郑州黄土状粉质黏土力学特性研究  

Study on Mechanical Properties of Loess Silty Clay in Zhengzhou

作　　者：范家玮 张玉芳 李健 袁坤 FAN Jiawei;ZHANG Yufang;LI Jian;YUAN Kun(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;National Key Laboratory of High-Speed Railway Track System,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]中国铁道科学研究院集团有限公司高速铁路轨道系统全国重点实验室,北京100081

出　　处：《中国铁道科学》2025年第1期15-26,共12页China Railway Science

基　　金：中国国家铁路集团有限公司科技研究开发计划课题(N2022G020);青海省重点研发与转化计划项目(2022-SF-158);中国铁道科学研究院集团有限公司院基金课题(2022YJ333)。

摘　　要：黄土遇水易湿陷、软化,研究黄土水敏软化的力学特性对于工程设计中参数的合理选取至关重要。通过原位静力触探试验、十字板剪切试验、标准贯入试验、旁压试验等现场试验与室内物理力学试验相结合的手段,研究郑州地区某铁路沿线黄土状粉质黏土不同含水率状态下的物理性质、力学性质及地基承载力,提出黄土状粉质黏土不排水抗剪强度、标准贯入击数及剪切模量的计算式。结果表明:郑州黄土状粉质黏土黏聚力与内摩擦角均随含水率的增大而减小,含水率从10.1%增大至29.3%时,黏聚力损失65.2%,内摩擦角损失22.1%;郑州黄土状粉质黏土不排水抗剪强度分别与静力触探试验锥尖阻力、比贯入阻力之间呈线性相关,提出的计算式可用于快速计算土体的不排水抗剪强度;含水率由9.3%增大至25.5%时,郑州黄土状粉质黏土标准贯入击数、剪切模量与含水率之间呈分段线性相关,该计算式可用于现场勘察,快速计算地基承载力与剪切模量;郑州黄土状粉质黏土因其干密度大、孔隙比小,与西北黄土相比密实程度高,基本不具备湿陷性。研究成果可为郑州地区某铁路沿线土性参数的合理选取提供参考。Loess is prone to collapse and softening upon water exposure.Studying the mechanical characteristics of loess water-sensitive softening is crucial for the rational selection of parameters in engineering design.By combining in-situ tests such as cone penetration tests,vane shear tests,standard penetration tests,pressuremeter tests with indoor physical and mechanical tests,this study investigates the physical properties,mechanical properties,and foundation bearing capacity of loess silty clay under various moisture contents along a railway line in Zhengzhou.Calculation formulas for undrained shear strength,standard penetration blow count,and shear modulus of loess silty clay are proposed.The results indicate that the cohesion and internal friction angle of loess silty clay in Zhengzhou decrease with the increase of moisture content.The moisture content increases from 10.1%to 29.3%,resulting in a cohesion loss of 65.2%and an internal friction angle loss of 22.1%.The undrained shear strength of loess silty clay in Zhengzhou is linearly correlated with the cone tip resistance and specific penetration resistance obtained from cone penetration tests.The proposed calculation formula can be used to quickly calculate the undrained shear strength of soil.When the moisture content increases from 9.3%to 25.5%,there is a segmented linear correlation between the standard penetration blow count,shear modulus,and moisture content of Zhengzhou loess silty clay.The proposed formula can be used for rapid calculation of foundation bearing capacity and shear modulus in field investigations.Zhengzhou loess silty clay,due to its high dry density and low porosity,has a higher degree of compaction compared to northwest loess and essentially lacks collapsibility.The research findings provide valuable reference for the appropriate selection of soil parameters along the discussed railway line in Zhengzhou area.

关 键 词：铁路路基 郑州黄土状粉质黏土 力学特性 不排水抗剪强度 原位试验 

分 类 号：TU413[建筑科学—岩土工程]