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Carbon emission reduction in the construction industry is crucial for promoting low-carbon transformation of the industry and for realizing the carbon peaking and carbon neutrality goals. This study analyzes the current status of carbon emissions in Chinese construction industry. It identifies that the production of building materials and the operation of buildings are the primary sources of carbon emissions in the overall construction process. Moreover, the growth rate of carbon emissions from the construction industry in China is decelerating, and the spatial characteristics of carbon emissions demonstrate an increase from the south to the north and from the west to the east. We have identified six key challenges that must be addressed to achieve carbon peaking and carbon neutrality in the construction industry of China: policy and standards framework, energy-efficient and carbon-reducing technologies, reduction of carbon emissions from existing buildings, carbon emission data collection and monitoring systems, economic incentives, and increased awareness of carbon reduction. Staged goals for the low-carbon development of the construction industry are also proposed. Furthermore, we suggest improving related policies and standards system, optimizing the use of energy-saving technologies, reducing carbon emissions in existing buildings, developing green finance, improving the ability to monitor carbon emissions, and enhancing the awareness of energy conservation and carbon reduction, so as to provide references for the low-carbon transformation and high-quality development of China’s construction industry.

Underground space and resources are crucial for solving energy, resource, and living space problems faced by mankind. Shafts are throats that extend from the ground into the strata and thus require safe, efficient, green, and intelligent construction. In this paper, we analyze the need and necessity for developing large-diameter drilling technology and equipment, examine the development status in China and abroad, and analyze the challenges faced by China from the perspectives of basic research, applied technology development, high-end equipment manufacturing, and project demonstration. Moreover, we pinpoint the development directions of shaft construction technology and equipment and propose that China should establish the development concept of intelligent drilling, clarify the development path and tasks of intelligent drilling, establish relevant standards and specifications of large-diameter drilling, and promote the construction of intelligent drilling platforms and demonstration projects, thereby providing support for shaft construction in fields such as mining, hydropower, transportation, and urban construction.

The interaction mechanism between grouted anchor cables and the surrounding rock mass or soil are complicated and difficult to investigate using conventional monitoring technologies. This study focuses on the in-situ pullout behavior of grouted anchor cables using Brillouin Optical Time-Domain Analysis technique. A series of pullout tests were conducted on anchor cables with five different anchor lengths and three grouting methods. Distributed fiber optic sensors were used to measure the strain distribution of cable bolts from tip to top. The in-situ pullout test results show that both ultimate pullout resistance and ultimate displacement at the ultimate pullout resistance increase with anchor length. The bond strength suffers a slight variation with an increase in anchor length. Both ultimate pullout resistance and the ultimate displacement for Type-B grouting (grouting with reaming) and Type-C grouting (secondary grouting) are larger than those for Type-A grouting (one-time grouting). The shear bond strength of Type-C grouting is greater than that of Type-A grouting. Results from Gaussian functions analysis show that it is feasible to use the function to characterize the axial stress of anchor cables. Furthermore, the overall mobilized percentage [eta] was evaluated. The anchor cables with smaller anchor lengths will result in greater [eta]. The [eta] for the anchor cables of 6 m reaches 92% at the last load, whereas the anchor cables of 18 m were mobilized by only 29% at the last load. The grouting method has a negligible effect on the [eta], increasing from 22% to 29% in process of the pullout test. Key words: distributed fiber optic sensor, anchor cables, pullout tests, pullout resistance, 1. Introduction Fully grouted anchor cables are common reinforcements widely used in mining, excavations, and slopes (Stillborg 1986; Hyett etal. 1996) due to their affordability, simplicity of installation, and versatility. [...]