Experimental study for joint leakage process of tunnel lining and particle flow numerical simulation

Most of urban ground collapses and tunnel failures are caused by joint leakage of shield tunnel lining. This paper conducts a series of model tests and particle flow simulations aiming to investigate the geo-hazards and explore the associated failure mechanism due to tunnel leaking. Based on critical width of leaky joint, taking leaky joint location, overburden depth and height of overlying water level as influencing factors, the settlement of the sand layer and the law of the water and sand loss is effectively predicted. Then, the focus is on designing a seepage tracer device to explore the distribution of the seepage field and its flow line variation. Finally, the particle flow numerical model of tunnel-sand is employed for the soil arching effect and flow line changes during seepage erosion to discover the fine scale influences of sand particle migration and loss around the shield tunnel on the surrounding environment.

Automated summary

This paper investigates the causes of urban ground collapses and tunnel failures, focusing on the joint leakage of shield tunnel lining. Through model tests and particle flow simulations, the study predicts the settlement of the sand layer and the law of water and sand loss, explores the distribution of the seepage field, and discovers the fine-scale influences of sand particle migration and loss on the surrounding environment.