Sand Rock Research Articles

Effects of different alternative soil forming materials on soybean growth index and yield

Aiming at the problems of soil poor and the decrease of cultivated land in the alluvial fan area in the northern slope of the Qinling Mountains, the selection of suitable alternative soil-forming materials to improve the soil in the piedmont area could provide a scientific reference for the improvement of soil quality. Therefore, we chose six different alternative soil-forming materials treatments, including vermiculite (M1), perlite (M2), clay shale (M3), gravel (M4), sand (M5), and soft rock (M6), which mixed with soil at a ratio of 0.5 L·m2 for field soybean planting experiments, respectively. The results showed that the order of soybean plant height from high to low in 6 different alternative soil-forming materials was M2> M6> M3> M5> M4> M1, the chlorophyll value of M2 and M3 was larger than that of the other four treatments, and the range of increase was 20.9%-26.6%, the figures showed M2 treatment was the most suitable for soybean plant growth. For soybean root dry weight, 100-grain weight and yield, the soybean root dry weight, 100-grain weight and yield under M2 and M1 treatment were larger. Comprehensive analysis of crop growth indicators and yield showed that M2 treatment was the most suitable as an alternative soil-forming material for soybean growth and soil improvement in mountainous areas.

Aquifer analysis of Durensewu-Karangjati water source in Pandaan, Pasuruan using 2D resistivity method in identifying pollution of domestic waste

Conservation of the availability and guarantee of water quality from the spring is indispensable. One of the company as a provider of raw water in Surabaya made several efforts in maintaining the balance between quality and availability of water for sustainability . One method that can be used in aquifer monitoring of springs is the 2D Resistivity method. This study aims to describe the two-dimensional subsurface aquifers of Durensewu and Karangjati springs. The inversion result of 2D resistivity data shows the constituent rocks in the research area in the form of clay, sand, and loam clay with resistivity value 50-150 Ohm.m where sand rocks are identified as aquifer rocks at depths of 2-7 meters and a thickness of about 2-5 meters. The aquifers of Durensewu and Karangjati water sources are shown to have different systems. Escherichia coli contamination from domestic waste found in Durensewu springs is caused by aquifer connected to surface water flow, but not found in Karangjati spring.

Effect of substrate type and pellet age on the resuspension of Atlantic salmon faecal material

The influence of substrate type and particle age on the remobilization of settled Atlantic salmon Salmo salar faecal material was studied through a set of controlled experiments in horizontal flow flumes, simulating different bottom conditions present in fish-farming locations along the coast of Norway. There was no significant effect of pellet age on remobilization for up to 1 week old faecal material, but critical shear stresses (τc) and velocities required for resuspending faecal pellets were strongly dependent on substrate type. Smooth substrates such as mud and rock slate required lower stresses for the onset of faeces resuspension (τc %%CONV_ERR%% 0.06 Pa) than rougher surfaces such as sand (τc %%CONV_ERR%% 0.12 Pa) or fragmented rock (τc %%CONV_ERR%% 0.32 Pa), where bedforms and large fractures shield the particles from the direct influence of the drag forces. These newly determined substrate-dependent τc resuspension thresholds will contribute to the construction of more accurate numerical models that include bottom type as a parameter regulating the extent of particle spreading, in contrast to the constant-value approach that has been used to date.

