土压平衡盾构土仓内黏性渣土堵塞的模拟判别与分析

Simulative Discrimination and Analysis of Clay Muck Blockage in Earth Pressure Balance Shield Chamber

摘要:

提出以剪切板扭矩评价土仓内渣土状态，然后通过模型试验明确该指标在土仓内黏性渣土堵塞前后的变化特征，最后建立实时判别土仓渣土堵塞的方法。研究表明：黏土层内盾构隔板附近渣土绕中轴线流动角速度出现差异后，渣土黏附趋势逐步向刀盘发展，同时土仓顶部发生渣土脱空。最终引发渣土堵塞。渣土堵塞风险可通过土仓顶部和下侧的渣土剪切扭矩的幅值差异来实时判别。

Abstract:

In this paper， an evaluation index for the muck status inside chambers based on shear plate torque is proposed. Then multiple sets of model tests are then conducted to reveal the change characteristics of this index before and after the clogging of clay muck inside the chamber. Finally， a real-time method for judging the muck clogging is established. The results show that the tendency of muck adhesion gradually develops toward the cutter head after the difference appears in the angular velocity of the muck around the central axis near the partition. At the same time， muck empties at the top of the chamber. Muck blockage eventually occurred. The occurrence of the void zone is the preliminary stage of the muck blockage and can be identified by the difference between shear plate torques on the top and underside of the shield chamber.