THEORETICAL ANALYSIS OF STRENGTH RESISTANCE TO DISPLACEMENT OF IMPROVED DIGGING WORKING BODY OF POTATOE HARVESTING COMBINE

The amount of energy required to perform technological processes in agriculture largely depends on the size of the resistance to the displacement of the working bodies of machines. The main factor of energy consumption performing the technological process of potato harvesting is the resistance to the displacement of the digestive working body. In order to reduce the resistance to displacement an improved design of the digging body is proposed. An analytical study was conducted to determine the problem of moving the working body in the soil environment. The strength of the soil resistance is determined and the regularity of the influence on its change of parameters and the shape of the blade and separation parts of the digging working body is established. Calculations are made using the Mathematica application programm. The graphic dependences and contours of the isoline of the traction flange of the working part of the working body are obtained. Analysis of the calculations allowed to set the parameters of the surface of the dashboard, which provide a minimum of traction resistance. The schedule and contours of isolines of the change of the total resistance to the displacement of the soil mass with the tubers by the separation surface of the working organ in the function of the distance between the bars and the size of their intersection are also obtained. Analysis of the dependence of soil resistance and tubers on the separation surface indicates that an increase in the size of the geometric size of the intersection of the rods leads to a significant increase in the resistance of the medium. The material presented in the article can be used for analytical determination of the resistance of the excavation working body of potato harvesting machines of arbitrary geometric shape in the soil medium with tubers.

Nonlinear vibrations of soil strata according to instrumental and numerical data

Исследования нелинейных явлений в грунтах, начатые в России почти 60 лет назад, явились стимулом современного развития исследований сейсмоаномальных явлений в комплексе геофизических показателей, наблюдающихся при сильных и разрушительных землетрясениях. Кроме чисто научных интересов большой интерес вызывает вопрос прогнозирования поведения грунтов и сооружений с точки зрения адекватности ожидаемому проявлению сейсмического воздействия. Адекватное изучение нелинейности, являющейся неотъемлемой характеристикой природных явлений, позволит приблизить соответствующее антисейсмические мероприятия к реальным особенностям проявлений сейсмического эффекта при сильных землетрясениях. Цельюработы являлось построение расчетной модели, описывающей явления, наблюдаемые в грунтовой среде при сильных сейсмических воздействиях и сопоставление расчетных данных с результатами инструментальных наблюдений. Методы. В работе анализируется иснтрументальная запись, полученная на слабых грунтах, на сонове вейвлет нанализа. Моделируются импульсы различной проолжитлеьности в среде с различной стпенью проявления нелинейных свойст (кртутизны нелиненйой заивисисмоти напряжение -деформация) методом конечных элементов. Результаты. В результате установлены различия в спектральном составе моделируемых импульсов. Сильное проявление нелинейных свойств характеризуется резкими изменениями фаз колебаний, в фазах высокой скорости нарастания амплитуд. В нелинейных спектрах происходит перераспределение энергии в более высокочастотную область, кратную основному пику, тем сильнее, чем сильнее нелинейность кривой наряжение-деформация. Studies of nonlinear phenomena in soils, which began in Russia almost 60 years ago, have stimulated the modern development of studies of seismically anomalous phenomena in the complex of geophysical indicators observed during strong and destructive earthquakes. In addition to scientific interests, the issue of forecasting the behavior of soils and structures from the point of view of adequacy to the expected manifestation of seismic impact is of great interest. An adequate study of nonlinearity, which is an integral characteristic of natural phenomena, will make it possible to bring the corresponding antiseismic measures closer to the real features of the manifestations of the seismic effect during strong earthquakes. Aim. The aim of the work was to build a computational model describing the phenomena observed in a soil medium under strong seismic effects and to compare the computed data with the results of instrumental observations. Methods.The paper analyzes an instrumental record obtained on soft soils using wavelet analysis. With the help of the finite element method pulses of different duration are modeled in a medium with different degrees of nonlinear properties manifestation (steepness of nonlinear stress-strain dependence). Results. As a result, differences in the spectral composition of the modeled pulses were determined. A strong manifestation of nonlinear properties is characterized by sharp changes in the phases of vibrations, in the phases of a high rate of amplitude rise. In nonlinear spectra, the energy is redistributed to a higher frequency region, which is a multiple of the main peak and the stronger the nonlinearity of the stress-strain curve is stronger.

Some aspects of thermal diffusivity for various soil layers in different harmonics

Values of thermal diffusivity (K) in different soil layers for the first three harmonics have been computed for six stations in the dry farming tract of India by using amplitude ratio and phase lag. In general, the combined effect of all these harmonics gives the values of K close to the order of the experimental values. It is found that the theory of simple heat conduction is not applicable to soil medium. While the lowest values of K in all the harmonics are found at Rajahmundry, the highest values are observed at either Hissar or Bhubaneshwar for the first two harmonics and at Pantnagar for the third harmonic. Strong annual and bi-annual cycles dominate at Hissar. Pantnagar and Bhubaneshwar while quarterly cycle is significant only at Pantnagar.

An Attenuation Model of Node Signals in Wireless Underground Sensor Networks

Wireless underground sensor networks (WUSN) consist of sensor nodes that are operated in the soil medium. To evaluate the signal attenuation law of WUSN nodes, in this study, a WUSN node signal transmission test platform was built in the laboratory. The signal intensity data of WUSN nodes under different experimental conditions were obtained by orthogonal test. The WUSN node signal attenuation model was established. The test results show that the transmission of WUSN node signals in the soil medium is seriously affected by soil moisture content, node burial depth, soil compactness, and horizontal distance between nodes. The R2 of the models was between 0.790 and 0.893, and the RMSE of the models was between 2.489 and 4.192 dbm. Then, the WUSN node signal attenuation model involving the four factors was established. The R2 and RMSE of the model were, respectively, 0.822 and 4.87 dbm. The WUSN node signal attenuation model established in this paper can facilitate WUSN node deployment.

