粒孔比对筋土界面直剪特性的影响
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摘要
为研究填料平均粒径与土工格栅网孔尺寸的比值对格栅-粗粒土界面抗剪特性的影响,试验所用粗粒土的粒径范围分为4种,采用一种方形网孔的土工格栅作为加筋材料,在竖向应力分别为30、60、90 kPa、剪切速率分别为0.25、1、2、5 mm/min、密实度分别为22%、55%、75%的条件下,使用室内大型直剪仪进行了一系列的单调直剪试验。试验结果表明,填料平均粒径与格栅网孔尺寸的比值越大,筋土界面的峰值剪应力和残余剪应力越大。当填料平均粒径与格栅网孔尺寸的比值从0.04增大到0.20时,峰值剪应力的似黏聚力从13.79 kPa增大到64.23 kPa,残余剪应力的似黏聚力从16.11 kPa增大到51.56 kPa,密实度为22%时土样在剪切过程中一直处于剪缩状态,密实度分别为55%、75%时两种土样在整体上均呈现明显的剪胀现象;剪切速率对筋土界面单调直剪特性的影响较小。
In order to study the effect of the ratio of geogrid aperture size to the average sand particle size on direct shear characteristics of geogrid-coarse soil interface, a series of direct shear tests are performed using a large-scale direct shear device. Four kinds of sand with different particle diameters, and a type of geogrids with square aperture, are tested under the condition of different vertical loads and different shear rates and different soil densities. The vertical loads are 30, 60, 90 kPa, respectively; the shear rates are 0.25, 1, 2, 5 mm/min, respectively; and the soil densities are 22%, 55%, 75%, respectively. The test results show that the peak shear stress and residual shear stress of geogrid-coarse soil interface both increase with the ratio of geogrid aperture size to the average sand particle size increases. When the ratio of geogrid aperture size to the average sand particle size increases from 0.04 to 0.20, the adhesion from peak stress of geogrid-coarse soil interface increases from 13.79 k Pa to 64.23 k Pa; and the adhesion from residual stress of geogrid-coarse soil interface increases from 16.11 k Pa to 51.56 k Pa. When soil density is 22%, the soil exhibits contraction throughout the tests. When soil density is 55% and 75%, respectively, the soil tends to be dilatant. Shear rate has little effect on shear behavior of geogrid-coarse soil interface in direct shear tests.
In order to study the effect of the ratio of geogrid aperture size to the average sand particle size on direct shear characteristics of geogrid-coarse soil interface, a series of direct shear tests are performed using a large-scale direct shear device. Four kinds of sand with different particle diameters, and a type of geogrids with square aperture, are tested under the condition of different vertical loads and different shear rates and different soil densities. The vertical loads are 30, 60, 90 kPa, respectively; the shear rates are 0.25, 1, 2, 5 mm/min, respectively; and the soil densities are 22%, 55%, 75%, respectively. The test results show that the peak shear stress and residual shear stress of geogrid-coarse soil interface both increase with the ratio of geogrid aperture size to the average sand particle size increases. When the ratio of geogrid aperture size to the average sand particle size increases from 0.04 to 0.20, the adhesion from peak stress of geogrid-coarse soil interface increases from 13.79 k Pa to 64.23 k Pa; and the adhesion from residual stress of geogrid-coarse soil interface increases from 16.11 k Pa to 51.56 k Pa. When soil density is 22%, the soil exhibits contraction throughout the tests. When soil density is 55% and 75%, respectively, the soil tends to be dilatant. Shear rate has little effect on shear behavior of geogrid-coarse soil interface in direct shear tests.
引文
[1]FERREIRA F B,VIEIRA C S,AND LOPES M L.Direct shear behavior of residual soil-geosynthetic interfaces influence of soil moisture content,soil density and geosynthetic type[J].Geosynthetics International,2015,22(3):257-272.
[2]VIEIRA C S,PEREIRA P M.Interface shear properties of geosynthetics and construction and demolition waste from large-scale direct shear tests[J].Geosynthetics International,2016,23(1):62-70.
[3]TAVAKOLI MEHRJARDI GH,GHANBARI A,MEHDIZADEH H.Experimental study on the behavior of geogrid-reinforced slopes with respect to aggregate size[J].Geotext Geomembranes,2016,44(6):862-871.
