Статті в журналах з теми "Rolling dynamic compaction"
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1
Scott, B., M. Jaksa, and P. Mitchell. "Ground response to rolling dynamic compaction." Géotechnique Letters 9, no. 2 (June 2019): 99–105. http://dx.doi.org/10.1680/jgele.18.00208.
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2
Gao, You Shan, Zhi Song, Ai Hong Wang, and Ze Kun Jin. "Dynamic Simulation for Rolling Impact Compaction Machine." Advanced Materials Research 430-432 (January 2012): 1610–13. http://dx.doi.org/10.4028/www.scientific.net/amr.430-432.1610.
Повний текст джерелаАнотація:
Through established the simulation model for the engine and the traction host powertrain of rolling impact compaction machine, Simulated the working load with time history with the simulation parameters of rolling impact compaction machine. The simulation accuracy was verified by compared between the test speed and the simulation speed. The speed, turbine torque, torque converter efficiency, torque converter, gear ratios, fuel consumption, engine power, torque are dynamic changes follow with the alternating load and slope load so as to adapt to the dynamic drag torque fluctuations. Traction host power must be equipped with a full host transmission of the internal combustion engine. Driveline should be hydraulic transmission fluid or hydraulic machinery.
3
Tayebali, Akhtarhusein A., John A. Deacon, and Carl L. Monismith. "Development and Evaluation of Dynamic Flexural Beam Fatigue Test System." Transportation Research Record: Journal of the Transportation Research Board 1545, no. 1 (January 1996): 89–97. http://dx.doi.org/10.1177/0361198196154500112.
Повний текст джерелаАнотація:
Although both mix variables and environmental variables are known to affect the fatigue response of asphalt-aggregate mixes, other factors—including specimen fabrication procedure and test equipment and procedures—are equally important. The development of a dynamic flexural beam fatigue test system is described, and the effects of specimen compaction method and equipment type on the precision of in situ fatigue lives of asphalt-aggregate mixes predicted by using laboratory strain-life relationships are discussed. Results indicate a coefficient of variation of 41 percent in fatigue life for the new fatigue equipment compared with one of 93 percent for an earlier electropneumatic version. The specimen compaction method was also found to influence significantly the precision of the predicted fatigue life. A 33 percent difference in coefficients of variation between the fatigue response of rolling wheel–compacted specimens and kneading-compacted specimens was observed. Consequently, twice as many specimens are required to achieve a given level of precision in in situ predicted fatigue life if kneading compaction is used instead of rolling wheel compaction. Similarly, if a pneumatic system and associated test procedure are used, approximately 12 times as many specimens are required to achieve similar precision in predicted fatigue life compared with the new servohydraulic fatigue test system.
4
Chen, Rong Jun, and Juan Guo. "The Test Research on Impact Compaction Reinforcement of the Soil Base." Advanced Materials Research 753-755 (August 2013): 673–77. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.673.
Повний текст джерелаАнотація:
This article verifies the feasibility to impact rolling technology instead of dynamic consolidation in soil areas soil region reinforcement processing by impact rolling soil base reinforcement experiments .In this essay, high soil areas embankment large area of reinforcement processing has opened up a new way.
5
Ranasinghe, Ranasinghe Arachchilage Tharanga Ma, Mark B. Jaksa, Fereydoon Pooya Nejad, and Yien Lik Kuo. "Predicting the effectiveness of rolling dynamic compaction using genetic programming." Proceedings of the Institution of Civil Engineers - Ground Improvement 170, no. 4 (November 2017): 193–207. http://dx.doi.org/10.1680/jgrim.17.00009.
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6
Scott, Brendan T., Mark B. Jaksa, and Peter W. Mitchell. "Influence of towing speed on effectiveness of rolling dynamic compaction." Journal of Rock Mechanics and Geotechnical Engineering 12, no. 1 (February 2020): 126–34. http://dx.doi.org/10.1016/j.jrmge.2019.10.003.
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7
Yu, Zhang, Liu JianKun, Fang JianHong, and Xu AnHua. "Application of dynamic compaction and rolling compaction in the subgrade improvement of Qarhan-Golmud Highway." Sciences in Cold and Arid Regions 5, no. 5 (2013): 603. http://dx.doi.org/10.3724/sp.j.1226.2013.00603.
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8
Yang, Changwei, Liang Zhang, Yixuan Han, Degou Cai, and Shaowei Wei. "Study on the Transmission and Evolution Characteristics of Vibration Wave from Vibratory Roller to Filling Materials Based on the Field Test." Applied Sciences 10, no. 6 (March 15, 2020): 2008. http://dx.doi.org/10.3390/app10062008.
Повний текст джерелаАнотація:
Compaction quality of railroad subgrade relates directly to the stability and safety of train operation, and the core problem of the Intelligent Compaction of railroads is the transmission and evolution characteristics of vibration wave. Aiming at the shortages in exploring the transmission and evolution characteristics of the vibration signal, the typical subgrade compaction project of Jingxiong Intercity Railway Gu’an Station was selected to carry out the field prototypes tests, and the dynamic response from the vibratory roller to filling materials was monitored in the whole compaction process, and some efficient field tests data will be obtained. Based on this, the transmission and evolution characteristics of the vibration wave from the vibratory roller to filling materials in the compaction process are studied from the time domain, frequency domain, jointed time–frequency domain and energy domain by using one new signal analysis technology—Hilbert–Huang Transform. Some conclusions are shown as follows: first, the vibration acceleration peak gradually decreases with the increase of buried depth, and when the buried depth reaches 1.8 m, the vibration acceleration peak is closed to zero. At the same time, when the vibration wave propagates from the wheel to the surface of filling, the attenuation rate of acceleration gradually increases with the increase of rolling compaction times, while the attenuation rate of other layers in different buried depths gradually decreases. Second, the vibration wave contains fundamental wave and multiple harmonics, and the dominant frequency of the fundamental wave is nearly 21 Hz. With the increase of buried depth, the amplitude of fundamental, primary, secondary, until fifth harmonics decreases exponentially and the concrete functional relationship among different amplitudes of harmonics can be summarized as y = Ae−BX. Third, the vibration energy focuses on the fundamental wave and primary wave, which can increase with the increase of rolling compaction times, and when the rolling compaction time reaches five, their energy reaches maximum. However, when the filling reaches a dense situation, the energy of the primary wave gradually decreases. Therefore, the maximum rolling compaction time is five in the practical engineering applications, which will be helpful for optimizing the compaction quality control models and providing some support for the development of the Intelligent Compaction theory of railway subgrade.
