循环荷载后原状与重塑饱和粉质黏土不排水强度性状研究  

Undrained strength characteristics of saturated undisturbed and remolded silty clay after cyclic loading

作　　者：郑刚[1,2] 霍海峰 雷华阳[1,2] 

机构地区：[1]滨海土木工程结构与安全教育部重点实验室,天津300072 [2]天津大学土木工程系,天津300072

出　　处：《岩土工程学报》2012年第3期400-408,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家重点基础研究发展计划(973计划)项目(2010CB732106);国家自然科学基金项目(51078262);天津大学自主创新基金项目(2010XJ-0101)

摘　　要：为研究循环荷载作用后原状土与重塑土不排水强度发展规律,针对天津典型粉质黏土做了一系列动、静力三轴试验。结果表明,振后原状土样不排水抗剪强度会发生衰减,当振后轴向应变大于3%时,衰减度β随动轴向应变增加呈现先增大后稳定的趋势;最大孔压比处于0.5～0.7之间时,不排水强度衰减较小,最大孔压比高于0.7时,振后强度开始迅速衰减;振后饱和粉质黏土不排水剪应力路径表现出超固结性质,随着β的增加,应力路径由正常固结向轻似超固结,再向重似超固结发展。对于重塑土,循环荷载作用后其不排水抗剪强度变化较小。Dynamic and static triaxial tests are carried out to study the patterns of undrained strength development of undisturbed and remolded clay after cyclic loading.The results show that the undrained strength of undisturbed saturated clay can degrade after cyclic loading,when the dynamic axial strain is higher than 3%,the reduction factor increases firstly and then keeps steady;the reduction factor keeps at low level when the ultimate pore pressure ratio stays at 0.5 to 0.7,and it will rise rapidly if it is higher than 0.7;and with the increase of the reduction factor β,the stress paths transform from normal consolidation to lightly quasi-overconsolidation,then to heavily quasi-overconsolidation.The strength of remolded saturated soft clay hardly changes after cyclic loading.

关 键 词：循环荷载作用 不排水强度 粉质黏土 饱和 不排水抗剪强度 性状 原状土样 轴向应变 

分 类 号：TU442[建筑科学—岩土工程]