含水率对稳定化飞灰力学特性影响的试验研究  

Effect of Moisture Content on the Mechanical Properties of Stabilized Fly Ash

作　　者：史建 曹文哲 汪迎硕 范惜辉 欧明霖 Shi Jian;Cao Wenzhe;Wang Yingshuo;Fan Xihui;Ou Minglin(Nanjing Environmental Group Co.,Ltd.;School of Erath Sciences and Engineering,Hohai University)

机构地区：[1]南京环境集团有限公司,南京市210026 [2]河海大学地球科学与工程学院,南京市211100

出　　处：《勘察科学技术》2024年第6期1-4,40,共5页Site Investigation Science and Technology

基　　金：南京市建设行业科技计划项目(项目编号:Ks2134)。

摘　　要：该文以南京某填埋场稳定化飞灰为研究对象,通过室内试验分析了飞灰的颗粒组成、力学特性和抗剪强度指标的变化规律,提出了飞灰峰值抗剪强度随含水率变化的预测方程。结果表明:稳定化飞灰的颗粒组成主要以粗颗粒为主,级配良好;飞灰偏应力-应变曲线大致分为弹性变形、应变软化、屈服和破坏四个阶段,随着含水率的增大初始压缩性增大,而线弹性段逐渐减小,屈服点降低;相同含水率条件下,飞灰的抗剪强度随着围压的升高而线性增加,但关系曲线的斜率随着含水率的增大而降低;相同围压条件下,飞灰抗剪强度随着含水率呈指数形式下降;飞灰的摩擦角随着含水率的增大而逐渐减小,但黏聚力呈先增大后减小,为保证堆积体的稳定性,建议飞灰的初始含水率控制在30%以下。研究成果可以为飞灰填埋场的设计和稳定性评估提供参考。This paper takes stabilized fly ash from a landfill in Nanjing as the research object,analyzing the particle composition,mechanical properties,and shear strength index through laboratory tests.A predictive equation for the peak shear strength of fly ash with changes in moisture content is proposed.The results show that the stabilized fly ash primarily consists of coarse particles,with well-graded characteristics.The deviatoric stress strain curve of fly ash can be roughly divided into four stages:elastic deformation,strain softening,yielding,and failure.As the moisture content increases,the initial compressibility rises,while the linear elastic section gradually shortens,and the yield point decreases.Under the same moisture content conditions,the shear strength of fly ash increases linearly with the increase of confining pressure,but the slope of the line segment decreases with the increase of moisture content.At the same confining pressure conditions,the shear strength of fly ash decreases exponentially with increased water content.The friction angle of fly ash gradually decreases with the increase of moisture content,while the cohesion first increases and then decreases.To ensure the stability of the accumulated body,it is recommended that the initial moisture content of fly ash should be controlled below 30%.The research results can provide reference for design and stability evaluation of fly ash landfills.

关 键 词：垃圾飞灰 室内试验 力学特性 抗剪强度指标 拟合方程 

分 类 号：TU4[建筑科学—土工工程]