【作者】 刘瑾；

【导师】 施斌；

【作者基本信息】 南京大学 ， 地质工程， 2011， 博士

【摘要】 近年来水土流失、边坡坡面失稳、沙漠化、沙尘暴、扬尘等生态环境问题已经严重影响了人们的生活。高分子土壤稳定剂作为一类新型土壤稳定材料,可以改变土壤的物理结构,提高土壤力学强度、水稳定性、抗冲刷性、抗风蚀性等,同时不影响植被生长,优化生态环境,因此成为国内外学者研究的热点。论文针对目前高分子土壤稳定剂研发方面的不足,从土质改良的基本原理出发,研制出两种性能优越、成本低廉、施工简便、竞争力强、生态环保的高分子土壤稳定剂系列产品,并对稳定剂改性土的强度、稳定性、抗冲刷等性质进行了室内测试分析,最后对其改良机理及应用进行了研究,获得如下成果。1.研制了一类新型聚醋酸乙烯酯粘性土稳定剂。从高分子聚合原理和粘性土改性机理出发,确定了稳定剂的反应时间、试剂用量、反应温度等聚合条件,最终研制出了聚醋酸乙烯酯粘性土稳定剂系列产品。该产品是一种性能优越、成本低廉、施工简便、竞争力强、生态环保的高分子土壤稳定剂,可适用于粘性土边坡生态防护和水土保持等领域。2.研究了聚醋酸乙烯酯粘性土稳定剂改性土的强度性能,分析了养护条件和稳定剂掺量对改性土试样无侧限抗压强度和剪切强度参数的影响,得出了稳定剂的最佳养护时间,确定了稳定剂的最佳掺量。3.研究了聚醋酸乙烯酯粘性土稳定剂改性土的胀缩性,分析了稳定剂掺量和土颗粒粒径对改性土无荷膨胀率和线收缩率的影响,分析结果表明：改性土的胀缩性得到了明显的改良,试样的无荷膨胀率在土颗粒平均粒径为0.75mm时呈现出最低值,收缩率随着土颗粒粒径的增大而减少,同时无荷膨胀率和线收缩率均随着稳定剂浓度的增大而不断减少。4.研究了聚醋酸乙烯酯粘性土稳定剂改性土的水稳定性和抗冲刷性能,分析了稳定剂掺量对水稳定性和抗冲刷性的影响,分析结果表明稳定剂可以明显地提高改性土的水稳定性和抗冲刷性能。5.研制了一类新型聚氨酯固沙剂。在大量试验基础上研制出了聚氨酯固沙剂系列产品。该产品可以很好地提高砂性土颗粒间的连接力,从而提高了砂性上的强度、抗冲刷性和抗风蚀性等,是一种性能优越、施上简便、竞争力强、生态环保的高分子土壤稳定剂,可适用于水土保持、沙漠化治理和抑尘等领域。6.研究了PUA、PUB和PUC三种聚氨酯固沙剂改性十的强度性能,分析了稳定剂掺量对改性上试样无侧限抗压强度和剪切强度参数的影响,分析结果表明三种固沙剂改性上的无侧限抗压强度和内聚力都随稳定剂浓度增加而增加,而内摩擦角随着浓度的变化基本上保持不变。7.研究了PUA、PUB和PUC三种聚氨酯固沙剂改性土的抗冲刷和抗风蚀性能,分析了稳定剂掺最对改性上试样抗冲刷和抗风蚀性的影响,分析结果表明聚氨酯固沙剂可以明显地提高改性上的抗冲刷和抗风蚀性能。8.分析了聚醋酸乙烯酯粘性上稳定剂和聚氨酯固沙剂的改性机理,从粘性上和砂性上的特性出发,对两种稳定剂的性能进行了评价,并对它们的应用前景进行了分析。更多还原

【Abstract】 Recently the environmental problems such as soil erosion, slope instability, desertification, dust storms and dust have seriously affected on people’s lives. A new type of soil stabilization materials named polymer soil stabilizer has become the key study due to its properties of changing the physical structure of soil; improving mechanical strength, water-stability, erosion resistance; unaffecting vegetation growth; optimizing the ecological environment. In this thesis, based on the principle of soil improvement, two types of soil stabilizers have been developed to modify the different soil properties of clay and sand. These soil stabilizers have the properties of superior performance, simple construction, high competitive and environmental protection. In the laboratory tests, the properties of strength, stability and erosion resistance were studied, the modification mechanism and application was analyzed and the corresponding findings are presented as follows:1. According to the principle of macromolecule polymerization and clay improvement, a new type of polyvinyl acetate soil stabilizer has been developed. Based on lots of experimental study, time of reaction, dosage of agents, temperature of reaction was understood, finally a series of polyvinyl acetate soil stabilizer products were obtained. They are the polymer soil stabilizers with superior performance, low cost, simple construction, high competitive, environmental protection, and can be applied to ecological protection, soil erosion control and other fields.2. The properties of unconfined compressive strength and shear strength parameters of the soil specimens treated by polyvinyl acetate soil stabilizers were studied. The best curing time and the optimal dosage of soil stabilizer were obtained. 3. Effect of soil stabilizer content and soil particle size on the linear swelling ratio and linear shrinkage ratio of soil specimens treated by polyvinyl acetate soil stabilizers were studied. The results show that polyvinyl acetate soil stabilizer can effectively suppress the swelling and shrinkage of expansive soils. The linear swelling ratio of specimen with the average particle diameter of0.75mm had a minimum value. The linear shrinkage ratio reduced with the increasing of soil particles size. Both linear swelling ratio and linear shrinkage ratio reduced with the increasing of soil stabilizers content.4. Effect of soil stabilizer content on water-stability and erosion resistance was studied. The results show that polyvinyl acetate soil stabilizer can improve the water-stability and erosion resistance of treated specimens.5. A new type of polyurethane soil stabilizer (or sand fixing agent) has been developed. Based on lots of experimental study, a series of polyurethane soil stabilizer products were obtained. The strength and erosion resistance of sand were improved by these products, due to the increasing of binding power during soil particles. They are the polymer soil stabilizers with superior performance, simple construction, high competitive, environmental protection, and can be applied to soil erosion control, desertification and dust prevention, sand fixation and other fields.6. The properties of unconfined compressive strength and shear strength parameters of the soil specimens treated by three types of polyurethane soil stabilizers were studied. The results show that the unconfined compressive strength and cohesion increases with the increasing of soil stabilizer, but the internal friction angle is rarely affected.7. Effect of soil stabilizer content on water erosion resistance and wind erosion resistance was studied. The results show that three types of polyurethane soil stabilizer can improve the erosion resistance of treated specimens.8. Base on the characteristics of clay and sand, the modification mechanism of two types of polymer soil stabilizers, named polyvinyl acetate and polyurethane soil stabilizer, was studied. Furthermore, the prospects of polyvinyl acetate and polyurethane soil stabilizer were analyzed.更多还原