冻融循环下煤渣改良土的强度及屈服特性  

Strength and yield characteristics of cinder improved soil under freeze-thaw cycles

作　　者：张向东[1] 任昆[1] ZHANG Xiangdong;REN Kun(School of Civil Engineering,Liaoning Technical University,Fuxin123000,China)

机构地区：[1]辽宁工程技术大学土木工程学院,辽宁阜新123000

出　　处：《煤炭学报》2018年第12期3371-3378,共8页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51774166);高等学校博士学科点专项科研基金资助项目(20112121110004)

摘　　要：为研究煤渣改良土强度及屈服特性,通过不同冻融循环次数下的三轴试验,获得了配合比及冻融循环次数对煤渣改良土强度特性及屈服面的影响。通过引入配合比影响因子及冻融次数影响因子对改良土屈服面的表达形式进行了修正,推导了改良土的双屈服本构关系。研究表明:随着煤渣掺量的提高,改良土的黏聚力先增大后减小,内摩擦角稍有增加。剪应变屈服面及体应变屈服面出现先扩张后收缩的变化规律。随冻融次数的增加改良土的黏聚力降低明显,内摩擦角的变化不大。剪应变屈服面及体应变屈服面随冻融次数的增加而逐渐向原点收缩。采用配合比影响因子及冻融次数影响因子可较好的反映改良土屈服面的演化规律,据此建立的本构关系具有一定的精度。To study the strength and yield characteristics of cinder-improved soil,the triaxial tests under different freeze-thaw cycles were carried out.The influence of mix proportion and freeze-thaw cycles on the strength characteristics and yield surface of cinder-improved soil were obtained through the tests.The expression of yield surface was modified by introducing the influence factor of mix proportion and freeze-thaw cycles,and the double yield constitutive relation of improved soil was obtained.The results show that with the increase of cinder content,the cohesion of the improved soil increases first and then decreases,the internal friction angle increases slightly.Shear strain yield surface and volumetric strain yield surface exhibit the rule of first expansion and then shrinkage.With the increase of freeze-thaw cycles,the cohesion of the improved soil decreases obviously,while the internal friction angle changes little.Shear strain yield surface and volumetric strain yield surface gradually shrink to the origin with the increase of freeze-thaw cycles.The influence factors of mix proportion and freeze-thaw cycles can better reflect the evolution of the yield surface of the improved soil.The constitutive relationship based on the results has a better accuracy.

关 键 词：改良土 配合比 冻融循环 强度 屈服面 影响因子 

分 类 号：TU43[建筑科学—岩土工程]