不同环境条件下堆石料变形特性的试验研究

探讨了对处于受压状态的堆石料进行干湿、冷热变化等环境因素作用下力学性质研究的试验方法。使用新研制的堆石料风化试验仪,对某种泥质粉砂岩堆石料进行了干湿循环、冷热循环以及湿冷-干热耦合变化三种环境条件下的长期变形特性试验研究,探讨了堆石料长期劣化变形的机制。试验结果表明,干湿循环试验和湿冷-干热耦合循环均可导致堆石体产生较大幅度的附加变形,其变形机制包括湿化变形、堆石体颗粒湿胀和干缩循环变形以及堆石料的劣化变形等。环境因素的循环变化可导致堆石体颗粒的劣化,堆石体劣化变形是高土石坝后期变形的重要组成部分。     

Experimental Study of Pore Pressure and Deformation of Suction Bucket Foundations Under Horizontal Dynamic Loading

Centrifuge experiments are carried out to investigate the responses of suction bucket foundations under horizontal dynamic loading. The effects of loading amplitude, the size of the bucket and the structural weight on the dynamic responses are investigated. It is shown that, when the loading amplitude is over a critical value, the sand at the upper part around the bucket softens or even liquefies. The liquefaction index （excess pore pressure divided by initial effective stress. In this paper, the developmental degree of excess pore pressure is described by liquefaction index） decreases from the upper part to the lower part of the sand foundation in the vertical direction and decreases from near to far away from the bucket＇s side wall in the horizontal direction, large settlements of the bucket and the sand around the bucket are induced by the horizontal dynamic loading. The dynamic responses of the bucket of a smaller height （when the diameter is the same） are heavier. A cyclic crack some distance near the bucket occurs in the sand.     

海洋平台吸力式基础的土工离心模拟研究与分析

综述了国内外已开展的海洋平台吸力式基础的离心模型试验研究,重点讨论了应用离心机模拟吸力式基础承载特性的研究现状。