9
Ranasinghe, R. A. T. M., M. B. Jaksa, F. Pooya Nejad, and Y. L. Kuo. "Genetic programming for predictions of effectiveness of rolling dynamic compaction with dynamic cone penetrometer test results." Journal of Rock Mechanics and Geotechnical Engineering 11, no. 4 (August 2019): 815–23. http://dx.doi.org/10.1016/j.jrmge.2018.10.007.
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10
He, Zhuoling, and Junyun Zhang. "Compaction Quality Inspection Method of Soil-Rock Filled Embankment Based on Continuous Compaction Control Technology." Advances in Civil Engineering 2021 (January 8, 2021): 1–12. http://dx.doi.org/10.1155/2021/8894042.
Повний текст джерелаАнотація:
Affected by the site construction conditions, the measurement passes of the Taihang Expressway K8 + 105 ∼ K8 + 341 (K8 worksite) in the Taihang Expressway did not meet the requirements of data analysis, and the quantity of the control points was insufficient so that the linear correlation between the dynamic deformation modulus () and the vibratory compaction value (VCV) was not strong. Therefore, the target value of VCV cannot be used to diagnose the E v d compaction quality of soil-rock filler. This paper analyzes the roller measurement VCV value and in situ measurements E v d value separately. Results reveal the difference between the VCV mean measured in the last two passes and the standard deviation of the measured VCV mean in the last pass are used as the main basis for the actual compaction quality. In addition, the E v d mean in the last rolling can be used as an auxiliary judgment basis for the quality control of the compaction.
11
He, Zhuoling, and Junyun Zhang. "Compaction Quality Inspection Method of Soil-Rock Filled Embankment Based on Continuous Compaction Control Technology." Advances in Civil Engineering 2021 (January 8, 2021): 1–12. http://dx.doi.org/10.1155/2021/8894042.
Повний текст джерелаАнотація:
Affected by the site construction conditions, the measurement passes of the Taihang Expressway K8 + 105 ∼ K8 + 341 (K8 worksite) in the Taihang Expressway did not meet the requirements of data analysis, and the quantity of the control points was insufficient so that the linear correlation between the dynamic deformation modulus () and the vibratory compaction value (VCV) was not strong. Therefore, the target value of VCV cannot be used to diagnose the E v d compaction quality of soil-rock filler. This paper analyzes the roller measurement VCV value and in situ measurements E v d value separately. Results reveal the difference between the VCV mean measured in the last two passes and the standard deviation of the measured VCV mean in the last pass are used as the main basis for the actual compaction quality. In addition, the E v d mean in the last rolling can be used as an auxiliary judgment basis for the quality control of the compaction.
12
Hou, Ziyi, Xiao Dang, Yezhen Yuan, Bo Tian, and Sili Li. "Research on Intelligent Compaction Technology of Subgrade Based on Regression Analysis." Advances in Materials Science and Engineering 2021 (September 8, 2021): 1–9. http://dx.doi.org/10.1155/2021/4100896.
Повний текст джерелаАнотація:
A remote monitoring system with the intelligent compaction index CMV as the core is designed and developed to address the shortcomings of traditional subgrade compaction quality evaluation methods. Based on the actual project, the correlation between the CMV and conventional compaction indexes of compaction degree K and dynamic resilient modulus E is investigated by applying the one-dimensional linear regression equation for three types of subgrade fillers, clayey gravel, pulverized gravel, and soil-rock mixed fill, and the scheme of fitting CMV to the mean value of conventional indexes is adopted, which is compared with the scheme of fitting CMV to the single point of conventional indexes in the existing specification. The test results show that the correlation between the CMV and conventional indexes of clayey gravel and pulverized gravel is much stronger than that of soil-rock mixed subgrades, and the correlation coefficient can be significantly improved by fitting CMV to the mean of conventional indexes compared with single-point fitting, which can be considered as a new method for intelligent rolling correlation verification.
13
Ranasinghe, R. A. T. M., M. B. Jaksa, Y. L. Kuo, and F. Pooya Nejad. "Application of artificial neural networks for predicting the impact of rolling dynamic compaction using dynamic cone penetrometer test results." Journal of Rock Mechanics and Geotechnical Engineering 9, no. 2 (April 2017): 340–49. http://dx.doi.org/10.1016/j.jrmge.2016.11.011.
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Liu, Kaihua, Marco Benetti, Marco Sozzi, Franco Gasparini, and Luigi Sartori. "Soil Compaction under Different Traction Resistance Conditions—A Case Study in North Italy." Agriculture 12, no. 11 (November 19, 2022): 1954. http://dx.doi.org/10.3390/agriculture12111954.
