地面出入式盾构引起地下管线附加荷载研究

考虑盾构仰俯角β(即隧道埋深变化)以及地下管线自身宽度,基于Mindlin解和统一土体移动模型三维解,推导出地面出入式盾构隧道掘进中正面附加推力、盾壳摩擦力、附加注浆压力和土体损失引起的土体附加应力计算公式,进而得到邻近地下管线附加荷载计算方法。算例分析结果表明:盾构上仰时,随着β增大,管线承受的总附加荷载最大值变小;随着管线埋深变大,隧道轴线两侧各0.5h范围内,y向附加荷载分布曲线呈上移趋势;隧道轴线两侧各0.5h范围外,y向附加荷载分布曲线呈下移趋势;隧道轴线两侧0.5h左右处,为管线附加荷载分布曲线的交点。

Research on Additional Load of Adjacent Underground Pipelines Caused by Ground Penetrating Shield Tunneling

Considering the pitch angle β of shield tunnel(namely the variation of the buried depth in tunnel)and the width of underground pipelines, based on Mindlin’s solution and three dimensional uniform ground movement model for shield tunnels, a new formula of additional stress caused by frontal additional thrust, friction force, additional grouting force and soil loss was derived, and the calculation method of additional load of adjacent underground pipelines caused by ground penetrating shield tunneling was obtained. The results of the case analysis show that: the maximum value of the additional load becomes smaller with the increasing of β when the shield is tunneling upward; In the tunnel axis on both sides of the 0.5h range, as the pipelines depth becomes larger, the curve of y direction additional load is inclined to upward; In other ranges, the curve of y direction additional load is inclined to downward; The intersections of the additional load distribution curves are at about 0.5h on both sides of the tunnel axis.