高速公路碎石桩复合地基加固数值模拟
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摘要
通过数值模拟分析了高速公路碎石桩复合地基在桩体施工、路堤填筑、运行期全过程和地震动荷载等作用下的受力问题。计算结果表明:碎石桩在路堤的填筑和运行期中起到明显的排水固结作用,当桩长大于6m后复合地基中的孔压最大值变化较缓慢;在桩长大于10m后路堤底面的沉降量和坡脚的水平位移量变化均会较小。地震荷载作用下路堤顶部的水平向加速度峰值较底面更大;在碎石桩加固范围内,复合地基的水平刚度大于天然地基,而在整个地基内,复合地基的竖向刚度均大于天然地基,在地基刚度较大的情况下位移最大值较大;天然地基在路堤坡脚下方、路堤边坡等位置较易发生液化,经过碎石桩加固后降低了地基液化的可能性。
A numerical analysis is studied on the construction,runtime and earthquake condition of stone columns reinforced foundation.Calculation results indicate that: the stone columns has a significant effect on drainage of excess pore pressure under construction and runtime,when pile length is larger than 6 m,maximum pore pressure changed slowly,when pile length is larger than 10 m,settlement developed under embankment and horizontal displacement developed under slope toe changed slowly.Under earthquake the maximum acceleration on top of the pave is larger than bottom of the model;in reinforced scope,horizontal stiffness of composite foundation is larger than natural foundation,in the whole foundation,vertical stiffness of composite foundation is larger than natural foundation,maximum displacement is larger in large stiffness foundation;toe position and slope of embankment is more liquefied under earthquake,but stone column composite foundation can reduce liquefaction possibility.
A numerical analysis is studied on the construction,runtime and earthquake condition of stone columns reinforced foundation.Calculation results indicate that: the stone columns has a significant effect on drainage of excess pore pressure under construction and runtime,when pile length is larger than 6 m,maximum pore pressure changed slowly,when pile length is larger than 10 m,settlement developed under embankment and horizontal displacement developed under slope toe changed slowly.Under earthquake the maximum acceleration on top of the pave is larger than bottom of the model;in reinforced scope,horizontal stiffness of composite foundation is larger than natural foundation,in the whole foundation,vertical stiffness of composite foundation is larger than natural foundation,maximum displacement is larger in large stiffness foundation;toe position and slope of embankment is more liquefied under earthquake,but stone column composite foundation can reduce liquefaction possibility.
引文
[1]Priebe H J.The design of vibro replacement[J].Ground Engineering,1995,(19):31-37.
[2]Han J,Ye S L.Simplified method for consolidationrate of stone column reinforced foundations[J].Jour-nal of Geotechnical and Geoenvironmental Engineer-ing,ASCE,2001,127(7):597-603.
[3]赵明华,邓岳保,杨明辉.路堤荷载作用下碎石桩复合地基桩土应力比计算及试验研究[J].岩土力学,2009,30(9):2623-2628.
[4]赵明华,孙建兵,张永杰,等.碎石桩复合地基复合模量极限值分析[J].中南大学学报,2009,40(6):1718-1723.
[5]Adalier K,Elgamal A,Meneses J,Baez J I.Stonecolumns as liquefaction countermeasure in non-plasticsilty soils[J].Soil Dynamics and Earthquake Engi-neering,2003,23:571-584.
[6]Adalier K,Elgamal A.Mitigation of liquefaction andassociated ground deformation by stone columns[J].Engineering Geology,2004,72:275-291.
[7]刘义怀,朱志铎,刘松玉.路堤荷载下碎石桩复合地基的有限元分析[J].公路交通科技,2002,19(5):11-13.
[8]河南工业大学.高速公路粉土地基碎石桩复合地基加固机理数值模拟及应用研究[R].郑州:河南工业大学,2011.
[9]沈珠江,徐刚.堆石料的动力变形特性[J].水利水运科学研究,1996,(2):143-150.
[2]Han J,Ye S L.Simplified method for consolidationrate of stone column reinforced foundations[J].Jour-nal of Geotechnical and Geoenvironmental Engineer-ing,ASCE,2001,127(7):597-603.
[3]赵明华,邓岳保,杨明辉.路堤荷载作用下碎石桩复合地基桩土应力比计算及试验研究[J].岩土力学,2009,30(9):2623-2628.
[4]赵明华,孙建兵,张永杰,等.碎石桩复合地基复合模量极限值分析[J].中南大学学报,2009,40(6):1718-1723.
[5]Adalier K,Elgamal A,Meneses J,Baez J I.Stonecolumns as liquefaction countermeasure in non-plasticsilty soils[J].Soil Dynamics and Earthquake Engi-neering,2003,23:571-584.
[6]Adalier K,Elgamal A.Mitigation of liquefaction andassociated ground deformation by stone columns[J].Engineering Geology,2004,72:275-291.
[7]刘义怀,朱志铎,刘松玉.路堤荷载下碎石桩复合地基的有限元分析[J].公路交通科技,2002,19(5):11-13.
[8]河南工业大学.高速公路粉土地基碎石桩复合地基加固机理数值模拟及应用研究[R].郑州:河南工业大学,2011.
[9]沈珠江,徐刚.堆石料的动力变形特性[J].水利水运科学研究,1996,(2):143-150.
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