EFFECT OF SODIUM CHLORIDE CONCENTRATION IN SAND BED AND WELL ON THE INDICATION OF NEUTRON LOGGING INSTRUMENTS

The requirements to the accuracy and reliability of the results of borehole geophysical measurements of the porosity coefficient in oil and gas fields are constantly increasing. Studies of the influence of chlorine on the readings of neutron logging equipment with different types of probes were carried out by mathematical modeling methods. Experimental evaluation of the simultaneous effect of sodium chloride concentration in the reservoir and in the well on the readings of neutron devices has not been carried out. A design description of the experimental bulk model of a porous watersaturated sand formation (a standard sample composition and properties of sand rock) crossed by a well created to study the effect of sodium chloride concentration in the formation and in the well on the readings of neutron logging equipment with various probes, as well as the results of metrological studies of the created model are given. A feature of the model design is the well simulator, made in the form of a cylindrical fiberglass cup and installed coaxially in a cylindrical stainless steel housing. The carriers of the model properties carriers are quartz gravel and an aqueous solution of sodium chloride (NaCl) in its pore space. Reproducible values of porosity model taking into account heterogeneity of crushed stone backfill (0.353 ± 0.002) with probability 1 defined by volumetric and gravimetric methods under normal conditions, the sandy layer, pore space which is filled with fresh drinking water. The results of experimental studies of the effect of aqueous NaCl solution in a sand formation and in a well with concentrations of 50, 100, 150 and 200 g/l on the indication of neutron logging equipment PRKL with probe NGK, RK5-76 with probe NNK-T and SRK-1 with probe NNKNT using individual calibration functions (CF). CF were built on the porosity standards of sandy water-saturated rocks with zero NaCl concentration in the Center of metrological research «Ural-Geo». Correction functions (CF) are given as a dependence of the correction to the readings of the equipment RK5-76 and PRKL on the concentration of NaCl in the formation at a fixed concentration in the well or on the concentration of NaCl in the well at a fixed concentration in the formation. The obtained results can be used in the development of techniques for performing downhole geophysical measurements of the porosity coefficient of rock formations in typical geological and technical conditions.

Large herbivores in restricted ecosystems: assessment of water sources value by high-usage movement pathways at Byriuchyi Island spit

An animal population permanently living in a certain area not only adapts to environmental conditions, but changes the environment as a result of their activities. The constant movement of animals between valuable resources in a certain territory forms a system of permanent trails. They are valuable source of information for solving problems of directed formation of ecosystems, organisation of protection and rational use of the territory. The territory of our study — Byriuchyi Island — is an alluvial type of sand and shell rock spit. It is covered with a variety of wetlands, meadows, and steppe vegetation. There are no natural sources of fresh water. Since the 1950s, several species of large herbivores have lived here: red deer, fallow deer, onagers, and feral horses. To provide animals with fresh water, artificial ponds called “kopanki” were created in the 1970s. In order to determine the intensity of use of drinking water on the Biryuchy Island spit, we assessed them based on the analysis of the system of permanent trails. Materials used in the work consist of data collected in 2014–2018 during field research and satellite images of the area. During the study period, the total number of ungulates ranged between 2700 to 3400 individuals. To assess the intensity of water use, the number and direction of permanent paths were determined, the distance to other water and fodder sources, shelter, microrelief and climatic features, anthropogenic factors were estimated. Data were collected for 31 artificial water sources. It has been found that permanent trails can extend from the source in up to 25 directions. However, more often they are concentrated in the northern and north-eastern directions. This is due to the most weather-protected area of the island — providing cover with reeds and a variety of nutritious food — being located in the north. The nearest sources of fresh water are in 2.5–3 km from the coast of the estuary. In general, the average distance between water crates on the spit is 0.9 km. Analysis of the permanent trails system of the island showed that 45 % of water resources are intensively used by ungulates, and 22 % have no visible trails.

Case Study on Slope Stability for Composite Subgrade with River Sand and Efflorescent Mudstone Rock

AbstractTo solve problems concerning insufficient subgrade filler in highway construction, the feasibility of river sand and efflorescent mudstone rock (EMR) to fill subgrade with steep slope were ...

Experimental study of salt-resisting slurry for undersea shield tunnelling

For undersea shield tunnelling projects, selection of a suitable slurry ingredient is a challenging issue due to the presence of massive ions. As a result it may be adverse for the formation of filter cake at the tunneling face, which would lead to a face instability. Using xanthan gum (XG) as an addictive to traditional sodium bentonite slurries was proposed in this paper. SEM images revealed that XG utilize its ‘wrapping effect’ to effectively alleviate the decrease in the Russian funnel viscosity caused by electrolytes present in seawater and to improve the control of water loss. The influences of XG contents on slurry properties under different salty water conditions were explored through a series of laboratory tests. When the seawater content exceeds 30%, the change in XG content required to maintain the basic properties of the mud is insensitive to increase in seawater content. The quality of filter cake and infiltration features of the developed slurries under medium coarse sand and fully-weathered rock strata conditions were evaluated through slurry infiltration tests. It was found that the bentonite water ratio is mainly related to the properties of the strata, and XG content is determined by the seawater content.

