摘要
高含水率废弃软土在改良过程中,易出现大量直径远大于10 mm且难以过筛的团聚体,严重制约了其作为填料资源的规模化、高效化利用。本文系统研究了在改良填料土中扩大团聚体粒径的可行性,通过室内试验重点考察了团聚体粒径和固化剂掺量对改良填料土路用性能的影响,并在此基础上推导出制备目标粒径团聚体的改良填料土所需固化剂的理论掺量计算公式,为工程实践中改良填料土的配合比设计与优化提供了理论参考值。同时,通过中试试验评估了废弃土填料化中试系统在实际工况下处理大批量废弃土料的运行效果与应用潜力。室内试验结果表明:团聚体最大粒径的增大会对改良填料土的路用性能产生负面影响,可通过控制固化剂掺量合理扩大团聚体最大粒径,若将团聚体最大粒径扩大至25~30 mm,固化剂掺量建议控制在4%左右,更高固化剂掺量下,团聚体最大粒径需控制在20 mm及以下;根据所推导的公式计算得出,在固化剂完全包裹土体的情况下,团聚体最大粒径扩大至15、20、25、30 mm时所需固化剂的理论掺量分别为6.63%、5.87%、5.10%、4.13%,与室内试验结果具有较高的一致性。中试试验结果表明:填料化中试系统可以有效提升生产效率,适用于处理现场大批量的废弃土料,且其对较大粒径团聚体表现出更好的适用性;虽然采用填料化中试系统对高含水率废弃软土进行二次掺灰拌合处理所得试样的CBR与回弹模量均低于通过人工拌合处理所得的试样,但均满足规范要求。总之,研究认为,在满足路基填料指标的前提下,对高含水率废弃软土进行二次掺灰拌合改良时,适当放宽团聚体筛分粒径,并结合理论计算优化固化剂掺量,可以显著提高废弃软土的处治效率和土料的产能,可为改良填料土在工程实际中的应用提供参考。
In the context of sustainable civil infrastructure development,the reuse of waste soft soil with high moisture content as engineered fillers presents both environmental and economic advantages.However,critical technical challenges exist during the stabilization and modification processes of waste soft soil,i.e.,a large number of soil aggregates with diameters much larger than 10 mm and difficult to sieve are prone to occur,thereby which seriously hinders its large-scale and efficient application as a filling material resource.To overcome this limitation,this study investigated the feasibility of expanding the particle size of aggregates in improved filler soil during the modification process.A series of laboratory tests were carried out,including the unconfined compressive strength test,water stability test,California bearing ratio test,and resilient modulus test,to investigate the influence of soil aggregate particle size and curing agent dosage on the road performance of modified filler soil.Based on the experimental results,a calculation formula for the theoretical dosage of curing agent required for the preparation of improved filler soil with the target particle size aggregates was derived,which provided theoretical reference values for the mix proportion design and optimization of modified filler soil in engineering applications.At the same time,pilot tests were conducted to simulate the on-site conversion of a large amount of waste soft soil into modified filler soil under actual working conditions,and the operation effect and application potential for the filler pilot system were evaluated.The laboratory test results indicate that the increase in the maximum particle size of the aggregate will have a negative impact on the road performance of the improved filler soil.To ensure the road performance of improved filler soil,the maximum particle size of aggregate can be appropriately expanded by controlling the dosage of curing agent.If the maximum particle size of the aggregate is expanded to 25-30 mm,the dosage of curing agent is recommended to be controlled at about 4%.Under higher dosage of curing agent,the maximum particle size of aggregate should be controlled at 20 mm below.According to the derived formula,it is calculated that when the soil was completely wrapped by the curing agent,the theoretical dosage of the curing agent required when the maximum particle size of the aggregate is expanded to 15,20,25,and 30 mm is 6.63%,5.87%,5.10%,and 4.13%respectively.These values exhibit a high degree of consistency with the results obtained from laboratory test.The pilot test results demonstrate that the filler pilot system can effectively improve the production efficiency and is suitable for handling large quantities of waste soil materials on site,exhibiting better adaptability for larger particle size aggregates.Although samples produced via secondary lime mixing treatment of waste soft soil with high moisture content using the filler pilot system show lower CBR and rebound modulus values than those produced by manual mixing treatment,they can all satisfy the specification requirements.In conclusion,the study suggests that when improving waste soft soil with high moisture content through secondary lime mixing under the premise of meeting the specifications of subgrade fill materials,appropriately relaxing the particle size of aggregates sieving and optimizing the dosage of curing agent in combination with theoretical calculation can significantly enhance the treatment efficiency of waste soft soil and the production capacity of soil materials,which can provide a reference for the application of improved fill soil in engineering practice.
作者
罗安祁
陈庚
陈永辉
孔纲强
陈龙
LUO Anqi;CHEN Geng;CHEN Yonghui;KONG Gangqiang;CHEN Long(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210024,China;Suzhou Institute for Advanced Research of Hohai University,Suzhou 215100,Jiangsu China)
出处
《河南科学》
2026年第1期126-135,共10页
Henan Science
基金
国家重点研发计划(2024YFC3211000)
江苏省社科应用研究精品工程习近平生态文明思想研究专项课题(STA-19)
连云港水利局科技项目(HDJS-QJYJ)。
关键词
改良填料土
团聚体粒径
高含水率废弃软土
固化剂掺量
路用性能
improved filler soil
particle size of aggregate
waste soft soil with high moisture content
dosage of curing agent
pavement performance
