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Abstract Determination of reasonable coal pillar width is key for ensuring stability of surrounding rock of fully mechanized caving roadway driving along next goaf. Taking track roadway of 11302 workface in Zhaolou colliery as the engineering background，a new side abutment pressure monitoring method was proposed；and the reasonable coal pillar width was determined by using the method of field stress monitoring and numerical simulation. Field stress monitoring and numerical analysis results show that the influence scope of workface side abutment pressure is 50–56 m，and low stress zone width is 12–15 m，considering pillar stress environment，pillar width should not be larger than 7–10 m. Meanwhile，considering being propitious to bolt anchoring，width of coal pillar should not be less than 4 m. Various elements such as coal pillar stability，secondary disaster control and resources recovery were considered comprehensively. Finally，the reasonable width of segment pillar is determined as 5 m. Reasonable pillar width is verified by using large-scale geomechanical model test and field test. Monitoring results show that variation of surrounding deformation along the empty wall is largest，followed by roof and entity wall，floor is least. After roadway driving along next goaf stability，roof to floor convergence is 271 mm；two walls convergence is 359 mm；the effect of roadway surrounding rock is well. Bolts and anchors forces are in their yield range；and set aside a sufficient margin for the recovery period. The results can provide a reference for segment pillar setting in other mines with similar mining conditions.
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Received: 06 May 2013
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2014, Vol. 33 
