抗疏力固化剂改性黄土工程性质及其改性机制  

Engineering properties and improvement mechanism of loess soil modified by consolid system

作　　者：彭宇[1] 张虎元[1,2] 林澄斌 王学文[1] 杨龙[1] PENG Yu ZHANG Huyuan LIN Chengbin WANG Xuewen YANG Long(School of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, China Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education, Lanzhou University, Lanzhou, Gansu 730000, China)

机构地区：[1]兰州大学土木工程与力学学院,甘肃兰州730000 [2]兰州大学西部灾害与环境力学教育部重点实验室,甘肃兰州730000

出　　处：《岩石力学与工程学报》2017年第3期762-772,共11页Chinese Journal of Rock Mechanics and Engineering

摘　　要：将抗疏力固化剂运用到黄土加固中,并对比水泥、石灰改性黄土性质,探究抗疏力固化剂改性机制。通过强度试验、崩解试验、渗透试验探索改性土工程性质。通过开展水滴入渗、X衍射、电镜扫描、压汞等试验分别分析土样土颗粒表面能、矿物成分、微观结构、孔隙充填情况以探究改性机制。试验结果表明:抗疏力固化剂改性黄土强度、抗崩解性显著提高,渗透性略有降低。水滴入渗试验显示抗疏力改性黄土土颗粒表面自由能极大降低,斥水性明显优于水泥、石灰改性土;不同抗疏力固化剂添量土样X衍射图谱中物象群峰基本相同;SEM图像显示随抗疏力固化剂掺量提高,黄土中粉土颗排列方式基本不变,细小黏附物发生凝聚,附着物略有增多;压汞数据显示抗疏力改性黄土中大、中、小孔隙体积均略有减小,微孔隙明显增多。初步得出抗疏力改性黄土的机制在于:降低土颗粒表面能以提高阻水、抗水性;抗疏力物质包裹土颗粒及细小黏土颗粒发生凝聚来连结土颗粒,强化骨架颗粒连结强度;抗疏力材料膨胀挤密作用较弱,改性黄土通透性好。抗疏力固化剂在改善黄土力学性质、水理性质的基础上,还一定程度上解决了传统固化剂在提高阻水性的同时通透性降低的矛盾。This paper studies the improvement mechanism of loess soil modified by the consolid system in comparison with the loess soil modified by cement and lime. The mechanical strength test, disintegration test and flexible-wall permeability test were conducted to measure the engineering property of soil. The water drop penetration time test, X-Ray diffraction test, scanning electron microscope（SEM） test and mercury intrusion porosimetry（MIP） test were carried out to investigate the microscopic properties, such as the surface energy, mineral composition, microstructure and pore filling condition of loess soil. The loess soil modified by the consolid system has higher strength, better durability of slaking and slightly lower permeability. The surface energy of soil particles is reduced greatly and the water repellency ability is obviously better than that of cement or lime modified loess soil. The phase peak groups are basically same in the X-ray diffraction patterns. The silt particle arrangement of loess soil remains unchanged with the increase of consolid system content, but the fine particles coagulate with more adhering material. The volume of large, medium and small pores in loess soil are reduced slightly while the micro pores are increased obviously. The improvement mechanism of loess soil modified by consolid system is that the decrease of surface energy of loess soil enhances the water repellency and water-resisting property, the consolid system reinforces the bonding strength of the microstructure of soil particle skeleton, the weak swelling and pore filling effect of consolid system lead to good permeability of loess soil. Apart from improving the mechanical and hydraulic properties, the consolid system solve the problem of improving the water resistance property and keeping the good permeability of loess soil to some extent.

关 键 词：土力学 黄土 抗疏力固化剂 工程性质 改性机制 

分 类 号：TU411[建筑科学—岩土工程]