【作者】 石明生；

【导师】 王复明；

【作者基本信息】 大连理工大学 ， 水工结构工程， 2011， 博士

【摘要】 本文针对我国堤坝防渗加固工程的迫切需要和高聚物注浆技术的发展,以非水反应类双组份发泡聚氨酯为浆材,在对材料特性进行系统研究的基础上,提出了堤坝防渗加固高聚物定向劈裂注浆方法,主要研究内容如下：(1)根据非水反应类双组份发泡聚氨酯材料的特点,研制了材料压缩、弯曲、拉伸试验所需的试样注浆成型模具及膨胀力、材料抗水渗透性能试验装置,对双组份发泡聚氨酯注浆材料的物理力学特性进行了较为全面的试验研究,获得了大量的材料特性试验成果；建立了材料密度与最大膨胀力、材料密度与起始渗水压力及材料密度与抗压强度、弯曲强度、拉伸强度的关系曲线。实验研究结果表明,双组份发泡聚氨酯是一种综合性能优良的堤坝防渗加固注浆材料。(2)通过大量的高聚物现场注浆试验,对双组份发泡聚氨酯高聚物注浆材料在土体中的扩散机理进行了深入研究；揭示了高聚物浆液在土体中主要以片状浆脉的方式扩散；具有自膨胀性的高聚物浆液对浆脉周围的土体还有挤密和渗透胶结作用。(3)根据高聚物注浆材料在土体中的扩散特征及高聚物注浆技术的特点,首次提出了堤坝防渗加固高聚物定向劈裂注浆方法,建立了定向劈裂缝扩展压力及开裂长度的理论计算公式。利用自行研制的定向劈裂钻具,采用定向劈裂注浆方法能定向构筑厚度为2～3 cIll左右的堤坝高聚物超薄防渗墙,墙体本身具有良好的力学和防渗性能,并能与墙体周围土体紧密结合,形成复合防渗体。(4)以流变学、断裂力学及岩土力学理论为基础,建立了非线性有限元粘结元模型,采用粘结元方法对高聚物定向劈裂注浆机理进行了数值模拟,计算出了不同注浆量时定向劈裂缝的扩展长度及开度,计算结果和现场试验的结果基本一致；为堤坝高聚物定向劈裂注浆方案的设计提出了一种有效方法。(5)在均质土坝上进行了高聚物定向劈裂注浆原型试验,现场注浆试验开挖结果表明,采用高聚物定向劈裂注浆技术在土体中形成的防渗体的厚度,扩展方向、扩展范围及搭接效果均达到预期效果,验证了堤坝高聚物定向劈裂注浆理论的正确性及方法的可行性。更多还原

【Abstract】 Aiming at the urgent need of reinforcement engineering in the dykes and dams and the development of the polymer grouting technology, using the non-aqueous reaction type two-component polyurethane foam as the grout material, the directional fracturing grouting technology is developed for anti-seepage reinforcement of dykes and dams on the basis of the systematic study of the material properties in this paper. The main researches are summarized below:(1) According to the characteristics of the two-component non-aqueous reaction type polyurethane foam, specimens grouting molds using in the compression, bending and tensile test and equipment testing the expansion force and permeability of material are developed. A large number of test results of material properties are obtained through the more comprehensive experimental study on the physical and mechanical properties of the two-component polyurethane foam grouting material. A group of curves are established including the largest expansion versus the density, the initial seepage pressure versus the density and the compressive strength, the bending strength and the tensile strength versus the density. The results show that two-component polyurethane foam is a comprehensive excellent grouting material in anti-seepage of dykes and dams.(2) Further studies on the diffusion mechanism of the two-component polyurethane foam polymer material propagation in the soil are carried through a large number of field tests. It reveals that the polymer grouting propagates in soil mainly in a mode of sheet veins and the self-expansion polymer grout is of compaction and penetration cementation to the surrounding soil.(3) Considering the characteristics of polymer injection material diffusion in the soil and the feature of the polymer grouting technology, the method using the polymer directional fracturing grouting in anti-seepage reinforcement of dykes and dams is firstly put forward. At the same time the theoretical formula on the directional fracturing crack propagation pressure and the cracking length is developed. Using the directional fracturing drilling tool developed by self and the directional fracturing method can directionally build a ultra-thin polymer anti-seepage wall about 2 to 3cm thickness which itself has good mechanical and anti-seepage properties and closely bonds with the surrounding soil, forming a composite impervious structure.(4) Based on the rheology, fracture mechanics and rock mechanics theory, a nonlinear finite element cohesive element model is established, and then the directional fracturing mechanism of the polymer grouting is simulated by using the bonding element method. As a result, the directional crack propagation length and opening width with the different grouting volume are obtained, which is basically consistent with the field test results. Thus an efficient method is presented for design in polymer directional fracturing grouting project of the dykes and dams(5) The polymer fracturing grouting prototype test is performed on the homogeneous earth dam. The site excavation results show that the impermeable body thickness, propagation direction, extended range and overlap effects formed in the soil reached expected results using the polymer directional fracturing grouting technique. It just verified correctness of the dam grouting polymer directional fracturing theory and feasibility of the method.更多还原