Moreover, loss of confining bed integrity often leads to penetration of water into surrounding rock mass. In structurally complicated areas, significant and complex in situ stresses and previous geological activities endow rock mass with considerable crack development and extensive fracturing failure, which stimulate challenges in the roadway maintenance. In the coal mining practice, operation passages such as roadways are usually placed near coal beds or adjacent sedimentary formations such as mudstones and sandstones. Compared with those coal seams with superior occurrence conditions, rock masses with deep burial depth or under complex geological conditions are subjected to extreme in situ stresses and are, thus, prone to creep and long-term large deformation. Tremendous coal production pressures force many coal mines to shift into deep-buried coal seams and those with inferior occurrence conditions. In 2018, China’s coal production reached 3.68 billion tons, growing by 4.5% every year. Findings of this research can provide valuable references for support engineering in the soft rock roadway under analogous geological conditions. Moreover, numerical simulation and field testing are conducted to validate the feasibility and effectiveness of the proposed approach, the results of which demonstrate the capacity of the proposed new support method to perfectly control the surrounding rock. Accordingly, a new combined support system of “bolt–cable–mesh–shotcrete + grouting” is proposed. Unfortunately, the current support system fails to restrain rock weathering and strength weakening, and the roadway is found with serious floor heave, roof subsidence, and large asymmetric deformation. The roadway roof and floor suffer from high stress concentration and continuous cracking, and are consequently seen with rock failure, strength weakening, and pressure relief. ![]() It is found that the stress evolution and crack development are affected by weathering and horizontal tectonic stresses. The failure mechanism of the roadway under water-saturating and weathering conditions is revealed by field tests and numerical simulation. ![]() Mechanic properties of rock mass related to the roadway are calibrated via a geological strength index method (GSI), based on which a corresponding numerical simulation model is established in the Universal Discrete Element Code (UDEC) software. This paper provides a case study on failure mechanisms and support approaches for a water-rich soft rock roadway in tectonic stress areas of the Wangzhuang coal mine, China. Large deformation and failure of soft rock are pressing problems in the mining practice.
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