农业工程学报
農業工程學報
농업공정학보
2014年
1期
1-9
,共9页
周云艳%徐琨%陈建平%王晓梅
週雲豔%徐琨%陳建平%王曉梅
주운염%서곤%진건평%왕효매
力学分析%植被%CT%根系固土%边坡加固%细观力学
力學分析%植被%CT%根繫固土%邊坡加固%細觀力學
역학분석%식피%CT%근계고토%변파가고%세관역학
mechanical properties%vegetation%computerized tomography (CT)%root reinforcement%slope stability%mesomechanics
为了探寻植物根系加固土体、防护边坡的作用机理，该文从细观角度对根系固土的力学特性进行了探讨，并利用长江科学院研制的CT三轴仪，分别对素土样和2种含根土样进行不固结不排水的CT实时三轴剪切试验。通过对试样3个断面在不同应变时刻所对应的CT扫描数据进行定量分析发现，3个扫描层中素土样的（CT数均值）ME-ε1关系曲线下降段和（CT 数方差）SD-ε1关系曲线上升段的变化幅度均大于2种含根土样曲线相应阶段的变化幅度；这说明含根土体内部缺陷发育速度更慢，含根土样内部裂纹萌生和扩展得更加缓慢，根系具有阻裂作用。文中重点对3种土样在高度的7/16处的断面上的CT扫描图片进行了定性和定量分析。利用Matlab软件自编后处理程序，对 CT 扫描图片进行了二值化处理，并统计出断面上的裂隙率、根附近区域及其之外区域的总裂隙大小、最大裂隙区域的长度和宽度信息。通过对含根土样和素土样受压过程的 CT 演化图片和断面上统计的裂缝数据信息进行比较分析，来对比说明素土和含根土样中裂纹扩展以及试样破坏过程的差异，从而揭露了根系的阻裂作用和桥联作用。最后得出根系固土的细观力学机理主要表现为根系对土体的阻裂作用和桥联作用。
為瞭探尋植物根繫加固土體、防護邊坡的作用機理，該文從細觀角度對根繫固土的力學特性進行瞭探討，併利用長江科學院研製的CT三軸儀，分彆對素土樣和2種含根土樣進行不固結不排水的CT實時三軸剪切試驗。通過對試樣3箇斷麵在不同應變時刻所對應的CT掃描數據進行定量分析髮現，3箇掃描層中素土樣的（CT數均值）ME-ε1關繫麯線下降段和（CT 數方差）SD-ε1關繫麯線上升段的變化幅度均大于2種含根土樣麯線相應階段的變化幅度；這說明含根土體內部缺陷髮育速度更慢，含根土樣內部裂紋萌生和擴展得更加緩慢，根繫具有阻裂作用。文中重點對3種土樣在高度的7/16處的斷麵上的CT掃描圖片進行瞭定性和定量分析。利用Matlab軟件自編後處理程序，對 CT 掃描圖片進行瞭二值化處理，併統計齣斷麵上的裂隙率、根附近區域及其之外區域的總裂隙大小、最大裂隙區域的長度和寬度信息。通過對含根土樣和素土樣受壓過程的 CT 縯化圖片和斷麵上統計的裂縫數據信息進行比較分析，來對比說明素土和含根土樣中裂紋擴展以及試樣破壞過程的差異，從而揭露瞭根繫的阻裂作用和橋聯作用。最後得齣根繫固土的細觀力學機理主要錶現為根繫對土體的阻裂作用和橋聯作用。
위료탐심식물근계가고토체、방호변파적작용궤리，해문종세관각도대근계고토적역학특성진행료탐토，병이용장강과학원연제적CT삼축의，분별대소토양화2충함근토양진행불고결불배수적CT실시삼축전절시험。통과대시양3개단면재불동응변시각소대응적CT소묘수거진행정량분석발현，3개소묘층중소토양적（CT수균치）ME-ε1관계곡선하강단화（CT 수방차）SD-ε1관계곡선상승단적변화폭도균대우2충함근토양곡선상응계단적변화폭도；저설명함근토체내부결함발육속도경만，함근토양내부렬문맹생화확전득경가완만，근계구유조렬작용。문중중점대3충토양재고도적7/16처적단면상적CT소묘도편진행료정성화정량분석。이용Matlab연건자편후처리정서，대 CT 소묘도편진행료이치화처리，병통계출단면상적렬극솔、근부근구역급기지외구역적총렬극대소、최대렬극구역적장도화관도신식。통과대함근토양화소토양수압과정적 CT 연화도편화단면상통계적렬봉수거신식진행비교분석，래대비설명소토화함근토양중렬문확전이급시양파배과정적차이，종이게로료근계적조렬작용화교련작용。최후득출근계고토적세관역학궤리주요표현위근계대토체적조렬작용화교련작용。
In order to explore the mechanism of soil reinforcement and slope protection by plant roots, in this paper, the mechanical characteristics of roots on soil stabilization were discussed from the meso angle, and using a CT triaxial apparatus developed at the Yangtze River Scientific Research, a series of unconsolidated-undrained CT real-time triaxial shear test of the non-rooted clay sample and two kinds of Broussonetia papyrifera-rooted clay samples with different root diameters were carried out. Through a quantitative analysis of CT scan data of three sections at the different strain for three kinds of samples, it was found that both the downward section of (mean CT number) ME-ε1 curve and the upward section of (the variance of CT number) SD-ε1 curve of the non-rooted soils had a greater changing amplitude than those of the rooted soils in three different scan layer sections. It indicated that the internal defects of the rooted soil grew more slowly and weakly, the initiation and propagation of internal cracks slower, and the roots resist cracks. This paper focused on the qualitative and quantitative analysis of CT scanning images of the height of a 7/16 cross section at the different strain for three kinds of soil samples. Using the program self-prepared in Matlab software, the CT scan images were binarized, and the statistical crack data of the scan layer section were obtained including the crack rate of cross section, the total crack size in the area near the root and beyond the root respectively, and the length and width of the maximum crack area. Through the comparative analysis of CT scan images evolution under pressure and the statistical crack data of them for the non-rooted soils and the rooted soils, the fundamental differences in destruction process of the soil and crack propagation between the non-rooted soil and the rooted soil were described, thus exposing the crack resistance and the bridging effect of roots. It was concluded that the mesomechanics mechanism of roots reinforcement is mainly the crack resistance and the bridging effect of root on the soil.
