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为了研究深埋条件下曲线钢顶管接触压力分布和变化规律,以拱北隧道曲线顶管管幕工程为背景,通过对曲线顶管施工现场监测的接触压力进行分析.结果表明:顶进力随顶进距离的增加基本呈线性增长,且中粗砂地层单位面积摩阻力大于砂质黏性土地层;接触压力顶进时发生波动并增大,顶进停止后逐渐趋于平稳,在浮力和顶进力侧向分力作用下,管道顶部和底部的接触压力数值较为接近,且顶部接触压力略大于底部压力,水平位置管道弯曲内侧接触压力小于弯曲外侧;附加接触压力随着掘进面与监测断面距离减小而增加,机头穿过监测断面后,已顶管道水平位置附加接触压力减小,而顶部接触压力由于土拱效应反而持续增长.
In order to study the contact pressure distribution and variation regularity of curved steel pipe under deep buried conditions, the contact pressure of curved pipe jacking construction site was analyzed based on curved pipe jacking project of Gongbei Tunnel.The results show that The increase of tip-in distance increased basically linearly, and the frictional resistance per unit area of middle-coarse sand formation was larger than that of sandy cohesive soil layer. When the contact pressure was increased, it fluctuated and increased, and then gradually stabilized after the top- Under the action of lateral force, the contact pressures at the top and bottom of the pipeline are close to each other, and the contact pressure at the top is slightly greater than the bottom pressure. The contact pressure at the horizontal pipe bend is less than the outside of the bend. After the head passes through the monitoring section, the additional contact pressure at the horizontal position of the topped pipe decreases, while the contact pressure at the top increases continuously due to the soil arching effect.