摘要
基于GDS动三轴试验系统,通过开展不同含砂率重塑夹砂软黏土的动力特性试验,系统探讨了荷载频率、含砂率对土体塑性累积变形、动剪切模量及阻尼比的影响规律。结果表明:塑性累积变形呈先快后慢的发展特征,随振动次数增加,土体骨架逐步密实化抑制塑性变形速率,但含砂率升高会导致累积变形量显著增大;无论荷载频率低于或高于1.0 Hz,动剪切模量均随含砂率增加呈递减趋势,含砂率每增加10%,模量降幅达12%~18%;振动过程中孔压系数A持续增长,土体剪缩效应增强,稳定性劣化,且含砂率增加会加剧该现象,致使动剪切模量与阻尼比曲线出现明显拐点(临界含砂率约20%);总体来说,含砂率通过改变土体骨架结构与排水路径,显著影响夹砂软黏土的动力响应机制。
Based on the GDS dynamic triaxial test system,a series of dynamic characteristic tests were conducted on remolded sand-mixed soft clay with varying sand contents to systematically investigate the influence of loading frequency and sand content on plastic cumulative deformation,dynamic shear modulus,and damping ratio.The results indicate that:The development of plastic cumulative deformation exhibits a rapid initial phase followed by a decelerating phase.As the number of vibrations increases,the densification of the soil skeleton inhibits the rate of plastic deformation,while higher sand content significantly amplifies the cumulative deformation.Regardless of whether the loading frequency was below or above 1.0 Hz,the dynamic shear modulus displayed a decreasing trend with increasing sand content.For every 10%increase in sand content,the modulus reduction reached 12%~18%.During vibration,the pore pressure coefficient A continuously increased,intensifying the shear contraction effect and deteriorating soil stability.Higher sand content exacerbated this phenomenon,resulting in distinct inflection points in the dynamic shear modulus and damping ratio curves(critical sand content approximately 20%).In summary,sand content significantly influences the dynamic response mechanisms of sand-mixed soft clay by altering the soil skeleton structure and drainage pathways,providing critical insights for constructing dynamic constitutive models and guiding seismic engineering design.
作者
王睢
方源明
周子冬
赵鹏
潘石磊
Wang Sui;Fang Yuanming;Zhou Zidong;Zhao Peng;Pan Shilei(School of Civil and Transportation Engineering,Ningbo University of Technology,Ningbo,Zhejiang 315211,P.R.China;Ningbo Metallurgical Investigation&Design Research Co.,Ltd.,Ningbo,Zhejiang 315000,P.R.China;School of Architectural Engineering,Chang an University,Xi an 710061,P.R.China)
出处
《地下空间与工程学报》
北大核心
2025年第3期882-890,共9页
Chinese Journal of Underground Space and Engineering
基金
山地城镇建设与新技术教育部重点实验室开放项目(LNTCCMA-20200104)
宁波市自然科学基金(2019A610394)
宁波工程学院科研启动基金(2140011540012)。
关键词
重塑软黏土
塑性累积变形
含砂率
荷载频率
动剪切模量
阻尼比
remodeled soft clay
plastic cumulative deformation
sand content
load frequency
dynamic shear modulus
damping ratio