Повний текст джерелаАнотація:
Tractive efficiency is essential in tillage operations to optimise traction performance. In this field experiment, the tractor performance was measured under different traction resistance conditions. This study quantified the soil stress, soil bulk density, soil moisture, soil cone index, soil surface disturbance, rolling resistance and slip rate under different numbers of passes and traction conditions. The actual power used under different soil and traction conditions was collected. Fuel consumption and savings were calculated between uncompacted soil, compacted soil and the permanent traffic lane. The results show that soil stress increases in each location as traction and the number of passes increase. Soil’s physical properties increase, such as the soil bulk density, soil cone index and soil surface disturbance. Additionally, the slip rate increases with traction in each soil condition as uncompacted soil, compacted soil and the permanent traffic lane. The results show that the permanent traffic lane has a lower slip rate under different traction conditions than the uncompacted and compacted soil. Furthermore, the permanent traffic lane has less energy consumption with the same traction resistance. The permanent traffic lane saved 25.50%, 29.23% and 42.34% fuel compared to the uncompacted field in 7.85, 14.71 and 24.52 kN traction conditions, respectively. Our results confirm that dynamic factors such as traction and rolling resistance should be considered in soil compaction research rather than static weight only. In practice, the controlled traffic farming (CTF) system or driving the tractor more frequently on the permanent traffic lane should be considered to improve working efficiency and reduce energy consumption.
15
KORCHAGIN, Pavel Aleksandrovich. "Mathematical model of the road vibrating roller." NEWS of the Ural State Mining University 1, no. 1 (March 23, 2020): 133–39. http://dx.doi.org/10.21440/2307-2091-2020-1-133-139.
Повний текст джерелаАнотація:
Introduction. The process of compaction of the soil foundation by a road vibrating roller is considered as the object of the study. The main purpose of vibrating rollers used in road construction is to reduce the energy consumption of the compaction process and increase the productivity of the operations performed Since the 80s of the last century, the engineering industry has noted a tendency to abstention the production of static rollers. By reducing the amplitude of oscillations or completely disconnecting the vibrator, you can get the same static modes, and accordingly the results of rolling. In addition, the reduction of dynamic impacts positively affects the physical condition of an operator of the road-building machine, stabilizes the well-being and increases productivity. Materials and methods. The mathematical model of the dynamic system “Supporting surface–roller–operator” is presented. The main components of the dynamic system are described in the form of ordered and interacting subsystems. The forces acting on the dynamic system are determined; they are sources of dynamic effects. The calculation schemes of the subsystems “Operator” and “Roller”, which are of the greatest interest from the point of view of vibration protection, are reflected. Results. The result of the work can be considered the compilation of generalized scheme of the dynamic system; calculation scheme of the dynamic system; mathematical model “Supporting surface–operator–roller”; implementation of the mathematical model in MathLab, its additional Simulink extension package. Discussion and conclusion. The presented mathematical model allows carrying out research of the processes occurring in the dynamic system “Supporting surface–roller–operator”. The most rational mathematical model can be used in the development of methods and tools aimed at improving the vibration protection system for operators of road rollers. The mathematical model of a road roller is planned to be used as a basis for creating a robotic complex with an automated control system designed to perform operations to compact coatings and foundations in road construction.
16
Vesenjak, Matej, Masatoshi Nishi, Toshiya Nishi, Yasuo Marumo, Lovre Krstulović-Opara, Zoran Ren, and Kazuyuki Hokamoto. "Fabrication and Mechanical Properties of Rolled Aluminium Unidirectional Cellular Structure." Metals 10, no. 6 (June 9, 2020): 770. http://dx.doi.org/10.3390/met10060770.
Повний текст джерелаАнотація:
The paper focuses on the fabrication of novel aluminium cellular structures and their metallographic and mechanical characterisation. The aluminium UniPore specimens have been manufactured by rolling a thin aluminium foil with acrylic spacers for the first time. The novel approach allows for the cheaper and faster fabrication of the UniPore specimens and improved welding conditions since a lack of a continuous wavy interface was observed in the previous fabrication process. The rolled assembly was subjected to explosive compaction, which resulted in a unidirectional aluminium cellular structure with longitudinal pores as the result of the explosive welding mechanism. The metallographic analysis confirmed a strong bonding between the foil surfaces. The results of the quasi-static and dynamic compressive tests showed stress–strain behaviour, which is typical for cellular metals. No strain-rate sensitivity could be observed in dynamic testing at moderate loading velocities. The fabrication process and the influencing parameters have been further studied by using the computational simulations, revealing that the foil thickness has a dominant influence on the final specimen geometry.
17
Lytvynenko, Anatoаlii, and Oksana Kushnirova. "Determination of normative values of mechanical indicators of bonded soils based on dynamic probing data." Automobile Roads and Road Construction, no. 109 (2021): 32–40. http://dx.doi.org/10.33744/0365-8171-2021-109-032-040.
