – with the 45 degrees’ angle towards the direction of the bucket moving.Materials and methods. To determine the speed of chains and the size of the soil layer the author carried out the bucket kinematics’ analysis and considered mathematical transformations. For checking the received parameters, the paper demonstrated the turn of the bucket on the leading 90 degrees’ lower drive. The author revealed the scheme of forces acting on the ground, located in the bucket, when it turned on the leading lower drive. Based on the system’s transformations of two equations and the inequality, the research established the inadmissibility of the bucket’s phasing out when it turned on the leading lower drive.Results. As a result, by using the developed method of determining parameters, based on the accepted raw data, the author calculated the speed of the chains, to which the buckets were attached, and the width of the soil, cut off by the bucket. After substitution of the received parameters in the inequality the author established that the ground would not fall out of the bucket by turning under such parameters of the bucket and of the leading lower drive.Discussion and conclusions. As a result, the author obtains the geometric parameters from the structural layout of the aggregate for removing the topsoil from the road sublayer. Based on the analysis of the kinematics of the interaction of the bucket with the ground, the paper reveals the speed of the chains, to which the buckets are attached and the width of the soil layer cut off by the bucket. Analysis of the forces acting on the ground and locating in the bucket at the moment of the bucket turn on the leading lower drive shows the rationality of the accepted and calculated parameters. The author determines the energy costs of cutting the ground with the buckets of the aggregate for removing the topsoil from the road sublayer.Financial transparency: the author has no financial interest in the presented materials or methods. There is no conflict of interest.

1949 ◽  
Vol 22 (1) ◽  
pp. 259-262
Author(s):  
J. F. Morley

Abstract These experiments indicate that softeners can influence abrasion resistance, as measured by laboratory machines, in some manner other than by altering the stress-strain properties of the rubber. One possible explanation is that the softener acts as a lubricant to the abrasive surface. Since this surface, in laboratory abrasion-testing machines, is relatively small, and comes repeatedly into contact with the rubber under test, it seems possible that it may become coated with a thin layer of softener that reduces its abrasive power. It would be interesting in this connection to try an abrasive machine in which a long continuous strip of abrasive material was used, no part of it being used more than once, so as to eliminate or minimize this lubricating effect. The fact that the effect of the softener is more pronounced on the du Pont than on the Akron-Croydon machine lends support to the lubrication hypothesis, because on the former machine the rate of wear per unit area of abrasive is much greater. Thus in the present tests the volume of rubber abraded per hr. per sq. cm. of abrasive surface ranges from 0.03 to 0.11 cc. on the du Pont machine and from 0.0035 to 0.0045 cc. on the Akron-Croydon machine. On the other hand, if the softener acts as a lubricant, it would be expected to reduce considerably the friction between the abrasive and the rubber and hence the energy used in dragging the rubber over the abrasive surface. The energy figures given in the right-hand columns of Tables 1 and 3, however, show that there is relatively little variation between the different rubbers. As a test of the lubrication hypothesis, it would be of interest to vary the conditions of test so that approximately the same amount of rubber per unit area of abrasive is abraded in a given time on both machines; this should show whether the phenomena observed under the present test conditions are due solely to the difference in rate of wear or to an inherent difference in the type of wear on the two machines. This could most conveniently be done by considerably reducing the load on the du Pont machine. In the original work on this machine the load was standardized at 8 pounds, but no figures are quoted to show how abrasion loss varies with the load. As an addition to the present investigation, it is proposed to examine the effect of this variation with special reference to rubbers containing various amounts and types of softener. Published data on the influence of softeners on the road wear of tire rubbers do not indicate anything like such large effects as are shown by the du Pont machine. This throws some doubt on the value of this machine for testing tire tread rubbers, a conclusion which is confirmed by information obtained from other workers.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
V. L. Knoop ◽  
M. Keyvan-Ekbatani ◽  
M. de Baat ◽  
H. Taale ◽  
S. P. Hoogendoorn

