波浪荷载作用下饱和钙质砂孔压特性及累积损失能量试验研究  

Experimental study on pore water pressure characteristics and accumulated loss energy of saturated calcareous sand under wave loading

作　　者：沈扬[1] 马英豪 芮笑曦 SHEN Yang;MA Ying-hao;RUI Xiao-xi(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210098,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098

出　　处：《岩土力学》2023年第8期2195-2204,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51979087)。

摘　　要：钙质砂是一种海洋生物成因土,为我国南海岛礁吹填的主要材料。研究其动力特性对开发南海资源意义重大。实际工程中,钙质砂主要受到幅值和主应力方向均变化的波浪荷载作用,其作用效果与一般定轴剪切试验有较大不同。因此,利用空心圆柱扭剪仪模拟波浪荷载,开展一系列饱和钙质砂的不排水试验,重点研究循环应力比CSR和相对密实度Dr对钙质砂孔压特性的影响,并与石英砂对比分析,发现颗粒形态差异导致了两类砂土不同的孔压发展模式。同时,引入能量法,初步探究钙质砂累积损失能量变化规律。在此基础上,建立了考虑不同相对密实度的钙质砂孔压-累积损失能量模式。Calcareous sand is a type of marine biogenic sand,which is the main material for the hydraulic filling of islands and reefs in the South China Sea.Studying dynamic characteristics of calcareous sand is of great significance to the development and utilization of resources in the South China Sea.In actual engineering,calcareous sand is mainly affected by wave loading that changes both in amplitude and principal stress direction.The effect of wave loading is quite different from that of fixed principal stress axes loading.Therefore,torsional shear apparatus that can simulate wave loading are used to carry out a series of undrained tests on saturated calcareous sand,mainly to study the influences of cyclic stress ratio(CSR)and relative density(Dr)on the characteristics of pore water pressure.The results are further compared with quartz sand,finding that differences in particle shape leads to the different pore water pressure development patterns between calcareous sand and quartz sand.In addition,the energy method is introduced to preliminarily examine the development of accumulated energy loss.On the basis,a model considering different relative densities is established to describe the relationship between pore water pressure and accumulated loss energy.

关 键 词：波浪荷载 钙质砂 孔压特性 累积损失能量 

分 类 号：TU452[建筑科学—岩土工程]