| By means of theories analysis, numerical simulation, model experiment together with field application, this thesis thoroughly studies the interactive mechanism of bolt-grouting support, systematically analyses and studies the combined support technique of bolt-grouting in soft rock underground. The main contents of this thesis are as follows with the result of the acquisition:(1) Soft rock definition, geology characteristic and mechanics properties is systematically discussed. Deformation destruction character and its influenced factor of soft rock are analyzed. Soft rock mechanical properties and its destruction mechanism of BeiGui roadway are completely analyzed.(2) In the basis of discussed the mechanism of support structure, support effects and common operation mechanism of reinforcing wall rocks by rock bolts and grout are discussed in detail. Effects of parameters variation of surrounding ground and support to the ground deformation, support structure load, interaction of ground and support are analyzed. Calculation analysis based on a project case served as a theoretical reference for reasonable support design and construction. Reasonable support principles and countermeasures are put forward in view of the situation of soft cracked ground of BeiGui roadway.(3) In the respect of experimental study, simulating criteria of ground and support are derived from the simulating theory and different support type of soft rock roadway model experiment is carried out. By means of model experiment, variation curves of ground deformation with load and different support type of soft rock roadway, variation relations of bolt axial force and load are obtained. Meanwhile, analysis of deformation breakage rules of ground served as a theoretical reference for reasonable support design.(4) Theoretical analysis and numerical simulation has indicated that it is fine to apply bolt-grouting when the deformation of ground is about 100mm, because deformation and plastic zone of ground is smaller and support structure load is well distributed at this right moment, so this time is reasonable support opportunity for second reinforcement using bolt-grouting support. Using finite difference programmer FLAC2D , effects of bedrock deformation with different parameters of bolt-grouting is studied; variation characters of deformation, stress, plastic region and bearing force condition of bolt are analyzed contrastively, so rationality and scientificalness of are demonstrated.(5) Based on analyzing method and technique of monitoring measurement in the construction, according to the measurement result, properties of ground deformation and bolt bearing force are analyzed. Through comparison and analysis of the results of theoretical analysis, model experiment, numerical simulation, it is shown that surrounding ground deformation degree of roadway, deformation rules, bearing force of bolt tally with its counterpart and because bolt-grouting support can obviously improve strength of ground and bearing capacity, soft rock deformation of deep soft rock roadway can controlled effectively.
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