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Stability Study And Processing Technical Of The High Steep Rock Bedded Slope In Red Beds Area Of Hunan Province

Posted on:2011-02-23Degree:DoctorType:Dissertation
Country:ChinaCandidate:J LiFull Text:PDF
GTID:1100360305492849Subject:Geological Engineering
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With the development of construction of infrastructure, the problem of the stability of the high steep rock bedded slope is met in the railway construction and the highway construction in mountain. The past engineering practice shows that the high steep rock bedded slope is most likely to failure in the rock slopes, and it causes enormous loss of the engineering project and the life and belongs of the people. Now, the system research of the stability of the high steep rock bedded slope, the relevant engineering measures and design methods are not developed. so, how to analyze the stability of the high steep rock bedded and raise the reasonable design scheme to prevent the failure of the high steep rock bedded become difficult problems to engineers.There are a lot of red, maroon or claret siltstone and mudstone deposited in continental facies at late-cretaceous System and tertiary in Hunan province. The stratum is called "Red beds" in engineering field. Due to its formation condition, Red beds with special engineering property is typical very slip stratum. There is many landslide happened frequently at rainy season.Based on the project of the high steep rock bedded slope in the highway from Changde to Jishou, the deformation and failure mechanism, stability analysis and support measures of high steep rock bedded slope are studied in detail by multiple methods. The main results and conclusions can be expressed as follows.1.Rock samples are made of the rock taken from in situ areas. The rock sample tests such as uniaxial compression test, tensile test, shear test and joint plane direct shear test are done. Compressive strength, elastic modulus, poisson's ratio, tensile strength, cohesion and friction angle of rock samples, weakness plane shear strength parameters C andφare obtained from the tests. Analyze are done to these parameters which will provide the data basis for forward mechanics analysis.2.To the high steep rock bedded slope, the major influence factors of stability are summarized. The major influence factors include geology factor, engineering factor and other factors. This article applied the uniform design to carry on the sensitive analysis of the multi-factors which affected the slope stability. The application of uniform design can effectively reduce the test times and improve the test effectiveness. The parameters include structural plane angleθ, internal friction angleφ, high of slope h, density of rock y and cohesion C.3.Based on the investigation and collection a large number of engineering examples, the distortion and destruction mode of the high steep rock bedded slope in red beds area are summarized. The unstability of the high steep rock bedded slope in red beds area includes distortion and destruction. There are not penetration failure plane in the slop is called distortion, which include loose and creep. The destruction includes falling, slip, toppling, buckling and tensile. The unstability model of the high steep rock bedded slope in red beds area includes creeping-tensile, slip-pressuring-tensile, slip-tensile, curving-tensile, flowing-tensile, slip-curving, and so on. In addition, the above pattern may combines in the time or the space, constitution combination pattern.4.The construction plane exist in the high steep rock bedded slope in red beds area of hunan province, Based on the mechanics analysis of the construction plane exist in the high steep rock bedded slope,the familiar destruction mode of the high steep rock bedded slope in red beds area are analysed by numerical analysis software.Because the especial physics mechanics character of red beds, the excavate rock bedded slope most glide obey the construction plane or lay,the plane glide destroy is the most destroy form.On the basis of investigation of lots of typical sites of the high steep rock bedded slope in red beds area of hunan province, the four types of rock bedded slope which familiar in red beds area is summarized, the deformation and failure mechanism are described.5.By using the numerical analysis software FLAC3D, the high steep rock bedded slope in red beds area reinforcement are studied. The analysis is done in the field of stress, displacement. The numerical simulation models consist of the high steep rock bedded slope with the reinforcement of anti-sliding piles, prestressed cable, anti-sliding piles with prestressed cable. The studied show that the high steep rock bedded slope reinforced by anti-sliding piles with prestressed cable, the whole stability of slope enhanced, the stress of the structure become reasonable. The abuse of anti-sliding piles and prestressed cable which used only is changed.6.Based on the fuzzy decision-making theory for multi-objective system, the index system for evaluating the project design was established for the seepage control scheme for support design of slope engineering. The combination of the method of AHP and of expert investigation was used to decide the weight for evaluation index, the optimum decision-making and evaluation model was deduced from fuzzy decision-making theory for multi-attribute system. The outcome is contrast to the numerical analysis software FLAC3D,and the two result is consistent,The outcome is proved authentic and valid.7.Based on the project of the high steep rock bedded slope in the highway from Changde to Jishou, deformation and failure character of slope and the slope form condition is analyzed. The slope incorporate creeping-tensile and slip-curving ladder combination pattern in space, the front of slope is slip-curving pattern, the back of slope is creeping-tensile pattern, which two pattern combination complex failure pattern. The slope through creeping-tensile and slip-curving pattern to slip-tensile pattern in time. When the anti-sliding piles with prestressed cable reinforcement measure is used in slope, the stability of slope is enhaced.
Keywords/Search Tags:rock bedded slope, deformation and failure mechanism, cretaceous system and Tertiary system red beds of Hunan, FLAC3D numerical simulation, stability, processing technical, anti-sliding piles with prestressed cable reinforcement measure
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