碱渣土的触变性与扰动后强度演化规律研究  

Study on Thixotropy of Soda Residue Soil and Its Strength Evolution After Disturbance

作　　者：王元战[1] 龚晓龙[1,2] 王轩 张春生[2] 谢涛[3] Wang Yuanzhan;Gong Xiaolong;Wang Xuan;Zhang Chunsheng;Xie Tao(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300354,China;Tianjin Port(Group)Co.,Ltd.,Tianjin 300461,China;PowerChina Huadong Engineering Corporation Limited,Hangzhou 311122,China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300354 [2]天津港集团有限公司,天津300461 [3]中国电建华东勘测设计研究院有限公司,杭州311122

出　　处：《天津大学学报（自然科学与工程技术版）》2023年第6期633-640,共8页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(51979191);天津港科技计划资助项目(2020-165).

摘　　要：碱渣是氨碱法制碱过程中产生的工业废渣,作为地基回填土应用于工程建设可以有效解决占地和环境污染问题.关于碱渣土的基本物理、力学性质和静力学特性已开展了一些研究工作,但与天然沉积土相比,碱渣土通常具有更高的含水率与更大的孔隙比,在外部荷载扰动下的触变性是其应用于工程实践中需要解决的关键问题.以天津港原状碱渣土为研究对象,开展振动-静置试验和无侧限抗压强度试验,研究了不同振动时间、振动频率及静置时间下碱渣土的触变性,结果表明:振动时间、振动频率对于碱渣土强度影响显著,静置过程中土体强度随时间增长恢复速度逐渐减缓,且无法恢复至扰动前的强度.引入触变强度比率A量化振动-静置过程对土体强度的影响,提出考虑振动时间、振动频率及静置时间的碱渣土触变强度模型.在此基础上,进一步开展振动-静置循环试验,研究了不同振动-静置循环次数与静置时间下碱渣土触变强度的演化规律,发现随着振动-静置循环次数的增加,土体累积的结构性损伤逐渐增多,强度恢复程度将持续减小.通过对试验数据的统计分析,建立了振动-静置循环条件下的碱渣土触变强度演化模型,并用试验实测值验证了演化模型的正确性.Soda residue is an industrial waste product from the soda production process when using the ammonia-soda method,which can be applied as a kind of foundation backfill in engineering construction to effectively solve problems such as land occupation and environmental pollution.Some research work has already been carried out on the basic physical and mechanical properties of soda residue soil(SRS)as well as its static performance.However,com-pared with natural sedimentary soil,SRS usually has a higher water content and a larger void ratio.The thixotropy of SRS under external load disturbance is a key problem to be solved in its applications to construction projects.In this paper,the undisturbed SRS in Tianjin Port was taken as a research object,and a vibration-standing test and an unconfined compressive strength test were conducted to explore the variations in its thixotropy under different vibration time,different vibration frequencies,and different standing time.Results show that the influences of vibration time and vibration frequency on the strength of SRS were obvious,the recovery speed of soil strength gradually slowed down during the standing process,and the strength of SRS after disturbance cannot be restored to its initial value.A thixotropic strength ratio A was introduced to quantify the influences of vibration-standing process on the soil strength,

关 键 词：碱渣土 触变性 振动-静置 演化模型 

分 类 号：TU521[建筑科学—建筑技术科学]