岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
10期
2763-2768,2809
,共7页
汪时机%韩毅%李贤%石朗晶%张雅倩%陈正汉
汪時機%韓毅%李賢%石朗晶%張雅倩%陳正漢
왕시궤%한의%리현%석랑정%장아천%진정한
膨胀土%CT-三轴试验%圆柱孔破损%结构演化%弱化
膨脹土%CT-三軸試驗%圓柱孔破損%結構縯化%弱化
팽창토%CT-삼축시험%원주공파손%결구연화%약화
expansive soil%CT-triaxial test%cylindrical hole damage%structural evolution%weakening
通过8组不同孔径破损膨胀土的CT-三轴试验,研究了圆柱孔破损重塑膨胀土的变形、强度特性以及破损结构的演化规律。试验结果表明:圆柱孔破损对膨胀土的强度有明显的弱化作用,但破损孔径大小的影响不大。吸力一定时,圆柱孔面积变化随着净围压的增加而减小;净围压相同时,吸力大的试样圆柱孔面积减少得越大。净围压在破损重塑膨胀土结构演化中发挥重要作用,随着净围压从50 kPa增加到200 kPa,CT图像的均值(ME值)提高幅度增大,试样内部的平均密度变大;相应地,CT图像的标准差(SD值)降低的幅度也增大,试样结构趋于均匀化。
通過8組不同孔徑破損膨脹土的CT-三軸試驗,研究瞭圓柱孔破損重塑膨脹土的變形、彊度特性以及破損結構的縯化規律。試驗結果錶明:圓柱孔破損對膨脹土的彊度有明顯的弱化作用,但破損孔徑大小的影響不大。吸力一定時,圓柱孔麵積變化隨著淨圍壓的增加而減小;淨圍壓相同時,吸力大的試樣圓柱孔麵積減少得越大。淨圍壓在破損重塑膨脹土結構縯化中髮揮重要作用,隨著淨圍壓從50 kPa增加到200 kPa,CT圖像的均值(ME值)提高幅度增大,試樣內部的平均密度變大;相應地,CT圖像的標準差(SD值)降低的幅度也增大,試樣結構趨于均勻化。
통과8조불동공경파손팽창토적CT-삼축시험,연구료원주공파손중소팽창토적변형、강도특성이급파손결구적연화규률。시험결과표명:원주공파손대팽창토적강도유명현적약화작용,단파손공경대소적영향불대。흡력일정시,원주공면적변화수착정위압적증가이감소;정위압상동시,흡력대적시양원주공면적감소득월대。정위압재파손중소팽창토결구연화중발휘중요작용,수착정위압종50 kPa증가도200 kPa,CT도상적균치(ME치)제고폭도증대,시양내부적평균밀도변대;상응지,CT도상적표준차(SD치)강저적폭도야증대,시양결구추우균균화。
The properties of deformation, strength and structural evolution of cylindrical hole damaged expansive soil are investigated by eight CT-triaxial tests. The results show that the strength of the samples with the cylindrical holes is significantly weakened because of the hole damage. Howerver, the hole size has little influence on the strength of the sample. The hole section area decreases when net confining pressure increases under a certain suction. The reduction of the hole section area is more obvious when the suction is larger under the same net confining pressure. Moreover, the net confining pressure plays an important role on the structural evolution of the cylindrical holes in the remolded expansive soils. The increment of the mean value (ME value) is enhanced gradually when the net confining pressure is changed from 50 kPa to 200 kPa. It means the sample becomes denser when the confining pressure is larger. Accordingly, the decrement of the standard deviation (SD value) increases gradually. The structure of the sample becomes homogenized during the test.