为研究黏土夹层对共振法处理可液化砂土地基效果的影响,按比例制备十字翼振杆并开展相关模型试验.根据加固前后轻型动力触探击数 N 10 、土颗粒峰值振动加速度 a 和砂土相对密度 D r 的变化,分析了黏土夹层对土体强度、能量传递规律及...为研究黏土夹层对共振法处理可液化砂土地基效果的影响,按比例制备十字翼振杆并开展相关模型试验.根据加固前后轻型动力触探击数 N 10 、土颗粒峰值振动加速度 a 和砂土相对密度 D r 的变化,分析了黏土夹层对土体强度、能量传递规律及密实程度的影响.结果表明, N 10 和 a 值随着测点与振杆径向距离的增加而减小.受黏土夹层影响,加固前后土体强度增长幅度降低64%~127%, a 值也相应减少,且振动有效影响半径由0.4 m减少为0.3 m,砂土相对密实度增长幅度下降4.2%~9.7%.现场标贯试验及地表峰值振速监测结果进一步验证了模型试验的可靠性.地基中黏土夹层可使振点处的排水通道受阻,降低土体排水固结及能量传递效率,减弱了加固效果.展开更多
Experiments were conducted to investigate bed forms and flow resistance of light-weight sediment in an open channel flow. Three different synthetic materials of specific gravity 1. 055, 1. 46, each with uniform sizes ...Experiments were conducted to investigate bed forms and flow resistance of light-weight sediment in an open channel flow. Three different synthetic materials of specific gravity 1. 055, 1. 46, each with uniform sizes D50 for 1. 25mm, 1. 05mm, 1. 40mm were used. Some conclusions were obtained from the resultS of these experiments and the data of other reliable sources[1, 2, 3, 4]. They indicate that the grain resistence is greatly affected by D50, and bed form resistances is the function of the downstream slope and the height of the dune. As well as natural sand, Y is not only the function of Y', but also affected by the relative roughness Rb/D50 and the size of the sediment.展开更多
文摘为研究黏土夹层对共振法处理可液化砂土地基效果的影响,按比例制备十字翼振杆并开展相关模型试验.根据加固前后轻型动力触探击数 N 10 、土颗粒峰值振动加速度 a 和砂土相对密度 D r 的变化,分析了黏土夹层对土体强度、能量传递规律及密实程度的影响.结果表明, N 10 和 a 值随着测点与振杆径向距离的增加而减小.受黏土夹层影响,加固前后土体强度增长幅度降低64%~127%, a 值也相应减少,且振动有效影响半径由0.4 m减少为0.3 m,砂土相对密实度增长幅度下降4.2%~9.7%.现场标贯试验及地表峰值振速监测结果进一步验证了模型试验的可靠性.地基中黏土夹层可使振点处的排水通道受阻,降低土体排水固结及能量传递效率,减弱了加固效果.
文摘Experiments were conducted to investigate bed forms and flow resistance of light-weight sediment in an open channel flow. Three different synthetic materials of specific gravity 1. 055, 1. 46, each with uniform sizes D50 for 1. 25mm, 1. 05mm, 1. 40mm were used. Some conclusions were obtained from the resultS of these experiments and the data of other reliable sources[1, 2, 3, 4]. They indicate that the grain resistence is greatly affected by D50, and bed form resistances is the function of the downstream slope and the height of the dune. As well as natural sand, Y is not only the function of Y', but also affected by the relative roughness Rb/D50 and the size of the sediment.