Utilization of alternative sand for preparation of sustainable mortar: A review

Abstract The rapid urbanization and industrialization in last few decades has led to depletion of the construction materials like sand and accumulation of industrial wastes. The detrimental effect of excessive dredging of sand from river beds on environment and unavailability of land for disposal of industrial wastes has forced the researchers to search for other feasible alternative. Recycling of industrial wastes in construction industry can be a promising approach for sustainable growth. On one side it helps in reducing the sand demand and on another other side provides eco-friendly method for waste disposal. Different researchers have investigated the feasibility of using industrial wastes as replacement to natural sand in mortar, termed as “Alternative Sand”. This paper first presents the comprehensive overview of physical, chemical, mineralogical and morphological characterization of the alternative sands which is followed by critical appraisal on the fresh, hardened and durability properties of alternative sand mortars. This study reviewed the alternative sands like coal bottom ash, crushed rock sand, copper slag, foundry sand and recycled fine aggregate. The paper ends with discussion outlining the challenges and direction for further research. The scientific value of the paper was to provide the substantial base of knowledge and scientific view for future studies and development of standards for conventional application of alternative sand mortar.

Compressive Strength By Partial Replacing of Sand with GBFS

The natural sand used acquired from the river bed is everlasting supply, but now the sand resources are getting depleted and exhausted. They are driven by the acute need to find a product that can match the properties of natural sand in concrete, the sand manufactured by crushing the natural rocks. The by-product (stone dust) of the crushing and screening process of coarse aggregates is a fine aggregate. Since rock sand contains more fine particles, it requires more water; hence, quality suffers resulting in low compressive strength and durability. The quality problems caused many concrete manufacturers to think for an alternative source of sand in-place of Rock sand, Thus by using GBFS as fine aggregate in replace of natural/rock sand, we may able to conserve natural resources and its use in concrete, and compressive strength results revealed that it could be as an alternative to sand.

Regression Analysis by Taguchi Method on Strength of Weathered Crystalline Rock Sand Concrete

Due to industrialisation, large constructions are going on all over the world which in turn requires huge quantity of cement and sand. Cement manufacture is a main source of carbon-di-oxide emission to the atmosphere and quarrying of river sand produces scarcity as well as environmental problems. There are various waste products obtained from manufacture of other materials as well as from quarries, the handling of which is difficult and creates environmental issues. These waste materials can be used as a replacement for cement and sand. In this study weathered crystalline rock sand which is obtained from the soft outer portion of rock in quarries is used as replacement for river sand and Ground Granulated Blast-furnace Slag (GGBS) obtained from iron industry is used as replacement for cement to reduce the environmental impact as well as to help waste handling and reuse.

Comprehensive Analysis of the Ceramics from the Early Layers of the Zhabotyn Settlement

