岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
z2期
115-120
,共6页
方祥位%申春妮%李春海%汪龙%刘厚健
方祥位%申春妮%李春海%汪龍%劉厚健
방상위%신춘니%리춘해%왕룡%류후건
Q2黄土%浸水%三轴%湿陷性
Q2黃土%浸水%三軸%濕陷性
Q2황토%침수%삼축%습함성
Q2 loess%wetting%triaxial%collapsibility
利用GDG型高压固结仪和自行研制的非饱和土湿陷三轴仪对陕西蒲城电厂Q2黄土一维和三维应力状态下的湿陷性进行了试验研究,分析了Q2黄土的湿陷特性。试验结果表明:一维状态下,Q2黄土以中等和弱湿陷为主,峰值湿陷系数随深度增加而变小,常规压力下不湿陷的Q2黄土在高压力下可能湿陷,Q2地层中黄土层的湿陷性总体上强于古土壤层,湿陷的敏感性较弱,大型工程宜用实际压力评价湿陷性。三维状态下,湿陷应变随浸水量的变化曲线可以近似分为3段,即湿陷应变缓慢增加段、快速发展段和基本不变段;浸水前的吸力、净围压、偏应力对湿陷过程均有影响,且偏应力和吸力的影响更明显;三轴浸水过程湿陷体应变随湿陷轴应变的增加而增大,几乎是一条直线,体现了湿陷变形的特殊性。
利用GDG型高壓固結儀和自行研製的非飽和土濕陷三軸儀對陝西蒲城電廠Q2黃土一維和三維應力狀態下的濕陷性進行瞭試驗研究,分析瞭Q2黃土的濕陷特性。試驗結果錶明:一維狀態下,Q2黃土以中等和弱濕陷為主,峰值濕陷繫數隨深度增加而變小,常規壓力下不濕陷的Q2黃土在高壓力下可能濕陷,Q2地層中黃土層的濕陷性總體上彊于古土壤層,濕陷的敏感性較弱,大型工程宜用實際壓力評價濕陷性。三維狀態下,濕陷應變隨浸水量的變化麯線可以近似分為3段,即濕陷應變緩慢增加段、快速髮展段和基本不變段;浸水前的吸力、淨圍壓、偏應力對濕陷過程均有影響,且偏應力和吸力的影響更明顯;三軸浸水過程濕陷體應變隨濕陷軸應變的增加而增大,幾乎是一條直線,體現瞭濕陷變形的特殊性。
이용GDG형고압고결의화자행연제적비포화토습함삼축의대협서포성전엄Q2황토일유화삼유응력상태하적습함성진행료시험연구,분석료Q2황토적습함특성。시험결과표명:일유상태하,Q2황토이중등화약습함위주,봉치습함계수수심도증가이변소,상규압력하불습함적Q2황토재고압력하가능습함,Q2지층중황토층적습함성총체상강우고토양층,습함적민감성교약,대형공정의용실제압력평개습함성。삼유상태하,습함응변수침수량적변화곡선가이근사분위3단,즉습함응변완만증가단、쾌속발전단화기본불변단;침수전적흡력、정위압、편응력대습함과정균유영향,차편응력화흡력적영향경명현;삼축침수과정습함체응변수습함축응변적증가이증대,궤호시일조직선,체현료습함변형적특수성。
A series of collapsibility tests on Q2 loess of Pucheng power plant in Shaanxi province under 1D and 3D stress conditions were conducted using GDG high pressure oedometer and unsaturated collapsible triaxial apparatus. Under 1D stress condition, the collapsibility of Q2 loess is moderate or weak. The maximum coefficient of collapsibility decreases with the increase of depth. The Q2 loess is not collapsible under low pressure, but it is possibly collapsible under high pressure. The collapsibility of Q2 loess layer is stronger than that of ancient layer. The collapsibility sensibility of Q2 loess is weaker. Large-scale projects should use actual pressure to evaluate collapsibility of Q2 loess. Under 3D stress condition, curves of collapsible strain in terms of quantity of wetting are divided into three stages:the collapsible strain increasing slightly, the collapsible strain increasing rapidly and the collapsible strain being almost unchanged. The influences of net confining pressure, deviatoric stress and suction, especially the latter two, on the collapsible strain during the process of wetting are obvious. The collapsible volumetric strain increases with the increase in the collapsible deviatoric strain and the relationship is almost linear.