Evaluating Biosedimentation for Strength Improvement in Acidic Soil

Marine clay soils are problematic soils in the construction industry when they are subjected to construction loads. When these soils are loaded, they lose their structure. This leads to the soil being unable to withstand loads of any magnitude without exhibiting significant, permanent deformations. In order to stabilize the marine soil, new methods for soil improvement were built upon biogrouting by incorporating physical, biological and chemical treatments into the soil. However, the biggest challenge of this method is the bacteria migration through the soil medium. To overcome this issue, the electrokinetic phenomenon can be utilized alongside biogrouting to prevent the bacteria migration. In this regard, the present study applied electrobiogrouting stabilization to investigate the improvement of acidic marine clay soil with a pH of 3.69. To accomplish this, two large-scale physical models with dimensions of 500 × 300 × 1200 mm were fabricated to examine the influence of two different treated distances between the inlet and outlet—450 mm (D45) and 600 mm (D60)—on the stability of the treated soil. It was observed that the shear strength of the treated soil improved significantly. The shear strength at the D45 treated distance increased from 3.65 kPa (untreated soil) to 28.14 kPa (treated soil). However, the strength increased by increasing the treated distance. In addition, compressibility and soil electrical conductivity were reduced significantly, and the Atterberg limits were significantly enhanced from OH to OL. The reasons for the enhancement of treated soil were the formation of CaCO3, which filled the soil voids, and that the water content was reduced. To address issues with marine clay soil, this study aims to minimize the high cost of a special foundation system and the use of non-environmentally friendly materials such as calcium-based binders, aside from the reduction of deformations caused by loading. The findings of this study can be used for acidic soils and the improvement of soil’s geotechnical behavior in general.

Effect of mycosilvi and soil ameliorant to change aluminium concentration by Albizia chinensis in silica sand post mining soil medium

This study aimed to analyze the concentration change of Aluminum in the soil with addition of MycoSilvi and soil ameliorant in silica sand post mining soil media. There are three types of MycoSilvi, single or combination, added with soil ameliorant which tested on Albizia chinensis (Osbeck) Merrill. The experimental design used was a factorial design with two factors, MycoSilvi (M) consisting of four levels (M0 = without MycoSilvi; M1 = MycoSilvi type 1; M2 = MycoSilvi type 2; and M3 = MycoSilvi type 3) and soil Ameliorant (LC) consisting of four levels (L0C0 = without soil ameliorant; L1C0 = lime; L0C1 = compost; L1C1 = lime and compost). Data analysis used analysis of variance (ANOVA). The results showed that the combination of MycoSilvi and soil ameliorant decreased aluminum concentration from 7.70 to 0.10 cmol(+)/kg and increased pH from 3.20 to 5.67 were positively correlated with total biomass. Significant changes were shown in MycoSilvi type 3 with the addition of lime and compost (M3L1C1). Application of MycoSilvi type 3 (M3L0C0) gave equivalent response with application of lime (M0L1C0) to increased dry biomass, so that lime can be replaced with MycoSilvi type 3 (M3L0C0) to promote plant growth, especially biomass of plant.

Assessment of Nutrient Usage and Discharge in Tomato Greenhouse

One of the contributors to eutrophication is from agricultural wastewater which contained nutrients such as nitrogen and phosphorus. The agricultural industry in Japan has practice greenhouse plantation recently. In this study, the amount of nutrient concentration and load in the wastewater were investigated. Water samples from water supply, soil medium and effluent were collected at a greenhouse in Japan which cultivated tomato plants in coconut husk medium. The assessment was conducted every two weeks for regular monitoring for three months. The results showed that concentrations of all nutrients have same concentration level in the water supply samples from January 13th to March 15th. The concentration of supplied nutrient on March 29th increased due to high concentration of nutrients in medium water samples which preventing the nutrient uptake by the plant. The nutrient uptake by the plants were in the same range which NH4-N was between 13.6 mg/L to 14.99 mg/L, NO2-N was between 2.3 to 2.5 mg/L, NO3-N was between 135.9 mg/L to 152.5 mg/L and PO4-P was between 70.12 to 76.64 mg/L. The concentration of nutrients in drainage was below the permissible limit of Japan’s Effluent Standard. As a result, it can be concluded that using greenhouses as an alternative farming method contributes in reducing nutrient discharge by controlling the nutrient supply to the plants.

Prediction of Soil Settlement using Numerical Modelling Based on Shear Wave Velocity Measurement

The method of Spectral Analysis of Surface Wave (SASW) is a seismic method that consider as a non-destructive geotechnical technique to determine the soil profile based on the shear wave velocity profile by utilizing the dispersive characteristic of Rayleigh wave through the soil medium. The shear wave velocity was found to be directly proportional to the strength of the soil. In this research, SASW measurement had been proposed to predict the soil settlements using numerical modelling. The frequency responses from SASW were acquired for shear wave profile analysis using WinSASW software. Thus, the borehole information which near to the conventional pile method and SASW were taken as the reference of the study. In obtaining the correlated N-value, equation that developed from previous research was used with the reference of N-SPT value. Hence, the correlated N-values were carried forward to obtaining the bearing capacity of foundation. Meanwhile, the numerical modelling has been developed in PLAXIS software in obtaining the soil settlement. The prediction of soil settlements of Site 1, Site 2 and Site 3 that calculated by conventional equation and modelled using PLAXIS were 0.003mm and 0.001mm, 0.002mm and 0.004mm, 0.003mm and 0.004m respectively. Based on the result obtained, this research has shown the potential used of shear wave velocity in the prediction of soil settlement.