• Structural Engineering and Mechanics
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• v.90 no.6
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• pp.577-590
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• 2024

Considering the Column-Supported Group Silos (CSGSs) often arranged by rows in practical applications, earthquake responses will be affected by group effect. Since group effect presenting uncertainties, establishing the analytic model and evaluating characteristics of CSGSs seems necessary. This study aimed at providing a simplified method to evaluate seismic performances of the CSGSs. Firstly, the CSGSs with different storage granule heights are used as numerical examples to derive the base shear formula for three-particle dynamic analytical model. Then, the base shear distribution coefficient is defined as the group effect index. The simplified calculation method of the group silos based on the distribution coefficients is proposed. Finally, based on the empty, half, and full granular storage conditions, the empirical design parameters for the group silos system are given by combining finite element simulation with shaking table test. The group effect of storage granule heights of group silos on its frequency and base shear are studied by comparative analysis between group silos and independent single silo. The results show that the frequency of CSGSs decreases with the increasing weight of the stored granule. The connection between the column top and silo bottom plate is vulnerable, and structural measures should be strengthened to improve its damage resistance. In case of different storage granule heights, distribution coefficients are effective to reconstruction the group effect. The complex calculations of seismic response for CSGSs can be avoided by adopting the empirical distribution coefficients obtained in this study. The proposed method provides a theoretical reference for evaluation on the seismic performances of the CSGSs.

• Structural Engineering and Mechanics
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• v.33 no.5
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• pp.561-572
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• 2009

Nowadays, Eurocodes have become the reference standards for silo design within the European Union. They include new procedures for load assessment and structural verifications aiming to design safer silos. However, many silo manufacturers are still reluctant to use them (or at least all their prescriptions) because of the loss of competitiveness they are experiencing in comparison with former standards. This paper shows how steel cost of flat-bottomed circular silos varies when different silo geometries and stored materials are considered. The influence of critical structural verifications on steel costs, such as buckling of the silo wall, were also analyzed and some conclusions and practical recommendations for silo designers were proposed.

• Advances in concrete construction
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• v.12 no.5
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• pp.377-389
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• 2021

Reinforced concrete vertical silos are universal structures that store large amounts of granular materials. Due to the asymmetric structure, heavy load, uneven storage material distribution, and the difference between the storage volume and the storage material bulk density, the corresponding earthquake is very complicated. Some scholars have proposed the calculation method of horizontal forces on reinforced concrete vertical silos under the action of earthquakes. Without considering the effect of torsional effect, this article aims to reveal the expansion factor of the silo group considering the torsional effect through experiments. Through two-way seismic simulation shaking table tests on reinforced concrete column-supported group silo structures, the basic dynamic characteristics of the structure under earthquake are obtained. Taking into account the torsional response, the structure has three types of storage: empty, half and full. A comprehensive analysis of the internal force conditions under the material conditions shows that: the different positions of the group bin model are different, the side bin displacement produces a displacement difference, and a torsional effect occurs; as the mass of the material increases, the structure's natural vibration frequency decreases and the damping ratio Increase; it shows that the storage material plays a role in reducing energy consumption of the model structure, and the contribution value is related to the stiffness difference in different directions of the model itself, providing data reference for other researchers; analyzing and calculating the model stiffness and calculating the internal force of the earthquake. As the horizontal side shift increases in the later period, the torsional effect of the group silo increases, and the shear force at the bottom of the column increases. It is recommended to consider the effect of the torsional effect, and the increase factor of the torsional effect is about 1.15. It can provide a reference for the structural safety design of column-supported silos.

• Korean Journal of Veterinary Service
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• v.44 no.4
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• pp.315-320
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• 2021

To analyze prevalence of mycotoxins, a total of 74 feedstuff samples were collected from silos (n=37) and hoppers (n=37) in nine pig farms. Six mycotoxins were tested with commercialized ELISA kits. All samples were contaminated with four or more mycotoxins. Zearalenone was detected in all of the tested samples. Ochratoxin, deoxynivalenol and H-2/HT-2 toxin were detected in more than 90% of the samples. And also, fumonisin was positive in 89.2% of the samples from the silos, 75.2% from the hoppers, respectively. On the other hand, aflatoxin was detected in about 40% of the samples. When the behavior of lactating sows was observed, possible mycotoxicosis was suspected. It was confirmed that their feedstuffs were contaminated with high levels of mycotoxins such as ochratoxin and T-2/HT-2 toxin. After cleaning the feedline, the clinical symptoms in sows suspected with mycotoxicosis were disappeared. Although mycotoxin concentration in most of the feedstuffs was below the acceptance level, these data indicate that what are required is more monitoring and continuous management for mycotoxins in pig feedstuffs.

