干湿循环下水泥 磷石膏稳定红黏土的动力特性研究  

Dynamic characteristics of cement-phosphogypsumstabilized red clay under dry-wet cycle

作　　者：黄文东 陈开圣[1] 张波浪 HUANG Wendong;CHEN Kaisheng;ZHANG Bolang(School of Civil Engineering,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学土木工程学院,贵州贵阳550025

出　　处：《广西大学学报（自然科学版）》2023年第6期1316-1330,共15页Journal of Guangxi University（Natural Science Edition）

基　　金：贵州省省级科技计划项目(黔科合基础-ZK[2023]重点016,黔科合支撑[2020]4Y038)。

摘　　要：为了解决贵州省内磷石膏大量堆积问题,考虑将磷石膏用于公路建设中,基于路基在运营过程中会受干湿循环及车辆荷载的影响,探究了干湿循环下水泥磷石膏稳定土动力特性。通过动三轴试验,以水泥质量分数为5%,SCA 2型固化剂质量分数为5%,磷石膏∶黏土=1∶1的质量比为配比,分析了干湿循环下磷石膏稳定红黏土在不同围压、频率及干湿循环次数下的动力特性。结果表明:分析Hardin-Drnevich模型和Monismith模型的缺陷,建立了新的经验动本构模型,混合料动应力动应变和动切变模量动应变可以用本文提出的本构模型来拟合;混合料动应力与围压、频率成正相关,随着土体经历干湿循环次数增加,动应力逐渐减小。动切变模量随着围压、频率的增加而增大,随干湿循环次数的增加而降低;影响混合料最大动切变模量的因素显著性由强到弱的顺序为干湿循环次数、围压、频率。混合料动态长期回弹模量满足《公路沥青路面设计规范》(JTG D50—2017)交通荷载等级为中等、轻、重的要求和《公路水泥混凝土路面设计规范》(JTG D40—2011)轻交通荷载等级的要求。In order to solve the problem of large accumulation of phosphogypsum in Guizhou province,phosphogypsum is considered for road construction.Based on the fact that the roadbed was affected by dry and wet cycles and vehicle loading during operation,the dynamic characteristics of cement phosphogypsum stabilized soil under dry and wet cycles were investigated.The dynamic properties of phosphogypsum stabilized red clay under dry and wet cycles with different surrounding pressure,frequency and number of dry and wet cycles were analyzed by dynamic triaxial tests with 5%mass fraction of cement dosing,5%SCA-2 curing agent and phosphogypsum∶clay=1∶1 ratio.The results show that:the shortcomings of Hardin-Drnevich model and Monismith model are analyzed,and a new empirical dynamic principal structure model is established,and the dynamic stress-dynamic strain and dynamic shear modulus-dynamic strain of the mixture can be fitted by the principal structure model proposed in this paper.The dynamic stress of the mixture is positively correlated with the surrounding pressure and frequency,and decreases with the increase of the number of wet and dry cycles experienced by the soil.The dynamic shear modulus increases with the increase of the surrounding pressure and frequency,and decreases with the increase of the number of wet and dry cycles.The order of significance of the factors affecting the maximum dynamic shear modulus of the mixture from strong to weak is the number of wet and dry cycles,surrounding pressure,frequency.The dynamic long-term rebound modulus of the mixture meets the requirements of the Highway Asphalt Pavement Design Specification(JTG D50—2017)for traffic load classes of medium,light and heavy and the Highway Cement Concrete Pavement Design Specification(JTG D40—2011)for light traffic load classes.

关 键 词：干湿循环 磷石膏 红黏土 动力特性 动本构关系 动本构模型 

分 类 号：TU446[建筑科学—岩土工程]