摘要
为掌握砂雨法制备砂土地基模型相对密实度Dr的主要影响因素,设计加工了包括点式和线式出砂头的成套砂雨装置,讨论了Dr随落距、出砂孔尺寸、出砂头总流量、移动速度的变化规律,分析了Dr空间均匀性分布特征。试验表明:1随落距增大,Dr随之提高,但增速逐渐减缓,可将Dr相对增速K介于±3%所对应落距范围内的Dr均值为稳定相对密实度;2稳定相对密实度与出砂孔尺寸呈线性负相关关系,同一流量下随出砂头移动速度表现出非线性变化特性,出砂头总流量对稳定相对密实度影响不明显;3无论是在水平层面还是沿深度的不同位置,模型箱中部附近的Dr分布均匀性都优于四边和四角处;4一线点式出砂头所制备的砂土Dr与目标值误差较筛孔点式小,具有较好的可控性。
In order to know the main effect of sand foundation model prepared by sand pourer on the relative density Dr, a set of point and line type sand shakeout device is designed. The variation rules of Dr with the drop height, size of sand production pore, total flow of sand production head and average speed are discussed. The spatial uniform distribution of Dr is analyzed. The tests show that:(1) With the increase of the drop height and potential of sand particles, Dr increases, but the growth rate gradually decreases. So it can be thought that when the relative increase of K of Dr is ±3%, the average value of Dr corresponding to this drop height is called the stable relative density. (2) The stable relative density has negative linear correlation with the size of sand production pore. Under the same condition of total flow, the average speed of sand production head and the stable relative density present nonlinear characteristics. The effect of the total flow of sand production head on the stable relative density is not obvious. (3) For the spatial uniformity distribution characteristics of Dr in the same plane or different planes along the depth, the uniformity of Dr in the center of model box is better than that at the four sides and four corners. (4) The error of actual relative density prepared by the line type of sand production mouth is smaller than that of the point type for target relative density, so the line type of sand production mouth has better controllability for Dr.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2014年第10期1872-1878,共7页
Chinese Journal of Geotechnical Engineering
基金
国家重点基础研究发展计划(973计划)项目(2013CB036204)
中央高校基本科研业务费专项资金项目(2682013ZT12)
关键词
砂土地基模型
砂雨法
标准砂
相对密实度
控制要素
sand foundation model
sand pourer
standard sand
relative density
control element
