| Deformation and failure of surrounding rock are a kind of underground coal mining, coaland rock dynamic phenomenon. With the increasing depth of coal mining, destruction ofoccurrence and harmfulness are revealed more and more serious deformation of surroundingrock, It has become a major problem which the deformation and stress characteristics andsupporting technology research of surrounding rock in mine construction project in china. Inthis paper, theoretical analysis, simulation test are used on the surrounding rock of coalrectangular roadway deformation and force analysis and failure properties, revealed the law ofdeformation and failure, and provided a theoretical basis for roadway support. The main workand conclusions:（1）The redistribution of the initial stress field will be caused tunnel excavation, theoriginal three to the equilibrium pressure is broken and formed the secondary stress field insurrounding rock of roadway. The size of the secondary stress field related with original rockstress field, it is generally2-3times of the the original rock stress and descend to it along therock free, The rock extruded the unbalanced two stress state and expansion damage to tunneldirection expansion, The main factors of surrounding rock deformation regularity are closelyrelated to the ground stress, geological structure, rock of lithology and roadway structure.（2）The result of the deformation of roadway instability occurs the interaction ofsurrounding rock with stress, deformation pressure and loose pressure to the retainingstructure. the stress deformation characteristic of rectangular section due to different structureform, Roof of roadway is mainly affected by the extrusion force of vertical and horizontalstress, and will be bending, caving form a certain range of caving arch; Two sides roadwaysurrounding rock easy to produce stress concentration and subjected to eccentric loading rolein the roof strata pinch in corners of the roadway, and side rock due to compression the longitudinal fissure extended through and failure. The tunnel roof and two wall rock andstructure has a great influence on stress and fracture characteristics of roadway surroundingrock.（3）Simulation test start from simplified unit of surrounding rock，it studied the force,deformation and failure of unit with different pressure, different constraints simulation ofdifferent strength of rock mass. The test results show that: the bearing capacity of rock will besignificantly decreased because bearing eccentric loading, and it will decrease with theeccentricity increase, the fracture from compression face side began to develop and firstfailure and outwards withing the loading duration, damage to the medial extension. itscompressive strength will be improved in the lateral binding effect. the damage of the samplefree side mainly as fissure extending along the vertical direction, forming a layered failureform certain, and reproduced and revealed deformation and failure of surrounding rockspalling during the formation and occurrence to a certain extent.（4）By using the similarity theory to build the roadway geometric similarity, equalstrength test model, and researching distribution, propagation characteristics of rectangularcavity around the stress with different rock strength and lateral constraints. The results showthat: the rectangular roadway surrounding rock finally failure forms are different duing todifferent forced characteristics, The roof is mainly affected by the crack and damaged, twosides mainly by fracturing failure, the vertex position is mainly controlled by shear force andfailure, At the same time, the more the soft surrounding rock of two sides, the more obviousside displays inverted wedge failure form, the two sides of roadway by fracturing failurepattern is consistent with the actual basic, The laboratory simulation of roadway surroundingrock deformation and failure process and characteristics is feasible. |
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