冻结二灰固化碳酸盐渍土及损伤模型研究
Investigation on Carbonated Lime-Ash Solidified Frozen Soil and Damage Constitutive Model
李治斌 1刘利骄 2黄帅 3丁琳 2柳艳杰2
作者信息
- 1. 中山大学土木工程学院,广州 510275
- 2. 黑龙江大学建筑工程学院,哈尔滨 150080
- 3. 东北林业大学林学院,哈尔滨 150040
- 折叠
摘要
在寒区工程中,盐-冻耦合效应往往会放大盐渍土体的强度损失.因此,考虑探究冻结作用下二灰固化碳酸盐渍土抗压性能的变化规律,以固化剂掺量、温度和加载速率作为影响因素,对二灰固化盐渍土进行了无侧限抗压试验,并提出一种考虑温度和加载速率的二灰固化盐渍土损伤本构模型.结果表明:石灰和粉煤灰能明显提高碳酸盐渍土的抗压强度,且使得改良土的应力-应变曲线由应变弱软化变为应变明显软化,当掺入3％石灰和12％粉煤灰时对碳酸盐渍土的固化效果最显著;温度和加载速率显著影响二灰固化土的抗压强度和弹性模量,三者之间关系可用非线性函数表达;二灰固化土抗压强度的影响因素按照重要性排序为温度＞固化剂掺量＞加载速率,且温度对改良土的影响远大于固化剂掺量和加载速率;所构建的二灰固化土损伤模型能较好地反映土体的应力应变关系和损伤变量的变化趋势.
Abstract
In engineering projects of cold regions,the salt-freezing coupling effect often exacerbates the strength degradation of saline soil.We aim to investigate the variations in compressive performance of lime-and-flyash-solidi-fied carbonate soil under freezing conditions.With curing agent dosage,temperature,and loading rate as influen-cing parameters,we conducted unconfined compression tests on lime-and-flyash-solidified carbonate saline soil and subsequently proposed a damage constitutive model considering temperature and loading rate.Results indicate that lime and fly ash significantly enhance the compressive strength of carbonate soil,altering its stress-strain curve from weak strain softening to distinct strain softening.Optimal curing occurs with the addition of 3％lime and 12％fly ash.Temperature and loading rate markedly affect the compressive strength and elastic modulus of the solidified car-bonate soil,with their relationship being expressed as a nonlinear function.Temperature exerts far more larger influ-ence on compressive strength than curing agent dosage and loading rate.The established damage model effectively captures the stress-strain relationship and the variation trend of soil damage variables.
关键词
冻结盐渍土/二灰改良/无侧限抗压强度/加载速率/损伤本构模型Key words
frozen saline soil/lime-flyash improvment/unconfined compressive strength/loading rate/damage constitutive model引用本文复制引用
基金项目
国家自然科学基金项目(41071049)
冻土工程国家重点实验室开放基金项目(SKLFSE201802)
冻土工程国家重点实验室开放基金项目(SKLFSE201919)
出版年
2024
国家科技期刊平台
NSTL
万方数据