减沉疏桩支撑路堤结构中路基填土抗力分析
|
摘要
为研究减沉疏桩支撑路堤结构中填土抗力与疏桩刺入稳定问题,将桩体向上对路堤填土的作用看作倒置的浅基础对地基的作用,分别采用Vesic极限承载力理论和Meyerhof-Hanna冲剪破坏理论,建立极限状态下均质路基与路基-垫层双层路堤结构的填土极限破坏抗力计算模型;同时,考虑正常工作状态下路基填土抗力的发挥,基于孔穴扩张理论建立了桩顶荷载反作用时路基填土局部塑性开展时的抗力分析模型。计算结果表明,填土力学性能(c、φ)的提高和基底灰土垫层或加筋碎石垫层的设置有利于其抗力的提高和路基的局部刺入稳定。
In order to study the embankment fills resistance and local stability in scattered piles-supported embankment caused by the pile penetration, the effect of the pile upward on the embankment is regarded as the effect of inverted shallow foundation on soils. Based on the Vesic theory of the ultimate bearing capacity and Meyerhof-Hanna punching failure theory, the calculation models of ultimate resistance of homogeneous fills and fills-cushion double layer embankment structure are established. Furthermore, a calculation method for local plastic development of embankment fills under the pile top load reaction is established by using pore expansion theory, in considering of the performance of embankment resistance under normal working state. Example analysis shows that the improvement of mechanical properties(c, φ) and the setting of lime-soil cushion or reinforced gravel cushion are conducive to the improvement of embankment resistance and local stability.
In order to study the embankment fills resistance and local stability in scattered piles-supported embankment caused by the pile penetration, the effect of the pile upward on the embankment is regarded as the effect of inverted shallow foundation on soils. Based on the Vesic theory of the ultimate bearing capacity and Meyerhof-Hanna punching failure theory, the calculation models of ultimate resistance of homogeneous fills and fills-cushion double layer embankment structure are established. Furthermore, a calculation method for local plastic development of embankment fills under the pile top load reaction is established by using pore expansion theory, in considering of the performance of embankment resistance under normal working state. Example analysis shows that the improvement of mechanical properties(c, φ) and the setting of lime-soil cushion or reinforced gravel cushion are conducive to the improvement of embankment resistance and local stability.
引文
[1] Han J,Gab M A.Numerical analysis of geosynthetic-reinforced and pile-supported earth platforms over soft soil[J].Journal of Geotechnical and Geoenvironmental Engineering,2002,128(1):44-53.
[2] 杨才,丰土根,杨景森.高填路堤稳定性影响因素研究[J].水利与建筑工程学报,2014,12(3):23-27.
[3] 费康,陈毅,王军军.桩承式路堤中填土破坏模式研究[J].重庆交通大学学报(自然科学版),2011,30(2):258-262.
[4] 杨庆年,郑俊杰,程科,等.桩承式路堤土拱效应分析的改进有限元模型[J].土木工程与管理学报,2017,34(4):19-23.
[5] 王勇,蔡智,屈洋,等.CFG桩复合地基加筋褥垫层作用机理数值分析[J].水利与建筑工程学报,2016,14(1):96-100.
[6] 王年云.复合地基上褥垫层设计的理论分析[J].建筑结构,1999(12):24-26.
[7] 张四化,毕苏萍,郭院成.刚性桩复合地基褥垫层厚度取值方法研究[J].郑州大学学报(工学版),2011,32(3):52-54.
[8] 池跃君,沈伟,宋二祥.垫层破坏模式的探讨及其与桩土应力比的关系[J].工业建筑,2001(11):9-11.
[9] 郑俊杰,陈健,骆汉宾,等.刚性桩复合地基垫层破坏模式及厚度分析[J].华中科技大学学报(自然科学版),2008,36(7):120-123.
[10] Vesic A S.Bearing capacity of shallow foundations[J].Foundation Engineering Handlook,1975,5(4):121-147
[11] Meyerhof G G.The ultimate bearing capacity of foundation[J].Geotechnique,1951,2(4):301-332.
[12] 张浩,石名磊,郭院成.基于分段荷载传递法的桩网路堤结构荷载效应整体分析模型[J].岩土工程学报,2016,38(9):1630-1639.
[13] 赵宇,石名磊,张浩.疏桩路基中基底垫层设置效应分析[J].公路交通科技,2015,32(4):52-58.
[14] 毛前,龚晓南.桩体复合地基柔性垫层的效用研究[J].岩土力学,1998,19(2):67-73.
[15] 张浩,石名磊,张瑞坤.桩承式灰土路堤基底荷载效应分析[J].公路交通科技,2011,28(6):25-31.
[2] 杨才,丰土根,杨景森.高填路堤稳定性影响因素研究[J].水利与建筑工程学报,2014,12(3):23-27.
[3] 费康,陈毅,王军军.桩承式路堤中填土破坏模式研究[J].重庆交通大学学报(自然科学版),2011,30(2):258-262.
[4] 杨庆年,郑俊杰,程科,等.桩承式路堤土拱效应分析的改进有限元模型[J].土木工程与管理学报,2017,34(4):19-23.
[5] 王勇,蔡智,屈洋,等.CFG桩复合地基加筋褥垫层作用机理数值分析[J].水利与建筑工程学报,2016,14(1):96-100.
[6] 王年云.复合地基上褥垫层设计的理论分析[J].建筑结构,1999(12):24-26.
[7] 张四化,毕苏萍,郭院成.刚性桩复合地基褥垫层厚度取值方法研究[J].郑州大学学报(工学版),2011,32(3):52-54.
[8] 池跃君,沈伟,宋二祥.垫层破坏模式的探讨及其与桩土应力比的关系[J].工业建筑,2001(11):9-11.
[9] 郑俊杰,陈健,骆汉宾,等.刚性桩复合地基垫层破坏模式及厚度分析[J].华中科技大学学报(自然科学版),2008,36(7):120-123.
[10] Vesic A S.Bearing capacity of shallow foundations[J].Foundation Engineering Handlook,1975,5(4):121-147
[11] Meyerhof G G.The ultimate bearing capacity of foundation[J].Geotechnique,1951,2(4):301-332.
[12] 张浩,石名磊,郭院成.基于分段荷载传递法的桩网路堤结构荷载效应整体分析模型[J].岩土工程学报,2016,38(9):1630-1639.
[13] 赵宇,石名磊,张浩.疏桩路基中基底垫层设置效应分析[J].公路交通科技,2015,32(4):52-58.
[14] 毛前,龚晓南.桩体复合地基柔性垫层的效用研究[J].岩土力学,1998,19(2):67-73.
[15] 张浩,石名磊,张瑞坤.桩承式灰土路堤基底荷载效应分析[J].公路交通科技,2011,28(6):25-31.