可视化软土隧道模型试验相似材料的配置及其物理力学特性研究  

Study on Configuration Method and Physical-mechanical Properties of Similar Materials for Visual Soft Soil Tunnel Model Test

作　　者：何晟亚 李亮 李恒一 张建经[2] 叶亮 文海家[3] 段虎辰 谢朋 HE Shengya;LI Liang;LI Hengyi;ZHANG Jianjing;YE Liang;WEN Haijia;DUAN Huchen;XIE Peng(Guangzhou Metro Design&Research Institute Co.,Ltd.,Guangzhou 510010;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031;School of Civil Engineering,Chongqing University,Chongqing 400045;School of Civil and Architectural Engineering,Hainan University,Haikou 570228)

机构地区：[1]广州地铁设计研究院股份有限公司,广州510010 [2]西南交通大学土木工程学院,成都610031 [3]重庆大学土木工程学院,重庆400045 [4]海南大学土木建筑工程学院,海口570228

出　　处：《现代隧道技术》2024年第4期202-209,共8页Modern Tunnelling Technology

基　　金：国家自然科学基金(42002293,52068019);海南省自然科学基金(520QN229,422RC599);河北省自然科学基金(E2020210006);海南大学科研基金资助项目(KYQD(2R)1969);广州地铁设计研究院股份有限公司专题研究项目(KY-2021-058);省部共建交通工程结构力学行为与系统安全国家重点实验室开放课题(KF2022-03).

摘　　要：可视化的模型试验是明晰软土隧道开挖诱发连锁事故触发机理的有效手段,而合理配比的相似材料是保证模型试验可靠性的关键。选取正十二烷、15#白油、熔融石英砂和纳米级白炭黑配置透明软土相似材料。通过密度与含油率测试、标准固结试验和固结快剪试验,开展配制材料力学和变形特性分析。研究结果表明:相似材料的密度在1.30~1.59 g/cm^(3)之间,含油率在36.13%~124.71%之间,初始孔隙比在0.70~2.34之间,压缩系数在0.09~1.04 MPa^(-1)之间,压缩模量在0.96~20.11 MPa之间,黏聚力在2.3~31 kPa之间,内摩擦角在14.82°~27.07°之间时,与天然软土相似。试样的e-p曲线均具有较为明显的“上凹型”,e-lgp曲线均呈近似直线下降趋势。每组配比的固结系数在7.87×10^(-4)~2.02×10^(-2)cm^(2)/s之间,符合天然软土固结系数取值范围。透明软土归一化后的剪应力-剪切位移曲线与天然软土的相同,均呈现应变硬化的特点。Visual model tests are an effective means to clarify the triggering mechanisms of chain accidents induced by soft soil tunnel excavation,and reasonably proportioned similar materials are key to ensuring the reliability of model tests.Transparent similar materials of soft soil were configured using n-dodecane,15#white oil,fused silica sand,and nano-scale white carbon black.Through density and oil content tests,standard consolidation tests,and con⁃solidated quick shear tests,the mechanical and deformation characteristics of the configured materials were analyzed.The results show that the density of similar materials ranges between 1.30 g/cm^(3)and 1.59 g/cm^(3),the oil content be⁃tween 36.13%and 124.71%,the initial void ratio between 0.70 and 2.34,the compression coefficient between 0.09 MPa^(-1)and 1.04 MPa^(-1),the compression modulus between 0.96 MPa and 20.11 MPa,the cohesion between 2.3 kPa and 31 kPa,and the internal friction angle between 14.82°and 27.07°,being similar to natural soft soil.The e-p curves of the samples exhibit a clear"concave upward"shape,and the e-lgp curves show an approximately linear downward trend.The consolidation coefficients of samples for each mix group range between 7.87×10^(-4)cm^(2)/s and 2.02×10^(-2)cm^(2)/s,being consistent with the value ranges for natural soft soil.The normalized shear stress-shear dis⁃placement curves of the transparent soft soils are identical to those of natural soft soil,both showing the strain hardening characteristics.

关 键 词：软土隧道 室内试验 透明相似材料 配置方法 物理力学特性 

分 类 号：U451.5[建筑科学—桥梁与隧道工程]