[4]徐超,孟凡祥.剪切速率和材料特性对筋-土界面抗剪强度的影响[J].岩土力学,2010,31(10):3101-3106.XU Chao,MENG Fan-xiang.Effects of shear rate and material properties on shear strength of geosynthetic-soil interface[J].Rock and Soil Mechanics,2010,31(10):3101-3106.
[5]刘炜,汪益敏,陈页开,等.土工格室加筋土的大尺寸直剪试验研究[J].岩土力学,2008,29(11):3133-3138.LIU Wei,WANG Yi-min,CHEN Ye-kai,et al.Research on large size direct shear test for geocell reinforced soil[J].Rock and Soil Mechanics,2008,29(11):3133-3138.
[6]PALMEIRA E M,GóNGORA I A G.Assessing the influence of some soil-reinforcement interaction parameters on the performance of a low fill on compressible subgrade.part I.Fill performance and relevance of interaction parameters[J].International Journal of Geosynthetics&Ground Engineering,2016,2(1):1-1.
[7]ARULRAJAH A,RAHMAN M A,PIRATHEEPAN J,et al.Evaluation of interface shear strength properties of Geogrid-reinforced construction and demolition materials using a modified large-scale direct shear testing apparatus[J].Journal of Materials in Civil Engineering,2013,26(5):974-982.
[8]CUELHO E,PERKINS S,MORRIS Z.Relative operational performance of geosynthetic used as subgrade stabilization[R].Montana:State of Montana Department of Transportation,2014.
[9]GONGORA I A M G,PALMEIRA E M.Assessing the influence of some soil-reinforcement interaction parameters on the performance of a low fill on compressible subgrade.part II.influence of surface maintenance[J].International Journal of Geosynthetics&Ground Engineering,2016,2(1):18-29.
[10]HAN Bing-ye,LING Jian-ming,SHU Xiang,et al.Laboratory investigation of particle size effects on the shear behavior of aggregate-geogrid interface[J].Construction and Building Materials,2018,158(15):1015-1025.
[11]HUSSAINI SKK.An experimental study on the deformation behaviour of geosynthetic reinforced ballast[Ph.D ThesisD].Australia:University of Wollongong,2013.
[12]BIABANI M M,INDRARATNA B.An evaluation of the interface behaviour of rail subballast stabilised with geogrids and geomembranes[J].Geotextiles and Geomembranes,2015,43(3):240-249.
[13]BIABANI M M,INDRARATNA B,NIMBALKAR S.Assessment of interface shear behaviour of sub-ballast with geosynthetics by large scale direct shear test[J].Procedia Engineering,2016,143:1007-1015.
[14]STAHL M,KONIETZKY H,KAMP L T,et al.Discrete element simulation of geogrid-stabilised soil[J].Acta Geotechnica,2014,9(6):1073-1084.
[15]MEHRJARDI G T,KHAZAEI M.Scale effect on the behaviour of geogrid-reinforced soil under repeated loads[J].Geotextiles and Geomembranes,2017,45(6):603-615.
[16]唐晓松,郑颖人,王永甫,等.关于土工格栅合理网孔尺寸的研究[J].岩土力学,2017,38(6):1583-1588.TANG Xiao-song,ZHENG Ying-ren,WANG Yong-fu,et al.Study on the reasonable size of geo-grid meshes[J].Rock and Soil Mechanics,2017,38(6):1583-1588.
[17]SAKLESHPUR V A,PREZZI M,SALGADO R,et al.Large-scale direct shear testing of geogrid-reinforced aggregate base over weak subgrade[J].International Journal of Pavement Engineering,2017,DOI:10.1080/10298436.2017.1321419,2018-06-12.
[18]徐超,孟凡祥.剪切速率和材料特性对筋-土界面抗剪强度的影响[J].岩土力学,2010,31(10):3101-3106.XU Chao,MENG Fan-xiang.Effects of shear rate and material properties on shear strength of geosynthetic-soil interface[J].Rock and Soil Mechanics,2010,31(10):3101-3106.
[19]SWETA K,KHAJA KARIMULLAH HUSSAINI S K K.Effect of shearing rate on the behavior of geogrid-reinforced railroad ballast under direct shear conditions[J].Geotextiles and Geomembranes,2018,46(3):251-256.
[2]VIEIRA C S,PEREIRA P M.Interface shear properties of geosynthetics and construction and demolition waste from large-scale direct shear tests[J].Geosynthetics International,2016,23(1):62-70.
