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
2010年
3期
485-492
,共8页
岩石力学%非贯通节理%直剪试验%Jennings准则%岩桥弱化%起伏角
巖石力學%非貫通節理%直剪試驗%Jennings準則%巖橋弱化%起伏角
암석역학%비관통절리%직전시험%Jennings준칙%암교약화%기복각
rock mechanics%intermittent joints%direct shear test%Jennings criterion%rock bridge weakening%undulating angle
通过对具有不同粗糙程度(以节理面起伏角表示)的共面非贯通人工节理进行不同法向应力水平下的直剪试验,研究节理面起伏角对非贯通节理剪切强度的影响,分析在剪切过程中岩桥力学参数的弱化机制.现有Jennings准则将岩桥视为完整岩块,计算所得的剪切强度与直剪试验结果存在较大偏差.在试验结果的基础上,考虑剪切过程中岩桥力学参数的弱化和节理面起伏角的影响,对Jennings准则进行修正.将修正Jennings准则计算的非贯通节理剪切强度结果与直剪试验结果对比,结果表明:修正Jennings准则的计算结果与试验结果吻合较好,能较好地预测具有规则起伏角的非贯通节理剪切强度.
通過對具有不同粗糙程度(以節理麵起伏角錶示)的共麵非貫通人工節理進行不同法嚮應力水平下的直剪試驗,研究節理麵起伏角對非貫通節理剪切彊度的影響,分析在剪切過程中巖橋力學參數的弱化機製.現有Jennings準則將巖橋視為完整巖塊,計算所得的剪切彊度與直剪試驗結果存在較大偏差.在試驗結果的基礎上,攷慮剪切過程中巖橋力學參數的弱化和節理麵起伏角的影響,對Jennings準則進行脩正.將脩正Jennings準則計算的非貫通節理剪切彊度結果與直剪試驗結果對比,結果錶明:脩正Jennings準則的計算結果與試驗結果吻閤較好,能較好地預測具有規則起伏角的非貫通節理剪切彊度.
통과대구유불동조조정도(이절리면기복각표시)적공면비관통인공절리진행불동법향응력수평하적직전시험,연구절리면기복각대비관통절리전절강도적영향,분석재전절과정중암교역학삼수적약화궤제.현유Jennings준칙장암교시위완정암괴,계산소득적전절강도여직전시험결과존재교대편차.재시험결과적기출상,고필전절과정중암교역학삼수적약화화절리면기복각적영향,대Jennings준칙진행수정.장수정Jennings준칙계산적비관통절리전절강도결과여직전시험결과대비,결과표명:수정Jennings준칙적계산결과여시험결과문합교호,능교호지예측구유규칙기복각적비관통절리전절강도.
The shear strength of intermittent joints in rock masses has an important influence on the stability of blocky rock system. For a single rock joint,the surface roughness is of paramount importance to its mechanical property,such as shear strength. Many theoretical criterions have been proposed to predict the shear strength of intermittent joints,of which the Jennings criterion is the most widely used one. However,in Jennings criterion,the mechanical parameters of joint surface and rock bridge are simply averaged by a weight coefficient called connectivity rate to calculate equivalent mechanical parameters and the surface roughness isn't taken into account. So the direct shear tests are carried out on artificial coplanar intermittent joints with different surface undulating angles under different normal stresses to investigate the influence of undulating angle on the strength of intermittent joint and analyze the mechanism of the weakening of rock bridge mechanical parameters. Based on the direct shear test data,modifications are made to the Jennings criterion by considering the weakening of the mechanical parameters of rock bridge and the surface undulating angle during shear process. And comparisons between the results computed with modified Jennings criterion and the shear test data are made to evaluate the effect of modification;it is shown that the calculated results according to the modified Jennings criterion agree well with the experimental data;and the modified Jennings criterion is able to predict the shear strength of the intermittent joints with regular surface undulating angle well.