轻质土动力特性研究进展  

Research progress on the dynamic characteristics of lightweight soil

作　　者：李梦瑶 刘松玉[1,2] 张翔 王正成 袁振扬 LI Mengyao;LIU Songyu;ZHANG Xiang;WANG Zhengcheng;YUAN Zhenyang(Institute of Geotechnical Engineering,Southeast University,Nanjing 210096,China;Nanjing Modern Multimodal Transportation Laboratory,Nanjing 211100,China)

机构地区：[1]东南大学岩土工程研究所,南京210096 [2]南京现代综合交通实验室,南京211100

出　　处：《工程科学学报》2024年第11期2099-2109,共11页Chinese Journal of Engineering

基　　金：国家自然科学基金面上资助项目(42277146);江苏省交通工程建设局科技项目(7621009140);江苏省研究生实践创新计划(SJCX23_0074)。

摘　　要：轻质土具有轻质、高强、保温、隔振、环保、经济等优点,在路基回填、软基处理、隧道减荷等岩土工程领域具有广阔的应用前景.作为新型土工材料,交通荷载、地震荷载、波浪荷载等振动荷载对轻质土力学特性的影响引发众多关注.本文阐述了配合比(轻质材料含量、固化剂掺量、含水率等)、应力状态、振动频率、干湿交替和冻融循环等因素对轻质土动力特性的影响规律,总结了轻质土动剪切模量和阻尼比计算模型.研究发现水泥等固化剂的使用大幅提升了轻质土抵抗动荷载的能力,轻质土独特的孔隙结构可显著提高其隔振效果,干湿、冻融循环会导致轻质土动力学性能劣化,在实际工程中可通过设置防水层延长其服役寿命.通过模型试验和数值模拟验证了轻质土在实际工程中具有良好的动力稳定性和耐久性.目前轻质土动力特性研究尚处于起步阶段,新型固废轻质土动力学性能尚未深入研究,复杂环境因素与动荷载耦合作用下轻质土的作用机理、力学性能和本构模型研究,以及轻质土在不同工程背景下的设计施工方法研究仍需探索.Lightweight soil is a novel technological material that boasts characteristics such as low density,high strength,thermal insulation,vibration isolation,environmental friendliness,and cost-effectiveness.These features make it highly suitable for a wide range of applications in geotechnical engineering,including roadbed backfill,soft foundation treatment,and tunnel load reduction.The influence of vibration loads resulting from transportation,earthquakes,waves,and other factors on the mechanical properties of lightweight soil has garnered considerable attention in recent research.This paper expounds on the influence of factors on the dynamic deformation characteristics and dynamic strength properties of lightweight soil.These factors include the mix ratio(such as the content of lightweight materials,dosage of curing agent,and moisture content),stress state,vibration frequency,dry–wet alternation effect,and freeze–thaw cycle.Additionally,we summarise the calculation model for the dynamic shear modulus and damping ratio of lightweight soil.The findings reveal that the incorporation of curing agents,such as cement and fly ash,substantially improves the resistance of lightweight soil to dynamic loads.Additionally,the distinctive pore structure of lightweight soil markedly enhances its vibration isolation effect.As dynamic strain increases,there is a nonlinear decrease in the dynamic modulus of lightweight soil while the damping ratio increases nonlinearly.Adjusting the content of lightweight materials and the dosage of curing agents can markedly improve the seismic reduction effect of lightweight soil,thus granting it greater dynamic stability.The coupling effects of dry–wet cycles,freeze–thaw cycles,and dynamic loads may lead to a degradation in the dynamic performance of lightweight soil.To extend its service life in practical engineering applications,the implementation of a waterproof layer is recommended.Model tests and numerical simulations substantiated the commendable dynamic stability and durability of l

关 键 词：轻质土 动模量 阻尼比 动强度 工程应用 

分 类 号：TU435[建筑科学—岩土工程]