近松散层突水涌砂诱发的沉降试验研究  

Experimental Study on Settlement Caused by Water and Sand Outburst of Near Unconsolidated Soil Layers

作　　者：张翔 刘成禹[1,2] 陈博文 

机构地区：[1]福州大学环境与资源学院,福建福州350116 [2]地质工程福建省高校工程研究中心,福建福州350116

出　　处：《水利与建筑工程学报》2017年第6期116-121,共6页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金资助项目(41272300)

摘　　要：针对近松散层突水、涌砂诱发的沉降问题,设计了一套可以改变涌口直径模拟砂、水涌出的可视化试验装置,对粒径0.075 mm^2 mm标准砂、5 mm^10 mm粗砂构成的砂体,在不同涌口尺寸及不同水力比降下突水、涌砂诱发的沉降规律进行了研究。试验结果表明:细颗粒含量87%、粗颗粒含量13%组成的砂体,当涌口直径大于8 mm时,砂体会发生沉降;继续增大涌口直径,大于16 mm后,砂体会发生溃砂;细颗粒含量60%、粗颗粒含量40%组成的砂体,当水力比降为3.5时,砂体会发生溃砂;当水力比降在6.0~7.5时,细颗粒在渗流力的作用下会在涌口上方形成土拱和滤层,阻止颗粒流失,砂体不会发生沉降。砂体发生沉降时,沉降影响半径和沉降中心深度与涌口直径和水力比降呈线性关系。In order to understand the mechanism of the underground engineering settlement caused by water and soil outburst,a set of visual test device that can change the blow mouth diameter and simulate gushing of water and sand is designed. This device is then used to study the water and sand outburst rule of standard sand（ particle size is 0. 075 mm ~ 2 mm） and coarse sand（ particle size is 5 mm ~ 10 mm） under the condition of different pouring mouth sizes and different hydraulic gradient. Experiment results show that：（ 1） For the soil consisted of 87% fine particle and 13% coarse particle,when the blow mouth diameter is more than 8 mm,settlement happens; when it keeps being larger until reach 16 mm,quicksand happens.（ 2） For the soil consisted of 60% fine particle and40% coarse particle,when hydraulic gradient reaches 3. 5 quicksand happens; when hydraulic gradient is within 6~ 7. 5,fine particles build soil arch and filters above the blow mouth by seepage force,which preventing particles loss,the soil will not settle.（ 3） As the soil settling,the diameter and middle depth influenced by settlement have a linear relationship with blow mouth diameter and hydraulic gradient.

关 键 词：沉降 涌口直径 水力比降 溃砂 

分 类 号：TU411[建筑科学—岩土工程]