泥炭质土地基流变非线性沉降计算  

Rheological nonlinear settlement calculationof peaty soil foundation

作　　者：陈海应 阮永芬[1] 丁海涛 施虹 乔文件 程芸 CHEN Haiying;RUAN Yongfen;DING Haitao;SHI Hong;QIAO Wenjian;CHENG Yun(Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming 650500,Yunnan,China;Capital Construction Management Office of Qilin District in Qujing City,Qujing 655000,Yunnan,China;YCIH No.1 Engineering Survey and Design Co.,Ltd.,Kunming 650031,Yunnan,China;Branch of the Investigation,Design Institute of Yunnan Province,Kunming 650228,Yunnan,China;No.5 Engineering Co.,Ltd.,China Railway 20th Bureau Group,Kunming 650000,Yunnan,China)

机构地区：[1]昆明理工大学建筑工程学院,云南昆明650500 [2]曲靖市麒麟区基本建设管理处,云南曲靖655000 [3]云南建投第一勘察设计有限公司,云南昆明650031 [4]云南省设计院集团勘察分院,云南昆明650228 [5]中铁二十局集团第五工程有限公司,云南昆明650000

出　　处：《地震工程学报》2023年第6期1324-1332,共9页China Earthquake Engineering Journal

基　　金：云南省重点研发计划(社会发展领域)(2018BC008)。

摘　　要：泥炭质土是一种特殊的区域性软土,其上建构筑物易产生较大工后沉降,对建构筑安全影响很大。将其沉降分为三个部分:侧向变形引起的沉降、侧限条件下产生的沉降及次固结沉降,根据邓肯-张本构模型建立压缩模量与割线模量间关系,结合广义胡克定律推导式,计算得到侧向变形产生的沉降。分别利用e-p、e-lgp及e-lnp曲线计算土压缩模量,用分层总合法计算侧限条件下的沉降。对泥炭质土进行高压固结蠕变试验,通过邓肯-张模型概念得到割线模量,并对原始五元件流变模型进行非线性改进,再引入修正系数φs对原始五元件流变模型及非线性模型进行修正;用修正后的两模型对蠕变试验曲线进行拟合,发现修正原始模型拟合效果极差,修正非线性模型拟合的相关系数都大于0.9,并得到适合描述泥炭质土蠕变的本构方程;最后采用修正后的两模型,结合分层总和法计算次固结沉降。研究结果表明泥炭质土最终沉降计算结果与实际调查结果吻合,验证了计算结果的合理性,也为泥炭质土的沉降计算提供了计算理论及能反映其蠕变特性的本构模型。Peaty soil is a special regional soft soil.Structures with peaty soil foundations are prone to produce large postconstruction settlements,largely affecting their safety.Thus,it is crucial to study the settlement of peaty soil.The settlement can be divided into three parts,which are as follows:settlement caused by lateral deformation,settlement under the confined condition,and secondary consolidation settlement.Based on the Duncan-Zhang constitutive model,the relationship between compression modulus and secant modulus was established.Combined with the generalized Hooke's law derivation,the settlement caused by lateral deformation was determined.The compression moduli of soil were calculated by the e-p,e-lg p,and e-ln p curves,and the settlement under the confined condition was calculated using the layer-wise method.Furthermore,a high-pressure consolidation creep test was performed on peaty soil.The secant modulus was calculated by the Duncan-Zhang model concept,and the nonlinear correction was performed on the original five-element rheological model.Subsequently,the original and nonlinear models were modified by the introduction of the correction coefficientφs.The two modified models were utilized to fit the creep test curves,and it was found that the fitting effect of the modified original model was very poor;moreover,the correlation coefficients of the modified nonlinear model were all greater than 0.9 and a constitutive equation suitable for describing the creep of peat soil was also obtained.Lastly,the two modified models were used to calculate the secondary consolidation settlement with the layer-wise summation method.It was revealed that the settlement calculation results of the peaty soil are consistent with the actual experiment results,confirming the rationality of the calculation results as well as providing a calculation theory and a constitutive model to reflect the creep characteristics of peaty soil.

关 键 词：泥炭质土 次固结沉降 分层总和法 本构模型 

分 类 号：TU433[建筑科学—岩土工程]