Study On Evaluation Index System And Method For TBM Adaptability In Deep Composite Strata

In the tunnel construction, the full-face tunnel boring machine (TBM) has the advantages of high efficiency, celerity, high quality and safety compared with the traditional drilling and blasting method, and has been widely used in the industries of energy, traffic, water conservancy, etc. In deep composite strata, the TBM will come up against some geological disasters such as fault fracture zone, rock burst, great wall rock distortion and water burst, etc. These disasters could directly affect the adaptability of TBM. Based on the condition of deep composite strata, this paper carried out the research of evaluation index system and evaluation methods of TBM adaptability. The main research contents and achievements are as follows.(1) Based on the investigation research of the TBM application and adaptability evaluation under complex geological condition at home and abroad, the influence factors on TBM adaptability are collected, counted and analyzed from five aspects. They are design of TBM. TBM construction, the geological conditions, the harmful geological problems and construction organization.(2) Based on the comprehensive evaluation theory of analytic hierarchy process (AHP) and fuzzy mathematics, an evaluation method of TBM adaptability in deep composite strata is proposed in the aspects of geological conditions, driving feasibility safety in construction, adjoining rock stability, etc.(3) On account of the selected influence factors of TBM adaptability, the evaluation index and system of TBM adaptability in deep composite strata are established, including the 4 criterion layers and 18 evaluation indexes based on the principles of gradation, validity and simplicity.(4) Through the quantitative analysis of the evaluation indexes, this paper carries out the evaluation indexes of adaptive membership function, and solves the problem of the commensurability of evaluation indexes. Then the judgment matrixes of the evaluation indexes are established. According to the properties and effect magnitude of the evaluation indexes, the analytic hierarchy process (AHP) is adopted to determine the weights and the sorting of each evaluation index. Finally, the evaluation model of TBM adaptability in deep composite strata is established.(5) Supported by the TBM construction in Liaoning northwest water supply engineering (2-5th stage), the TBM fitness is evaluated by the proposed evaluation model. The evaluation results are in conformity with the actual TBM construction situation, validating the rationality of the adaptability evaluation model presented in this paper.The research results of this paper are of significant practical value for adaptability evaluation and the selection of TBM in deep composite strata.