| 87 | 0 | 68 |
| 下载次数 | 被引频次 | 阅读次数 |
植被根系可以提高土体抵抗剪切的能力，抑制浅层滑坡。但是，根系是否可以增强黄土的循环抵抗能力，以及地震荷载下各种因素对根系力学加固效应的影响缺乏相关的研究。通过进行一系列动单剪试验和离散元模拟来探究加根黄土的循环行为。首先调查了初始静剪应力和加载频率对根土复合体试样循环抵抗能力的影响。之后基于离散元方法(PFC3D),进行常体积循环直接简单剪切模拟，探究根系几何、力学特性及根土间胶结强度对加根黄土循环强度的影响。研究结果表明根系可以有效提高黄土的循环抵抗能力。根土复合体的循环抵抗能力随初始剪应力的增加先下降，后上升，随频率的增加不断提高。模拟结果表明根系弹性模量、根土间胶结强度的增加均可以提升根土复合体的循环抵抗能力。当根系的初始倾斜角度为90°时，根土复合体的循环抵抗能力获得最大值。
Abstract：Plant roots are widely known to provide mechanical reinforcement to soils against shearing and further increase slope stability. However, whether roots provide reinforcement to loess cyclic re-sistance and how various factors affect roots reinforcement during seismic loading have rarely been studied. The objective is to conduct a series of cyclic direct simple shear tests and DEM numerical simulation to investigate the cyclic behaviour of rooted loess. The effects of initial static shear stress and loading frequency on the cyclic resistance of root-soil composites were first investigated. After that, cyclic direct simple shear simulations at constant volume were carried out based on the discrete element method(PFC3D) to investigate the effects of root geome-try, mechanical traits and root-soil bond strength on the cyclic strength of rooted loess. It was discovered that the roots could effectively improve the cyclic resistance of loess. The cyclic resistance of the root-soil composite decreases with the increase of the initial shear stress, then increases, and improves with the increase of the frequency. The simulation result show that increases in root elastic modulus and root-soil interfacial bond strength can all enhance the cyclic resistance of root-soil composites, and the maximum cyclic resistance of the root-soil composite was obtained when the initial inclination angle of the root system was 90°.
[1] SCHENK H J,JACKSON R B.The global biogeography of roots[J].Ecological Monographs,2002,72(3):311.
[2] FAN C C,SU C F.Role of roots in the shear strength of root-reinforced soils with high moisture content[J].Ecological Engineering,2008,33(2):157-166.
[3] SCHMALTZ E M,STEGER S,GLADE T.The influence of forest cover on landslide occurrence explored with spatio-temporal information[J].Geomorphology,2017,290:250-264.
[4] WALDRON L J.The shear resistance of root-permeated homogeneous and stratified soil[J].Soil Science Society of America Journal,1977,41(5):843-849.
[5] MASI E B,SEGONI S,TOFANI V.Root reinforcement in slope stability models:a review[J].Geosciences,2021,11(5):212.
[6] POLLEN N.Temporal and spatial variability in root reinforcement of streambanks:Accounting for soil shear strength and moisture[J].Catena,2007,69(3):197-205.
[7] GREENWAY D R.Vegetation and Slope Stability[M].New York:Wiley Press,1987.
[8] BRUAND A,COUSIN I,NICOULLAUD B,et al.Backscattered electron scanning images of soil porosity for analyzing soil compaction around roots[J].Soil Science Society of America Journal,1996,60(3):895-901.
[9] GUIDI G,POGGIO G,PETRUZZELLI G.The porosity of soil aggregates from bulk soil and from soil adhering to roots[J].Plant and Soil,1985,87(2):311-314.
[10] TISDALL J M,COCKROFT B,UREN N C.The stability of soil aggregates as affected by organic materials,microbial activity and physical disruption[J].Soil Research,1978,16(1):9.
[11] YOUNG I M.Biophysical interactions at the root-soil interface:A review[J].The Journal of Agricultural Science,1998,130(1):1-7.
[12] MUZYLO A,LLORENS P,VALENTE F,et al.A review of rainfall interception modelling[J].Journal of Hydrology,2009,370(1):191-206.
[13] CHEN Z F,LI H,JIANG N S.Freeze-thaw time and moisture content affect shear strength of loess reinforced with Sophora japonica roots[J].Bulletin of Soil and Water Conservation,2023,43(2):43-49.