The results of a comprehensive analysis using the methods of natural sciences of the samples of handmade dishes from layers of VIII—mid—VII c. BC are shown. Pottery was found at the Zhabotyn settlement, which is dated from VII to the middle of VII c. BC. 50 samples of vessels of different types were selected. The following analytical methods were used: petrography, microtomography, electron microscopy (SEM-EDS). The aim of this paper was to present the results obtained in the study of ceramics of the Zhabotyn 1 horizon using the methods of natural sciences and compare them with archaeological data. The research resulted in the identification of six technological groups (with subgroups), which reflect the archeometric characteristics of the molding mass of handmade ware of all kinds, which is found in the early layers of the settlement (Zhabotyn1 horizon). Comprehensive information about this collection is included in the Database, which was created by a team of authors. Conclusions: 1. The most common was ceramics made of two types of molding mass, in the plastic mass of which smectite (group 2.3) and illite (group 3) clays predominate. When degreasing, the masters used sand impurities (22—28%) (group 2) or combinations of impurities - sand, grog, and crushed rocks (group 3). The composition of these groups of vessels contains all types of polished and simple ware that are found at the settlement. Paste fillings in the ornamentation of vessels of these groups were almost never used. The exceptions are samples from two taverns of group 2 — 469 and 470, in the decoration of which pasta of recipe no. 1 is noticed. 2. The vessels of the group 1.1 (mainly smectite clay, admixtures — chamotte (12—23 %) and sand (15—35 %)) are represented exclusively by black-polished S-shaped ladles. All ornaments of such examples were polished with white paste of recipe no. 1 (quartz + quartzite + smectite + bone meal). We also used paste of recipe no. 2 (epidote + chlorite + smectite + pyroxene (powder). 3. The use of the archaeometric methods for studying the molding mass allowed refuting one of the ladle reconstructions (subgroup 2.4, Fig. 7; 11), which supposedly consisted of three fragments. Unfortunately, according to the composition of the molding material, all three fragments used in the reconstruction belong to different subgroups and cannot belong to the same vessel. 4. Group 4 samples (kaolinite and illite clays; admixtures: sand and crushed rocks) belonged to the vessels with high-quality orange polishing and a pot with two handles that have analogies among the Basarabi culture ceramics. The data of archaeometric studies confirmed the assumption of archaeologists about imported origin of these ware. 5. A comparison of some vessels with the materials of the steppe zone Scythian burials of the in the Northern Black Sea region indicates that some ware from the workshops of the Zhabotyn settlement came to the steppe nomadic population. 6. Thus, Matrix-Groups of Refiring analyses provide the view of vessels manufacturing process. Several production recipes for making handmade pottery have been identified. That is, the latter was produced in small workshops, within home production. Such an assumption has already been made by the authors on the basis of archaeological data. At present, it is confirmed and refined by the methods of natural sciences. 7. The Zhabotyn settlement is one of 12 settlements of the Late Bronze Age — Early Iron Age, samples of which were taken to create the Database. Each of these settlements has its own set of techniques and methods for making handmade pottery. Their combination creates a special, “appearance” of ceramic production of each settlement or hillfort. That is, the vessels are markedly different from the ceramics of other settlements in the region of study. It is important to note that the analysis of clays from the vicinity of the settlements also confirms the presence of ceramic production in place. This conclusion is especially important for comparing the materials of settlements with the materials of the pre-Scythian time burials, which, in the end, will allow us to draw certain conclusions in solving the problem of relations between the settled and nomadic peoples of the steppe zone in the Northern Black Sea region.

The Analysis of Doosan S500-LCV Excavator Maintenance Planning to Reduce Downtime Using Reliability Centered Maintenance (RCM) Method

PT X is a company engaged in construction field and heavy machinery services. PT X uses excavators as a tool to mine rock sand. In 2018, the company has planned to increase production capacity. The increase of production capacity will be directly related to the operational capability of the unit which must always be maintained. The problem in this study is the occurrence of unit downtime that cannot be predicted and occurs in a relatively long time. The components damage of the excavator causes the unit to be unable to operate to increase production. The maintenance of the Doosan S500-LCV excavator at PT X is currently not optimal because the downtime that occurs in the unit is still relatively high. Standard maintenance procedure of excavator units need to be evaluated in order to minimize the occurrence of downtime so that the unit can be used for maximum production. The method used in this analysis is the Reliability Centered Maintenance (RCM) method with evaluating maintenance carried out and giving the right maintenance suggestion. From the results of the analysis and discussion, the critical components of the S500-LCV excavator in PT X are Bucket, Control Valve, Radiator, Alternator and Hydraulic Breaker. Proposed maintenance based on the RCM method and the consideration of S500-LCV maintenance costs at PT X are bucket with preventive maintenance, control valve with a combination of preventive and corrective maintenance, radiator with preventive maintenance, alternator with a combination of preventive and corrective maintenance and hydraulic breakers with preventive maintenance

Deflection and failure of high-stiffness cantilever retaining wall embedded in soft rock

In this study, a centrifuge modelling system has been developed, in which the loading process from design conditions to the ultimate failure conditions can be simulated on an embedded wall in soft rock at a constant centrifugal (50g) acceleration. Soft sand rock was artificially modelled by using a sand−cement−clay mixture. In-flight excavation and the lateral loading processes were simulated by means of draining water from the wall front and feeding water to the retained soil side, respectively. Two centrifuge model tests have been carried out to investigate the influence of embedment depth on the stability of large-stiffness cantilever walls having flexural rigidity equivalent to a 2·5 m steel tubular pile wall. The results observed reveal that the wall can stand in the design condition with relatively small embedment depth, and provides a reasonable safety margin against ultimate failure. The stiff cantilever walls move by rigid-body rotation about a pivot point under ultimate loads, and a small increment in the embedment depth – for example, 20% – can significantly increase the stability of the wall considered in this study. A compression failure of the embedded medium at the shallow wall front and a shear wedge failure at the wall back from the wall toe were observed.

