带翼缘板圆钢管顶进过程土体变形数值模拟

Numerical Simulation of Soil Deformation During Jacking of Circular Steel Pipes with Flange Plates

在传统管幕工法的钢管两侧分别焊接上下两条钢板(称为翼缘板),并将相邻钢管翼缘板焊接形成新型管幕结构.由于翼缘板的存在,顶进过程土体变形规律与圆形钢管不同.本文应用Midas GTS有限元分析软件,对不同钢管直径、翼缘板位置的带翼缘板圆钢管顶进过程进行模拟.结果表明,随上下翼缘板间距增大或管径的不断增加,管顶土体沉降、管底土体隆起、翼缘板处土体竖向位移不断增大;当顶管开挖面距离监测断面一节管长时,监测断面位置土体隆起;顶至监测断面位置时,土体变形变为沉降;当顶管位置超过监测断面一节管长后,土体变形趋于稳定;同时通过拟合曲线,得到了土体变形与上下翼缘板间距、管径的函数关系.

In the traditional pipe curtain construction,two steel plates,known as flange plates,are welded on both sides of the original circular steel pipe,creating a circular steel pipe with flange plates.Adjacent steel pipe with flange plates are welded together to form a new pipe curtain structure.The presentence of the flange plate cause the soil deformation law during jacking process to differ from that of circular steel pipes.In this study,Midas GTS finite element analysis software was used to simulate the jacking process of circular steel pipes with flange plates of different pipe diameters and flange plate positions.The results show that the soil settlement at the pipe top,the soil uplift at the bottom of the pipe,and the vertical displacement of the soil at the flange plate increase continuously with an increase in the spacing between the upper and lower flange plates or an increase in pipe diameter.When the top excavation surface is one section length away from the monitoring section,soil uplift occurs at the monitoring section position.When the top reaches the monitoring section position,the soil deformation becomes settlement.When the top position exceeds one section length of the monitoring section,the soil deformation tends to stablize.Meanwhile,the functional relationship between soil deformation and spacing between upper and lower flange plates,as well as pipe diameter,is obtained by fitting the curve.