[3]TAVAKOLI MEHRJARDI GH,GHANBARI A,MEHDIZADEH H.Experimental study on the behavior of geogrid-reinforced slopes with respect to aggregate size[J].Geotext Geomembranes,2016,44(6):862-871.
[4]徐超,孟凡祥.剪切速率和材料特性对筋-土界面抗剪强度的影响[J].岩土力学,2010,31(10):3101-3106.XU Chao,MENG Fan-xiang.Effects of shear rate and material properties on shear strength of geosynthetic-soil interface[J].Rock and Soil Mechanics,2010,31(10):3101-3106.
[5]刘炜,汪益敏,陈页开,等.土工格室加筋土的大尺寸直剪试验研究[J].岩土力学,2008,29(11):3133-3138.LIU Wei,WANG Yi-min,CHEN Ye-kai,et al.Research on large size direct shear test for geocell reinforced soil[J].Rock and Soil Mechanics,2008,29(11):3133-3138.
[6]PALMEIRA E M,GóNGORA I A G.Assessing the influence of some soil-reinforcement interaction parameters on the performance of a low fill on compressible subgrade.part I.Fill performance and relevance of interaction parameters[J].International Journal of Geosynthetics&Ground Engineering,2016,2(1):1-1.
[7]ARULRAJAH A,RAHMAN M A,PIRATHEEPAN J,et al.Evaluation of interface shear strength properties of Geogrid-reinforced construction and demolition materials using a modified large-scale direct shear testing apparatus[J].Journal of Materials in Civil Engineering,2013,26(5):974-982.
[8]CUELHO E,PERKINS S,MORRIS Z.Relative operational performance of geosynthetic used as subgrade stabilization[R].Montana:State of Montana Department of Transportation,2014.
[9]GONGORA I A M G,PALMEIRA E M.Assessing the influence of some soil-reinforcement interaction parameters on the performance of a low fill on compressible subgrade.part II.influence of surface maintenance[J].International Journal of Geosynthetics&Ground Engineering,2016,2(1):18-29.
[10]HAN Bing-ye,LING Jian-ming,SHU Xiang,et al.Laboratory investigation of particle size effects on the shear behavior of aggregate-geogrid interface[J].Construction and Building Materials,2018,158(15):1015-1025.
[11]HUSSAINI SKK.An experimental study on the deformation behaviour of geosynthetic reinforced ballast[Ph.D ThesisD].Australia:University of Wollongong,2013.
[12]BIABANI M M,INDRARATNA B.An evaluation of the interface behaviour of rail subballast stabilised with geogrids and geomembranes[J].Geotextiles and Geomembranes,2015,43(3):240-249.
[13]BIABANI M M,INDRARATNA B,NIMBALKAR S.Assessment of interface shear behaviour of sub-ballast with geosynthetics by large scale direct shear test[J].Procedia Engineering,2016,143:1007-1015.
[14]STAHL M,KONIETZKY H,KAMP L T,et al.Discrete element simulation of geogrid-stabilised soil[J].Acta Geotechnica,2014,9(6):1073-1084.
[15]MEHRJARDI G T,KHAZAEI M.Scale effect on the behaviour of geogrid-reinforced soil under repeated loads[J].Geotextiles and Geomembranes,2017,45(6):603-615.
[16]唐晓松,郑颖人,王永甫,等.关于土工格栅合理网孔尺寸的研究[J].岩土力学,2017,38(6):1583-1588.TANG Xiao-song,ZHENG Ying-ren,WANG Yong-fu,et al.Study on the reasonable size of geo-grid meshes[J].Rock and Soil Mechanics,2017,38(6):1583-1588.
[17]SAKLESHPUR V A,PREZZI M,SALGADO R,et al.Large-scale direct shear testing of geogrid-reinforced aggregate base over weak subgrade[J].International Journal of Pavement Engineering,2017,DOI:10.1080/10298436.2017.1321419,2018-06-12.
[18]徐超,孟凡祥.剪切速率和材料特性对筋-土界面抗剪强度的影响[J].岩土力学,2010,31(10):3101-3106.XU Chao,MENG Fan-xiang.Effects of shear rate and material properties on shear strength of geosynthetic-soil interface[J].Rock and Soil Mechanics,2010,31(10):3101-3106.
[19]SWETA K,KHAJA KARIMULLAH HUSSAINI S K K.Effect of shearing rate on the behavior of geogrid-reinforced railroad ballast under direct shear conditions[J].Geotextiles and Geomembranes,2018,46(3):251-256.