新拌固化淤泥的流动性和黏滞性试验研究  

Flowability and viscosity of freshly solidified dredged materials

作　　者：黄英豪 戴济群[1] 徐锴 HUANG Ying-hao;DAI Ji-qun;XU Kai(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing 210024,China;Geotechnical Department,Nanjing Hydraulic Research Institute,Nanjing 210024,China)

机构地区：[1]水文水资源与水利工程科学国家重点实验室,江苏南京210024 [2]南京水利科学研究院岩土工程研究所,江苏南京210024

出　　处：《岩土工程学报》2022年第2期235-244,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51879166);江苏省交通运输科技项目(2021Y07-1);中央级公益性科研院所基本科研业务费项目(Y320002)。

摘　　要：固化方法是当前处理大规模疏浚淤泥的重要方法,固化淤泥的流动性直接关系到能否进行大规模流动化浇筑施工,分别采用截锥圆模和旋转黏度计研究了两种淤泥和新搅拌固化淤泥的流动性和黏滞性。初始含水率对淤泥的流动性影响显著,并存在临界含水率w’≈2.0w_(L),高于此含水率时,流动性快速增大。淤泥固化后,流动性降低,水泥添加量越高,新拌固化淤泥流动性越小,且主要发生在水泥添加量ac≤50 kg/m^(3)。初始含水率对新拌固化淤泥流动性的影响也存在临界含水率w’_(s),w’_(s)和水泥添加量有关,当a_(c)=50 kg/m^(3),w’_(s)≈2.8w_(L),此时新拌固化淤泥的流动性约为未固化淤泥的2/3。黏滞性试验表明:含水率w>12.0w_(L),淤泥为牛顿流体;2.0w_(L)≤w≤12w_(L),为宾汉姆流体;w<2.0w_(L),为带屈服值的伪塑性流体。当淤泥的初始含水率w>2.8w_(L)时,新拌固化淤泥为宾汉姆流体;当w<2.8w_(L)时,新拌固化淤泥近似为带屈服值的幂律流体。新拌固化淤泥的黏滞系数μ和动切力τ_(0)都大于原泥的,且都随初始含水率增大而减小。水泥添加量对对黏滞系数的影响主要发生在ac≤50 kg/m^(3)。当淤泥或者固化淤泥满足宾汉姆流体方程时,根据浅水方程推导了屈服应力和流动度之间的关系。The solidification method is an important way to dispose a large amount of dredged materials,and the flowability of freshly solidified dredged materials determines how to construct.The flowability and viscosity of two kinds of freshly solidified dredged materials are examined by the cone-cut and rotational viscometer tests.The initial water content influences the flowability and there is a critical water content,w’ ≈2.0 w_(L).When w is above w’,the flowability increases quickly.The flowability decreases a lot after solidified.The more the cement amount,the less the flowability,and it mainly happens when ac≤50 kg/m^(3).There is also a critical water content w’_(s) that influences the flowability of freshly solidified dredged materials,and w’_(s) is related to the cement content.When a_(c)=50 kg/m^(3),w’_(s) ≈2.8 w_(L),and the flowability of freshly solidifed dredged materials is about 2/3 of that of rawly dredged materials.The rotational viscometer tests show that when w>12.0 w_(L),the dredged materials are the Newtonian fluid;when 2.0 w_(L) ≤w≤12 w_(L),they belong to the Bingham fluid;and when w<2.0 w_(L),they are the pseudoplastic fluid with yield value.When w>2.8 w_(L),the freshly solidified dredged materials are defined as the Bingham fluid;and when w<2.8 w_(L),they are defined as the power-law fluid.The values of μ and τ_(0) of freshly solidified dredged materials are larger than those of rawly dredged materials,and both of them decrease with the increasing water contents.The cement content influences μ and τ_(0) mainly when ac≤50 kg/m^(3).When the dredged materials and freshly solidified dredged materials are the Bingham fluid,the relationship between τ_(0) and flowability is determined according to two-dimensional shallow water equation.

关 键 词：流动性 新拌固化淤泥 临界含水率 黏滞性 黏滞系数 动切力 宾汉姆流体 

分 类 号：TU444[建筑科学—岩土工程]