Abstract: Segment assembly is a critical aspect of shield tunneling, in which selecting key segment points is vital for tunnel quality and construction efficiency. The selection process must consider multiple influencing factors and adapt to complex and variable construction conditions, posing challenges in meeting practical construction needs. Therefore, a context-based optimal selection method for key segment points is proposed. A hierarchical filtering model for context-based selection is established by designing a generator, simulation predictor, and evaluation optimizer. This method classifies complex working conditions into various construction contexts based on the spatial relationship between the shield and tunnel and its deviation correction capabilities. The corresponding optimization objectives and weight coefficients are set for each context. Factors such as segment assembly requirements, tail clearance, and cylinder stroke differences are incorporated into the optimization objectives as constraints, enhancing the flexibility, comprehensiveness, objectivity, and rationality of the selection process. A simulation experiment on the Shanghai Bid 12 right-line project demonstrates that the context-based selection model improves the accuracy and rationality of point selection. Moreover, a comparison with different optimization objective design methods confirms the effectiveness, accuracy, and applicability of the model in selecting optimal assembly points under various construction contexts.

Key words: segment assembly, shield tunnel, point selection, construction context, optimization objectives