[14] WU T H,MCKINNELL W P,SWANSTON D N.Strength of tree roots and landslides on prince of Wales Island,Alaska[J].Canadian Geotechnical Journal,1979,16(1):19-33.
[15] DE BRITO GALV?O T C,PEREIRA A R,PARIZZI M G,et al.Bioengineering techniques associated with soil nailing applied to slope stabilization and erosion control[J].Natural Hazards Review,2010,11(2):43-48.
[16] FAN C C.A displacement-based model for estimating the shear resistance of root-permeated soils[J].Plant and Soil,2012,355(1/2):103-119.
[17] ABE K,ZIEMER R R.Effect of tree roots on a shear zone:Modeling reinforced shear stress[J].Canadian Journal of Forest Research,1991,21(7):1012-1019.
[18] SCHWARZ M,LEHMANN P,OR D.Quantifying lateral root reinforcement in steep slopes-from a bundle of roots to tree stands[J].Earth Surface Processes and Landforms,2010,35(3):354-367.
[19] POLLEN N.Temporal and spatial variability in root reinforcement of streambanks:Accounting for soil shear strength and moisture[J].Catena,2007,69(3):197-205.
[20] JI J N,MAO Z,QU W B,et al.Energy-based fibre bundle model algorithms to predict soil reinforcement by roots[J].Plant and Soil,2020,446(1/2):307-329.
[21] LIANG T,KNAPPETT J A.Centrifuge modelling of the influence of slope height on the seismic performance of rooted slopes[J].Géotechnique,2017,67(10):855-869.
[22] KARIMZADEH A A,LEUNG A K,HOSSEINPOUR S,et al.Monotonic and cyclic behaviour of root-reinforced sand[J].Canadian Geotechnical Journal,2021,58(12):1915-1927.
[23] BERNHARDT M L ,BISCONTIN G ,O′SULLIVAN C.3D discrete element method simulations of a laminar-type simple shear apparatus[C]//ASCE.Geo-Congress 2014:For Sustainability 2014.San Diego,CA(US):Geotechnical Special Publication,2014:614-623.
[24] AL TARHOUNI M A,HAWLADER B.Monotonic and cyclic behaviour of sand in direct simple shear test conditions considering low stresses[J].Soil Dynamics and Earthquake Engineering,2021,150:106931.
[25] LASHKA R I,FALSAFIZAD E H,RAHMAN M.Influence of linear coupling between volumetric and shear strains on instability and post-peak softening of sand in direct simple shear tests[J].Acta Geotechnica,2021,16(11):1-22.
[26] LBIBB S,MANZARI M T.Stress-strain behavior of Ottawa sand in cyclic direct simple shear and modeling of cyclic strength using Artificial Neural Networks[J].Soil Dynamics and Earthquake Engineering,2023,164:107585.
[27] LIU F C,CHEN L,WANG H D.Evaluation of dynamic shear modulus and damping ratio of rubber-sand mixture based on cyclic simple shear tests[J].Rock and Soil Mechanics,2016,37(7):1903-1913.
[28] WANG Q,ZHANG Z,SHAO S J,et al.Experimental study on seismic compression of Chinese loess under cyclic direct simple shear testing[J].Advances in Civil Engineering,2022,2022(9):5689912.
[29] MCCARRON W,LAWRENCE J,WERNER R,et al.Cyclic direct simple shear testing of a Beaufort Sea clay[J].Canadian Geotechnical Journal,1995,32(4):584-600.
[30] ELGHORAIBY M A,PARK H,MANZARI M T.Stress-strain behavior and liquefaction strength characteristics of Ottawa F65 sand[J].Soil Dynamics and Earthquake Engineering,2020,138:106292.
[31] YE B,LU J F,YE G L.Pre-shear effect on liquefaction resistance of a Fujian sand[J].Soil Dynamics and Earthquake Engineering,2015,77:15-23.
[32] CHIARO G,KOSEKI J,SATO T.Effects of initial static shear on liquefaction and large deformation properties of loose saturated Toyoura sand in undrained cyclic torsional shear tests[J].Soils and Foundations,2012,52(3):498-510.
[33] NEMAT-NASSER S,TOBITA Y.Influence of fabric on liquefaction and densification potential of cohesionless sand[J].Mechanics of Materials,1982,1(1):43-62.
[34] YANG J,SZE H Y.Cyclic behaviour and resistance of saturated sand under non-symmetrical loading conditions[J].Géotechnique,2011,61(1):59-73.
