干湿循环对风化砂改良膨胀土无侧限抗压强度的影响

发布时间：2018-06-30 21:16

本文选题：改良膨胀土 + 干湿循环　；参考：《武汉大学学报(工学版)》2014年04期

【摘要】：以掺风化砂改良的膨胀土为研究对象,通过系统的室内无侧限抗压强度试验,研究了在干湿循环作用下,掺砂改良膨胀土的无侧限抗压强度的变化规律,深入分析了干湿循环过程中不同风化砂掺量下试样的破坏形态及机理,并且建立了干湿循环作用及风化砂掺量耦合影响下的无侧限抗压强度预估模型.结果表明:1)随着干湿循环次数的增加,掺砂改良膨胀土的无侧限抗压强度呈指数函数形式衰减,并且该过程可划分为3个阶段:急速衰减阶段、减速衰减阶段和衰减稳定阶段;2)在干湿循环作用下,随着风化砂掺量的增加,试样的无侧限抗压强度衰减幅度逐渐减小,试样自身的松散剥落及裂隙发育情况有了显著改善;3)通过无侧限抗压强度计算值与实测值的散点图,验证了所建预估模型的精确性,该模型对于不同风化砂掺量下的膨胀土均实用,具有较高的推广应用价值.
[Abstract]:Taking the expansive soil modified with weathered sand as the research object, the variation law of the unconfined compressive strength of the expansive soil modified by the sand under the action of dry and wet cycle was studied through the laboratory unconfined compressive strength test. The failure mode and mechanism of samples with different weathering sand content during dry and wet cycle were analyzed, and the prediction model of unconfined compressive strength under the influence of dry and wet cycle and coupling of weathered sand content was established. The results show that with the increase of dry-wet cycle times, the unconfined compressive strength of modified expansive soil with sand decreases in the form of exponential function, and the process can be divided into three stages: rapid attenuation stage. Under the action of dry and wet cycle, the attenuation amplitude of unconfined compressive strength decreases with the increase of the content of weathered sand. The loose spalling and fracture development of the sample have been improved remarkably. The accuracy of the prediction model is verified by the scattered plot of the calculated and measured compressive strength without lateral limit. The model is practical for expansive soil with different content of weathered sand, and has high value of popularization and application.
【作者单位】：三峡大学三峡地区地质灾害与生态环境湖北省协同创新中心;三峡大学土木与建筑学院;宜昌市交通运输局;
【基金】：湖北省教育厅自然科学研究重点项目(编号:D20131304)
【分类号】：U414

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