Повний текст джерелаАнотація:
In the work on the basis of analytical analysis of tabular data, both current and previous domestic regulatory documents on civil engineering, for mechanical indicators of bonded soils of natural occurrence graphic and analytical (formula) interpretation of these values in relation to the values of the dynamic probing index of Pd, MPa, and yield index IL, units, for the degree of water saturation of these soils Sr ≥ 0.8 units is given. Correlation with the value of dynamic probing of Pd, MPa allows not only to differentiate engineering and geological (geotechnical) cross-sections, more or less detailed, but also to estimate the load-bearing capacity of selected layers of bonded soils accurately enough. The theoretical analysis has shown that the values of mechanical indicators of natural bonded soils adopted in the current regulatory documents, even taking into account their structural strength, can not be directly used as a prototype to assess similar indicators of compacted technogenic soils of artificial structures in the form of embankments of hydraulic dams, road embankments or airfields. This is due to the fact that in the vast majority of cases in civil construction assessed the properties of soils in the plastic state, which tend to have a lower density of dry soil than at the border of rolling, and a mandatory condition for the use of such soils in artificial soil structures is their compliance with the requirements of the so-called standard compaction, that is, the density of dry soil there should be more than the density of dry soil at the border of rolling. These soils are in a solid state (their concentration is ≥ 85 %) and indeed (through direct contact between the soil parts) work as an elastic body and can be characterized by a modulus of elasticity with a corresponding small elastic deflection lmax and a sufficiently large design critical resistance value of R0 ≥ 0.6 MPa, which must be determined at each laboratory test of the samples before they fracture or disproportional movement of the stamp.
18
Fathi, Aria, Cesar Tirado, Sergio Rocha, Mehran Mazari, and Soheil Nazarian. "Incorporating Calibrated Numerical Models in Estimating Moduli of Compacted Geomaterials from Integrated Intelligent Compaction Measurements and Laboratory Testing." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 4 (March 18, 2020): 75–88. http://dx.doi.org/10.1177/0361198120912743.
Повний текст джерелаАнотація:
Proof rolling after completion of compaction of earthwork using intelligent compaction (IC) technology can be used to assess the uniformity of the compacted geomaterials and to identify less stiff compacted areas. To better understand the process of quality management using IC technology, a three-dimensional finite element model was developed to document the theoretical limitations and the sensitivity of IC technology. The model can also be used for setting the target values, and can be part of a methodology to extract the moduli of geomaterials in more rigorous and defensible specifications. Different levels of complexity in relation to linear versus nonlinear behavior of geomaterial and different levels of roller operating conditions (static versus dynamic, moving versus stationary) can be assigned to the model. Such model can only be used with confidence if it is calibrated and validated with experimental field data. Five test sites including single-layer (subgrade only) and two-layer (subgrade and base) geosystems were instrumented using in-ground sensors for calibrating the model. Different vibratory IC rollers from different manufacturers were used to implement IC tests at vibratory stationary as well as moving conditions at the test sites. In all scenarios, a locally calibrated transfer function was necessary to accommodate the differences in the numerical models and vibration data obtained from the IC measurements on test sections with distinct geomaterial conditions. The study also concluded that the predictive power of the numerical models improves if the field measurements and laboratory data are integrated, and more importantly the variability of the materials is incoprorated.
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Lytvynenko, Anatolii. "DETERMINATION OF NORMATIVE VALUES OF MECHANICAL INDICATORS OF BONDED SOILS BASED ON DYNAMIC PROBING DATA." Avtoshliakhovyk Ukrayiny 1, no. 265 (March 25, 2021): 52–56. http://dx.doi.org/10.33868/0365-8392-2021-1-265-52-56.
Повний текст джерелаАнотація:
In the work on the basis of analytical analysis of tabular data, both current and previous domestic regulatory documents on civil engineering, for mechanical indicators of bonded soils of natural occurrence graphic and analytical (formula) interpretation of these values in relation to the values of the dynamic probing index of Pd, MPa, and yield index IL, units, for the degree of water saturation of these soils Sr ≥ 0.8 units is given. Correlation with the value of dynamic probing of Pd, MPa allows not only to differentiate engineering and geological (geotechnical) cross-sections, more or less detailed, but also to estimate the load-bearing capacity of selected layers of bonded soils accurately enough. The theoretical analysis has shown that the values of mechanical indicators of natural bonded soils adopted in the current regulatory documents, even taking into account their structural strength, can not be directly used as a prototype to assess similar indicators of compacted technogenic soils of artificial structures in the form of embankments of hydraulic dams, road embankments or airfields. This is due to the fact that in the vast majority of cases in civil construction assessed the properties of soils in the plastic state, which tend to have a lower density of dry soil than at the border of rolling, and a mandatory condition for the use of such soils in artificial soil structures is their compliance with the requirements of the so-called standard compaction, that is, the density of dry soil there should be more than the density of dry soil at the border of rolling. These soils are in a solid state (their concentration is ≥ 85 %) and indeed (through direct contact between the soil parts) work as an elastic body and can be characterized by a modulus of elasticity with a corresponding small elastic deflection lmax and a sufficiently large design critical resistance value of R0 ≥ 0.6 MPa, which must be determined at each laboratory test of the samples before they fracture or disproportional movement of the stamp. Keywords: regulatory documents, tabular data, bonded soils, natural, mechanical properties, graphical interpretation, analytical dependencies.
20
Zhang, Qinglong, Zaizhan An, Zehua Huangfu, and Qingbin Li. "A Review on Roller Compaction Quality Control and Assurance Methods for Earthwork in Five Application Scenarios." Materials 15, no. 7 (April 1, 2022): 2610. http://dx.doi.org/10.3390/ma15072610.
