Abstract Excavation face stability plays a major role in the control of settlements during shield tunneling. As a supporting media, the excavation face soil is required to have the characteristics of excellent plasticity and fluidity, soft consistency, a small internal friction angle, and permeability. However, most soils cannot fully meet these requirements, and therefore soil improvement is required. At present, bentonite mud, foam, and other additives are often used to improve the performance of the soil. This paper discusses the Shanghai Bund bypass project in which laboratory tests, simulation experiments, and field tests were carried out to identify the effects of soil improvement and determine the dosage of additives and the percentage of foaming. The soil improvements adopted effectively ensured the stability of the working face and reduced the shield thrust, cutterhead wear, and mechanical load.
Abstract:
Excavation face stability plays a major role in the control of settlements during shield tunneling. As a supporting media, the excavation face soil is required to have the characteristics of excellent plasticity and fluidity, soft consistency, a small internal friction angle, and permeability. However, most soils cannot fully meet these requirements, and therefore soil improvement is required. At present, bentonite mud, foam, and other additives are often used to improve the performance of the soil. This paper discusses the Shanghai Bund bypass project in which laboratory tests, simulation experiments, and field tests were carried out to identify the effects of soil improvement and determine the dosage of additives and the percentage of foaming. The soil improvements adopted effectively ensured the stability of the working face and reduced the shield thrust, cutterhead wear, and mechanical load.
HUANG De-Zhong
.Research of Soil Improvement during Super Large Diameter Earth Pressure Balanced Shield [J] MODERN TUNNELLING TECHNOLOGY, 2011,V48(4): 65-71