[35] VAID Y P,CHERN J C.Effect of static shear on resistance to liquefaction[J].Soils and Foundations,1983,23(1):47-60.
[36] PARK S S,NONG Z Z,LEE D E.Effect of vertical effective and initial static shear stresses on the liquefaction resistance of sands in cyclic direct simple shear tests[J].Soils and Foundations,2020,60(6):1588-1607.
[37] MICKOVSKI S B,STOKES A,VAN BEEK R,et al.Simulation of direct shear tests on rooted and non-rooted soil using finite element analysis[J].Ecological Engineering,2011,37(10):1523-1532.
[38] MAO Z,YANG M,BOURRIER F,et al.Evaluation of root reinforcement models using numerical modelling approaches[J].Plant and Soil,2014,381(1/2):249-270.
[39] CUNDALL P A,STRACK O D L.A discrete numerical model for granular assemblies[J].Géotechnique,1979,29(1):47-65.
[40] JIANG M J,YAN H B,ZHU H H,et al.Modeling shear behavior and strain localization in cemented sands by two-dimensional distinct element method analyses[J].Computers and Geotechnics,2011,38(1):14-29.
[41] XU D S,TANG J Y,ZOU Y,et al.Macro and micro investigation of gravel content on simple shear behavior of sand-gravel mixture[J].Construction and Building Materials,2019,221:730-744.
[42] DABEET A.Discrete Element Modeling of Direct Simple Shear Response of Granular Soils And Model Validation Using Laboratory Tests[D].Vancouver:University of British Columbia,2014.
[43] ASADZADEH M,SOROUSH A.Fundamental investigation of constant stress simple shear test using DEM[J].Powder Technology,2016,292:129-139.
[44] AI J,LANGSTON P A,YU H S.Discrete element modelling of material non-coaxiality in simple shear flows[J].International Journal for Numerical and Analytical Methods in Geomechanics,2014,38(6):615-635.
[45] ASADZADEH M,SOROUSH A.Macro- and micromechanical evaluation of cyclic simple shear test by discrete element method[J].Particuology,2017,31:129-139.
[46] BERNHARDT M L,BISCONTIN G,O’SULLIVAN C.Experimental validation study of 3D direct simple shear DEM simulations[J].Soils and Foundations,2016,56(3):336-347.
[48] ASADZADEH M,SOROUSH A.Evaluation of stress and strain non-uniformity during cyclic simple shear test using DEM:Effect of the horizontal platen asperities[J].Granular Matter,2018,20(3):43.
[49] ZHANG L,EVANS T M.Investigation of initial static shear stress effects on liquefaction resistance using discrete element method simulations[J].International Journal of Geomechanics,2020,20(7):04020087.
[50] BOURRIER F,KNEIB F,CHAREYRE B,et al.Discrete modeling of granular soils reinforcement by plant roots[J].Ecological Engineering,2013,61:646-657.
[51] DABEET A,WIJEWICKREME D,BYRNE P.Simulation of cyclic direct simple shear loading response of soils using discrete element modeling[C]//IAEE.Proceedings of the 15th World Conference on Earthquakes Engineering.Lisbon,Portugal:Sociedade Portuguesa de Engenharia Sismica,2012:10780316.
[52] CIANTIA M O,PREVITALI M,CAKIR T.Experimental and DEM study of monotonic and cyclic simple shear testing of an angular sand[C]//RAHMAN M M.Proceedings of the 20th International Conference on Soil Mechanics and Geotechnical Engineering.Sydney:Australian Geomechanics Society,2021:141802.
[53] O’SULLIVAN C,CUI L,STUART C O′ N E I L L.Discrete element analysis of the response of granular materials during cyclic loading[J].Soils and Foundations,2008,48(4):511-530.
[54] MA Y,HUANG H.DEM analysis of failure mechanisms in the intact Brazilian test[J].International Journal of Rock Mechanics and Mining Sciences,2018,102:109-119.
[55] JIANG M,LIU J,SHEN Z F,et al.Exploring the critical state properties and major principal stress rotation of sand in direct shear test using the distinct element method[J].Granular Matter,2018,20:1-18.
[56] TANG C S,SHI B,ZHAO L Z.Interfacial shear strength of fiber reinforced soil[J].Geotextiles and Geomembranes,2010,28(1):54-62.
[57] VAID Y P,SIVATHAYALAN S.Static and cyclic liquefaction potential of Fraser Delta sand in simple shear and triaxial tests[J].Canadian Geotechnical Journal,1996,33(2):281-289.
