受酸腐蚀砂岩力学特性及其统计损伤本构模型  

Mechanical Properties and Statistical Damage Constitutive Model of Acid-corroded Sandstone

作　　者：苗子臻 李曙光[1,2] 霍润科 任少强[2] 吴应明[2] 杨星智[2] MIAO Zizhen;LI Shuguang;HUO Runke;REN Shaoqiang;WU Yingming;YANG Xingzhi(School of Civil Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China;Post-doctoral Research Workstation,China Railway 20th Bureau Group Co.,Ltd.,Xi′an 710016,China)

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055 [2]中铁二十局集团有限公司博士后科研工作站,陕西西安710016

出　　处：《铁道学报》2023年第1期141-149,共9页Journal of the China Railway Society

基　　金：国家自然科学基金(42077274,52178393);国家重点研发计划(2018YFC0808701);中国博士后科学基金(2020M673525);陕西省自然科学基础研究计划(2022JQ-563)。

摘　　要：酸性侵蚀环境使得隧道、桥梁、房屋等结构劣化,耐久性和承载性能降低,服役时间缩短,最终导致各种灾害事故发生。为深入探究酸性溶液对岩石力学性能的影响,采用室内长期加速腐蚀试验,对pH=1、3、5的盐酸HCl以及pH=7的蒸馏水(H 2O)腐蚀作用下砂岩的单轴力学劣化特性进行系统研究。基于连续损伤力学和统计理论,借助CT扫描试验分析结果,引入化学-荷载共同作用损伤变量,建立考虑受酸腐蚀砂岩应力-应变曲线压密段的统计损伤本构模型,基于单轴压缩试验结果对模型进行验证。研究结果表明,腐蚀岩样单轴压缩应力-应变曲线的压密段变长,弹性段变短,轴向峰值应力、弹性模量和泊松比减小,轴向、径向峰值点应变增大;腐蚀岩样的裂隙闭合点应变增大、裂隙压缩段变长、裂纹扩展段延长,其脆性特征减弱,柔性特征增强,岩样越来越表现出柔性材料的特征;浸泡溶液pH值越小,浸泡时间越长,岩样损伤软化效应越明显。试验曲线与理论曲线的对比结果表明,所建立的统计损伤本构模型能够较好地反映受酸腐蚀砂岩在荷载作用下的变形特性。研究结果可为受酸腐蚀岩体的稳定性及减防灾分析提供理论基础。Acid corrosion environment leads to structural deterioration of tunnels,bridges and buildings,reduction of durability and bearing capacity,shortening of service time,and results in various disasters and accidents.To explore the influence of acid corrosion on sandstone mechanical properties,laboratory long-term accelerated corrosion test was conducted to study the mechanical degradation characteristics of sandstone subjected to hydrochloric acid(HCl)with pH=1,3,5 and distilled water(H 2O)with pH=7.With the help of the analysis results of the CT scan test,continuous damage mechanics and statistical theory,by introducing the chemical-load damage variables,the statistical damage constitutive model considering the stress-strain curve of the acid-corroded sandstone was established.The model was verified based on the uniaxial compression test results.The results show that the compression section of the uniaxial compressive stress-strain curve of the corroded sandstone samples becomes longer as the elastic section becomes shorter.With the decrease of the axial peak stress,elastic modulus and Poisson’s ratio,the axial peak point strains increase.With the increase of the strain at the crack closure point of the acid-corroded rock samples,the lengthening of the crack compression section,and the extension of the crack expansion section,the brittleness characteristics of the rock samples are weakened and the flexible features are enhanced,showing the characteristics of flexible materials.The lower the pH value and the longer the immersion time,the more obvious the damage softening effect of the rock sample.The comparison between the test curve and the theoretical curve shows that the statistical damage constitutive model established in this paper can well reflect the deformation characteristics of the acid-corroded sandstone under load.The research results can provide a theoretical basis for the stability and disaster reduction analysis of the acid-corroded rock masses.

关 键 词：砂岩 酸腐蚀 力学特性 损伤 本构模型 

分 类 号：TU45[建筑科学—岩土工程]