Повний текст джерелаАнотація:
Successful quality control and quality assurance (QC/QA) of earthwork compaction is critical to the long-term performance of roads, railways, airports, dams, and embankments. The purpose of this paper is to provide insights into the current practice, existing problems, challenges, and future development trends of QC/QA methods from the perspective of bibliometrics and the development stage. A bibliometric analysis is presented. Through quantitative analysis of literature and qualitative analysis of the development stage, insights into the current research practices and future directions of QC/QA methods have been derived from the perspectives of literature, cluster analysis, classification, different types of QC/QA methods, conclusions, and recommendations. It is found that the current QC/QA methods can be roughly divided into conventional compaction, digital rolling compaction, automatic rolling compaction, and intelligent control compaction. Currently, QC/QA methods are mainly confronted with the issues of accurate detection of compaction quality, autonomous optimization and intelligent decision-making of compaction process, multi-machine coordination, QC/QA-related specification formulation, and process standardization. To address these issues, several critical potential research directions are further identified: comprehensive CCI measurement system; simple and realistic mathematical representation of the complex compaction dynamics; parallel computing and distributed management of multi-source heterogeneous data; standardized application workflow and the cost–benefit assessment in the context of the full life cycle; intelligent control theories, methods, and technologies of earthwork compaction based on multidisciplinary integration. The paper enables researchers to obtain a comprehensive understanding of QC/QA methods for earthwork compaction as well as the suggested solutions for future work.
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Acquah, Kobby, and Ying Chen. "Discrete Element Modelling of Soil Compaction of a Press-Wheel." AgriEngineering 3, no. 2 (May 19, 2021): 278–93. http://dx.doi.org/10.3390/agriengineering3020019.
Повний текст джерелаАнотація:
Press-wheels are wheels designed to compact the soil above seeds in the “seed cover” region. Soil compaction, produced by the press-wheels of seeders, affects seedling emergence and early plant growth. The Discrete Element Method (DEM) was used to model the amount of soil compaction from a press-wheel with varying down forces. The model was used to predict sinkage and rolling resistance of the press-wheel. The model results were validated with data from soil bin tests of the press-wheel in a sandy loam soil under varying soil moisture content levels (low, medium, and high). The sinkage results from the soil bin tests were 27.7, 26.7, and 25.2 mm for the low, medium, and high soil moisture content levels, respectively. The corresponding rolling resistances obtained from the tests were 104.4, 89.9, and 113.6 N. The press-wheel model adequately predicted the sinkage and rolling resistance for each soil moisture content level with overall Relative Mean Errors (RME) ranging from 13 to 23%. Additional simulation results show that average peak soil stresses across the three soil moisture contents at a depth of 0.12 m were 22,466.7, 8700.0, and 6900.0 Pa for vertical, horizontal, and lateral directions, respectively. The results enhance the understanding of the dynamics of the soil–press-wheel interaction and provided useful information for seeder press-wheel design.
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Wang, Chao, Ran Song, Gaohui Wang, Sherong Zhang, Xuexing Cao, and Peiyong Wei. "Modifications of the HJC (Holmquist–Johnson–Cook) Model for an Improved Numerical Simulation of Roller Compacted Concrete (RCC) Structures Subjected to Impact Loadings." Materials 13, no. 6 (March 17, 2020): 1361. http://dx.doi.org/10.3390/ma13061361.
Повний текст джерелаАнотація:
Structures made of Roller Compacted Concrete (RCC) may be subjected to dynamic loads during their service life. Understanding the dynamic material properties of RCC and the performance of RCC structures is essential for better analysis and design of RCC structures. As full-scale tests are often unaffordable, numerical simulation methods are continuously employed. However, in numerical simulations, determining a reasonable constitutive relationship for RCC materials is still limited due to the complexity of the composite and the special rolling and compacting construction technology. In this paper, the triaxial compressive test and split Hopkinson pressure bar (SHPB) experimental results for RCC are introduced as an experimental foundation. Parameter calibrations and modifications in terms of the strength yield surface, the strain rate effect and the failure criterion for the RCC materials are presented. Numerical verification is illustrated for simulating the SHPB experiment and predicting the dynamic compressive characteristics of RCC specimens with a modified HJC model. The results reveal that the simulation results for the modified model have better agreement with the test data than those with the model before modification and have better simulation results. Sensitivity studies of the key parameters on the yield surface of the modified HJC model are conducted to improve the simulation effect for numerically predicting the performance of RCC structures exposed to explosive and impact loads.
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Ye, Zhoujing, Yanxia Cai, Chang Liu, Kaiji Lu, Dylan G. Ildefonzo, and Linbing Wang. "Optimization of Embedded Sensor Packaging Used in Rollpave Pavement Based on Test and Simulation." Materials 15, no. 6 (March 19, 2022): 2283. http://dx.doi.org/10.3390/ma15062283.
Повний текст джерелаАнотація:
Rollpave pavement, as a rollable prefabricated asphalt pavement technology, can effectively reduce the overall road closure time required for pavement construction and maintenance. Sensors can be integrated into Rollpave pavement, thereby avoiding sensor damage that may otherwise result from high temperatures and compactive forces during the rolling process, as well as pavement structural damage resulting from cutting and drilling. However, the embedment of sensors into Rollpave pavement still presents certain challenges, namely poor interfacial synergy between the embedded sensor and the asphalt mixture. To solve this problem, three-point bending tests and dynamic response FEM simulations were used to optimize the embedded sensor’s packaging. The influence of sensor embedment on Rollpave pavement under different working conditions was analyzed. Results of these analyses show that low temperature and the epoxy resin negatively affect the bending performance of specimens, and that packaging with cylindrical shape, flat design, and consisting of a material with modulus similar to that of the asphalt mixture should be preferred. This study is conducive to improve the intellectual level and service life of road infrastructure.
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Kornecki, Ted S., and Manuel R. Reyes. "Equipment Development for Small and Urban Conservation Farming Systems." Agriculture 10, no. 12 (December 2, 2020): 595. http://dx.doi.org/10.3390/agriculture10120595.
