Abstract
As a specialized tunnel excavation tool, the shield machine offers advantages of high efficiency, safety, and rapid construction, and is widely employed in urban rail transit and railway tunnel projects. However, during shield construction, excavation trajectory exceeding limits (including horizontal/vertical deviations and cross-section over-excavation) may occur due to factors such as sudden geological condition changes, unreasonable equipment selection and parameter settings, or improper manual operation. This paper addresses the difficulty in controlling shield tunneling attitude in composite strata, which can even result in shield machine entrapment, by summarizing the self-adjustment and external intervention measures adopted for shield rescue or when vertical attitude limits are exceeded, and analyzes their respective advantages and disadvantages. This project pioneers the innovative concept of utilizing ultra-high pressure fluid to assist in-situ attitude axis correction for shield machines, while successfully overcoming the technical challenge of precise obstacle removal within confined spaces, achieving for the first time the efficient application of ultra-high pressure fluid technology in the complex environment outside the shield shell. This technology features low labor intensity, large working range, precise removal location, no generation of intense vibration during the removal process, no stress diffusion, and the capability to progressively fracture obstacles at arbitrary depths, making it particularly suitable for targeted removal operations in confined spaces. By employing the complete set of equipment for "Precise Obstacle Removal with Ultra-High Pressure Fluid in Confined Spaces", establishing safe shield body opening/closing technology, and optimizing low-damage opening and repair techniques, the stability of the shield shell during the opening process is ensured and structural performance is fully restored. The successful application of ultra-high pressure fluid technology to achieve precise obstacle removal in the narrow space outside the shield enables in-situ recovery of shield machine attitude, breaks through the limitations of traditional mechanical correction, realizes dynamic correction of shield vertical attitude, and provides a reference for solving similar problems in the industry.
Full Text
Preamble
Research on Key Technologies for Auxiliary Unsticking and Attitude Correction of Shield Machines in Composite Strata (External to the Shield Shell)
Li Jia, Liang Hongbing
Guangzhou Metro Engineering Consulting Co., Ltd., Guangzhou 510000, Guangdong
Abstract
As a specialized tunnel excavation tool, shield machines offer significant advantages in efficiency, safety, and speed, making them widely employed in urban rail transit and railway tunnel construction. However, during shield tunneling operations, various factors—including sudden geological condition changes, improper equipment selection and parameter settings, or human operational errors—can lead to excessive excavation trajectory deviations (encompassing horizontal/vertical misalignment and cross-section over-excavation).
This paper addresses the challenge of controlling shield tunneling attitude in composite strata, where machines may become trapped, by summarizing both self-adjustment and external intervention methods employed during unsticking operations or when vertical attitude limits are exceeded, and analyzing their respective advantages and disadvantages. This project pioneers an innovative methodology utilizing ultra-high pressure fluid to assist with in-situ attitude and axis correction for shield machines. Simultaneously, it successfully overcomes the technical challenge of precisely removing obstacles within confined and enclosed spaces, achieving the first efficient application of ultra-high pressure fluid technology in the complex environment external to the shield shell.
This technology offers numerous advantages, including low labor intensity, a large operational range, precise removal location, absence of violent vibration during the removal process, no stress diffusion, and the capability to break layers at arbitrary depths. These features make it particularly suitable for targeted clearance operations in confined spaces. By adopting a complete set of equipment for "precise obstacle removal using ultra-high pressure fluid in enclosed spaces" and establishing safe shield body opening and sealing technologies, this research optimizes low-damage opening and repair techniques. This ensures shield shell stability during the opening process and complete restoration of structural performance. The successful application of ultra-high pressure fluid technology for precise obstacle removal in the narrow space external to the shield shell has enabled in-situ recovery of shield machine attitude, overcome the limitations of traditional mechanical deviation correction methods, and achieved dynamic correction of vertical shield attitude. These accomplishments provide valuable references for addressing similar challenges within the industry.
Keywords: Shield deviation correction; Ultra-high pressure fluid cutting; Vertical attitude control; In-situ treatment