Papers by Keyword: Rock Slope

Abstract: To study the creative design method for slope greening, introduced extension theory and method, took the method of new concept slope design as breakthrough point, and analyzed the feasibility and method of highway rock slope creative design using extension method. Case analysis shows that applying extension method to new concept slope design is appropriate and feasible; it can reduce the dependence on experience, inspiration and other individual ability of the creative design process. This method is expected to be used in the whole new concept highway design after further studying.

Abstract: The special geographical, climatic conditions and geological structure in Tibetan Plateau making high steep rock slopes along the valleys wide-spread in this area, and they are especially common in the construction of highways. In this study, geological genesis and potential sliding mode are discussed firstly, then numerical model results as well as actual data are used to analyze the cause and influence depth of unloading fissures. Finally, common problems exist in rock slope are summed up. Based on these, natural state, disturbed state and steady state after reinforcement are analyzed respectively. It is believed that rock slopes in this area should be considered to minimize unloading, changing their shapes, and should try to reinforce actively or take positive reinforcement measures, so that the disturbance caused by rock soil environment will be effectively controlled, and the ecological restoration work will be done.

Abstract: To the problem of slope stability analysis and slope-cutting of rock slope, the traditional method Limit Equilibrium Method has many shortcomings as assuming the position and shape of the slip plane first. However, with the new theory of Strength Reduction Method, the problem can be easily solved. By selecting the appropriate criterion of instability and failure of sliding surface of slope, the Strength Reduction Method simulates the gradual development process of slope-cutting. By this method, we can simulate the failure process of slope and obtain the safety factors and slipping surface. This paper put forward the process of cutting slop by Strength Reduction FDM (Finite Difference Method) which had new insights into the choice of instability criterion, flow rule and slip plane.

Abstract: Excavation unloading zone corresponds to stress decreased area of slope rock mass after excavation. Quality of slope rock mass in this area will be degraded due to excavation disturbance, and the mechanical parameters of rock mass will be also degraded accordingly. Therefore, determining the range of excavation unloading zone accurately is one of the key factors to ensure the rationality and validity of numerical simulation results of rock slope excavation. In this paper, the range of excavation unloading zone is determined by comparing stress field before and after excavation, choosing stress component perpendicular to excavation face as comparative standard in calculation, which can be calculated by computer program with FLAC software. Stress adjustment of slope rock mass due to excavation is a dynamic and changing progress, so the range of excavation unloading zone is changing during excavation, which can be achieved by a cycling program in numerical simulation. The correctness and usefulness of this method is proved by the calculation results of example analysis.

Abstract: This paper uses 2D DDA program to simulate the failure process of highly jointed rock slope with a fault. In addition, seismic forces, as a most common triggered factor of landslide, are also simplified simulated by applying an initial velocity to the slope. Based on the simulation results, the weakest discontinuity, fault, determines the slide path of rock blocks; the accumulation of blocks' displacements leads to the overall failure of slope; and the existence of highly developed joints provide the possibility of the accumulation of displacements.

Abstract: Based on the lower bound theory for the plastic limit analysis, rock slope is divided into rigid block and structural surface. And the mathematical programming model which takes the safety factor as the objective function is established for the calculation of slope stability. This model has to meet the balance equations of the blocks, the Mohr-Coulomb yield conditions and the boundary conditions of slope. In the end, a classic model of rock slope on consideration of the pore water pressure and earthquake force is analyzed, and its lower bound solution is worked out. This result is compared to the result worked out by limiting equilibrium to test the validity and correctness of the method and procedure used in this paper.

Abstract: In the region of Hubei Shuibuya hydropower station, the paper studied the variation of slope positions and years to the artificial ecological substrate on Sanyouping highway rock slope by field sampling and office processing. The indexes which were measured and analyzed in experiment mainly included unit weight, water ratio and organic matter. The results showed that the distribution of the three indexes of artificial ecological substrate on the slope were different, and lacked rules to follow. The maximum of unit weight was the middle slope, and the maximum of water ratio was the lower slope, but the organic matter of upper slope was the maximum. As the implementation of ecological restoration project went on, the unit weight of artificial ecological substrate gradually reduced, and the content of organic matter steadily rose, but the water ratio was greatly affected by seasonal rainfall and fluctuated with years. Overall speaking, three kinds of indexes on the slope with the change of years gradually tended to the natural slope. It shows that the rock slope can be restored preferably as long as the ratio of artificial substrate is properly.

Abstract: Based on the assumption of the improved groundwater pressure distribution, the calculation expression of anti-sliding stability factor for typical water-saturated rock slope is deduced through limit equilibrium method. Considering the combined effect of slope overload, seismic load, anchoring effect, ice frost, slip surface drag force and slope groundwater pressure, the comparative analysis of typical rock slope sliding stability under waterless and saturated conditions shows that, the outflow joint blocking and the groundwater levels rising have obvious adverse effects on the anti-sliding stability of rock slope. Figures about the relationship of stability factors and geometric factors were drawn and the anti-sliding stability factor can be directly obtained from these figures. All would be the references for the similar engineering projects.

Abstract: In order to real time monitor and analyze the rock fracturing due to continuous construction and consolidation at the left slope of Jinping I hydropower station, southwest of China, a microseismic monitoring system was conducted and an optimal design for the sensor arrays was investigated. The sensor array was designed on the basis of P method and Powell algorithm. The artificial fixed blasting tests were applied to adjust the positioning accuracy of the monitoring system. The results show that the location error of seismic source is less than 12 m in the scope of the sensor array, which demonstrates the monitoring system has high positioning g accuracy. The contour of source location shows that the location errors near the main tunnels at the left bank slope is below 6 m. Signals from 689 microseismic events with moment magnitude ranging from -2.1 to -0.2 were recorded during the first year monitoring period from June 15, 2009. The spatial distribution of microseismicity can identify and delineate the potential failure at the left bank slope, which provides some references for the future excavation and consolidation of the hydropower station.

Abstract: Under the combined effects of various external factors, such as temperature, seepage, alternate wetting and drying and so on, the mechanical properties of rock mass are susceptible to be deteriorated, and its strength characteristics are significantly degraded with time. The mesoscopic damage accumulated inside the rock, contributing the rock slope instability with weak structure planes, generate the time-dependent deformation, and eventually lead to the slope failure. Given the time-dependent deformation of the rock, numerical simulations are conducted to investigate the key factors influencing the long-term stability of slopes. Numerical results show that the catastrophic failure time of slopes is linear to its cohesion, and the bigger cohesion and friction angle increase catastrophic failure time, i.e., the stability of rock slope increase. In addition, the configuration of the intact rock bridge can also influence the time-dependent slope stability. Slope height can significantly affect the slope stability and the maximum horizontal displacement. Differences in rock mass storage environment play an important role in the long-term stability of slopes.