Повний текст джерелаАнотація:
The number of local small farms in the USA is on the rise due to a consumer demand for locally grown produce such as tomatoes. These farms often use small walk-behind tractors, but most field activities are still performed by hand requiring heavy physical labor. Recent efforts from USDA have been encouraging producers to adopt no-till techniques using cover crops for benefits such as reduced runoff and soil erosion, increased infiltration and water holding capacity, increased soil organic carbon, decreased soil compaction and improved weed control. However, lack of specialized no-till equipment inhibits widespread adoption of cover crops. To help small farms reduce hand labor and adoption of conservation systems with cover crops, no-till equipment such as a no-till drill, powered roller/crimper, and no-till transplanter have been developed for walk-behind tractors at the National Soil Dynamics Laboratory in Auburn (AL, USA). A replicated three-year field test (2017–2019) was conducted to evaluate effectiveness of the experimental powered coulter drill to plant cereal rye cover crop (Secale cereale, L.), patented powered roller/crimper to terminate rye, and transplanting cash crop tomato (Solanum lycopersicum L.) seedlings with a patented no-till transplanter. These three pieces of equipment were compatible with BCS 853 walk-behind tractor. The experiment was conducted on two different soils: Hiwassee sandy loam soil and Davidson clay to determine the performance of developed machines under different soil types. Results have shown that the powered coulter drill generated effective rye seed emergence (83%) for optimum biomass production. The experimental powered roller/crimper generated 95% rye termination rate three weeks after rolling, and the no-till transplanter performed as anticipated providing less than 10% variation of plant spacing uniformity. Tomato yield varied among years ranging from 15.9 Mg ha−1 to 28.3 Mg ha−1 and was related to different soil and weather conditions at each growing season. Numerically higher tomato yield on Davidson clay might be associated with less insect/pathogen pressure, higher plant available water, and reduced weed pressure due to greater cereal rye biomass production. Results from this experiment indicate that developed experimental equipment can be a practical solution for small no-till farming operations with cover crops.
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Прасолов, Є. Я., С. А. Бєловол, Б. С. Черненко та А. В. Ужищенко. "Дослідження та обґрунтування раціональних парметрів плівкоукладача". Вісник Полтавської державної аграрної академії, № 3 (28 вересня 2018): 161–67. http://dx.doi.org/10.31210/visnyk2018.03.25.
Повний текст джерелаАнотація:
Наведено результати дослідження згідно методики нормативних документів. Визначено технологічні параметри плівкоукладача. Для зменшення трудомісткості і тривалості досліджень було використано матричне планування. Встановлено залежності параметрів оптимізації від впливових факторів: діаметра та кута нахилу ґрунтового покриття диска з кваліфікованою швидкістю; діаметру та глибини занурення ґрунтово-покривного диска та швидкості руху по висоті. Визначено вплив покриття поверхні ґрунту на динаміку випаровування вологи в залежності від часу спостережень. Встановлено вплив ширини плівки на термічний режим ґрунту. Результати досліджень опробовані в ПП Агрофірма «Анастасія» та ТОВ АФ «ім. Довженка» ВП АФ «Орданівка». Використання плівкоукладача має сезонний характер і окупиться за один рік.
The article presents the results of the study in accordance with the methodology of normative documents. The technological parameters of the plumbing machinery for growing vegetable crops are determined. At the beginning of the strip, the plumbing machinery is outputted to its original position and clinging to the traction of the tractor. The front of the plumbing roller is equipped with a tooth compactor, which is connected to the rolling pin, and the width of the frame is set: a roll with a plumbing roll and conveyor rollers and a universal knife that rotates around the axis with a clip position for cutting the plumbing with the flow control sensor of the plumbing. It includes a device for determining the direction and velocity of the compiler; sensor for determining the depth and width of the strip-dip under pinion wheels; a plant recognition sensor and a computer for processing data and making corrections to the work of the compiler, creates the optimum pressure on the paddle wheels adjusting the loader. The edges of the plumbing from the roll are fascinated by universal clamps and they are sent to the rolling wheels. The direction of motion and the speed of the compiler are controlled by the device and the data is transmitted to the computer to adjust the corrections. During the compiler's motion, the front roller makes the leveling strips at the width in front of the rolling wheels. Wheels moving during loading of the compiler under the certain optimum values of the loader press the edges of the plumbing from the roll to the surface of the soil, and the rear trap clogs the film. Releases the clips of the film and return to the original position, and the plumbing at the expense of the natural tension passes through the guide rollers and unfolds along the surface of the soil. At the end of the strip, the plumbing is automatically trimmed, the plumbing machinery is raised by the lift, the tractor turns and goes to the starting position of the new strip and the process continues. Matrix planning was used to reduce the complexity and duration of the research. The dependencies of optimization parameters on influential factors are established: the diameter and angle of the soil surface of the disk with the qualified speed; diameter and depth of submersion of the soil-covering wheel and speed of movement in height. The influence of the surface of the soil on the dynamics of moisture evaporation, depending on the time of observation, is determined. The influence of the width of the plumbing on the thermal regime of the soil is established. The results of the research were tested in the PP agricultural firm «Anastasia» and LLC AF «named after Dovzhenko» VF AF «Ordanivka». The use of the plumbing is seasonal and will pay off in one year.
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Scott, Brendan, Mark Jaksa, and Peter Mitchell. "Depth of influence of rolling dynamic compaction." Proceedings of the Institution of Civil Engineers - Ground Improvement, April 17, 2019, 1–10. http://dx.doi.org/10.1680/jgrim.18.00117.
Повний текст джерела
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Li, Yuxiao, David Airey, and Mark Jaksa. "Evaluating the Effective Depth of Rolling Dynamic Compaction with a Three-sided Compactor." International Journal of Physical Modelling in Geotechnics, January 4, 2021, 1–34. http://dx.doi.org/10.1680/jphmg.20.00079.