Freeways form an important part of the road network. Yet, driving behavior on freeways, in particular lane changes and the relation with the choice of speed, is not well understood. To overcome this, an online survey has been carried out. Drivers were shown video clips, and after each clip they had to indicate what they would do after the moment the video stopped. A total of 1258 Dutch respondents completed the survey. The results show that most people have a strategy to choose a speed first and stick to that, which is the first strategy. A second, less often chosen, strategy is to choose a desired lane and adapt the speed based on the chosen lane. A third strategy, slightly less frequently chosen, is that drivers have a desired speed, but contrary to the first strategy, they increase this speed when they are in a different lane overtaking another driver. A small fraction have neither a desired speed nor a desired lane. Of the respondents 80% use the right lane if possible, and 80% avoid overtaking at the right. Also 80% give way to merging traffic. The survey was validated by 25 survey respondents also driving an instrumented vehicle. The strategies in this drive were similar to those in the survey. The findings of this work can be implemented in traffic simulation models, e.g., to determine road capacity and constraints in geometric design.


Author(s):  
Carmen-Magdalena Camenidis ◽  
◽  
Irina Băițel ◽  
Amalia Oatu ◽  
Octavian Amzulescu ◽  
...  

The objective of this case study is to observe the existence of an anticipation mechanism at the muscle groups level of the upper limbs. We tried to highlighted this anticipation process by measuring the potential of surface electric for some muscle groups representing the kinematic chain on the right side, involved in the motor action of catching a basketball and a 3kg medicine ball with two hands to the chest. We conducted a case study of a 13-year-old child, female gender. As a measurement method, we used surface electromyography signals of the EMG Trigno Delsys wireless system with 16 electrodes. We determined the moment when the muscles come into action by increasing the potential of surface electric and the moment when the action of catching the ball takes place, using the information provided by the accelerometers incorporated in the sensors of the Delsys equipment used. Therefore, we obtained information about how different muscle groups come into action which helped us to get an idea of how the child's movement is structured. Based on results of accelerations and EMG signals acquired we have formulated conclusions regarding the neuromuscular control of the tested subject. We also planned for the future to test a larger group of participants in the study research of anticipation mechanism in children who do not practice any performance sports.


2018 ◽  
Vol 196 ◽  
pp. 04026
Author(s):  
Sergey Sannikov ◽  
Sergey Kuyukov ◽  
Alexey Zamyatin ◽  
Alexandr Zhigailov

The paper presents a complex method for increasing water resistance and reducing crack formation by using a prefabricated foundation of soil-cement slabs with surface processing with a hydrophobizing material on basis of organosilicon compounds. Theoretical, laboratory and full-scale experimental studies were made. Theoretical studies are based on the substantiation of the geometric parameters of the slab in order to exclude the probability of its destruction under its own weight during building and installation works. The result of the first stage of laboratory studies is the determination of the optimum composition of soil-cement mixture in order to achieve a grade of strength M20. At the second stage, the effectiveness of the influence of hydrophobizing materials "Tiprom U" and "Penetron-Admix" on water absorption and compressive strength of soil-cement was determined. The final stage of the research was a full-scale experiment. In the factory environment, soil-cement slabs were manufactured in metal forms. Based on the results of the research, conclusions about the effectiveness of this complex method were made. The use of soil-cement slabs allows reducing crack formation, as well as to work all year round due to manufacturing and surface treatment of slabs in the factory conditions.


PMLA ◽  
2011 ◽  
Vol 126 (2) ◽  
pp. 483-499
Author(s):  
Georges Poulet

Cormac McCarthy's Pulitzer prize–winning novel the road (2006) addresses the cliché that at the moment of death the endangered individual experiences a “life review” during which his life “flashes before his eyes.” McCarthy's protagonist intuits that “the right dreams for a man in peril were dreams of peril and all else was the call of languor and death” (18). Thus, in the view of McCarthy's unnamed hero, during a crisis one must focus on survival, escape, sustenance, or the successful execution of a plan. However, once all possibilities of survival are exhausted, the dying person will experience either an intense acceleration of cognition due to panic or a slackening of interest due to the acceptance of death. In either of these two scenarios, Henri Bergson posits, all the memories of the individual's lifetime will rush into consciousness. The following essay by Georges Poulet analyzes the development of Bergson's thought on this issue, supplementing Bergson's notions with examples from literature, history, and philosophy.


Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 490 ◽  
Author(s):  
Danilo G. Quadros ◽  
Tammi L. Johnson ◽  
Travis R. Whitney ◽  
Jonathan D. Oliver ◽  
Adela S. Oliva Chávez

Ticks and tick-borne diseases are a significant economic hindrance for livestock production and a menace to public health. The expansion of tick populations into new areas, the occurrence of acaricide resistance to synthetic chemical treatments, the potentially toxic contamination of food supplies, and the difficulty of applying chemical control in wild-animal populations have created greater interest in developing new tick control alternatives. Plant compounds represent a promising avenue for the discovery of such alternatives. Several plant extracts and secondary metabolites have repellent and acaricidal effects. However, very little is known about their mode of action, and their commercialization is faced with multiple hurdles, from the determination of an adequate formulation to field validation and public availability. Further, the applicability of these compounds to control ticks in wild-animal populations is restrained by inadequate delivery systems that cannot guarantee accurate dosage delivery at the right time to the target animal populations. More work, financial support, and collaboration with regulatory authorities, research groups, and private companies are needed to overcome these obstacles. Here, we review the advancements on known plant-derived natural compounds with acaricidal potential and discuss the road ahead toward the implementation of organic control in managing ticks and tick-borne diseases.


2020 ◽  
Vol 17 (2) ◽  
pp. 172-181 ◽  
Author(s):  
V. A. Nikolaev

Introduction. In order to the road to be durable at the minimum necessary cost for its construction, the topsoil should be carefully removed without disturbing the soil located under the topsoil. The problem of cheapening the roads construction without reducing their quality can be solved by creating a continuous unit for the formation of the underlying layer. The main working elemens of the unit are shovels. The blade of the cantilever knife fixed on the shovel cuts the topsoil from the bottom. It is located at the angle of 45 ° to the direction of movement of the shovel and also has a sharpening angle. The front angle of the blade of the cantilever knife.The method of research. The cantilever knife is divided into the elements: the edge of the blade, the upper face of the blade, the surface of the cantilever knife, a lower plane. The consecutive impact of many cantilever knives on the ground within the operating unit width with the ground of one notional cantilever knife at a distance necessary for the excavation of one cubic meter of soil was replaced. The interacting forces of a notional cantilever knife with soil are called notional forces. The methodology of calculating energy costs when penetrating the edge of the blade of the cantilever knife into the soil is presented: to separate a layer from the body of the soil, to create a gap in the body of the soil, to overcome the friction of the soil against the edge of a blade of a cantilever knife. The total energy consumption during the interaction of a edge of a blade of a cantilever knife in the soil excavation with a volume of one cubic meter was obtained by adding the particular energy consumption.Results. Based on the developed calculation method, the distance at which a cantilever knife has to move to excavate one cubic meter of soil, and the time of this movement determined. The energy costs are calculated when penetrating the edge of the blade of the cantilever knife into the soil: to separate a layer from the body of soil, to create a gap in the body of soil, to overcome the friction of the soil against the edge of a blade of a cantilever knife. The total energy consumption and their structure during the interaction of the edge of a blade of a cantilever knife with the soil during the soil excavation with a volume of one cubic meter are determined.Conclusion. The total energy consumption during the interaction of an edge of a blade of a cantilever knife with the soil during the development of soil with a volume of one cubic meter is about 7 thousand J/cubic meter. In the energy costs structure during the interaction of an edge of a blade of a cantilever knife with the soil, energy costs prevail to overcome the friction of the soil against an edge of a blade. To determine the total energy consumption for cutting soil with cantilever knives shovels of the unit for removing the upper soil layer from the underlying layer of a road, it is necessary to analyze the interaction of other elements of cantilever knives with the soil.Financial transparency: the authors have no financial interest in the presented materials or methods. There is no conflict of interest.


