纤维素类固化剂加固砂土边坡作用机理及抗冲蚀效应研究

The traditional slope protection technology is mainly composed of frame, spray protection, three-dimensional network, facing wall, etc. These measures improved the overall stability of slope and in the engineering application is more widely, however, there are some shortcomings in the above technology in soil slope treatment, such as the structure easy to fall off, weak ability to resist water scouring and poor ecological effect and so on. In view of these problems, the self-developed cellulose-based curing agent (GCMC) by our research team is a new green environment-friendly sand curing material which has the advantages of strong competitive adsorption capacity, fast adsorption speed, good water holding capacity, irreversibility of curing reaction and suitable for vegetation growth and so on. In order to further improve the reinforcement performance of the curing agent and erosion resistance ability of the sandy siol slope, the research project first through the theoretical analysis, laboratory tests and microcosmic observations, discuss the dialysis and adsorption effect and matrix bonding process between sandy soil mediums when the curing agent migration inside soils, determine the dialysis characteristics inside sandy soils and the adsorption configuration with sandy soil particles of the curing agent, build the matrix bonding models with it reinforced the sandy soil mass. Finally the erosion resistance effect of the curing agent would be researched with the aids of laboratory simulation and field comparison tests of rainfall. The achievements will be of great importance in the soil and water loss control project for the popularization and application of cellulose curing agent （GCMC）in our country.

传统的边坡防护技术主要有框格梁、喷护、三维网、护面墙等，这些措施提高了边坡整体稳定性，并且工程应用较为广泛，但以上技术在砂土边坡治理中存在结构易脱落、抗水流冲刷能力弱、生态效果差等不足。针对这些问题，研究团队自主研发的纤维素类固化剂（GCMC）是一种新型的绿色环保型砂土固化材料，它具有竞争吸附能力强、吸附速度快、良好的持水性、固化反应的不可逆性以及适宜植被生长等优点。为了进一步提高该固化剂的加固性能以及砂土边坡的抗水流冲刷能力，本研究项目首先通过理论分析、室内试验和微观结构观测，探讨固化剂在砂土介质中的渗析和吸附效应以及与砂土颗粒的基质胶结过程，确定固化剂在砂土中的渗析特征以及吸附构形，构建固化剂加固砂土体的基质胶结模型。然后采用降雨冲蚀室内模拟和现场对比试验相结合，对固化剂的抗冲蚀效应进行研究。研究成果对于纤维素类固化剂（GCMC）在我国水土流失治理工程中的推广应用具有重要意义。

沙土边坡遇水容易发生坡面侵蚀、水土流失等灾害，传统防护技术主要有框格梁、喷护、三维网、护面墙等，存在结构易脱落、抗冲刷能力弱、生态效果差等不足。研发的纤维素类固化剂（GCMC）是一种新型的绿色环保型砂土固化材料，可以提高砂土体的水稳定性、抗冲蚀性等，不仅有利于边坡坡面的稳定、防止水土流失，而且绿色环保无污染。本项目通过探讨该固化剂在砂土体中迁移时的渗析和吸附效应以及基质胶结过程，确定该材料在砂土体中的渗析变化特征以及吸附构形，建立该材料加固砂土体的基质胶结模型。然后选用坡度、降雨强度、降雨持时、液固质量比等因素作为试验参数，采用降雨冲蚀模拟试验对固化剂的抗冲蚀效应进行研究。主要结果如下：①GCMC固化剂进行渗析扩散作用分子量主要集中在100×104～1×104之间，扩散渗析能力较强分子集中在1×104～10×104之间，溶液渗析系数在0.0099～0.0036m/h之间。GCMC固化剂在液固质量比1:3时达到最优吸附量，吸附量平衡在84mg/g左右，吸附力学行为属于化学吸附。②液固比1:4时3d的WSA0.25为92%，14d达到96%，28d达到97%。1～0.25mm的团聚体含量从3d的33%下降到14d的21%，28d降到14%。＞1mm的团聚体含量从3d的59%上升到14d的75%，28d达到82%。在液固比1:3时，3d的WSA0.25为96%，14d达到98%。1～0.25mm的团聚体含量从3d的21%下降到14d的19%。＞1mm的团聚体含量从3d的74%上升到14d的80%。液固比1:4试样的MWD从3d的2.18mm增加到28d的3.59mm，GMD从3d的1.31mm增加到28d的2.63mm。液固比1:3试样的MWD从3d的2.91mm增加到14d的3.29mm，GMD从3d的2.01mm增加到14d的2.32mm。③冲刷影响因素重要性程度是液固比＞降雨强度＞斜坡坡度＞降雨持时。液固比1:2组合的水流平均入渗速度为1.09cm/min、平均冲刷量为48.41g、平均冲蚀模数为5.71 g/m2/min；液固比1:3组合的水流平均入渗速度为1.34cm/min、平均冲刷量为21.81g、平均冲蚀模数为3.13 g/m2/min，低于裸坡条件下的水流平均入渗速度2.35cm/min、冲刷量110.28g以及平均冲蚀模数14.28 g/m2/min。