改性黄泛区松散粉砂土的渗透试验研究  

Permeability Test of Loose Silty Soil in Modified Yellow River Flood Area

作　　者：岳建伟[1] 王文坛 赵丽敏[1] 韩溥 YUE Jian-wei;WANG Wen-tan;ZHAO Li-min;HAN Pu(Civil Engineering College,Henan University,Kaifeng 475000,China)

机构地区：[1]河南大学土木建筑学院,开封475400

出　　处：《科学技术与工程》2024年第36期15607-15618,共12页Science Technology and Engineering

基　　金：国家自然科学基金青年科学基金(12302149);河南省重点研发与推广专项(科技攻关)支持项目(232102221012)。

摘　　要：黄泛区地下室周围回填粉沙土存在回填不密实,极端降雨雨水渗入地下室四周引起地下室上浮,通过降低松散粉砂土的渗透系数防止雨水渗入,采用水玻璃、碳酸氢钠、苯丙乳液对松散粉砂土进行改性。开展凝胶时间、变水头渗透试验、浆液入渗研究。结果表明:混合浆液中各组分与水的比例:水玻璃为5∶45和15∶45、苯丙乳液为5∶45和15∶45、碳酸氢钠为(0.8~1.5)∶45时凝胶时间大于10 min能凝结成整块凝胶体符合注浆改性要求。改性粉砂土渗透系数随水玻璃用量增加而减小,水玻璃与苯丙乳液和碳酸氢钠和水的比例为15∶15∶1.2∶45时,粉砂土的渗透系数为1×10^(-8)cm/s。土体含水量对浆液渗透距离影响显著,改性施工宜在春天进行;水玻璃的用量对浆液渗透距离改变变化显著,距离需求可通过调节水玻璃用量来实现。浆液由上到下进行渗透,改性土渗透系数由1×10^(-8)cm/s逐渐增大到接近素土的渗透系数1×10^(-4)cm/s。通过电镜微观分析得出:浆液主要通过在土体表面形成阻水凝胶层和在土体内凝胶体填充土颗粒间孔隙且土颗粒间相互黏结起到阻水作用。The backfilled silty soil around the basement in the Yellow River Flood Area is not dense,and the extreme rain water penetrates around the basement,causing the basement to float.By reducing the permeability coefficient of the loose silty soil,the loose silty soil is prevented from penetrating.Water glass,sodium bicarbonate and styrene acrylic emulsion were used to modify the loose silty soil.The gel time,variable head penetration experiment and slurry infiltration were studied.The results show that when the ratio of each component to water in the mixed grout is 5∶45 and 15∶45 for water glass,5∶45 and 15∶45 for styrene acrylic emulsion and(0.8~1.5)∶45 for sodium bicarbonate,the gel time is greater than 10 min,the whole gel can be coagulated to meet the requirements of grouting modification.When the ratio of sodium silicate to styrene acrylic emulsion and sodium bicarbonate to water is 15∶15∶1.2∶45,the permeability coefficient of the silt is 1×10^(-8) cm/s.Soil water content has significant influence on slurry permeation distance,so modification should be carried out in spring.The amount of water glass has a significant effect on the change of slurry penetration distance,and the distance demand can be achieved by adjusting the amount of water glass.The permeability coefficient of the modified soil gradually increases from 1×10^(-8) cm/s to 1×10^(-4) cm/s close to that of the plain soil when the slurry permeated from top to bottom.According to the microscopic analysis of electron microscope,the grout can inhibit water mainly by forming a hydrogel layer on the soil surface and filling the pores between the soil particles with gel in the soil body.

关 键 词：水玻璃 苯丙乳液 渗透系数 渗透距离 松散粉砂土 

分 类 号：TU463[建筑科学—结构工程]