| In the mountainous area, potential problems in the construction arise with theincrease of numbers of constructions of slopes; meanwhile, stability of slopes in theconstruction has become a significance research project. As a result, the paper intents tomake a systematic study of stability of building soft rock slopes in Chongqing area withrelatively intact texture specific to the stepwise working model in the construction ofsoft rock slopes by means of laboratory test, theoretical research, numerical simulationand field monitoring. Main contents as follows:①Summary of current situation of failure mechanism of rock, effect ofexcavation unloading and effects of sequence of construction of construction on slopesand bracing structure. Meanwhile, the main study and method used of the paper wasdrawn.②On the basis of widely investigation, engineering properties of slope rock massin Chongqing area is summarized. By using servo experiment machine, uniaxial,ordinary triaxial loading and triaxial unloading experiments of sand shale are made tostudy the relations between deformation characteristics and stress characteristics underdifferent confining pressure and different stress path. As a result the mechanicparameters and overall stress-strain curve of sand shale is obtained.③Considering a practical project as a prototype, numerical simulation is made todiscuss the effects of using ordinary method and method considering unloading processon results and to analyze the effects of different sequence of construction on rock basedsoft rock slope by using FLAC3D.④In the process of slope excavation, slope deformation, supporting structure forceand rock pressure are monitored. By long period monitoring, large amount of data areobtained, variations of horizontal displacement, axial force of anchor rod and sidepressure of soft rocks are analyzed.⑤Sensitive analysis of factors effecting stability of ordinary rock based slopes aremade. By establishing numerical model, effects of excavation ratio, staging method,width of the stage, incidence, length and spacing of anchor rod to the stability of slope.⑥Optimize the parameters of bolt-shotcrete support and parameters of anchorage,for instance, excavation rock slope, excavation ratio, height of stage, width of stage,length, spacing and incidence of rod. Programming optimizing programme accordingly, optimized results are obtained to compare with ordinary results.In the study of this paper, results of numerical simulation fits well with themonitoring results, theoretical results can well explain the results of tests. Three partsverdicts each other, results is meaningful to similar programmes specific to theoptimization of design and construction. |
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