花蓮の砂利地層における深層マイクロトンネリング縦坑のアップフロント炭素フットプリント

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Provides an expanded LCA framework for underground infrastructure that integrates geological and material factors, useful for further research in construction carbon assessment.

🏢実務担当者:Offers actionable insights for specifying low-carbon concrete in deep excavation projects to offset geological energy penalties, aiding in carbon reduction targets.

🏛政策担当者:Highlights the need for including geological conditions in carbon accounting standards for infrastructure, informing procurement policies and low-carbon material mandates.

Trenchless technologies are essential for urban sewerage infrastructure; however, standard Life Cycle Assessment (LCA) boundaries often overlook the upfront carbon footprint of vertical nodes (working shafts and precast manholes), particularly under deep excavation and difficult geological conditions. To bridge this research gap, this study establishes a comprehensive upfront carbon (Stages A1–A5) assessment model based on the EN 15804 standard, calibrated against empirical microtunneling inventory data from Hualien, Taiwan, characterized by deep excavations (10–12 m) and hard gravel strata (SPT N > 50). The empirical results reveal a dual carbon challenge: a geologically induced energy surge during construction (Stage A5, contributing 42.5% of total assessed upfront emissions) and an embodied carbon lock-in within high-strength permanent structures (Stages A1–A3, contributing 51.1%). To isolate these effects, a progressive four-scenario matrix was evaluated. Scenario simulations demonstrate that adopting high-volume supplementary cementitious materials (SCM) concrete manholes (50% cement replacement: 37.5% GGBS and 12.5% fly ash) achieves a material reduction factor (Rmat) of 15.0% in Stages A1–A3, fully offsetting the isolated 3539 kgCO2e construction-energy increment imposed by the hard gravel strata, although total upfront emissions in Scenario IV remain slightly higher than the baseline Scenario I when evaluated across the complete A1–A5 boundary. This study provides an expanded LCA framework and empirical evidence for integrating geological constraints and low-carbon material specifications into underground infrastructure procurement and engineering design.

• openalex https://doi.org/10.3390/su18178911first seen 2026-09-03 05:16:47
• semanticscholar https://doi.org/10.3390/su18178911first seen 2026-09-08 05:22:28 · last seen 2026-09-22 05:12:12