摘要
基于数字图像技术及离散傅里叶变换理论,通过Matlab编制程序,实现了自然块石二维轮廓的识别、离散与重构.结合分形理论,设计了一种可根据指定块石粒径、含石率以及分形维数生成土石混合体地层模型的便捷方法.在此基础上建立了土石混合地层数值模型,并针对隧道施工过程中的地层变形特性进行了探究.计算结果表明：相比于传统均质模型,土石混合模型能够反映地层中块石对隧道掌子面挤出位移和地表沉降的影响,更真实地呈现土石混合体地层中围岩土体的变形规律;与均质模型中所描述的规则单一的塑性区不同,土石混合地层中,隧道掌子面后的塑性区发展存在明显的＂绕石效应＂,其扩展路径更为复杂、多元,且滑动带的路径明显延长,一定程度上增加隧道施工扰动的影响范围.
Based on digital image technology and discrete Fourier transform theory,identification,dispersion and reconstruction of two-dimensional contour of natural stone were realized.Combined with fractal theory,a convenient method for generating soil-rock mixture stratum was designed according to the specified block size,stone content and fractal dimension.On this basis,a numerical model of soil-rock mixture stratum was established to study the deformation characteristics of stratum during tunnel excavation.The calculation results indicate that compared to the traditional homogeneous model,soil and rock mixture model is able to show the effects of stone on tunnel face deformation and ground settlement,which means it can offer a better description of the deformation law of the surrounding rock mass in the soil-rock mixture stratum.Different from the single plastic zone described in the homogeneous model,there is an obvious＂rock around effect＂in the development of the plastic zone,which is behind the tunnel face,in the soil-rock mixture model,and its expansion paths are more complex,multivariate and have longer sliding paths.To a certain extent,the characteristics mentioned above will increase the influence range of the tunnel construction disturbance.
作者
林越翔
彭立敏
王翔
雷明锋
Lin Yuexiang;Peng Limin;Wang Xiang;Lei Mingfeng(School of Civil Engineering;Key Laboratory of Engineering Structure of Heavy Haul Railway, Central South University, Changsha410075, China)
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2018年第4期35-40,45,共7页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51508575,U1734208,U1361204)
中央高校基本科研业务费专项资金资助项目(2017zzts154,1053320170801)
关键词
土石混合体
数字图像技术
离散傅里叶变换
构造方法
地层变形
soil-rock mixture
digital image technology
discrete Fourier transform
construction method
stratum deformation
