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| Silva,Anderson Rodrigo da; Lima,Renato Paiva de. |
| ABSTRACT There are many methods for determining precompression stress (σp), whose value is affected by the slope of the soil compression curve. This study was designed to evaluate the hypothesis that for a certain compression curve all methods used to determine σp present the same value and accuracy. The aim of this study was to compare the accuracy and the relationship among seven of these methods by computational simulation of soil compression curves under nine scenarios. The following methods were used: Casagrande, Pacheco Silva, intersection of the initial void ratio with the virgin compression line (VCLzero), and the regression methods based on 2 (reg1), 3 (reg2), 4 (reg3), and 5 (reg4) points for modeling the elastic curve. Under each scenario,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil stress; Soil compression curve; Soil compaction. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100413 |
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| 大友, 功一; 岸本, 正; OHTOMO, Koichi; KISHIMOTO, Tadashi. |
| 自由転動剛性車輪の法線応力予測モデルを提案し, 室内実験でその予測精度を検討した。法線応力の予測には Bekker の応力式を導入した。この応力に関する速度の影響分は Pope の速度モデルを組み込むことで対応した。スキッドの予測には剛性車輪の実験から得た経験式を用いた。またモデル化していない接線応力は, 接線応力と法線応力との比から実験式を求めて予測した。土壌の復元現象による応力は未解析で, このモデルに組み込むに至っていない。広範囲に荷重を変えて実証実験を行ない, 計算値と実測値でよい一致が見られた。 A prediction model of a normal stress acting on a towed rigid wheel was proposed. Model accuracy was discussed with the comparison of the calculated and measured data. Pope's model including a sinkage rate was coupled to the Bekker's stress equation to evaluate its effect. Wheel skid was predicted with an empirical equation obtained from experiment of the towed rigid wheel. A tangential stress which has not been modeled was predicted from the tangential to the normal stress ratio and wheel contact angles.... |
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Palavras-chave: 自由転動車輪; 剛性車輪; 法線応力; 土壌応力; 応力モデル; Towed wheel; Rigid wheel; Radial stress; Soil stress; Stress model. |
| Ano: 1999 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2954 |
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| 全, 亨奎; 谷口, 哲司; 大友, 功一; 岸本, 正; 玉利, 達人; JUN, Hyung-gyu; TANIGUCHI, Tetsuji; OHTOMO, Ko-ichi; KISHIMOTO, Tadashi; TAMARI, Tatsuto. |
| 6個の圧力センサを利用して耕盤での土中応力状態を測定可能な土中応力測定器 (以下測定器) を開発した。測定器をタイヤ進行方向のタイヤ中心部およびタイヤ側端のラグ直下ならびにタイヤ側端のアンダートレッド直下の3ヶ所に土壌表面から深さ25cmの耕盤上に埋設し, タイヤを走行させて土中応力を測定した。得られたデータから応力状態を算出し, 主応力を求めた。次に, 測定器の埋設位置の違いによる最大主応力を検討した。その結果, タイヤ中心部ラグ直下における最大主応力が, タイヤ側端部でのそれの2倍以上になっていることが分かった。 A transducer was developed to determine the stress state in the soil on a hard pan. Principal stresses， octahedral normal and shearing stresses can be calculated from the data measured with six pressure cells on the transducer in the six predetermined directions. The transducer was buried in three locations in the soil at 25cm depth : under the lug at the centerline and the edge of the tire and under the undertread at the edge of the tire. The effect of changes in the locations of buried transducer... |
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Palavras-chave: 土壌踏圧; 動荷重; 空気圧; 土中応力; 応力テンソル; 農用タイヤ; ラジアルタイヤ; Soil compaction; Dynamic load; Inflation pressure; Soil stress; Stress tensor; Agricultural tractor tire; Radial tire. |
| Ano: 1997 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2950 |
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