考虑初始级配影响的粗粒土非线性弹性模型研究  

Nonlinear elastic constitutive model of coarse-grained soils considering the effect of initial grain size distribution

作　　者：张春顺 林正鸿 杨典森 陈嘉瑞 ZHANG Chun-shun;LIN Zheng-hong;YANG Dian-sen;CHEN Jia-rui(School of Civil Engineering,Wuhan University,Wuhan,Hubei 430072,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan,Hubei 430072,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072 [2]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072

出　　处：《岩土力学》2025年第3期750-760,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No.52278367);中央高校基本科研业务费专项资金(No.2042024kf0032)。

摘　　要：大量研究表明,粗粒材料的强度和变形特性受初始颗粒级配(grain size distribution,简称GSD)影响显著。然而,当前关于考虑颗粒初始GSD影响的粗粒材料本构模型的研究尚不多见。通过引入能够反映颗粒破碎难易程度的初始级配指标?,将材料初始GSD和终极GSD相联系,系统地探究并阐明了?对粗粒材料峰值抗剪强度qp和峰值应变εap以及e-p平面临界状态线(critical state line,简称CSL)位置的影响机制。针对?对qp和εap影响的研究表明,随着?增加,qp降低;而εap则随着?的增加而增加。结合上述结论,以沈珠江提出的驼峰型二次曲线模型为基础,建立了考虑初始级配和围压影响的切线杨氏模量;针对?对CSL位置影响的研究显示,随着?减小,CSL向下移动的同时还会沿逆时针方向旋转。基于此结论,以临界状态土力学为框架,通过引入状态参数,建立了考虑初始级配和围压影响与状态相关的切线泊松比。对一种粗粒材料而言,该模型只用一套模型参数,且模型预测结果与试验结果较为吻合。Numerous studies have demonstrated that the strength and deformation characteristics of coarse-grained materials are significantly influenced by the initial particle size distribution(GSD).However,research on constitutive models for coarse-grained materials that consider this influence is still limited.In this study,we introduced an initial GSD index,ϑ,which reflects the ease of particle breakage and links the initial GSD to the ultimate GSD.We systematically investigated and elucidated the mechanism by whichϑaffects the peak shear strength(qp),peak strain(eap),and the position of the critical state line(CSL)on the e-p plane.The results regarding the effect ofϑon qp and eap indicate that asϑincreases,qp decreases,whereas eap increases.Based on these findings and the hump-shaped quadratic curve model proposed by Shen Zhujiang,we established a tangent Young’s modulus that considers the effects of initial GSD and confining pressure.The study on the effect ofϑon the CSL position reveals that a decrease inϑleads to a downward shift and a counterclockwise rotation of the CSL.Subsequently,within the framework of critical state soil mechanics(CSSM),we proposed a state-dependent tangent Poisson’s ratio that considers the effects of initial GSD and confining pressure.For a specific type of coarse-grained material,the model only requires a set of model parameters,and the model’s high accuracy is evidenced by the good agreement between the modeling results and the experimental data.

关 键 词：初始级配 非线性弹性本构模型 粗粒土 应力-应变关系 

分 类 号：TU411[建筑科学—岩土工程]