盾构切削木桩试验研究

结合上海新建路越江隧道穿越旧木桩工程,以φ1 800大型盾构模拟试验平台为基础,采用模型试验的方法,研究了盾构直接切削木桩和在土体中切削木桩两种工况,得到了实际施工中所需盾构道具改制方案以及土体加固参数。试验结果表明:盾构推进速度越慢而刀盘转速越快,则切削的效果越好,而推进速度在1 cm/min左右效果最好;增加先行刀的数量以及在盾构周边安装先行刀,可使得切削下来的木屑较易排出;在盾构切削木桩过程中,木桩位移以平动为主,转动位移较小,且桩体位移可以通过加固桩周土体得到控制。

Experimental Study on Cutting Wood Pile during Shield Tunneling Construction

Based on the construction of Shanghai Xinjian Road Cross-river Tunnel which crossed through existing wood piles, two construction conditions of cutting wood piles laid barely and in soils by shield machine were studied respectively using model tests conducted in the φ1800 Large-scale Shield Machine Integrated Simulation Platform. Through the studies, the optimal schemes of shield cutters as well as the reinforcement parameters of soil were gained. The results of tests show that the cutting effects improved as the driving speed increases and the cutter head speed decreases, achieving optimization when the driving speed reaches 1cm/min or so; the wood cuttings will be eliminated easily when adding prior knives and installing prior knives on the periphery of the cutter head; the wood piles mainly move translationally and the rotational displacement is small during the cutting process, and the displacements can be controlled by reinforcing soils around the piles.