黄土湿陷系数同初始含水率和上覆压力的关系研究  

Study on Relation of Loess Collapsibility Coefficient to its Initial Moisture Content and Overburden Pressure

作　　者：赵成[1] 赵纪飞[1] 

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,西安710065

出　　处：《西北水电》2017年第4期4-7,共4页Northwest Hydropower

摘　　要：黄土湿陷变形使得工程造价变高,且工程事故引起的损失增大,湿陷性仍是值得研究和探索的问题。湿陷变形量的计算目前常用的方法有原位浸水试验和规范建议的湿陷系数法。原位浸水测试结果准确但成本高、耗时长,湿陷系数法更为常用,但计算结果和实际值差异很大,为此需对湿陷系数的影响因素进行研究。文章旨在探索湿陷系数与初始含水率和上覆压力的关系,在甘肃兰州和平镇取样进行基本物理力学性质的测试,取环刀样烘干后配置不同含水率的固结试验,双线法获得不同初始含水率和压力下的湿陷系数,分析其关系。结果表明:相同初始含水率下,湿陷系数随着压力的增大先快速增大后基本保持不变;相同压力下,初始含水率越高,湿陷系数越小。湿陷系数与初始含水率和上覆压力的关系可在三维空间中湿陷面表示,根据试验结果文章建立了该湿陷面的数学表达式。The loess collapsible defbnnation has the project cost increase and loss from the engineering incident becomes higher. Theretbre, col- lapsibility is still the topic to be studied and explored. The common calculation methods for the collapsible deformation currently applied include infiltration test in situ arm tire coefficient of collapsibility. Tire result of the infiltration test in situ is accurate but it costs highly and is time corrsu- ruing. The coetficient of collapsibility is a method comn^nly applied. But the calculation result by this method is quite different from the actual value. Factors impacting the coefficient of collapsibility shall be studied accordingly. In the paper, the relation of the loess coefficient of collaps- ibility to the initM moistare content and overburden pressure is explored. The physical and mechanical tests on sanrples from Heping Township, I anzhou, Gansn province have been can%d out. The consolidation tests on the samples taken by cutting ring and after being dried with different coisture contents have been performed. The coefficients of collapsibility under different initial moisture contents and pressure are achieved by application of the double-line method. The relation among them is studied. The study presents that under condition of the same initial moisture content, the coefficient of collapsibility increases rapidly then remains unchanged with the pressure increase. Under condition of the same pressure, the higher the initial moisture content is, the lower the coefficient of collapsibility is. The relation of the coefficient of collapsibility to the initial ,~fisture content and the overburden pressure can be displayed in the collapsible plane in 3D. The mathematic representation of tire collapsible plane is built in the paper based on the test results.

关 键 词：黄土 湿陷系数 初始含水率 上覆压力 湿陷面 

分 类 号：TU475.3[建筑科学—结构工程] TV223.21[建筑科学—土工工程]