高速远程滑坡裹气流态化模型试验研究  

Study of fluidized characteristics of rock avalanches under effect of entrapped air

作　　者：王玉峰[1] 程谦恭[1] 张柯宏 仲昱全 罗忠旭 

机构地区：[1]西南交通大学地质工程系,成都610031

出　　处：《岩土力学》2014年第10期2775-2786,共12页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.41172260;No.41372292;No.51108393);国家重点基础研究发展计划(973)项目(No.2008CB425801);高等学校博士学科点专项科研基金项目(No.20110184110018);西南交通大学博士生创新基金

摘　　要：为分析高速远程滑坡运动过程中碎屑流的裹气流态化特性，以汶川地震触发的谢家店子滑坡为原型，运用自行设计的流化床试验装置，开展了一系列高速远程滑坡碎屑流裹气流态化特性的试验研究。结果表明：（1）对于颗粒粒径变化范围广（0.1～7 mm者均有）、颗粒形状极不规则、且底部细颗粒含量高的类滑坡碎屑，其床层压降随着供风量的增加并非呈线性增长趋势，而是表现出明显的气泡控制性特征，随堆积体内部气泡和气垫层位置的不同，堆积体各部位床层压降相差较大；（2）当供风量较低时，碎屑堆积体整体稳定性较好，在堆积体表面仅可见有限气体逸散孔的分布；当供风量达到一定值后，堆积体内部流态化特性增强，可见砂质密云、气孔、纵向脊等一系列与高速远程滑坡实例中相类似现象的出现；（3）对于滑坡类不规则颗粒，其间容易形成架桥现象，增强碎屑流整体稳定性，使气流不易扩散，在堆积体下方形成高压气垫层，产生空气擎托现象。For the study of the flow behavior of rock avalanches under the effect of entrapped air, the Xiejiadianzi rock avalanche is studied with a series of experiments, equipped with a fluidized bed designed by authors. Based on the experimental data, the following results are reached：（1） For materials having wide grain size distribution （ranging from 0.1 to 7 mm）, sharp irregular shapes, and high fine-grain content at its lowest part, an obvious bubbling control characteristic, not a linear increasing trend, is displayed as the quantity of air increases. Variation of the positions of bubbles or the air cushion layer causes significant differences in bed pressure drops. （2） When air quantity is low, the deposit presents a high stability with limited air holes observed. As the increase of air quantity, the fluidization intensity of the deposit increases obviously with some fluidization characteristics observed, such as dense sandy cloud, air holes, and ridges, which are similar to the phenomena observed in field rock avalanche deposits. （3） For such irregular shaped debris, bridging phenomenon is easy to form, which can strengthen the stability of deposit and prevent the escape of entrapped air. When air quantity is high enough, an air cushion effect can be observed at the bottom of deposit with air born system formed.

关 键 词：高速远程滑坡 流化床 石英颗粒 供风量 床层压降 流态化 

分 类 号：P64[天文地球—地质矿产勘探]