黄原胶生物聚合物改良膨胀土裂隙演化规律研究  

Development of cracks in expansive soil improved by xanthan gum biopolymer

作　　者：欧阳淼 张红日 邓人睿 王桂尧 肖杰[4] 赵亚 OUYANG Miao;ZHANG Hongri;DENG Renrui;WANG Guiyao;XIAO Jie;ZHAO Ya(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China;Guangxi Transportation Science and Technology Group Co.,Ltd.,Nanning 530007,China;Department of Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;School of Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410114 [2]广西交科集团有限公司,广西南宁530007 [3]上海交通大学土木工程系,上海200240 [4]长沙理工大学交通运输工程学院,湖南长沙410114

出　　处：《岩土工程学报》2025年第1期106-114,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金重点项目(42330701);国家自然科学基金项目(42477143,52178416);广西重点研发计划项目(桂科AB23075184);国家重点研发计划项目(2019YFC 1509800);湖南省研究生科研创新项目(QL20220195)。

摘　　要：采用既可抑制膨胀土裂隙扩展,又不影响坡面植被生长的黄原胶生物聚合物对膨胀土进行改良,是膨胀土边坡生态防护新思路。对黄原胶改良膨胀土开展室内干湿循环试验,利用数字图像处理技术(PCAS)对裂隙发育的整个过程进行定量分析,探究了黄原胶掺量对膨胀土裂隙形态特征指标的影响规律,并通过扫描电镜(SEM)、X射线衍射(XRD)试验分析了改良前后膨胀土的微观结构与矿物成分的变化,结合膨胀率试验结果探讨了黄原胶对膨胀土的改良机理。研究结果表明,黄原胶的掺入可以有效提高膨胀土的保水性和抗裂性,试样的平均失水速率和裂隙率均随着掺量的增加呈减小趋势;黄原胶能够降低干湿循环效应对膨胀土的影响,将裂隙宽度控制在较小范围内,增湿过程中易闭合;黄原胶主要通过两个方面抑制膨胀土开裂,一方面通过成键和胶结作用与土颗粒形成“桥联”结构,整体增强土体的抗拉强度;另一方面通过填充和成膜作用阻隔水分与土颗粒接触,减小黏土矿物的水化膜厚度。The use of xanthan gum biopolymer,which can suppress the expansion of cracks of in expansive soil without affecting the growth of slope vegetation,is a new approach for ecological protection of expansive soil slopes.The indoor wet dry cycle tests are conducted on the xanthan gum-modified expansive soil,and the digital image processing technology is used to quantitatively analyze the entire process of crack development.The influences of xanthan gum content on the characteristic indices of crack morphology in expansive soil are explored,and the changes in microstructure and mineral composition of expansive soil before and after improvement are analyzed through the scanning electron microscopy and X-ray diffraction experiments,The improvement mechanism of xanthan gum on expansive soil is explored based on the results of the expansion rate tests.The research results indicate that the addition of xanthan gum can effectively improve the water retention and crack resistance of expansive soil,and the average water loss rate and crack rate of the sample decrease with the increase of dosage.The Xanthan gum can reduce the impact of wetting-drying cycle on expansive soil,control the crack width within a small range,and make it easy to close during the humidification process.It mainly inhibits the cracking of expansive soil through two aspects.On the one hand,it forms a"bridging"structure with soil particles through bonding and cementation,enhancing the overall tensile strength of the soil.On the other hand,by filling and film-forming,it blocks the contact between water and soil particles,reducing the thickness of the hydration film of clay minerals.

关 键 词：道路工程 黄原胶生物聚合物 干湿循环 裂隙 微观结构 

分 类 号：TU43[建筑科学—岩土工程] U416[建筑科学—土工工程]