考虑温度效应的盾构刀盘黏附试验及堵塞防治OA北大核心CSTPCD
Adhesion test and blockage prevention of shield tunneling cutterhead considering temperature effect
土压平衡盾构在黏性地层掘进时易产生刀盘结泥饼、堵塞等问题,不仅会导致排渣不畅降低掘进效率,并且频繁的开仓处理会增加工程风险,而掘进会产生大量热量影响土体黏附性.采用自主研发的刀盘旋转黏附试验系统,探究刀盘温度与含水率、黏土含量、黏土类型等因素联合作用下刀盘黏附效果,并分析了泡沫剂、抗黏剂在不同掺入比下堵塞防治效果.研究结果表明:温度升高会使得旋转扭矩与刀盘表面的土体黏附量降低,但会加速黏土硬化;土体含水率、黏土含量对于扭矩影响趋势相反,但对黏附量影响规律相同,随着土体含水率或黏土含量增加,黏附量先增加后降低,含水率在20％、黏土含量在30％时黏附性最强;膨润土比高岭土黏附性更强;土体含水率、黏土含量与黏土类型对于黏附量的影响可以使用稠度指数进行表征,随着稠度增加黏附量会出现先增加后降低的趋势,稠度指数在0.50～0.75时土体黏附性最强,低稠度指数土体对温度敏感性更强;单独添加泡沫剂会降低土体黏附量,但在注入比为70％时,仍存在大量土体黏附;使用泡沫剂+抗黏剂联合改良在注入比为50％时改良效果较好,继续增加注入比对土体改良效果影响较小.研究成果对于评估黏性地层土压平衡盾构掘进堵塞风险与黏性土渣土改良方案选择具有一定的指导意义.
In cohesive strata,earth pressure balance shield tunneling often encounters issues such as mud cake formation and cutting edge blockage.These problems not only hinder the efficient discharge of excavated material,leading to decreased excavation efficiency,but also increase the risk of frequent silo openings during the construction process.Furthermore,heat generated during excavation can affect soil adhesion.To explore the adhesion effects on the cutter head considering cutter head temperature,water content,clay content,clay type,and other factors,a self-developed rotary adhesion test system for the cutter head was employed.The system also examined the preventive and control effects of foam agents and anti-adhesion agents at different mixing ratios to mitigate blockage.The findings indicate that an increase in temperature reduces rotational torque and soil adhesion on the cutter head's surface,but it accelerates clay hardening.The trends of soil moisture content and clay content on torque are inverse,yet they similarly affect adhesion.As moisture content or clay content increases,adhesion initially increases and then decreases.The highest adhesion occurs at 20％moisture content and 30％clay content.Furthermore,bentonite exhibits greater adhesion compared to kaolin.The adhesion effects of soil moisture content,clay content,and clay type can be assessed using a consistency index.As consistency increases,adhesion initially increases and then decreases.The soil shows the highest adhesion when the consistency index ranges between 0.5 and 0.75,and low consistency index soil is more temperature-sensitive.While the addition of foam agents alone decreases soil adhesion,substantial adhesion persists at a 70％injection ratio.However,a 50％injection ratio shows better improvement with the combined use of foam agents and anti-adhesion agents.Additionally,increasing the injection ratio has minimal impact on soil improvement.These findings offer valuable guidance for evaluating blockage risks in earth pressure balance shield tunneling through cohesive strata and choosing suitable soil improvement strategies for cohesive soil remnants.
王修伟;李树忱;刘祥坤;万泽恩;彭科峰
山东大学岩土与地下工程研究院,山东济南 250014||山东大学齐鲁交通学院,山东济南 250002山东大学岩土与地下工程研究院,山东济南 250014||中国矿业大学力学与土木工程学院,江苏徐州 221116山东大学岩土与地下工程研究院,山东济南 250014中国矿业大学力学与土木工程学院,江苏徐州 221116
土木建筑
土压平衡盾构刀盘堵塞黏性地层温度效应渣土改良
earth pressure balance shieldcutter head cloggingviscous formationtemperature effectmuck improvement
《岩土力学》 2024 (008)
2299-2310 / 12
国家自然科学基金青年科学基金(No.52108373,No.52308423);山东省自然科学基金(No.ZR2021ZD36,No.ZR2021QE127);中国博士后科学基金面上资助(No.2022M723402).This work was supported by the National Natural Science Foundation of China for Young Scholars(52108373,52308423),the Natural Science Foundation of Shandong Province(ZR2021ZD36,ZR2021QE127)and the General Program of Postdoctoral Science Foundation of China(2022M723402).
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