宝兰客专第三系泥岩物性参数与力学特性研究  

Study on Physical Parameters and Mechanical Characteristics of Tertiary Mud Stone in Baoji-Lanzhou High-speed Railway

作　　者：靳宝成[1] 王新东 贺思悦 符亚鹏[1] 何永旺[1] 史先伟[1] JIN Baocheng;WANG Xindong;HE Siyue;FU Yapeng;HE Yongwang;SHI Xianwei(China Railway First Survey and Design Institute Group Co.Ltd,Xi'an,Shaanxi 710043,China;State Key Laboratory of Intelligent Geotechnics and Tunnelling,Xi'an,Shaanxi 710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043 [2]极端环境岩土和隧道工程智能建养全国重点实验室,西安710043

出　　处：《铁道工程学报》2024年第8期30-38,共9页Journal of Railway Engineering Society

基　　金：中国国家铁路集团有限公司科技研发计划重大课题铁一院配套项目(K2020G034-PT01);中铁第一勘察设计院集团有限公司科研开发课题(17-20)。

摘　　要：研究目的:膨胀性地层中隧道施工是一个较难的工程问题,本文以宝兰客专北二十里铺隧道的膨胀性及地下水情况测试为基础,对泥岩膨胀特性等展开深入的研究,有利于明确泥岩膨胀对隧道内轨道变形的影响,完善隧道设计理论。研究结论:(1)第三系泥岩具有弱膨胀性;(2)膨胀岩的弹性模量和单轴抗压强度、单轴抗拉强度、三轴抗压强度在浸水后都呈现出明显的降低,随着浸泡时间的增加,各强度降低的速率逐渐下降;(3)单轴压缩试验表明,平均单轴抗压强度由29.18 MPa减少为4.65 MPa,衰减了84%,平均弹性模量由2.32 GPa减小为0.85 GPa,减小了63%;巴西劈裂试验表明,膨胀岩的平均抗拉强度由2.66 MPa减少为0.36 MPa,衰减了86.5%;三轴压缩试验表明,随着浸水时间的不断增加,膨胀岩的内聚力出现大幅的降低,尤其是在浸水初期下降迅速,由5.82 MPa降至1.34 MPa,减小了77%,膨胀岩的内摩擦角虽有所降低,但下降幅度不大,浸水15 d内总共降低4.07%;(4)本研究成果可为类似膨胀性泥岩铁路隧道设计提供参考。Research purposes:Tunnel construction in expansive strata is a difficult engineering problem.Based on the expansion and groundwater test of the Beiershilipu tunnel in Baoji-Lanzhou High-speed Railway,an in-depth study of soil expansion characteristics of mud stone is conducive to determining the influence of mud stone expansion on the track deformation of tunnel and improving tunnel design theory.Research conclusions:(1)Tertiary mud stone has weak expansibility.(2)The elastic modulus,uniaxial compressive strength,uniaxial tensile strength and triaxial compressive strength of expansive rock decrease significantly after soaking,and the decreasing rates of each strength gradually decrease with the increase of soaking time.(3)The uniaxial compression tests show that the average uniaxial compressive strength decreases from 29.18 MPa to 4.65 MPa,decreasing by 84%,and the average elastic modulus decreases from 2.32 GPa to 0.85 GPa,decreasing by 63%.The Brazilian splitting tests show that the average tensile strength of the expansive rock decreases from 2.66 MPa to 0.36 MPa,decreasing by 86.5%.The triaxial compression tests show that the cohesive force of the expansive rock decreases significantly with the increase of immersion time,especially in the initial stage of immersion,from 5.82 MPa to 1.34 MPa,which decreases by 77%.However,the internal friction angle of the expansive rock decreases,but the decrease is not large,and the total decrease is 4.07%within 15 days of immersion.(4)The research results can provide reference for the design of railway tunnels similar to expansive mud stone.

关 键 词：宝兰客专 膨胀性地层 第三系泥岩 三轴抗压强度 单轴抗压强度 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]