不同固结条件下花岗岩残积土剪切特性试验研究  

Experimental study on shear characteristics of granite residual soil under different consolidation conditions

作　　者：尹松[1] 何文源 白林杰 李玉儒 贺雅 郑丝月 YIN Song;HE Wenyuan;BAI Linjie;LI Yuru;HE Ya;ZHENG Siyue(School of Civil Engineering and Architecture,Zhongyuan University of Technology,Zhengzhou 450007,China)

机构地区：[1]中原工学院建筑工程学院,河南郑州450007

出　　处：《信阳师范大学学报(自然科学版)》2025年第1期51-58,共8页Journal of Xinyang Normal University(Natural Science Edition)

基　　金：国家自然科学基金项目(51709290);河南省高等学校青年骨干教师培养计划项目(2020GGJS136);中原工学院优势学科实力提升计划项目(GG202218)。

摘　　要：为研究不同固结条件下花岗岩残积土的三轴不排水剪切特性,对原状花岗岩残积土在等压和K_(0)固结方式下进行不同固结应力范围(10~50 kPa、100~300 kPa)的三轴不排水剪切试验,分析其剪切特性。结果表明:固结方式对于花岗岩残积土的应力应变关系存在影响,等压固结试样孔压值高于K_(0)固结试样,围压小于50 kPa时出现负孔压,随围压的增大孔压逐渐增大,试样破坏形态与孔压所表现出的剪切状态一致;基于莫尔-库伦强度准则进行数据拟合时,高应力下所得土的黏聚力值较大,内摩擦角值较小,K_(0)固结所得黏聚力值较高;广义幂函数能够很好描述花岗岩残积土的强度非线性,K_(0)固结试样总应力切线摩擦角高于等压固结试样,低应力时K_(0)固结所得有效应力切线摩擦角值较大;固结方式对于花岗岩残积土的变形特性影响较大,采用等压固结方式易高估其极限应变,影响工程安全。In order to study the triaxial undrained shear characteristics of granite residual soil under different consolidation conditions,the triaxial undrained shear tests of undisturbed granite residual soil with different consolidation stress ranges(10~50 kPa,100~300 kPa)were carried out under isobaric and K_(0)consolidation conditions,and the shear characteristics were analyzed.The results showed that:The consolidation method affected the stress-strain relationship of granite residual soil.The pore pressure value of the isobaric consolidation sample was higher than that of the K_(0)consolidation sample,and the negative pore pressure appeared when the confining pressure was less than 50 kPa.The pore pressure gradually increased with the increase of the confining pressure,and the failure mode of the sample was consistent with the shear state shown by the pore pressure.When the data were fitted based on the Mohr-Coulomb strength criterion,the cohesion value of the soil obtained under high stress was larger,the internal friction angle value was smaller,and the cohesion value obtained by K_(0)consolidation was higher.The generalized power function could describe the strength nonlinearity of granite residual soil.The total stress tangent friction angle of the K_(0)consolidated sample was higher than that of the isobaric consolidated sample,and the effective stress tangent friction angle obtained by the K_(0)consolidation was larger at low stress.The consolidation method had a great influence on the deformation characteristics of granite residual soil.It was easy to overestimate the ultimate strain and affect the safety of the project by using the isobaric consolidation method.

关 键 词：花岗岩残积土 K_(0)固结 等压固结 剪切特性 强度非线性 

分 类 号：TU411.7[建筑科学—岩土工程]