Study on Cusp Catastrophe Mutation of Slope Destability

A complete theoretical model for slope destabilizing mutation has been set up by studying the geomechanical model and the influences of all circumstantial factors on slope stability,and by applying nonlinear theory.This paper analyzed the influence of controlled variables in the mutation model on the slope in causing slow or fast creeping.As the limit equilibrium stability analysis method of rigid bodies has some defects in slope stability assessment,the new theory of rigidity destabilization is helpful in forming criteria for judging slope creep destabilization.This analysis explains well the underlying causes of creeping slope destabilization and proves the feasibility of studying slope creep with a mutation model.     

Research on Evaluation of the Slope Stability Based on the Extension Theory

The stability of rock-mass slopes is a very complicated system which is controlled by lots of factors. It is always a very important research subject to evaluate the slope stability reasonably through some evaluation methods. Based on matter-element theory and dependent function,the extension theory is applied to evaluate the stability of rock mass slope,and the extension method for the stability of rock mass slopes is proposed. Taking a real slope project for example,based on the reasonable selection of evaluation factors of slope stability,an extension model for evaluation of slope stability is built,whose result is contrasted with the fuzzy evaluating one. As a result, it is practical and feasible to apply the extension method to estimate the rock slope stability.     

Forecasting Method of the Slope Displacement Based on the ANFIS Model

The forecasting model of ANFIS(Adaptive Neuro-Fuzzy Inference System) is applied to forecast the displacement values at observation point of the slope at the Shilong garden of Chongqing Shizitan Hydroelectric Power Plant.The forecast results show that the errors between the forecast values and the observation values are very little.It shows that this model may be well applied for the forecast of the displacement in the deformation of the slopes.     

Numerical analysis on the evolutionary features of deformation and failure modes of slopes

The failure of slope is a gradual accumulation process. Under the effect of many interior and exterior factors, some parts in the slope reach yield with the increase of stress, and sliding surface forms gradually till complete transfixion. With continuous increase of the plastic strain, overall failure happens on the slope. Traditional analysis method cannot display the mechanic conditions and the whole process of deformation, transfixion of sliding surfaces and failure. Meanwhile, FEM strength reduction can quantitatively show the deformation features and the process of occurrence and development of sliding surface. Based on the previous researches, the paper classifies slopes according to the features of rock and soil and the slope structure. Through analyzing the graphs of deformation and the nephograms of plastic strain under different reduction factors or safety factors, the researchers can directly find the deformation tendency of slopes and the whole process of the extension, transfixion and failure of sliding surface with the reduction of safety factor. So, the failure mechanism of slope can be found intuitively, which can provide effective basis for the prevention and governance of slopes.     

Rainfall''s Effect on the Stability of Unsaturated Slopes

Aimed to analyze the influence of rainfall on slope stability. The finite element method (FEM) is used for the calculation of 2-D transient seepage in the unsaturated slope, while the method of limit equilibrium is used for computing its safety factor. The change of pore water pressure, slip surface and safety factor are investigated through numerical calculations with consideration of various intensity and duration of rainfall. Special attention has been paid to slope stability after rainfall. It is found that sometimes the minimum safety factor may occur several hours or several days after the rainfall, instead of the time during the rainfall or when the rain just stops.     

Application of Coordinate Difference Method in Safe Monitor of High Slope with Total Station Actively

The most common used method for safe monitor of high slope is to set a fixed observation point to monitor the transformation. But in urban area, due to restriction of the site and telecommunication conditions the transformation of high slope may have an impact to the fixed point and the result and the result we take from the point may be not correct. To avoid the impact and improve the accuracy, in this paper, a coordinate difference method to monitor the transformation of high slope with Total station actively is put forward and the principle, error analyses of this method are described and its application in safe monitor of high slope is introduced.     

Couple Analysis of the Slice and Gravity Increasing Methods of Slope Stability

The finite element or finite difference method and the limit equilibrium method, with their respective merits, were used to analyze soil slope stability in detail. On the basis of the slice and gravity increase methods, a fundamental principle of couple analysis, and a procedure for calculating the slope safety factor were put forward. ANSYS finite element software and finite difference software FLAC were used to determine the most dangerous sliding face and the stress-stain in slopes. The slope safety factor was determined using the slices limit equilibrium method. The calculation shows that the result obtained using couple analysis is close to the results produced using other methods in the example, and the analysis of the effects of the intensity indices is more precise. The results can provide a basis for consolidating design of the sliding slope.     

Laboratory similar model test investigation of prestressed anchor rope strengthened slope fractured rock mass

Now in the highway construction of the mountain area, fractured rock mass slope always strengthened by the anchor rope. In order to investigate the strengthen effect of the slope fractured rock mass strengthened by the prestressed anchor rope, laboratory similar model test was designed and preceded. By the self-made facilities, a new method of modeling prestressed anchor rope was used in the test. Nylon ropes and the aluminum flakes were used to model the anchor rope and discrete rock mass joints. Gypsum based mix material was used to model rock. According to the real slope engineering site circumstances, six sorts of different disposed prestressed nylon rope strengthened model specimens and the specimens without prestressed nylon rope were made by the similar theory. With the test results, the strength and deformation properties of different model specimens were investigated. Comparison to different anchor effects of the different model specimens was made. The final analysis shows that in order to make full use of the anchor rope's strengthen ability, anchor rope should be disposed perpendicularly to the fracture structure rock mass's main joint direction and should be placed in the upper or top area of the fractured rock mass slope.     

