Abstract:

The key sources and influencing factors of emissions from the construction of inclined shafts of highway tunnels remain unclear. Therefore, a data inventory is developed for the materials used and energy consumed in the construction of inclined shafts, and the characteristics of carbon emissions from inclinedshaft construction are studied. Further, the emission coefficient method is employed to calculate the carbon emissions resulting from adopting different procedures and materials for the construction. In addition, the influence of the slope and length of the inclined shaft on carbon emissions from excavation and mucking is analyzed. For this, support designs of an inclined shaft with Grades Ⅳ and Ⅴ surrounding rocks are used and quota standards, such as the〖WT5BX〗 Highway Engineering Budget Quota 〖WT５《TNR》〗and〖WT5BX〗 Highway Engineering Machinery Machine Team Cost Quota, 〖WT５《TNR》〗are followed. The following results are obtained: (1) The carbon emissions from the inclined shaft excavation and support in Grades Ⅳ and Ⅴ surrounding rocks are 17.95 tCO2eq and 27.00 tCO2eq per meter, respectively. (2) The carbon emissions from the construction of shotcrete and a steel support increase rapidly as the grade of the surrounding rocks increases. (3) The carbon emissions from excavation and mucking increase by 0.15~0.2 tCO2eq per 100 m of the inclinedshaft length for lengths exceeding 1 500 m. (4) For a shaft slope of 7°, 9°, 12°, or 25°, the carbon emissions from mucking range from 0.37 to 0.69 tCO2eq per meter. Meanwhile, for shaft slopes >12°, rail transportation produces lower carbon emissions than other mucking methods.

Key words:  , highway tunnel, inclined shaft, carbon emission, emission coefficient method, slope