Повний текст джерела
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Shan, Hong-Yu, Han-Cheng Dan, Shi-Ping Wang, Xiang Liu, and Hao Wang. "Theoretical and Experimental Investigation on Dynamic Response of Asphalt Pavement Under Vibration Compaction." Frontiers in Materials 8 (February 11, 2022). http://dx.doi.org/10.3389/fmats.2021.816949.
Повний текст джерелаАнотація:
This study aims to investigate the dynamic response regulation by combining the theoretical analysis and field test under the vibration rolling condition. Based on the viscoelastic theory of a multilayer system, the dynamic stiffness method (DSM) incorporating multidimensional Fourier transform is proposed to solve the 3-dimensional (3D) dynamic response of pavement under vibration compaction. The stiffness matrix of each pavement layer and the global stiffness matrix of the whole pavement structure are obtained. By combining vibration load with boundary conditions, the 3D exact solution is obtained and validated by the finite element method. In addition, the field test is also conducted using a series of sensors and equipment (e.g., SmartRock sensor, acceleration sensor, temperature sensors, and non-nuclear density meter) to calibrate the theoretical model to determine the wave number and dynamic modulus during the vibration rolling process. Then, considering the factors during compaction, the rules of displacement variation and pavement acceleration are investigated in terms of modulus, thickness, and density. The results show that the 3D displacement and acceleration components both vibrate with high frequencies during compaction, and peak acceleration in the vertical direction prevails. For the vertical displacement, its distribution beneath the drum of the roller is almost even except that it drops to zero abruptly around the drum edge. The relationship between thickness and acceleration follows a linear function, and the acceleration on the pavement surface rises when the thickness increases. Although the density and modulus increase with rolling times, the effect of modulus on acceleration is more obvious and prominent than that of density. In summary, the DSM presented in this article provides a robust method to calculate the dynamic response of pavement under vibratory compaction and to back-calculate the modulus of compacted pavement layers. Moreover, the regulation also sheds insight on the understanding of vibration compaction mechanism that there is a potentially strong correlation between compaction state, modulus, and vibration acceleration.
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Chen, Yue, Mark B. Jaksa, Yien Lik Kuo, and David Airey. "Experimental Analysis of Rolling Dynamic Compaction Using Transparent Soils and Particle Image Velocimetry." Canadian Geotechnical Journal, April 27, 2021. http://dx.doi.org/10.1139/cgj-2020-0573.
Повний текст джерелаАнотація:
Rolling Dynamic Compaction (RDC) is a soil compaction technique, which is capable of improving thick layers of soil at a relatively fast operating speed. The paper presents the results of laboratory experiments conducted on 1:13 scale models of the 4-sided, 8- and 12-tonne, Broons BH-1300 and BH-1300 HD impact rollers to study the performance of the scale model at four different operating speeds. A series of laboratory tests are undertaken using transparent soils and the particle image velocimetry (PIV) technique to investigate the effectiveness of the models. The transparent soil employed in this study consists of fused quartz and a pore fluid which matched the refractive index of the fused quartz. A one-particle thick layer of coloured fused quartz is embedded in the centre plane of the transparent soil to visualise soil internal displacements and a digital camera is used to capture the speckled pattern during the scale model testing process. The results show that the heavier module induces greater soil displacements at each operating speed. The optimal operating speed is approximately 299 mm/s for both module weights. The most significant soil displacements occur within the first 20 passes and, no obvious ground improvement is observed after 35 passes. The results of this study demonstrate the unique capability of transparent soil to study soil displacements induced by the ground improvement scale models.
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Chen, Yue, Mark B. Jaksa, Yien-Lik Kuo, and David W. Airey. "Investigating the effectiveness of Rolling Dynamic Compaction (RDC) using Discrete Element Method (DEM)." Granular Matter 23, no. 4 (September 22, 2021). http://dx.doi.org/10.1007/s10035-021-01164-9.
Повний текст джерела
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Buhari, Rosnawati, Chong Ai Ling, Mohd Ezree Abdullah, Siti Khatijah Abu Bakar, Nurul Hidayah Mohd Kamarudin, Mustafa Kamal Shamsudin, Mohd Khairul Ahmad, and Saifullizam Puteh. "THE PHYSICAL AND RHEOLOGICAL CHARACTERISTICS OF MODIFIED ASPHALT BINDER WITH TITANIUM DIOXIDE R15." Jurnal Teknologi 78, no. 7-3 (July 27, 2016). http://dx.doi.org/10.11113/jt.v78.9475.
Повний текст джерелаАнотація:
The objectives of this study include determine the physical and rheological properties of the modified asphalt and also to examine the effectiveness of TiO2 in lowering the viscosity of the asphalt compared to control asphalt. Nano-titanium dioxide R15 of 2%, 4%, 6%, 8% and 10% by weight of asphalt has been incorporated into unaged 80/100 asphalt mix in order to improvise its performance. The asphalt modified and control were examine using penetration test, softening point test, storage stability test, dynamic shear rheometer test (DSR), rotational viscosity (RV) and rolling thin film oven test (RTFO). As a conclusion, the decrease in compaction and mixing temperature of modified asphalt compared to original asphalt shows an improvement in the viscosity of the asphalt. Through DSR, the nano-TiO2 modified asphalt does not degrade the performance grade when compared to control asphalt, where the values of complex modulus, G* does not differ much from each other for each of the concentration. This indicates that the modified asphalt is as competent as the original binder in resisting rutting at high temperature.
