Study On The Stability Of Jointed Slope And The Effect Of Bolting And Grouting Reinforcement Method

In resent years, there are more and more large-scale jointed slopeprojects. It becomes more and more complex and important in field ofslope stability. Rock bolt is widely used in slope reinforcement as aregular reinforcement method. When slope reinforced by rock bolt, thestress state of rock bolt in the area of slip plane will become bad becauseof great slippage force. The prestressed rock bolt will lose its stress withcreep of rock and plasticity of reinforcing steel bar. In slopereinforcement design, the anisotropic characteristic of rock mass will leadto contradiction that the shear resistance strength of jointed reinforced byrock bolt and pull-out resistant force can not exert at the same time. Thedisadvantages of rock bolt will lead to the invalidation of reinforcementcharacteristic, which will bring hidden troubles in the slope stability. Thecraft of bolting and grouting combine the advantages of bolting andgrouting. It makes the composite structure with bolt and grouted material.The craft exert the advantage of bolting and grouting separately in thereinforcement of slope, which avoids the disadvantages of bolt andavoids the phenomenon of stress concentration. The reinforcementmethod of bolting and grouting makes the stress state in rock mass morereasonable, and avoid the hidden troubles in slope stability. It isimportant to study the effect of bolting and grouting reinforcement inslope is studied so as to provide the guidance for the optimum design ofslope reinforcement method. The scientific research of HuNancommunications ministry with title of'Study of bolting and grouting inrock jointed slope of ChangDe-ZhangJiajie speedway'is chosen as thestudy background, the stability of rock jointed slope and effect of boltingand grouting are studied.First of all, the mechanical model of slope stability is foundedaccording to the failure characteristic of rock jointed slope. According tomechanical theory, the effect of weakness plane to the strength andstability of slope is studied. The reason of failure in jointed slope isanalyzed according to the strength theory and potential slip plane theory.According to the mechanical characteristic of slope with the reinforcement of bolting and grouting, the mechanical models arefounded for the reinforcement of bolting and grouting. According thetheory of jointed mechanic in rock mass, and take into consideration ofthe characteristic of rock joint, bolting and grouting strengthcharacteristic and constitutive relation, the shear strength of bolting andgrouting joint is deducted. By the compare analysis of characteristic forregular joint, bolting joint, bolting and grouting joint, the mechanicalcharacteristic for the effect of bolting and grouting in reinforcementmethod of joint slope.By the RYL-600 rock shear test machine, the shear experiment ofrock sample is done. The shear characteristic of joint plane for differenttype of structural state is studied. Different curves are obtained to analyzethe characteristic of stress-strain. By the result of analysis, the effectfactor and the characteristic of strength and deformation of joint with thereinforcement of bolting and grouting are obtained. It is different inmechanical characteristic of joint between regular joint and joint withbolting and grouting reinforcement.By using the numerical analysis software FLAC3D, jointed slopeswith bolting and grouting reinforcement are studied. The analysis is donein the field of stress, displacement and the characteristic of monitoringpoints. The numerical simulation models consist of jointed slope with thereinforcement of bolting, grouting, bolting and grouting. The effect of thereinforcement to the jointed slope is studied.According to the theory of fracture mechanics and damagemechanics, the effect of bolting and grouting to the jointed slope arestudied. The disadvantages of rock bolt when it exerts alone are studied.The latest mechanical theories, the advanced experiment methods andnumerical simulation methods are adopted in this paper to study tostability of jointed rock slope and the effect of bolting and groutingreinforcement. The research work in this paper can open up themechanism of combined supporting in jointed slope and provide thetheoritical and practical meaning for the optimum design.