生态酯类材料砂土改良及工程护坡应用

为提高砂土边坡的稳定性并实现生态护坡，采用生态酯类材料——纳米水性黏合剂对砂土进行改良，通过凝胶渗透色谱法和热重法分别对纳米水性黏合剂的相对分子质量及分布、热稳定性等进行了测试与分析；通过设计并开展不同纳米水性黏合剂掺入量条件下砂土的无侧限抗压强度试验和直接剪切试验，研究了砂土的强度改良效果与规律；通过崩解试验和边坡冲刷模型试验，研究了砂土的遇水稳定性和坡面抗冲刷能力的改良效果与规律，并进一步分析了砂土改良及生态护坡机制。结果表明，纳米水性黏合剂能提高砂土的强度、水稳定性及坡面抗冲刷能力。随黏合剂掺入量的增加，砂土的无侧限抗压强度和黏聚力增大，黏聚力的增加幅度可达46%～77%，而内摩擦角变化较小；砂土的崩解系数和峰值崩解速率减小，最大崩解速率出现的时间越发滞后；坡面冲刷率降低约68%～86%。边坡防护工程实际应用效果表明，纳米水性黏合剂的固土效果好，作用时间长，促进植被生长，实现了边坡的长效生态防护。

Improvement of eco-ester materials on sandy soils and engineering slope protection

To improve the stability of sandy slope and achieve ecological slope protection, a kind of eco-ester-polymer named as Aqua-Dispersing-Nano-Binder (ADNB) was used to reinforce sandy soils. Properties of molecular weight and thermal stability of ADNB were tested through gel permeation chromatography (GPC) method and thermogravimetric (TG) method. The effects and the regularity of strength improvement of sandy soils were studied by designing and carrying out tests of unconfined compressive strength (UCS) and direct shear under the condition of different ADNB dosages. Finally, the disintegrating test and the slope scour model test have been performed to investigate the improvement effect and regularity of both water stability of sandy soils and the anti-erosion ability of slope surface, and the improvement mechanism of sandy soils and ecological slope protection was further analyzed. Results show that ADNB can improve the strength and water stability of sandy soils, and the erosion resistance of sandy slope surface is improved. With the increase of ADNB dosage, the UCS and cohesive force of sandy soils are increased, in which the increase of cohesive force is 46%-77% while internal friction angle has no significant change; the peak disintegration rate and the disintegration coefficient of sandy soils decreases, besides, the occurrence time of the maximum disintegration rate is more and more delayed; the erosion rate of slope surface decreases about 68%-86%. The application effect of slope protection engineering shows that ADNB performed well on stabilizing soils with a long time and promoting the vegetation growth. As a result, the long-term ecological protection of slope is achieved.