干湿动载耦合作用下石灰岩宏细观复合损伤模型研究  

Limestone Macro Composite Damage Model Under Dry and Wet Load Coupling

作　　者：段继超 宗琦[1] 高朋飞[1,2] 汪海波 吕闹[1] 王浩 DUAN Ji-chao;ZONG Qi;GAO Peng-fei;WANG Hai-bo;LYU Nao;WANG Hao(College of Civil Architecture,Anhui University of Science and Technology,Huainan 232001,Anhui,China;Anhui Jiangnan Blasting Engineering Co.Ltd.,Xuancheng 242300,Anhui,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001 [2]安徽江南爆破工程有限公司,安徽宣城242300

出　　处：《中国公路学报》2025年第3期264-277,共14页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(52074009);安徽高校自然科学研究项目(2023AH051167)。

摘　　要：为研究边坡干湿消落带石灰岩的损伤劣化特性,采用直径50 mm分离式霍普金森压杆(SHPB)试验系统对不同干湿循环等级石灰岩开展不同应变率下的单轴压缩试验,分析了石灰岩的单轴压缩力学特性劣化规律及机理,基于Lemaitre应变等效原理构建了干湿动载耦合作用下石灰岩宏细观复合损伤本构模型,并验证了该模型的有效性。试验结果表明:随着干湿循环次数的增加,试样内部细观结构不断弱化,进而在宏观物理特征上表现为纵波波速、抗压强度和弹性模量的逐渐降低以及孔隙度、峰值应变的不断增加;随着应变率的增加,试样耗散能增加,内部更多的微裂纹萌生并活化,试样强度表现出显著的应变率增强效应,同时弹性模量、峰值应变及损伤程度呈现出逐渐增加的趋势;干湿循环引起的细观损伤与动载引起的宏观损伤相互叠加作用,共同加剧了试样的损伤破坏;基于Lemaitre应变等效原理建立的石灰岩宏细观复合损伤演化曲线可分为初始损伤保持、损伤缓慢增加、损伤加速及损伤减速终止4个阶段,实现了对复合损伤演化全过程完整统一的模拟;建立的本构模型可以较好地表征干湿动载耦合作用下石灰岩变形破坏过程中应力、应变特征,与试验数据吻合度高,且模型参数物理意义明确。模型为干湿循环岩石强度的估算和岩石变形、损伤、破坏等问题提供了参考。To study the deterioration characteristics of limestone in dry and wet slope areas,uniaxial compression tests were conducted on limestone with varying dry and wet cycle levels at different strain rates using a 50 mm diameter split Hopkinson pressure bar(SHPB)test system.The deterioration law and mechanism of the uniaxial compression mechanical properties of limestone were investigated,and a macro-micro composite damage constitutive model of limestone under the coupled action of dry and wet dynamic loads was established based on the Lemaitre strain equivalence principle.The effectiveness of the proposed model was verified.The experimental results show that as the number of dry-wet cycles increases,the internal microstructure of the sample weakens,which is reflected in the gradual decrease of longitudinal wave velocity,compressive strength,and elastic modulus,as well as in the increase in porosity and peak strain.As the strain rate increases,the sample dissipates more energy,leading to the formation and activation of additional microcracks.The strength of the sample exhibits a significant strain rate enhancement effect,whereas the elastic modulus,peak strain,and degree of damage only gradually increase.The microscopic damage caused by the wet and dry cycles and the macroscopic damage caused by the dynamic load superimpose,jointly aggravating the damage and destruction of the sample.The macro-micro composite damage evolution curve of limestone,established based on the Lemaitre strain equivalence principle,can be divided into four stages:initial damage retention,slow damage increase,accelerated damage,and damage deceleration and termination for a complete and unified simulation of the entire process of composite damage evolution.The established constitutive model can effectively represent the stress-strain characteristics of limestone deformation and failure under the coupled effect of dry and wet dynamic loads,demonstrating a high degree of agreement with the experimental data.This model provides a valuable referenc

关 键 词：路基工程 边坡 干湿循环 石灰岩 损伤本构模型 宏细观损伤 

分 类 号：U416.14[交通运输工程—道路与铁道工程]