MICP固化钙质砂的统计损伤本构模型  

STATISTICAL DAMAGE CONSTITUTIVE MODEL OF MICP-TREATED CALCAREOUS SAND

作　　者：姜启武 黄明[1] 许凯 崔明娟 JIANG Qiwu;HUANG Ming;XU Kai;CUI Mingjuan(College of Civil Engineering,Fuzhou University,Fuzhou 350116,China)

机构地区：[1]福州大学土木工程学院,福州350116

出　　处：《工程地质学报》2024年第5期1526-1535,共10页Journal of Engineering Geology

基　　金：国家自然科学基金项目(资助号:41972276);福建省自然科学基金项目(资助号:2020J06013)。

摘　　要：目前关于微生物固化体的本构模型研究较少,本文基于Lemaitre应变等价性理论的损伤模型,假定微生物固化体的微元强度服从对数正态随机分布,假设微元破坏符合D-P准则,建立MICP固化钙质砂的统计损伤本构模型。根据试验数据确定本构模型中的参数S_(0)和参数F_0,并对其物理意义进行讨论,将该模型理论结果与试验结果进行对比,验证了该模型的合理性,最后分析了损伤变量D,参数S_(0)和参数F_0随碳酸钙含量变化的演化规律。研究结果表明:参数F_0反映微生物固化钙质砂的极限强度特性,参数S_(0)代表其脆性和延性特征;胶结水平越高,损伤速度越快,损伤值越大,随轴向变形持续增大,损伤变量最终会趋于稳定;该模型能够较好地模拟应变软化和应变硬化现象,同时可以反映体积应变曲线的剪胀和剪缩特性。本研究成果可为MICP固化土体的工程应用提供一定的理论基础。There are few studies on the constitutive model of bio-cemented calcareous sand.In this paper,the statistical damage constitutive model of bio-cemented calcareous sand was established based on the Lemaitre strain equivalence theory.The model assumed that the microelement strength of bio-cemented sand obeys the log-normal random distribution and the D-P criterion.The parameters S_(0) and F 0 in the constitutive model were determined by the experimental data,and their physical significance were discussed.The theoretical results of the model were compared with the experimental results to verify the reasonableness of the model.Finally,the evolution of the damage variable(D),parameter S_(0) and F 0 were analyzed with different calcium carbonate content.The results show that:The parameter F 0 reflects the limiting strength characteristics of MICP-treated calcareous sand,and the parameter S_(0) represents its brittleness and ductility characteristics.The higher the level of cementation,the faster the damage rate and the larger the damage value.The damage variables eventually reaches a stable value as the axial deformation increases.The model can reflect the strain softening and strain hardening phenomena well,which can also represent the shear expansion and shear contraction characteristics of the volume strain curve.The research can provide some theoretical support for the engineering application of MICP-treated calcareous sand.

关 键 词：钙质砂 微生物固化体 D-P准则 对数正态分布 损伤本构模型 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]