岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2014年
7期
1388-1397
,共10页
许江%张敏%李波波%杜伟%周婷%曹偈
許江%張敏%李波波%杜偉%週婷%曹偈
허강%장민%리파파%두위%주정%조게
岩石力学%循环荷载%稳定时间%渗透率%滞后性
巖石力學%循環荷載%穩定時間%滲透率%滯後性
암석역학%순배하재%은정시간%삼투솔%체후성
rock mechanics%cyclic loads%stabilization time%permeability%lagging effect
为探讨在采动应力反复扰动下煤的变形及渗透特性,利用自主研发的含瓦斯煤岩热流固耦合三轴伺服渗流装置,进行不同稳定时间条件下煤的循环荷载试验。研究结果表明:(1)不同稳定时间条件下煤的循环加卸载应力-应变曲线不相重合,形成塑性滞回环;随着稳定时间的增加,渗透率有相同的变化趋势,初始渗透率下降幅度亦减小。渗透率与轴向应变随主应力差增加呈负相关变化,轴向应变增大渗透率减小,反之亦然。(2)煤的轴向应变最大值随稳定时间增加先减小后增大,并在稳定时间为100 s时到达最小;渗透率最小值随稳定时间增加先增大后减小,并在稳定时间为100 s时到达最大。煤的渗透率变化与轴向变形的发展密切相关。(3)不同稳定时间条件下煤的渗透率变化均滞后于体积应变变化,且随稳定时间的增加,滞后量有增大的趋势。
為探討在採動應力反複擾動下煤的變形及滲透特性,利用自主研髮的含瓦斯煤巖熱流固耦閤三軸伺服滲流裝置,進行不同穩定時間條件下煤的循環荷載試驗。研究結果錶明:(1)不同穩定時間條件下煤的循環加卸載應力-應變麯線不相重閤,形成塑性滯迴環;隨著穩定時間的增加,滲透率有相同的變化趨勢,初始滲透率下降幅度亦減小。滲透率與軸嚮應變隨主應力差增加呈負相關變化,軸嚮應變增大滲透率減小,反之亦然。(2)煤的軸嚮應變最大值隨穩定時間增加先減小後增大,併在穩定時間為100 s時到達最小;滲透率最小值隨穩定時間增加先增大後減小,併在穩定時間為100 s時到達最大。煤的滲透率變化與軸嚮變形的髮展密切相關。(3)不同穩定時間條件下煤的滲透率變化均滯後于體積應變變化,且隨穩定時間的增加,滯後量有增大的趨勢。
위탐토재채동응력반복우동하매적변형급삼투특성,이용자주연발적함와사매암열류고우합삼축사복삼류장치,진행불동은정시간조건하매적순배하재시험。연구결과표명:(1)불동은정시간조건하매적순배가사재응력-응변곡선불상중합,형성소성체회배;수착은정시간적증가,삼투솔유상동적변화추세,초시삼투솔하강폭도역감소。삼투솔여축향응변수주응력차증가정부상관변화,축향응변증대삼투솔감소,반지역연。(2)매적축향응변최대치수은정시간증가선감소후증대,병재은정시간위100 s시도체최소;삼투솔최소치수은정시간증가선증대후감소,병재은정시간위100 s시도체최대。매적삼투솔변화여축향변형적발전밀절상관。(3)불동은정시간조건하매적삼투솔변화균체후우체적응변변화,차수은정시간적증가,체후량유증대적추세。
To study the characteristics of deformation and permeability of coals under repeated disturbance of stresses,cyclic loading tests with different time lengths of stabilization were carried out using a servo-controlled triaxial seepage device which was developed in house. The loading and unloading stress-strain curves with different time lengths of stabilization form plastic hysteresis loops. As the time lengths of stabilization increased, the initial permeability reduced slowly but the trends of variation of the permeability remained the same. The permeability decreased with the increasing of the principal stress. The maximum axial strain of coal decreased initially and then increased as the time lengths of stabilization increased and it reached the minimum value at the time lengths of stabilization of 100 s. The minimum permeability of coal increased initially and then decreased and it reached the maximum value at the time lengths of stabilization of 100 s. The permeabilities of coals are closely related to the development of axial deformation. The variations of permeability were always lagged behind that of the volumetric strains. The lagged time lengths increased with the increasing of the time lengths of stabilization.