Influence of the Loading Condition on Single Grain Crushing in DEM Simulation

Grain crushing is of essential importance for understanding the mechanical behavior of granular materials such as sand, gravel or broken rock under higher pressures. In order to investigate the breakage mechanism of a single grain under different loading conditions, numerical simulations are carried out using DEM. Two different types of boundary conditions are considered to apply displacement-controlled load: loading using platens and loading by uncrushable macro-grains. A 2D crushable macro-grain is built up from a large number of micro-grains which are connected with respect to breakable parallel-bond properties. The response of the crushable macro-grain for different coordination numbers and location of the contact points is discussed. The numerical results show that the type of loading condition can influence the loading capacity and fragmentation patterns of the crushable macro-grain.

Prediction of Particle Packing Density of Alternative Fine Aggregates by Artificial Neural Network Applications

Particle packing density mainly influences the behavior of concrete. Experimental determination of particle packing density is arduous and time-consuming. Thus, artificial neural network (ANN) is a tool that helps in determining particle packing density faster and accurately. ANN is used to predict the properties of the concrete with natural aggregates only. However, utilization of alternative fine aggregates is a need of hour. The aim of this paper is to apply ANN to predict particle packing density of combined aggregates, viz. coarse, intermediate and fine aggregates. In addition, alternative fine aggregates, namely crushed rock sand (CRS), recycled fine aggregate (RFA) and coal bottom ash (CBA) are used. In this study, the main constraints used to design ANN are size distribution and packing density of individual aggregates. Feedforward network is used to determine particle packing density of combined aggregates. A total of 231 experimental datasets are used to train ANN for each alternative fine aggregate, and the results were compared. It was observed that the error percentages are well below 5% of experimental and ANN optimization analyses. The optimum packing proportions for river sand, CRS, RFA and CBA were 40:20:40, 30:30:40, 30:30:40 and 30:20:50, respectively.

Using recursive inversion as input for gross-rock volume extraction from lithology prediction volumes: How bad can it be?

SummaryReserves and Resources can be directly estimated by using seismic lithology prediction volumes generated from AVO inversion, calibrated to wells, to estimate sand rock volumes within a stratigraphic interval. However, high quality AVO inversion data and studies are not always available. This case study utilises recursive inversion to generate prediction cubes for input to geobody based gross rock volume estimates.Here, relative recursive inversions of the near and far seismic stacks are generated. EEI rotation theory was applied to calculate relative AI and Vp/Vs volumes. These have then been converted to band-limited absolute inversion volumes by adding a low frequency model built using seismic horizons, well logs and rock physics trends. Finally, probability density functions calibrated to wells were estimated to calculate lithology prediction volumes. A sand probability volume is then calculated using these probability density functions. A relative approach has not been applied due to poor separability of different lithologies in cross-plot space.This method is applied to an area where a single multiazimuth PSDM seismic survey covers two gas fields and several deep exploration prospects. However, previous inversion studies were limited to the individual fields (each inverted separately), incorporated fluid contact information and did not cover the deeper exploration, so were therefore considered sub-optimal.Although there is potential for results from this method to be “bad”, this case study was successful. The inversion volumes generated as part of this study enabled a wholistic view of the fields and exploration prospectivity, which had not been previously possible with the available QI volumes. The seismic data used for input was exceptionally good, and there was abundant well control to provide control and for use in blind testing. The amount of validation and quality-control applied to this project cannot be under-stated. It is critically important to be mindful of the limitations and broad assumptions that are applied as part of this work-flow. These include the addition of the low-frequency model, wavelet affects not being taken into account and depth decay of the lithology predictions due to the application of a single PDF.

