软土地层TBM开挖面支护压力计算模型及可视化

Visualization and calculation models for TBM face support pressure in soft ground

隧道掘进机(TBM)近年来在世界范围内得到了广泛应用,通常通过完全充满压力仓的泥土或泥浆来支护开挖面。但在较差的地层和水力条件下,开挖面失稳时有发生。事实上,TBM开挖面的支护压力的大小直接决定了施工安全及地表变形。基于所建立的开挖面支护压力计算模型,并考虑复合地层下土体分层带来的影响,通过计算机编程方法,建立了界面友好、使用便捷的开挖面支护压力可视化计算平台(TBM Studio);并结合阿拉斯加隧道、钱江隧道工程实例进行了不同模型结果的验证分析,给出了各模型计算结果的差异性;讨论了软土复合地层条件下,土体自稳性对开挖面稳定的影响,认为软土地层中定量确定有效支护压力和水头高度至关重要,研究为正确评价TBM开挖面稳定性提供了相应的计算模型。

The tunnel boring machine （TBM） tunnelling has been successfully applied worldwide in recent years, and TBMs provide continuous support to the tunnel face by using the freshly-excavated wet soil or slurry which completely fills up the work chamber under pressure. Under extremely unfavorable geological and hydrogeological conditions, however, face instabilities may occur. In fact, the excavation face support pressure for TBM in soft ground determines the construction safety and surface deformation. A visual platform for calculating the excavation face support pressure conveniently, TBM Studio, is constructed by computer programming based on the suggested models. In this visual platform, the influence of stratified soils can be considered. Furthermore, a comparison of the results of Alaskan way tunnel and Qianjiang tunnel by different calculation models is done, the differences between different models are revealed. In addition, the effects of the stratified soil layers’ self-stability on excavation face stability in complex strata are also discussed, demonstrating that it is crucial for determining quantitatively the relationships between the effective support pressure required and the hydraulic head in the soft ground.