Characterization of particle size distribution of rock chips and evaluation of rock breaking efficiency of TBM based on multifractal theory: A case study

IF 6.7 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology Pub Date : 2025-01-21 DOI:10.1016/j.tust.2025.106418

Jianping Liu , Zhijia Zhou , Yucong Pan , Quansheng Liu

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引用次数: 0

Abstract

In the process of rock breaking by a TBM (Tunnel boring machine), the particle size distribution of rock chips is affected by both rock lithology and TBM operational parameters, showing typical variability and inhomogeneity. Multifractal theory can describe the variability and inhomogeneity of the particle size distribution of rock chips more comprehensively. Therefore, this study attempts to quantitatively analyze the particle size distribution of rock chips by using multifractal parameters based on multifractal theory. Based on the TBM tunnel project in Jiajin Mountain, a method of calculating the volume of rock chips sampled in the field is proposed, and field sieving tests are carried out. The multifractal behaviors of rock chips of sandstone and slate are verified, and the correlations between the multifractal parameters and TBM performance parameters are analyzed. The results show that: under the two lithological conditions, the particle size distribution of rock chips both meets the three conditions of multifractal theory, confirming that the multifractal behavior of the particle size distribution of rock chips is objective. It is further observed that the inhomogeneity of small-sized rock chip intervals is higher than that of large-sized rock chip intervals. In addition, lithology is shown to have a significant impact on the heterogeneity of the particle size distribution of rock chips. Under the two lithological conditions, the information dimension D(1) is positively correlated with the coarseness index (CI) and negatively correlated with the specific energy (SE), while the Hölder index of zero order α(0) is negatively correlated with CI and positively correlated with SE. The use of multifractal parameters D(1) and α(0) can provide a new method for characterizing the particle size distribution of rock chips and evaluating rock breaking efficiency. When D(1) reaches its maximum value and α(0) reaches its minimum value, the corresponding SE is the lowest, and TBM is in an “optimal” rock breaking state. A new method can be provided for optimizing rock breaking state of TBM using multifractal parameters.

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来源期刊

Tunnelling and Underground Space Technology 工程技术-工程：土木

CiteScore

11.90

自引率

18.80%

发文量

454

审稿时长

10.8 months

期刊介绍： Tunnelling and Underground Space Technology is an international journal which publishes authoritative articles encompassing the development of innovative uses of underground space and the results of high quality research into improved, more cost-effective techniques for the planning, geo-investigation, design, construction, operation and maintenance of underground and earth-sheltered structures. The journal provides an effective vehicle for the improved worldwide exchange of information on developments in underground technology - and the experience gained from its use - and is strongly committed to publishing papers on the interdisciplinary aspects of creating, planning, and regulating underground space.