长江科学院院报2017，Vol.34Issue(8)：135-138,143,5.DOI:10.11988/ckyyb.20160767
分级加载条件下深部灰岩蠕应变特性研究
Creep Strain Characteristics of Deep Limestone under Step Loading
摘要
Abstract
In the aim of exploring the creep characteristics of deep limestone,uniaxial creep tests were conducted with GDS-VIS triaxial rheometer by step loading on specimens from different depths.According to the test results,the mean value (0.758) of the ratio of long-term strength to instantaneous strength decreases as depth increases.Furthermore,the variation law of axial creep strain increment of limestone in different depths under different stress levels was investigated,and then axial creep strains were obtained by accumulating creep strain increment.Results revealed that creep strain increment decreased first and then increased dramatically with the increasing of stress level.As depth increased,the percentage of stress corresponding to the minimum creep strain increment obviously increased.Moreover,with the increase of loading level,the axial creep strain experienced three development stages from decelerated growth,constant growth and accelerated growth.When the stress percentage ratio of constant load was within the range from 60％ to 70％,creep strain tended to be stable;whereas beyond the range,the creep strain acceleratedly increased until creep failure.Therefore,the range of stress percentage could be taken as reference for identifying whether creep failure will happen or not for deep limestone.关键词
采矿工程/深部灰岩/蠕应变特性/单轴蠕变试验/分级加载/长期强度Key words
mining engineering/deep limestone/creep strain characteristics/uniaxial creep test/step loading/long-term strength分类
矿业与冶金引用本文复制引用
肖伟晶,王晓军,陈辰,卓毓龙,李永欣..分级加载条件下深部灰岩蠕应变特性研究[J].长江科学院院报,2017,34(8):135-138,143,5.基金项目
国家自然科学基金项目(51564012) （51564012）
江西省科技支撑计划项目(20141BBE50005) （20141BBE50005）
