CAJ | 학술논문

介绍数字图像处理的基本过程,根据其技术原理编写程序,实现由实拍数字图像直接生成颗粒流模型,为土石混合体力学行为的颗粒流模拟提供新的建模方法.利用该方法,采用PFC~(2D)程序对土石混合体(SRM)进行双轴压缩试验的数值模拟,并与均质土体的试验结果相比较.结果显示,一定碎石含量的土石混合体试样其应力-应变关系呈现出台阶状分布的特征,第一平台段所对应的主应力差基本反映土颗粒的屈服强度;之后强度的提高则与碎块石存在形成的应变硬化现象相关.数值模拟反映出的规律与现场试验结果一致.通过分析土石混合体试样的破坏形态,发现其破坏过程与形态要比均质土体复杂的多,由于碎块石的存在,破裂面往往不规则,不像均质土体那样呈明显的条带状破坏.
개소수자도상처리적기본과정,근거기기술원리편사정서,실현유실박수자도상직접생성과립류모형,위토석혼합체역학행위적과립류모의제공신적건모방법.이용해방법,채용PFC~(2D)정서대토석혼합체(SRM)진행쌍축압축시험적수치모의,병여균질토체적시험결과상비교.결과현시,일정쇄석함량적토석혼합체시양기응력-응변관계정현출태계상분포적특정,제일평태단소대응적주응력차기본반영토과립적굴복강도;지후강도적제고칙여쇄괴석존재형성적응변경화현상상관.수치모의반영출적규률여현장시험결과일치.통과분석토석혼합체시양적파배형태,발현기파배과정여형태요비균질토체복잡적다,유우쇄괴석적존재,파렬면왕왕불규칙,불상균질토체나양정명현적조대상파배.
The basic process of digital image processing technique is described firstly. Based on the technique,a program is designed to directly set up particle flow model from digital image,which provides a new modeling method for particle flow simulation about mechanical behaviors of soil and rock mixtures(SRM). Then,using the proposed modeling method,a series of biaxial tests are simulated by the particle flow code in 2 dimensions(PFC~(2D)). After that,the results of these biaxial tests for SRM are compared with those of homogeneous soils. The results show that the stress-strain curve of SRM has a feature of stepwise;and the differential value between principal stresses at the first step basically corresponds to the yield strength of soil;and the strength increase is due to strain hardening phenomenon caused by gravel,which is consistent with the field test result. Finally,the failure mode of SRM is studied;and the results show that there is a great difference comparing to that of homogeneous soils;and the failure zone is irregular for SRM;but when the homogeneous soil fails,there exists a banded shear zone.