• The Journal of Engineering Geology
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• v.27 no.4
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• pp.463-474
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• 2017

Heterogeneous background fractures of granite and sedimentary rocks in Gyeongju LILW (low-intermediate level radioactive waste) facility area have been characterized quantitatively by analyzing fracture parameters (orientation, intensity, and size). Surface geological survey, electrical resistivity survey, and acoustic televiewer log data were used to characterize the heterogeneity of background fractures. Bootstrap method was applied to represent spatial anisotropy of variably oriented background fractures in the study area. As a result, the fracture intensity was correlated to the inverse distance from the faults weighted by nearest fault size and the mean value of electrical resistivity and the average volumetric fracture intensity ($P_{32}$) was estimated as $3.1m^2/m^3$. Size (or equivalent radius) of the background fractures ranged from 1.5 m to 86 m and followed to power-law distribution based on the fractal property of fracture size, using fractures measured on underground silos and identified surface faults.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.523-528
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• 2007

This study was conducted to evaluate the feeding value of jambo grass (Sorghum $bicolour{\times}Sorghum$ sudanefe) silage and mott grass (Pennisetum purpureum) silage as a replacement of conventional fodder (jambo grass) in the diet of lactating Nili buffaloes (Bubalus bubalis). Thirty early-lactating ($45{\pm}4$ days), multi-parous Nili buffaloes, ten in each group, were allotted to three experimental diets. Jambo grass and mott grass were ensiled with molasses (at 2% of fodder DM) in two trench silos for 30 days. The control diet (JG) contained 75% jambo grass while the other two diets contained 75% jambo grass silage (JGS) and 75% mott grass silage (MGS). The remaining 25% DM in each diet was supplied by concentrates. Diets were mixed daily and fed twice a day ad libitum for 120 days. Dry matter intake (DMI) was higher with the JG diet compared with JGS and MGS diets. However, DMI as % body weight did not differ significantly in buffaloes fed either fodder or silage based diets. Crude protein (CP), digestible CP and NDF intakes were significantly higher on JG compared with silage-based diets. Apparent total tract digestibilities of DM, CP and NDF were similar in buffaloes fed JG, JGS and MGS diets. Milk yield (4% FCM) was similar in buffaloes fed JG and silage based diets. Fat, total solids, solid not fat, CP, true protein and non-protein nitrogen content of milk were similar in buffaloes fed fodder or silage based diets. The present results indicated that jambo grass and mott grass ensiled with 2% molasses for 30 days could safely replace the conventional fresh grass fodder (75% DM) in the diet of lactating Nili buffaloes without affecting their milk yield.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.475-478
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• 2005

This study was conducted to evaluate feeding value of berseem and lucerne silage as a replacement for conventional fodder (berseem fodder) in lactating Nili buffaloes. Fifteen early lactating multi-parous Nili buffaloes, five buffaloes in each group were allotted three experimental diets. Berseem and lucerne fodders were ensiled at 30% DM (wheat straw was used to adjust the DM of fodders) with molasses (at the rate of 2% of fodder DM) in two bunker silos for 30 days. The diets contained 75% DM from berseem fodder (BF), 75% DM from berseem silage (BS) and 75% DM from lucerne silage (LS). Each diet contained 25% concentrate DM. Diets were mixed daily and fed twice a day at ad libitum intakes. Dry matter intake (DMI) was significantly higher (13.8 kg/d) in buffaloes fed BF diet than those fed LS (12.5 kg/d) and BS (11.9 kg/day) diets. The differences in digestible DMI and DMI as percent body weight were significant between fodder and silage based diets but non-significant when BS and LS were compared. Lower DMI with silage-based diets was probably because of low silage pH. Intake of NDF (NDFI) was higher (5.68 kg/d) in buffaloes fed BF diet followed by those fed LS (5.50 kg/d) and BS (5.00 kg/d) diets. The difference was significant (p<0.05) across fodder and silage based diets but NDFI was non-significant across both silage-based diets. The apparent DM digestibility was significantly different (p<0.05) between fodder and silage-based diets but was non-significant between LS and BS diets. Four percent fat corrected milk yield was significantly different (p<0.05) between fodder and silage-based diets but was non-significant between LS and BS diets. Higher milk yield with fodder based diet was because of more digestible nutrient intake (Table 3) compared with silage based diets. Milk CP, TP and NPN and SNF did not show any treatment effects. The present results indicated that the berseem and lucerne fodder ensiled at 30% DM level with 2% molasses could safely replace (75% DM) the conventional leguminous fodder in the diets of lactating Nili buffaloes.