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Yaacob, Haryati, Moazzam Ali Mughal, Ramadhansyah Putra Jaya, Mohd Rosli Hainin, Dewi Sri Jayanti, and Che Norazman Che Wan. "RHEOLOGICAL PROPERTIES OF STYRENE BUTADIENE RUBBER MODIFIED BITUMEN BINDER." Jurnal Teknologi 78, no. 7-2 (July 26, 2016). http://dx.doi.org/10.11113/jt.v78.9503.
Повний текст джерелаАнотація:
The study investigates the rheological properties of bitumen of 60-70 penetration grade modified with Styrene Butadiene Rubber (SBR). SBR is an elastomer which is an important sort of synthetic rubber. It is a copolymer whose molecular structure primarily consists of organic compound styrene and butadiene chain. Bitumen is visco-elastic in nature. The rate of load application and temperature has a great influence on its performance. Various fundamental properties of bitumen were evaluated, namely complex shear modulus (G*), short-term ageing, long-term ageing, viscosity, penetration and softening point by using Dynamic Shear Rheometer (DSR), Rolling Thin Film Oven Test (RTFOT), Pressure Aging Vessel (PAV), Rotational Viscometer (RV), Penetrometer and Ring and Ball Test, respectively. The binders were mixed with varying percentage of SBR i.e. 0, 1, 2, 3, 4, and 5% by the weight of bitumen binder. The use of SBR has played an active role in improving the viscoelastic properties of bitumen. The use of SBR modifier changes the rheological behavior of bitumen by increasing its complex shear modulus (G*) and the resistance of mixture against permanent deformation (rutting). It was also found that increasing the content of SBR led to the increase in viscosity of modified bitumen, which helps in elevating the mixing and compaction temperature of asphalt mixtures.
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Shustik, L., V. Pogoriliy, N. Nilova, T. Gaiday, S. Stepchenko, and S. Sidorenko. "ROLLERS OF DIFFERENT CONSTRUCTIONS. ENGINEERING ANALYSIS." Technical and technological aspects of development and testing of new machinery and technologies for agriculture of Ukraine, no. 27(41) (December 25, 2020). http://dx.doi.org/10.31473/2305-5987-2020-2-27(41)-9.
Повний текст джерелаАнотація:
Comparative field tests of similar in design ring-spur and gear-spur rollers for soil rolling provide their developers and users with information on the understanding of the design and technological features. The Goal of research – engineering analysis of structures of ring-spur and gear-spur rollers according to the criteria of weight, shape of working surfaces, soil pressure, completeness of compaction, penetrating ability in the range of depth of pre-sowing and surface tillage. Methods and Materials. Engineering analysis involved the study of three types of rollers. The research hypothesis assumed that the combination of weight characteristics of rollers and their geometric shapes of working surfaces in contact with the soil, in statics will provide the inherent properties of each cat (the first stage of research), which will potentially focus on choosing the most acceptable criteria for comparing functional features of rollers. necessary for field research in dynamics (the second stage of research). According to the criteria of static research were selected: penetrating ability (1); soil pressure (2); completeness of compaction of the area (3); direction of clamping forces (4); features of working surfaces (5); the nature of the mounting of solid disks on the shaft (6). Methodologically, the first three criteria required special adaptations (capacities) with the ability to change the height of the soil layer in the range of depths of pre-sowing and sowing tillage. Other criteria were supposed to be carried out by organoleptic evaluation. The study was supposed to be carried out on soil characteristic of the Forest-Steppe zone and homogeneous in fractional composition, to exclude the influence of soil inclusions of different sizes. Evaluation of soil characteristics was performed by thermostatic-weight method, according to the generally accepted method of "cutting ring" [Kaczynski, 1947] with a cylinder volume of 100 cm3. To determine the area of one elementary working surface of the annular disk, the application of a marking grid on its imprint on the surface left in the soil layers hmin, hmid, hmax was used. When determining the pressure on the soil, depending on the height of the treated layer, the marking grid was superimposed on the imprint of several areas of elementary working surfaces, which were fixed on the chord of immersion in the soil of the annular segment. Statistical analysis of experimental data was performed by the method of analysis of variance according to [Dospekhov, 1985] and interpreted by standard computer programs Excel and graphs. Results. According to the physical characteristics (weight and geometric parameters) of the roller combines the proximity of the diameter of the disks, the width of the working surfaces on the edge of the generator, the presence of spurs. The difference lies in the dimensional characteristics that fall on the width of the grip, the presence of aggressive protruding shapes (teeth) in the gear-spur structure. Each roller has an individual layout of elementary work surfaces. This allowed the conditional marking of rollers as "classic", "modernized" and "specialized". The working surfaces of the classic and specialized rollers provide vertical and lateral action of the clamping forces, while the modernized forms them in the vertical direction. These forces for each of the rollers are derived from the orientation of the working surfaces of different configurations (flat narrow, flat wide; a combination of point-focused with trapezoidal). In addition, work surfaces can have a one- or two-level sequence of contact with the soil at a variable depth. It is established that the nature of the attachment of adjacent disks on the shaft can be rigid or movable. Definitions of concepts and their estimation on indicators of pressure, completeness of consolidation, penetrating ability are resulted. Conclusions. According to the indicators of engineering analysis, each of the three rollers is predicted to have its inherent dominant feature for the most effective use in milling, pre-sowing and post-sowing tillage operations. It is determined that the most acceptable criteria for further research in the dynamics of variable speed should be the intensity of crushing lumps, the degree of soil compaction, the intensity of soil compaction, sticking of the working surface of the roller in high humidity, self-cleaning ability. The criteria of further research in dynamics are determined.