泥炭土地基条件下地下综合管廊沉降分析

Settlement Analysis of Underground Comprehensive Pipe Gallery Based on Peat Soil Foundation

当地下综合管廊地基下伏泥炭土夹层时,综合管廊的工后沉降有待进一步明确和探索。依托保山市某综合管廊工程,基于ABAQUS有限元软件,对地下综合管廊的施工回填过程与管廊正常工作阶段时综合管廊沉降规律进行数值模拟。考虑综合管廊地基土层出现3 m厚泥炭土夹层及3 m厚泥炭土夹层-粉质黏土交界段的情况,结果表明:相较于泥炭土采用摩尔库伦本构模型,当泥炭土采用邓肯-张本构模型时,数值计算结果与实际沉降监测值能够较好吻合;交通荷载对管廊沉降总量有显著影响,当车辆荷载施加至30 kPa时,管廊底板跨中沉降量增加了18 mm;由于泥炭土夹层的存在,在泥炭土-粉质黏土交界段,两标准段管廊底板出现明显不均匀沉降,最大沉降差达到10 mm。

When the peat soil interlayer is under the foundation of the underground comprehensive pipe gallery,the post-construction settlement of the comprehensive pipe gallery needs to be further clarified and explored.Relying on an integrated pipe gallery project in Baoshan city,this paper,based on ABAQUS finite element software,carries out a numerical simulation on the construction backfilling process of the underground integrated pipe gallery and the settlement law of the integrated pipe gallery during the normal working stage of the pipe gallery.Considering the presence of a 3 m thick peat soil interlayer and a 3 m thick peat soil interlayer-silty clay junction in the foundation soil of the integrated pipe gallery,the results show that compared with peat soil using the Moore Coulomb constitutive model,when peat soil uses the Duncan-Zhang constitutive in the model,the numerical calculation results are in good agreement with the actual settlement monitoring values;the traffic load has a significant impact on the total settlement of the pipe gallery,and when the vehicle load is applied to 30 kPa,the mid-span settlement of the pipe gallery floor increases by 18 mm;due to peat soil in the presence of interlayers,at the junction of peat soil and silty clay,the bottom plates of the two standard sections of pipe gallery appear uneven settlement,and the maximum settlement difference reaches 10 mm.