纳米硅溶胶改良辽宁台安砂土的抗液化性能研究  

Liquefaction resistance of Taian sand in Liaoning Province treated with nano colloidal silica

作　　者：刘钢[1,2] 任星龙[1,2] 赵明志 郭文博 张冲 LIU Gang;REN Xinglong;ZHAO Mingzhi;GUO Wenbo;ZHANG Chong(School of Architecture and Civil Engineering,Xihua University,Chengdu 610039,Sichuan,China;Institute of Geotechnical Engineering,Xihua University,Chengdu 610039,Sichuan,China)

机构地区：[1]西华大学建筑与土木工程学院,四川成都610039 [2]西华大学岩土工程研究所,四川成都610039

出　　处：《地震工程学报》2024年第1期39-49,共11页China Earthquake Engineering Journal

基　　金：国家自然科学基金(51878560);国家自然科学基金青年基金项目(51408491);教育部春晖计划项目(z2016155)。

摘　　要：辽宁台安砂土属于易液化砂,提升其抗液化性能具有重要的工程意义。文章针对纳米硅溶胶(CS)对辽宁台安砂土抗液化性能的改良效果进行探究,通过不排水动三轴试验,对纯砂样和改良砂样的液化特性进行对比研究,分析CS浓度和固化时间两个参量对改良砂样动力特性的影响。研究结果表明:(1)CS能够显著提升台安砂土的抗液化性能,在动载作用下改良砂样均未发生液化破坏。(2)随CS浓度和固化时间的增加,试样动孔压u_(d)、动应变ε_(d)呈现先迅速下降后趋于平缓的发展规律;当CS浓度增至4%、固化时间达到3周后,试样抗液化性能的提升效果不再明显。(3)改良砂样的滞回曲线变得更加稳定。随CS浓度增加,阻尼先降低后趋于稳定,动弹性模量逐渐增大并趋于平缓,但伴随有一定的波动;随固化时间增大,阻尼呈减小趋势,动弹性模量呈增大趋势。研究成果可为辽宁台安地区砂土液化治理提供参考依据。As a type of liquefiable sand,the sand in Taian,Liaoning Province,has liquefaction resistance,which is of great engineering importance.To explore the improvement effect of nano colloidal silica(CS)on the liquefaction resistance of Taian sand,a series of undrained dynamic triaxial tests was conducted to compare the liquefaction characteristics of pure and treated sand samples.The effects of CS concentration and curing time on the dynamic characteristics of the sand samples were analyzed.The research results indicate that(1)CS improves the liquefaction resistance of Taian sand.Under the action of a dynamic load,no liquefaction damage occurs in the treated sand samples.(2)The dynamic pore pressure and dynamic strain of the samples rapidly decrease at first and then stabilize with increasing the CS concentration and curing time.When the CS concentration increases to 4%and the curing time reaches three weeks,the improvement effect of the sample's liquefaction resistance is not obvious.(3)The hysteresis curve of CS-treated sand samples becomes more stable than that of the pure sand samples.With increasing CS concentration,the damping decreases first and then tends to be stable,and the dynamic elastic modulus gradually increases and then tends to be gentle,with a certain fluctuation.With increasing curing time,the damping decreases and the dynamic elastic modulus increases.The research results provide a reference for sand liquefaction treatment in the Taian region of Liaoning Province.

关 键 词：纳米硅溶胶 台安砂土 动三轴试验 抗液化性能 动力特性 

分 类 号：TU435[建筑科学—岩土工程]