Abstract

ZHANG, P.S. et al. Experimental study on the stability of surrounding soft rocks of gob-side entry retaining in fully mechanized caving. J. S. Afr. Inst. Min. Metall. [online]. 2018, vol.118, n.5, pp.481-492. ISSN 2411-9717.  http://dx.doi.org/10.17159/2411-9717/2018/v118n5a5.

Theoretical and field investigations were combined to analyse and determine the design parameters for a field roadway and roadside support. A gob-side entry retaining model was created with similar materials, and physical tests and numerical simulation were carried out to study the stability of surrounding soft rocks in fully mechanized caving using specific roadway and roadside supports with different stress states. The study shows that mining the upper and lower panels causes a superposition effect to the gob-side entry retaining roadway, and the deformation of the surrounding rock is further exacerbated during mining of the lower panel. Moreover, the lateral residual abutment stress in the gob area could easily cause the entire roadside support to topple. A support method coupling 'long/short anchor cable plus bolts plus net' to a composite suspension beam provided excellent support for roadways with fractured roofs. As long as the roadside support strength is maintained, the secondary support provided by roof-contact yielding material will facilitate benign deformation of the roadway roof to release energy and stabilize the roadside support.

Keywords : gob-side entry retaining; similar material; simulation test stress states; fully mechanized caving; physical model.

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