红层河谷区泥岩水化损伤特性试验及本构模型研究  

Experiment of Water-Rock Damage Characteristics of Red Mudstone in Foundation Pit and Construction of Constitutive Model

作　　者：张海康 肖曦 王展 洪武峄 ZHANG Hai-kang;XIAO Xi;WANG Zhan;HONG Wu-yi(College of Civil Engineering and Architecture,Hainan University,Haikou 570228,China)

机构地区：[1]海南大学土木建筑工程学院,海南海口570228

出　　处：《水电能源科学》2020年第2期147-150,175,共5页Water Resources and Power

基　　金：国家自然科学基金项目(50668001)。

摘　　要：红层地区河谷附近的深基坑开挖后在降雨和地下水作用下极易发生坍塌或局部滑塌,为了研究水对红层泥岩力学特性的影响,采用基坑内部钻芯取得的原状岩体,制备不同含水率的试样,通过开展室内扫描电镜及三轴压缩力学试验,对岩体的细观结构及力学参数随含水率的变化规律进行分析。研究结果表明,富水条件下泥岩微观结构疏松,裂缝发育明显。随着含水率的增大,泥岩内摩擦角小幅降低,而粘聚力大幅下降,且含水率与抗压强度及弹性模量均呈负相关。含水率较高条件下,岩样的应力-应变曲线表现为压密阶段区间增大,屈服阶段更为明显。基于微观特性及宏观力学试验结果,提出了考虑红层泥岩水-岩劣化效应的分段式损伤本构模型,并对该模型进行了验证。研究结论可为红层区受水-岩作用影响明显的岩土工程设计提供支撑。For the deep foundation construction in red-bed area of river valley,it is easy to collapse under the action of rainfall and groundwater after excavation.To study the impact of moisture on the mechanical characters of mudstone,undisturbed rock mass are obtained by drilling core and laboratory test of scanning electron microscopy and triaxial compression mechanics on samples with different moisture content are conducted.The microstructure difference of rock mass with different water content and the variation of mechanical parameters with water content are analyzed.The results show that the microstructure of mudstone is loose and there are many cracks inside the rock under the condition of rich water.With the increase of moisture content,the internal friction angle in mudstone decreases slightly,while the cohesive force decreases significantly,and the moisture content is negatively correlated with the compressive strength and elastic modulus.Under the condition of high water content,the stress-strain curve of rock sample shows that the interval of compaction stage increases and the yield stage becomes more significant.Based on the microscopic characteristics and macroscopic mechanical test results,apiecewise damage constitutive model is proposed considering the water-rock deterioration effect of red mudstone,and the model is verified.The research results can provide support for design of geotechnical engineering in red zone which is obviously affected by the effect of water-rock interaction.

关 键 词：红层泥岩 含水率 劣化效应 损伤模型 

分 类 号：TU411.3[建筑科学—岩土工程]