砂砾料液化机理与孔压特性的试验研究  

Laboratory study on the mechanism and behaviour of saturated sand-gravel composites

作　　者：徐斌[1] 孔宪京[1] 邹德高[1] 娄树莲[1] 

机构地区：[1]大连理工大学土木水利学院,大连116023

出　　处：《东南大学学报（自然科学版）》2005年第A01期100-104,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(50278009);高等学校博士学科点专项科研基金资助项目(1999014126)

摘　　要：利用自行研制开发的高精度中型动三轴仪(试样尺寸φ200×510mm),对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5mm后的模拟料,采用相似级配法,运用DS-2T型动三轴仪(试样尺寸φ61.8×125mm)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和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,后者应变幅值在循环荷载作用过程中一直稳定增加.对影响砂砾料液化的主要因素进行了初步定量研究.By use of medium scale dynamic triaxial apparatus （specimen size φ200×500mm） made by ourselves, the development of axial strain and pore water pressure in sand-gravel composites tested during liquefaction is studied. Meantime, using DS-2T dynamic triaxial device （specimen sizeφ61.8×125 mm）, scalping the oversized gravel particles and taking similar grade method, a series of parallel tests are carried out, The development of shear strain and pore water pressure of sand-gravel composites and substituted material due to cyclic loading are 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 cannot reach the initial effective confining pressure. 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 is considered as the liquefaction standard, Once initial liquefaction occurred, specimens suddenly reach 3%-4% double amplitude strain. Some factors influencing sand-gravel composites liquefaction properties are investigated in quantity.

关 键 词：砂砾料 振动孔压 轴向应变 液化 含砾量 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]