Abstract
As a novel tunnel cross-section configuration, the rectangular-like tunnel employs a single-tunnel double-track layout, which substantially conserves underground space and reduces demolition and modification costs compared to conventional circular tunnels. Moreover, its distinctive structural and cross-sectional characteristics render its construction surveying methodology distinct from that of traditional circular tunnels, necessitating the formulation of corresponding measurement approaches tailored to the specific features of rectangular-like tunnels to ensure breakthrough accuracy. This paper, utilizing the Ningbo S31KY project as a case study, elaborates comprehensively on the key technical challenges and focal points of rectangular-like tunnel construction surveying technology, along with targeted technical measures and their implementation effectiveness. It also explicates the distinctions between rectangular-like tunnel construction surveying and circular tunnel construction surveying, thereby providing a reference foundation for future construction surveying endeavors in rectangular-like tunnel projects.
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A Brief Discussion on Construction Surveying Technology for Quasi-Rectangular Tunnels
Dong Zhimin
Shanghai Tunnel Engineering Co., Ltd., Shanghai 200000, China
Abstract
Quasi-rectangular tunnels represent a novel tunnel cross-section form featuring a single-tunnel, double-track layout that substantially reduces underground space requirements and demolition costs compared to conventional circular tunnels. However, their distinctive structural and cross-sectional characteristics also introduce unique challenges to construction surveying that diverge from traditional circular tunnel practices. Consequently, specialized surveying methodologies must be developed to address these features and ensure accurate tunnel breakthrough. This paper examines the Ningbo S31KY project as a case study, systematically elaborating the key technical challenges, targeted measures, and implementation outcomes of quasi-rectangular tunnel construction surveying technology. It further clarifies the fundamental differences between surveying practices for quasi-rectangular and circular tunnels, providing a valuable reference for future quasi-rectangular tunnel engineering projects.
Keywords: quasi-rectangular tunnel; connection surveying; cross-section measurement