Technological and Managerial Innovation and Application Practice of Shield Residue Soil Premixed Mortar

Abstract

Against the backdrop of China's drive to achieve a comprehensive green transformation of economic and social development and its implementation of the "Dual Carbon" strategy, the large-scale resource utilization of residue soil generated by shield tunneling has become one of the core topics for green and low-carbon development in the construction sector. Traditional shield grouting materials rely on primary resources such as sand, gravel, and cement, resulting in high costs, significant carbon emissions, and serious ecological damage. Meanwhile, the disposal of shield residue soil is difficult due to strict off-site dumping regulations, high safety risks, and mounting environmental pressure—all of which have become bottlenecks constraining the high-quality development of shield construction. This paper innovatively proposes a technology for manufacturing premixed mortar from shield residue soil: using shield excavation waste soil as the core raw material, and through undisturbed soil solidification technology, precise mix proportioning, and standardized process control, it prepares high-performance synchronous grouting premixed mortar. The paper systematically elaborates on the industry background, core principles, technical pathways, performance indicators, and benefit advantages of this technology. Combined with engineering practice in projects such as Nanjing Metro Line 6 and the extension of Ningbo Metro Line 4, the paper verifies its significant value in cost reduction and efficiency improvement, ecological and environmental protection, and construction safety. Research demonstrates that this technology achieves in-situ resource utilization of residue soil. Compared with traditional synchronous grouting mortar: the 7-day early compressive strength is improved by more than 60%, impermeability is enhanced by one order of magnitude, and initial setting time is reduced by 50%. It can effectively reduce ground settlement and segment floating, lower overall construction costs, and is aligned with the philosophy of green and low-carbon development, thereby providing a replicable and scalable technical paradigm for the resource utilization of construction waste from shield tunneling projects.