结构面泥岩非线性蠕变特性试验研究  

Experimental Study of Nonlinear Creep Characteristics of Mudstone with Structural Surface

作　　者：刘晓林[1] 苏荣华[1] 马壮[1] 沈洪爽 王莹 

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000

出　　处：《实验力学》2017年第6期865-870,共6页Journal of Experimental Mechanics

基　　金：国家自然科学基金面上项目(51474120)资助

摘　　要：利用自制蠕变试验装置对含有平直闭合结构面的泥岩试样进行单轴蠕变试验研究。结果表明:轴向应力为8~12MPa时,结构面泥岩蠕应变与总应变比值呈线性增加;随着轴向应力增加,蠕应变与总应变比值突变呈上凹型增加,继而呈上凸型变化;结构面泥岩蠕变速率随轴向应力增加衰减显著,与时间为负指数关系。为描述不同轴向应力下结构面泥岩蠕变规律,提出一种非线性元件与时间呈负指数关系的非线性黏滞体,构建结构面泥岩法向非线性蠕变模型,并进行参数辨识及拟合分析。分析发现改进的Burgers模型能很好地描述结构面泥岩的法向非线性蠕变特性。Structural surface has an important influence on rock creep characteristics.Using self-made creep experimental device,uniaxial creep experiment was carried out for mudstone specimens with flat closed structural surface.Experimental results show that when axial stress is 8~12 MPa,the ratio of creep strain to total strain of mudstone with structural surface increases linearly.With the increase of axial stress,the ratio of creep strain to total strain varies nonlinearly,exhibiting concave first convex later pattern.Creep rate of mudstone with structural surface obviously decreases with the increase of axial stress,exhibiting negative exponent relation with time.In order to describe creep characteristics of mudstone with structural surface under different axial stresses,a kind of nonlinear elementnonlinear viscous body,which has negative exponential relation with time,was proposed.Combining with Burgers model,a normal nonlinear creep model of mudstone with structural surface was established,based on which,parameter identification and fitting analysis was performed.This improved Burgers model can well describe the creep characteristics of mudstone with structural surface.

关 键 词：结构面泥岩 单轴蠕变试验 非线性黏滞体 蠕变模型 

分 类 号：TU45[建筑科学—岩土工程]