Glutathione supplementation prevents iron deficiency in Medicago scutellata grown in rock sand under different levels of bicarbonate

The effects of root glutathione (GSH) supplementation on leaf chlorophyll, Fe concentrations and contents in leaves, stems and roots, and traits associated to Fe deficiency were studied in Medicago scutellata plants grown in rock sand under conditions of Fe deficiency, in the presence of different concentrations of bicarbonate. Plants were grown in acid-washed rock sand irrigated with a zero Fe solution (pH 7.8 with 0.5 g L−1 CaCO3) or a 45 μM Fe(III)-EDDHA solution (5 mM MES, pH 5.5), with 0, 5 or 15 mM NaHCO3, and 250 mL of 1 mM GSH was added daily to half of the pots. Iron deficiency caused characteristic symptoms in plants, with GSH supplementation relieving them. Glutathione supplementation led to increases in total Fe, chlorophyll and leaf total and extractable Fe, whereas root Fe concentrations decreased. Traits associated to Fe deficiency, including changes in biomass, root morphology, carboxylate contents and antioxidant parameters became less intense with GSH supplementation. Glutathione supplementation allowed plants to take up Fe from the rock sand via a reductive solubilization mechanism. Also, the distribution of Fe within the plant changed, with more Fe being allocated to the shoot tissues and less to the roots.

Study on quantification method for aggregate gradation of discrete Cemented Sand Gravel and Rock

As a new damming technique, Cemented sand gravel and rock damming technique could fill the gap between the earth-rock dam and the concrete dam in material and improve the construction system. The largest characteristic of this material is that it directly adopts the aggregates in the engineering field and only aggregates with a particle size above 150 mm are screened. The aggregate gradation is discrete and fluctuating, so it is significant to study the methods of quantization and characterization of aggregate grading. Based on Fuller curve, this paper quantified the variation and dispersion of aggregate gradation via using similarity coefficient of aggregate gradation, average similarity coefficient, mean average similarity coefficient and standard deviation of similarity coefficient, which has provided significant guidance for the real practice. Relevant quantization methods not only assist to differentiate the grading boundary including the thinnest and roughest graded aggregate, but also master the grading changes and predict the dispersion degree of strength of Cemented sand gravel and rock from the dispersion degree of aggregate, which could provide a scientific reference for the mixing design of Cemented sand gravel and rock

Estimated justification of the bearing capacity of the lining when opening auxiliary workings in conditions of local freezing of the rock mass

For performance of works on the device of tunnel constructions in the conditions of the water-saturated unstable soils having character floating, their stabilization and strengthening is provided. During the construction of combined ventilation and technological failure of the existing subway, planned for the production of construction and installation works by mining in water-saturated fine Sands, provides for the implementation of measures to freeze the soil mass. For the safe construction of the workings of the decision on the implementation of the calculations and mathematical modeling of the impact on the lining and tongue and groove fencing in the production of works for freezing, opening the lining and thawing of the soil array. The article presents the results of analytical studies of the state of the rock sand massif in freezing conditions. The algorithm of numerical realization of the spatial inelastic problem using the method of finite differences and finite elements of MacCormack of the second order for dynamic problems is used and implemented to calculate the structure on mechanical effects. The finite element method is used in the Lagrange formulation of dynamic and static problems. The model of concrete and soil, described by the theory of plastic flow for shear, taking into account the rate of loading under volumetric deformation, is applied. To solve static (quasi-static problems), the method of establishing an explicit implementation or a quasi-static method in the absence of inertial terms is used. The layered two-phase medium, each layer of which is homogeneous and isotropic, is considered. This medium simulates the behavior of water-saturated soil, one phase of which is in the melt, and the other in the frozen state.

Effect of clay in alternative fine aggregates on performance of concrete

The worldwide utilization of alternative fine aggregates (AFA) in the construction sector is increasing exponentially these days due to extensive exploitation of natural sand. However, presence of excessive clay in AFA is considered harmful for fabrication of concrete and mortar. The existence of fine sediments like clay at the interstices of AFA highly influence the performances of concrete. Three types of AFA such as crushed rock sand (CRS), coal bottom ash (CBA) and recycle fine aggregates (RFA) are used in present study. Keeping in view, assessment of clay content in AFA is carried out by methylene blue test and their effects on performance of concrete. In this study, the volume fraction of AFA is varied by 30%, 50%, 75% and 100% respectively. Efforts were also made to develop standard correlation curve of methylene blue value of fine aggregates to corresponding clay content. The methylene blue value for all fine aggregates were well within 6 mg/g and correspondingly less than 5% clay content. Results indicated that MBV greater than or equal to 1.50 is not suitable for preparing concrete. It is also observed that properties and durability of these AFA concrete depend on the amounts of clay.