摘要
利用自行研制、开发的高精度中型动三轴仪,对文选定的砂砾料液化过程中的孔隙水压力增长和轴向应变发展模式进行了研究。同时,对剔除粒径大于5 mm后的模拟料,采用相似级配法,运用DS-2T型动三轴仪进行了一组平行试验。着重比较了砂砾料和模拟料在振动荷载作用下孔压、应变发展模式的区别。结果表明:在均压固结条件下,砂砾料在循环应力作用下,其孔压的发展模式与模拟料不同,可以用修正的反正弦进行拟合,而模拟料振动孔压的发展模式可用反正弦拟合;二者振动孔压均达不到初始有效固结围压,约为初始围压的90%左右。模拟料与砂砾料在振动荷载作用下,应变发展模式不同。前者在初始液化前应变幅值较小且无明显增长,临近初始液化时应变大幅度增加导致试样突然破坏;后者在循环荷载作用过程中应变幅值一直稳定增加。
By use of medium scale dynamic triaxial apparatus made by Earthquake Engineering Research Division, Dalian University of Technology, the development of axial strain and pore water pressure in sand-gravel composites during liquefaction is studied experimentally. At the same time, using DS-2T dynamic triaxial device scalping the oversized gravel particles and taking similar gradation method, a series of parallel tests proceeded. The development of shear strain and pore water pressure of sand-gravel composites and substituted material due to cyclic loading were compared. The results show that with isotropic consolidation, the development of dynamic pore water pressure in sand-gravel composites differs from that in substituted material and its curve can be fitted by corrected arcsine. However, the pore water pressure curve in substituted material can be fitted by arcsine function. The maximum value of dynamic pore water pressure in both of them can not reach the initial effective confining pressure. Also, the response of axial strain in sand-gravel composites is variant from that in substituted material and it increases steadily during cyclic stress action. The development in substituted material is not appreciable before initial liquefaction; when pore water pressure reaches its maximum value which is considered as the liquefaction standard, once initial liquefaction occurred.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2006年第6期925-928,共4页
Rock and Soil Mechanics
基金
国家自然科学基金(No.5027800950578029)
大连理工大学海岸和近海工程国家重点试验室主任基金(No.LP0505)
关键词
砂砾料
振动孔压
轴向应变
液化
sand-gravel
dynamic pore water pressure
axial strain
liquefaction
