【作者】 张春雷；

【导师】 朱伟；

【作者基本信息】 河海大学 ， 岩土工程， 2007， 博士

【摘要】 疏浚工程中会产生大量的疏浚淤泥，固化方法可以有效的将废弃淤泥转化为土资源进行使用。针对淤泥固化机理难以定量研究的问题，本文提出从水分转化的角度对水泥加固淤泥的固化机理进行研究。具体研究内容如下：(1)淤泥固化过程中的水分转化规律研究。研究首先对水泥加固淤泥的特点进行了分析，提出将固化淤泥和水泥水分产物中的水分划分为自由水、结合水和矿物水，并以土水结合势能pF＞7.0作为矿物水的划分，以pF3.8～7.0作为结合水的划分。通过对三种淤泥在不同水泥量和不同龄期固化过程中矿物水和结合水的测定，分别建立了淤泥固化过程中随水泥量和龄期增加的水分转化模型。模型表明，水泥在固化淤泥过程中，首先与淤泥中低势能的自由水进行反应，将淤泥中的自由水转化为水泥水化产物中的矿物水和结合水。水化产物中的矿物水量可以用来表征结晶态水泥水化产物的量，水化产物中的结合水量可以用来表征凝胶态水泥水化产物的量。(2)固化淤泥力学性质研究。对三种淤泥在不同水泥量和龄期下固化后进行了无侧限抗压强度试验、等向压缩试验和固结不排水三轴剪切试验。通过试验明确了固化淤泥的强度、变形、破坏模式、抗剪强度参数、变形系数、结构屈服应力、等向压缩系数、固化淤泥孔隙比等指标随水泥量和龄期的变化规律。基于对力学性质的分析，提出了水泥加固淤泥过程的强度来源于水泥水化产物的胶结、填充和骨架支撑作用。(3)水分转化量与固化淤泥力学性质的关系。通过将水泥固化淤泥中水化产物中的矿物水量和结合水量与力学性质指标的定量分析，提出了结晶态水化产物对强度一直有贡献，而凝胶态水化产物的量当值比较低时，对强度贡献作用较低，增加到一定量时对强度起主导作用。当两种水化产物的量都比较低时，固化淤泥不具有明显的强度。更多还原

【Abstract】 Large amount of dredged materials (DM) may produce in dredging projects, solidification method can transfer it to useful soil resource effectively. As to the difficulties for quantitatively mechanism study, a new method was proposed to study the solidification mechanism from waster transfer angle. The particular content includes:(1) water transfer rule study during cement treated DM. The characteristics of cement solidification was analyzed firstly, a water phases classification method was proposed to classify water as free water, bound water and hydration water in solidified dredged material and cement hydration resultants. The soil-water suction potential index pF value was used to classify soil water, when pF value higher than 7.0, the water is hydration water. When pF value lies between 3.8 and 7.0, the water is bound water. Through the hydration water content and bound water content determination of different cement and curing time for three DMs, two water transfer models were built each for different cement content and different curing time. The water transfer models show cement reacts firstly with free water, the reaction can transfer free water to hydration water and bound water in cement hydration resultants. The hydration water in cement hydration resultants may be used to indicate the content of crystallized hydration resultants, while the bound water may be used to indicate the content of gel like hydration resultants.(2) Mechanical characteristics study of solidified DM. As to the three solidified DM at different cement content and curing time, unconfined compressive tests, iso-compression tests and consolidated undrained triaxial compression tests were done. Through tests the change rule of unconfined compressive strength, deformation, failure type, effective cohesion, deformation coefficient, structure failure stress, iso-compression coefficient and void ratio with cement content and curing time were make clear. Based on the analsis of mechanical behaviors of solidified DM, the conclusions of solidified DM strength comes from binding, filling and skeleton bracing actions of cement hydration resultants were drown.(3) Correlation analysis of water transfer content and mechanical properties. Through the quantitative analysis of hydration water content and bound water content- in cement hydration resultants with mechanical properties, the results show crystallized hydration resultants attribute to strength continuly, while when the content of gel like hydration resultants is small, the attribute is low, when the content increase to a certain value, the action of gel like hydration resultants exceed crystallized hydration resultants. When the two hydration resultants contents were small, the solidified DMs have no strength.更多还原