[58] KIM S J.Behavior of Sand in Cyclic Simple Shear Test[D].Busan:Pusan University,2009.
[59] ISHIHARA K.Liquefaction and flow failure during earthquakes[J].Geotechnique,1993,43(3):351-451.
[60] SIVATHAYALAN S,HA D.Effect of static shear stress on the cyclic resistance of sands in simple shear loading[J].Canadian Geotechnical Journal,2011,48(10):1471-1484.
[61] SEED H B,IDRISS I M,MAKDISI F,et al.Representation of Irregular Stress Time Histories by Equivalent Uniform Stress Series in Liquefaction Analysis[M].California:University of California,1975.
[62] XU D S,TANG J Y,ZOU Y,et al.Macro and micro investigation of gravel content on simple shear behavior of sand-gravel mixture[J].Construction and Building Materials,2019,221:730-744.
[63] O’SULLIVAN C.Particulate Discrete Element Modelling[M].London:CRC Press,2011.
[64] XU H,WANG X Y,LIU C N,et al.A 3D root system morphological and mechanical model based on L-Systems and its application to estimate the shear strength of root-soil composites[J].Soil and Tillage Research,2021,212:105074.
[65] JIANG M J,ZHU Y G,XI B L.Investigation into the soil-root composites using distinct element method[C]//LI X K,FENG Y T,MUSTOE G.Proceedings of the 7th International Conference on Discrete Element Methods.Singapore:Springer,Singapore,2017:1075-1083.
[66] SUN Y,LI H,CHENG Z F,et al.Experimental and numerical simulation study on mechanical properties of shallow slope root-soil composite in Qinghai area[J].KSCE Journal of Civil Engineering,2023,27(7):2834-2852.
[67] WANG J,LIU F Y,WANG P,et al.Particle size effects on coarse soil-geogrid interface response in cyclic and post-cyclic direct shear tests[J].Geotextiles and Geomembranes,2016,44(6):854-861.
[68] NONG Z Z,PARK S S,JEONG S W,et al.Effect of cyclic loading frequency on liquefaction prediction of sand[J].Applied Sciences,2020,10(13):4502.
[69] NONG Z Z,PARK S S.Effect of loading frequency on volumetric strain accumulation and stiffness improvement in sand under drained cyclic direct simple shear tests[J].Journal of Geotechnical and Geoenvironmental Engineering,2021,147(12):04021159.
[70] TANG C S,SHI B,ZHAO L Z.Interfacial shear strength of fiber reinforced soil[J].Geotextiles and Geomembranes,2010,28(1):54-62.
[71] FAN C C,TSAI M H.Spatial distribution of plant root forces in root-permeated soils subject to shear[J].Soil and Tillage Research,2016,156:1-15.
[72] GENET M,STOKES A,SALIN F,et al.The influence of cellulose content on tensile strength in tree roots[J].Plant and Soil,2005,278(1/2):8768.
[73] THOMAS R E,POLLEN-BANKHEAD N.Modeling root-reinforcement with a fiber-bundle model and Monte Carlo simulation[J].Ecological Engineering,2009,36(1):47-61.
[74] WALDRON L J,DAKESSIAN S.Soil reinforcement by roots[J].Soil Science,1981,132(6):427-435.
[75] GHESTEM M,VEYLON G,BERNARD A,et al.Influence of plant root system morphology and architectural traits on soil shear resistance[J].Plant and Soil,2014,377(1/2):43-61.
[76] MASI E B,SEGONI S,TOFANI V.Root reinforcement in slope stability models:a review[J].Geosciences,2021,11(5):212.
[77] FAN C C.A displacement-based model for estimating the shear resistance of root-permeated soils[J].Plant and Soil,2012,355(1/2):103-119.
[78] JEWELL R A,WROTH C P.Direct shear tests on reinforced sand[J].Geotechnique,1987,37(1):53-68.
基本信息:
DOI：10.13928/j.cnki.wrahe.2025.S1.100
中图分类号:TU41
引用信息:
[1]孙渊,李辉,陈智锋.根土复合体在循环单剪条件下的响应行为及离散元模拟研究（英文）[J].水利水电技术(中英文),2025,56(S1):665-680.DOI:10.13928/j.cnki.wrahe.2025.S1.100.
基金信息:
Key Research,Development and Transformation Projects of Qinghai Science and Technology Department in Qinghai Province(No.2022-SF-159)~~