2020 ◽  
Vol 17 (4) ◽  
pp. 452-463
Author(s):  
V. A. Nikolayev ◽  
D. I. Troshin

Introduction. To solve the problem of accelerating the construction of roads, improving their quality, it is advisable to use a continuous action unit to form a underlying layer. The main working bodies of this unit are buckets, which cut off the soil layer from below and on the side. At the same time, the bottom knife cuts off the ground layer from below, the right knife on the side, and the console knife partially cuts the top layer of soil from below for the next bucket. In particular, the analysis of interaction with the soil of the right knife of the continuous action unit is of theoretical and practical interest. To do this, the right knife is divided into elements and analyzed the interaction of these elements with the ground. The consistent impact on the soil of many right knives, within the width of the grip of the unit, is replaced by the impact on the ground of one conventional right knife at a distance necessary for the development of one cubic meter of soil. The forces of interaction of the conventional right knife with the ground are called conditional forces.The method of research. The method for calculating the energy costs during punching the right knife into the ground is shown: on separating the formation of the ground from its body, on overcoming the ground friction on the edge of the blade, on overcoming the ground pressure on the edge of the blade, on accelerating the ground of the blade by means of the axle, on overcoming the ground friction on the shelf, to overcome the ground friction against the outside surface.The total energy costs of interacting with a soil of one cubic meter are derived from the addition of private energy costs. The method of calculating the horizontal longitudinal force needed to move the right knife is given.Results. On the basis of the methodology developed, energy costs are calculated when introducing the right knife into the ground: on separating the soil from its body, on overcoming the friction of the ground on the edge of the blade, on overcoming the pressure of the ground on the face of the blade, on the acceleration of the ground with a fascia blade, on overcoming the ground friction on the face. The total energy costs of the right knife interact with the soil of one cubic meter. The horizontal long-lived force needed to move the right knife has been determined.Conclusion. As a result of the calculations: the energy needed to cut the ground with the right knives, more than 71 J/cube. The horizontal longitudinal force needed to move the right knife is 730 N. To determine the total energy spent on cutting the ground by buckets of the unit to remove the top layer of soil from the underlying layer of the road, it is necessary to analyze the interaction with the soil of other elements of the bucket.


Author(s):  
Brian Baya Sembiring. ST ◽  
Parada Afkiki Eko Saputra, ST,MT

Road is a land transportation infrastructure that covers all parts of the road, including complementary buildings and equipment intended for traffic. Road Structure Improvement is one project that aims to improve the quality of roads. As the object of work to be studied is the widening of the sp. Ujung Aji - Limits of the City of Kabanjahe. Road construction with a flexible layered pavement with cover or without overlays is usually often damaged such as: cracks, hollows, bumps on the road surface. In other conditions it is often seen that the grooves of the former water flow to the subgrade are visible. The situation is more extreme and often occurs, namely the road surface peels to reach the foundation layer, so that the aggregate looks scattered. This study uses the direct observation method in the widening project of Jalan Simpang Ujung Aji - Bts. Kabanjahe City. This research was carried out at the time of laying and compaction of the bottom road foundation layer such as Base B and Base A. Activities carried out included data collection, data processing, analysis and observations in the Laboratory. The results of the filter analysis of rough gradations are good, which is in the middle between the given gradation boundaries, does not coincide and does not come out of the given gradation limit. Based on aggregate filter analysis data, it can be concluded that the results of the gradation of aggregate class A percent are retained and passed the filter in accordance with the general specifications of Bina Marga 2010 revision 3 and according to class A aggregate planning. the specimen is completely waterless, so the weighing results in the right balance.


2018 ◽  
Vol 45 ◽  
pp. 00081 ◽  
Author(s):  
Izabela Skrzypczak ◽  
Wojciech Radwański ◽  
Tomasz Pytlowany

There are two technologies for road construction, e.g. an asphalt one and a concrete one, that exist in the market of road infrastructure at the moment and they both have their advantages and disadvantages [prof Jan Deja of Krakow Mining Academy, Cathedral of Building Materials Technology].The advantage of concrete pavement consists of the fact that it doesn’t require bigger financial expenditures within 10 – 20 years of exploitation (provided that necessary pavement maintenance treatments are carried out). In the case of asphalt pavement it is necessary to mill the wear off layer of the road already after 6-7 years. It leads to the question: which of these technologies should be chosen, which is better? The work hereby carries on analyses concerning a comparison of the technologies for road constructions; the asphalt one and the concrete one. Based on the analyses carried out with the use of the Hellwig method it was found that the achieved values of synthetic meters for asphalt and concrete pavements are close to each other, which may indicate that both technologies are comparable within the sectors taken for analyses in relation to accepted technological-technical and usability features.


Sign in / Sign up

Export Citation Format

Share Document