水利与建筑工程学报
水利與建築工程學報
수리여건축공정학보
TECHNIQUE OF SEEPAGE CONTROL
2015年
2期
99-102
,共4页
卸荷%回弹变形%卸荷变形模量%卸荷抗剪强度参数
卸荷%迴彈變形%卸荷變形模量%卸荷抗剪彊度參數
사하%회탄변형%사하변형모량%사하항전강도삼수
unloading%springback deformation%unloading deformation modulus%unloading parameters of shear strength
针对三峡库区中砂岩进行了三轴加载试验，及不同应力路径的三轴卸荷试验。试验结果表明：与加载破坏相比，卸荷破坏岩样表现出较强的脆性。卸荷作用引起了岩样变形模量、内摩擦角、黏聚力等力学参数的劣化，从而导致岩样质量的降低。卸荷路径不同时卸荷阶段应力－应变曲线形态有很大区别。按照轴压、围压等速率减小的路径卸载，卸荷阶段应力－应变曲线呈下凹形态且出现回弹变形，回弹变形占卸荷段总变形的比例随初始围压值的增大而减小。
針對三峽庫區中砂巖進行瞭三軸加載試驗，及不同應力路徑的三軸卸荷試驗。試驗結果錶明：與加載破壞相比，卸荷破壞巖樣錶現齣較彊的脆性。卸荷作用引起瞭巖樣變形模量、內摩抆角、黏聚力等力學參數的劣化，從而導緻巖樣質量的降低。卸荷路徑不同時卸荷階段應力－應變麯線形態有很大區彆。按照軸壓、圍壓等速率減小的路徑卸載，卸荷階段應力－應變麯線呈下凹形態且齣現迴彈變形，迴彈變形佔卸荷段總變形的比例隨初始圍壓值的增大而減小。
침대삼협고구중사암진행료삼축가재시험，급불동응력로경적삼축사하시험。시험결과표명：여가재파배상비，사하파배암양표현출교강적취성。사하작용인기료암양변형모량、내마찰각、점취력등역학삼수적열화，종이도치암양질량적강저。사하로경불동시사하계단응력－응변곡선형태유흔대구별。안조축압、위압등속솔감소적로경사재，사하계단응력－응변곡선정하요형태차출현회탄변형，회탄변형점사하단총변형적비례수초시위압치적증대이감소。
Triaxial compression tests and unloading confining tests were conducted with the medium sandstone of Three Gorges Reservoir as test rock samples .The results indicate that the sandstone sample undergone unloading failure is more brittle than that from the loading failure .Unloading failure leads to the deterioration of rock sample mechanical parame-ters ,namely deformation modulus ,internal friction angle ,and cohesion ,which means lower quality of the rock sample . Shapes of unloading stress-strain curves are very different due to different unloading paths .When the maximum and mini-mum stresses decrease simultaneously ,curves of unloading stage concave downward ,and springback deformations occur . In addition ,springback deformations decrease with the increase of initial confining pressure .
