Research on Integrated Urban Utility Tunnel and Metro Joint Construction Mode in Central Urban Area

[Objective] Due to the constraints of surface implementation conditions and underground space limitations, the implementation of underground utility tunnel in central urban area has poor feasibility. To address this issue, the concept of integrating the utility tunnel with metro system is proposed to achieve synchronized planning, design, and implementation, and to explore different modes of integrated utility tunnel and metro joint construction. [Method] The necessity and principles of utility tunnel and metro joint construction are studied, and the integrated construction of both is analyzed. Taking the joint construction project of Guangzhou central urban underground utility tunnel engineering and Guangzhou Metro Line 11 as example, the characteristics and applicability of different integration modes are analyzed from the perspective of land saving, construction difficulties, and coordination requirements. The applicability of joint construction modes is discussed based on typical cases and their practical implications. [Result & Conclusion] Integrating utility tunnel with metro system through synchronized planning, design and implementation can reduce land resource occupation and reasonably utilize underground space resources. Co-construction and co-structure are the preferred utility tunnel and metro joint construction modes, saving construction costs significantly and leveraging the benefits of joint construction to the maximum degree. The final determination of the integration scheme between the utility tunnel (shaft) and the main and ancillary structures of metro should be tailored to context-specific and comprehensive consideration based on actual site conditions.