软土结构性对次固结系数的影响  

Effect of soft clay structure on secondary consolidation coefficient

作　　者：张先伟[1,2] 王常明[1] 

机构地区：[1]吉林大学建设工程学院,长春130000 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071

出　　处：《岩土力学》2012年第2期476-482,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.40572153)

摘　　要：天然沉积的软土普遍具有结构性,常规计算软土次固结变形的方法并没有反映结构性的影响。通过对漳州与青岛地区原状软土与重塑土进行次固结试验,研究软土结构性对次固结系数C a的影响。结果表明,软土的C a随压力P增大而增大,在P接近结构屈服压力k时达到最大值,此后逐渐减小,受P影响减弱,最后与重塑土的C a趋于一致;重塑土的Ca受压力影响很小,可视为常数。根据次固结系数与压缩指数比值a cC/C确定C a可能存在一定误差。由于结构性的影响,正常固结软土表现出"假超固结"现象,采用超固结角度对结构性软土Ca变化规律进行说明并不合适,而根据不同压力下软土结构破损的情况可以很好解释这一现象。The natural sedimentary soft clay behaves the structural characteristic,the influence of which can not be reflected in the process of computing secondary consolidation of soft clay by conventional method.Secondary consolidation test on undisturbed and remolded soil samples from Zhangzhou and Qingdao are performed for researching the influence of soft soil structural characteristic on the secondary consolidation coefficient.It is shown that soft soils＇ increases with the increasing pressure P,and it gets to maximum while P gets close to yield pressure,and then it decreases and influenced little by P.Finally,it tends to be consistent with remolded soil clays＇.The remoulded soft clays＇ which is influenced little by P is regarded as a constant.Determing according to may have some error.The normally consolidated soft clay may show false over-consolidation because of soil＇s structural characteristic,therefore,it is improper to illustrate structural soft clays＇ by using normally consolidated soft clay;it can be well illustrated according to the damage of soft clay structure under different pressures.

关 键 词：软土结构性 次固结系数 结构屈服压力 

分 类 号：TU435[建筑科学—岩土工程] TU413.6[建筑科学—土工工程]