@phdthesis{oai:muroran-it.repo.nii.ac.jp:00010924,
 author = {ZHAO, Yafei and ジャオ, ヤフェイ},
 month = {2022-06-30, 2022-06-30},
 note = {application/pdf, 軟弱な基礎部分では，しばしば残留沈下が発生して道路の性能に影響を与えたり，車両の正常な運行に影響を与えたりする。残留沈下の影響を低減する方法の一つとして，下層路盤の軽量化が挙げられる。そこで本研究では，一般的に使用されている下層路盤材料に代わる新たな軽量下層路盤材料の開発を目的とし，一連の単調および繰返し三軸試験を実施し，新たな路盤材料の強度・変形特性を検討した。1. 単調載荷三軸圧縮試験では，排気および排水条件にて0.18 mm/min の軸ひずみ速度で試験を実施した。繰返し三軸試験では，周波数0.125 Hzで，軸差応力を49.4±10 kPaにて正弦波載荷を行い，1万サイクルの繰返し載荷履歴を与えた。2. 単調載荷三軸圧縮試験においては，3種類の拘束圧（29.4，49.0，68.6 kPa）で載荷した供試体の強度・変形特性に及ぼす繰返し載荷履歴の影響を検討した。試験結果より，最大軸差応力qmax，初期変形係数E0は，拘束圧の増加に伴って大きくなること，また，繰返し載荷履歴を与えると，強度および剛性が大きくなることが明らかとなった。3. 最適含水比によって作製した供試体と絶乾状態で作製した供試体に対する単調載荷三軸圧縮試験を実施して，強度・変形特性に及ぼす供試体内の水分の影響について検討した。最適含水比で作製した供試体と絶乾状態で作製した供試体に対する試験結果の比較・検討から，絶乾状態で作製した供試体の最大軸差応力qmax，および接線変形係数Etan，初期変形係数E0は，最適含水比で作製した供試体に比べて大きくなることが明らかとなった。4. 変形特性に及ぼす間隙水，拘束圧，繰返し載荷回数の影響を検討した結果，3種類の拘束圧（29.4，49.0，68.6 kPa）の下では，拘束圧が等価変形係数Eeqに与える影響が大きいことが明らかとなった。また，絶乾状態で作製した供試体の等価変形係数Eeqは，最適含水比で作製した湿潤供試体の等価変形係数Eeqより大きくなった。一方，等価変形係数Eeqは，繰返し載荷回数の増加とともに，ほぼ一定の値を示しており，すべての供試体がシェイクダウン範囲の境界範囲Aに属すると考えられるとともに，ポアソン比は繰返し載荷回数の増加に伴って変動し，その変動幅は同条件で0.05 以内であることが明らかとなった。, Residual settlement often appears in the soft foundation, which affects the road performance and impact on the normal operation. One way to reduce the effects of residual settlement is reducing the weight of the subbase course. Therefore, the objective of this study is to develop a new lightweight subbase course material to replace the commonly used upper subbase course material. A series of monotonic and cyclic triaxial tests were conducted to investigate the strength and deformation characteristics of the materials. 1. Through the monotonic triaxial tests were conducted under the exhaust and drainage conditions at a constant rate of 0.18 mm/min. The cyclic triaxial tests of specimens were conducted under 10,000 cycles of vertical loading at a frequency of 0.125 Hz, where the vertical stress was changed between 49.4±10 kPa in a sinusoidal wave. 2. Experimental research on the effects of cyclic loading on the strength and deformation under three confining pressures (29.4, 49.0, and 68.6 kPa) of the specimen are analyzed by monotonic triaxial test. The test results revealed that the maximum deviator stress qmax and initial Young's modulus E0 of specimen increase with the increase of confining pressure. After cyclic loading, the strength and stiffness of specimen becomes greater. It also increases cohesion and decreases friction angle in the specimen. 3. Experimental research on the effects of moisture on the strength and deformation of the specimen are analyzed by monotonic triaxial test. From the results of specimens studied with moisture and without moisture, it was found that maximum deviator stress qmax, the tangential Young’s modulus Etan and the initial Young's modulus E0 of the dry specimen were greater than the case of the wet specimen. 4. The effects of moisture, confining pressure and number of cyclic loadings on the deformation characteristics of specimen are analyzed. The results revealed that under three confining pressures (29.4, 49.0, and 68.6 kPa), it was found that the confining pressure has a greater impact on the equivalent Young's modulus Eeq of specimen. In addition, the moisture reduces the friction between the particles and the skeleton structure becomes unstable. The equivalent young's modulus of dry specimen is greater than the case in the wet specimen. The equivalent Young's modulus maintains stable with number of loading cycles of the specimens, all specimens belong to range “A” in the shakedown range boundaries. It was also found that the Poisson's ratio fluctuates with the increase of loading cycles and the fluctuation range is within 0.05 under the same condition.},
 school = {室蘭工業大学, Muroran Institute of Technology},
 title = {Study on strength-deformation behavior of artificial lightweight geomaterials with sand under monotonic and cyclic loading conditions\n},
 year = {}
}