泥炭土的水力和电阻率特性试验研究  

An experimental study of the hydro-mechanical and electrical properties of peat

作　　者：常高黎 公飞 赵红芬 CHANG Gaoli;GONG Fei;ZHAO Hongfen(School of Civil Engineering,Sun Yat-sen University,Zhuhai 519082,China)

机构地区：[1]中山大学土木工程学院,广东珠海519082

出　　处：《中山大学学报（自然科学版）（中英文）》2023年第4期10-20,共11页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：National Natural Science Foundation of China(5227912)。

摘　　要：泥炭土是一种高度结构化,复杂多孔介质,具有独特的水-力特性。土体结构、孔隙比和纤维含量等物理性质对泥炭土的力学特性有十分重要的影响。感应极化(IP)技术通过测量电导率的实部(σ’)和虚部(σ’’)来评估岩石和土体的物理、化学和水文地质性质。目前,泥炭土的电导率(σ’和σ’’)与其物理性质之间的关系还不明确。本文改进了固结仪使其能进行电导率测量,针对原状样和重塑样开展了系列试验。试验结果表明,纤维泥炭土微观结构上的各向异性导致了其水-力和电导率呈现出各向异性。在固结过程中,泥炭土的结构不断演化,各向异性程度逐渐降低,伴随着σ’的降低,σ’’则没有受到显著影响。σ’和σ’’都随着孔隙流体电导率σ_(w)的增加而显著增加,且近似于σ_(w)的幂指数关系。Peats are structured and highly complex porous media,with unique hydro-mechanical responses.The complex behaviour of peats is affected by several soil properties,such as soil fabric,void ratio,and fibre content.The induced polarization(IP)technique measuring the real(σ')and the imaginary part(σ'')of the complex electrical conductivity has been used to estimate the physical,chemical and hydrogeological properties of rock and soils.However,the relationships between electrical conductivity(σ'andσ'')and those peat properties are rarely known.For this purpose,a modified hydraulic oedometer cell with electrical measurement was built for laboratory investigation.A series of tests on natural and reconstituted peat samples were performed.The test results show that the fabric anisotropy of fibrous peats plays a crucial role in the hydro-mechanical and electrical conductivity anisotropy.The degree of anisotropy decreases gradually during the consolidation process,accompanied by a decrease inσ',whereas theσ''is not significantly affected.Both theσ'andσ''are strongly increased with pore fluid conductivityσ_w,approximating power-law dependence onσ_w.

关 键 词：电导率 土体结构 各向异性 孔隙流体电导率 

分 类 号：TV213.4[水利工程—水文学及水资源]