摘要
为预估沟谷型黄土高填方的总沉降量并指导现场施工,对压实黄土的加载变形本构模型进行研究。在侧限条件下,利用自建Gunary EXT模型拟合不同初始压实度和初始含水率条件下压实黄土的应力-应变关系;在此基础上利用割线模量法建立压实黄土的加载变形本构模型;在仅考虑竖向变形的理想条件下,利用该模型预估沟谷型黄土高填方的总沉降量。研究结果表明:Gunary EXT模型可较好地拟合不同初始条件下压实黄土的应力-应变关系;加载变形本构模型预估沟谷型黄土高填方的总沉降量的方法可行,该方法的预估结果可用于指导现场施工。
To estimate the total settlement of high loess-filled embankment in valley type and directing site operation,this paper carries out research on the load deformation constitutive model of compacted loess. A self-defined extended Gunary modelwas used to expressthe vertical pressure-strain curves of compacted loess with different initial compaction degree and initial water contentin confined compression. On the basis,a load deformation constitutive model of compacted loess was built based on secant modulus method,and the total settlement of high loess-filled embankment in valley type was estimated by this model under the ideal conditions of considering the vertical deformation only.The results show that the vertical pressure-strain curves of compacted loess with different initial conditions can be expressed well with extended Gunary model,and it is feasible to estimate the total settlement of high loess-filled embankment in valley type by using the load deformation constitutive model. The estimated results can provide reference for the site operation of the high loess-filled embankment.
引文
[1]陈正汉.重塑非饱和重塑黄土的变形、强度、屈服和水量变化特性[J].岩土工程学报,1999,21(1):82.
[2]方祥位.Q2黄土的微细观结构及力学特性研究[D].重庆:后勤工程学院,2008.
[3]黄雪峰,陈正汉,哈双,等.大厚度自重湿陷性黄土场地湿陷变形特征的大型现场浸水试验研究[J].岩土工程学报,2006,28(3):382-389.
[4]陈正汉.非饱和土与特殊土力学的基本理论研究[J].岩土工程学报,2014,36(2):201-272.
[5]沈珠江.结构性粘土的弹塑性损伤模型[J].岩土工程学报,1993(3):21-28.
[6]陈正汉,黄海,卢再华.非饱和土的非线性固结模型和弹塑性固结模型及其应用[J].应用数学和力学,2001(1):93-103.
[7]姚仰平,牛雷,杨一帆,等.考虑温度影响的非饱和土本构模型[J].岩土力学,2011,32(10):2881-2888.
[8]徐明,宋二祥.高填方长期工后沉降研究的综述[J].清华大学学报(自然科学版),2009,49(6):786-789.
[9]中华人民共和国水利部.土工试验方法标准GB/T 50123─1999[S].北京:中国计划出版社,1999.
[10]李旭东,黄雪峰,杨宝山,等.延安新区压实Q2黄土增减湿高压压缩变形特性[J].后勤工程学院学报,2015,31(1):11-16.
[11]魏汝龙.整理压缩试验资料的一种新方法[J].水利水运科学研究,1980(3):90-93.
[12]刘保健,张军丽.土工压缩试验成果分析方法与应用[J].中国公路学报,1999,12(1):37.
[13]陈开圣,沙爱民.压实黄土变形特性[J].岩土力学,2010,31(4):1023-1029.
[14]胡长明,梅源,王雪艳.吕梁地区压实马兰黄土变形与抗剪强度特性[J].工程力学,2013,30(10):108-114.