Abstract
To recommend the excavation procedures and design parameters for underground powerhouses, excavation procedures of fifty-one underground powerhouses in China were summarized and analyzed based on in situ stress conditions. Firstly, the complex stress environment in China was introduced and fifty-one underground powerhouses with their engineering scale, size, lithology, rock classification and in situ stress level were listed in detail. Subsequently, to evaluate the influence of in situ stress levels on excavation procedure design, the correlation between excavation procedures and in situ stress level in three main excavation zones were analyzed accordingly. Moreover, to provide the excavation design recommendations, the strength–stress ratio (SSR) was promoted to analyze and recommend the design parameters, and the blasting excavation design based on the stress transient unloading control was also supplemented. The results show that excavation procedures have different priorities under different in situ stress levels, and the design parameters show an obvious relationship with in situ stress levels. Moreover, the excavation procedure parameters are suggested to adjust accordingly under different SSR. The discussion of influencing factors and specification ensures its rationality and accuracy. It is believed that the summary and recommendations can provide a good reference for excavation procedure optimization of underground powerhouse under high in situ stress.
Highlights
It can be seen that the existing excavation procedure design method is more and more unsuitable for stability control of underground cavern excavation of large hydropower stations with increasingly complex construction conditions, especially in the case of high in situ stress and low rock strength–stress ratio
Vibration inducedinduced by stress transient unloading is proportionate to in situ stress level, which can be more stress transient unloading is proportionate in situ stress level,can which can be more by stressby transient unloading is proportionate to in situtostress level, which be more than 50%
(1) Fifty-one underground powerhouses in China were summarized in detail, includexcavation behavior should be considered in a specific situation, even if there are support ing their engineering scale, size, lithology, rock classification and in situ stress level
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. It can be seen that the existing excavation procedure design method is more and more unsuitable for stability control of underground cavern excavation of large hydropower stations with increasingly complex construction conditions, especially in the case of high in situ stress and low rock strength–stress ratio. To this end, a short introduction on the basis of the stress environment and excavation procedure technology development in China was given firstly. It is beneficial to quantify the correlation between excavation procedure parameters and in situ stress, and to recommend a better excavation procedure optimization
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