Types of Bank Slope and Its Stability form Yibin to Baihetan on Jinsha Rive

By researching the locale and studying geologic background and rock-mechanics surroundings on hyroeijectric zone of Jinsha river(Yibing-Baihetan),the authors divide bank slopes into 9 types according to structure of rock and soil and terrain,and expatiate the distributing character and stability of each bank slope types,which serves as scientific geo-accordings in forecasting and controlling of bank slope's unsteady on hyroeijectric zone of Jinsha river.     

Safety Evaluation of High cutting Slope along Highway in Mountainous Area

Slope safety stability is the bottleneck problem for the development of mountainous highway, especially high class highway in China, which results from greatness slopes along highway in mountainous area, complex geological environment and short forming age. The important degree arrangement of various indexes was carried out based on simple dependent function. And weighting system of indexes was modified with analytic hierarchy process and expert reliability. With indexes and weighting system, matter element extension model for high cutting slope along highway in mountainous area was proposed by matter element extension method. A case study was undertaken for K88+680 high cutting slopes along Wushan Wuxi road in Chongqing city based on the model. It was indicated that the safety grade is Ⅲ and the slope is instable.     

Optimized regenerative braking strategy for a medium hybrid electric vehicle cruising downhill

The regenerative braking process of hybrid electric vehicles (HEVs) cruising downhill was analyzed. Based on the charging efficiency, temperature model of battery, and efficiency model of the generator, instantaneous and global optimal control strategies were proposed, with the goal of maximum of instantaneous regenerative braking energy and total regenerative braking energy respectively. Regenerative braking energy efficiency on roads of differing slopes and slope lengths were obtained. The results show that global optimal control strategy is better than instantaneous optimal control strategy, and the steeper the slope or the longer the slope is, the more distinct the increase of regenerative braking energy efficiency with a global optimal control strategy is. The influence of battery temperature on efficiency of regenerative braking energy of HEVs was also discussed.     

Multiplex analytical method for metal three dimensional flow of heavy rail rolling by universal mill

With the monitoring data of groundwater level of some reservoir slope, the nonlinear combined model was established on the basis of establishing the time series method and speed analysis method. Upon the comparison, it was found that the precision of non linear combined model was higher than that of single model. It was an effective prediction method for groundwater level of reservoir slope and could be employed for stability prediction of reservoir slope.     

Seismic Behavior of a Slope Protected by a Soil Nailing Retaining Wall during an Earthquake

The dynamic elastic plastic finite element method was used to study the seismic performance of a slope protected by a soil nailing retaining wall. On the basis of working in parallel and interaction between loess and a flexible retaining wall, a 3 D nonlinear finite element method (ADINA) also was established. Rational earthquake excitation and damping were discussed for geological engineering. Horizontal and vertical excitations were considered simultaneously in the analyses. A model capable of simulating the nonlinear static and dynamic elastic plastic behavior of soil was used to model the soil, and a bilinear elastic plastic model having hardening behavior was used to model the soil nailing. A friction element was employed to describe the soil structure interaction behavior. Our research focused on the seismic performance of the horizontal and vertical slope deformation, soil nailing axial force, and earth pressure subjected to horizontal and vertical excitations. The results show that the seismic performance of slope protected by soil nailing is good; soil nailing axial force increases after an earthquake; permanent slope displacement occurs during an earthquake; and the peak earth pressure distribution during an earthquake is similar to the earth pressure before the earthquake. These conclusions can provide references for seismic analyses and design in soil nailing engineering.     

Mechanical Analysis of Herbaceous Plant Strengthening Slope

Since there are the root systems of herbaceous plant in the shallow layer of soil masses of slope, the shallow layer of slope becomes a compound materials made of soil masses and root system.Owing to friction action and tensile resistance action of roots, the shear strength of soil layer with root system is increased.And a comprehensive mechanical analysis of how herbaceous plants strengthen slope was carried out.Not only a mechanical model of interaction between root and soil, but also a quantitative calculation of increase of shear strength and stability coefficient of slope was put forward.As a result, the theoretical basis of herbaceous plant ecological slope protection was provided.     

Analyses on Stability of Saturated-Unsaturated Bank Slope with Revetment During Rise and Fall of River Level

The bank slope failure is closely related to the rise and fall of river level generally. In order to analysis the influence of the rise and fall of river level on Jin’an River bank slope stability in Fuzhou, the saturated-unsaturated seepage of bank slope with revetment was modelled based on the engineering geological condition of some bank of Jin’an River, and the effect of rise and fall of river induced by the DRWWOS(Drawing River Water to Wash Out Sewage) project on bank slope stability was studied. The results show the silt lying on the slope toe impedes pore water change, manifesting as in its sphere of influence river water is hard to flow into the bank when river rises, and the pore water pressure can not dissipate in time when drawdown. The faster the river rises, the more stable the bank slope becomes. On the contrary, the larger river level falling rate is more likely to leads to bank slope failure. Due to the poor bank drainage performance, the frequent rise and fall of river level results in pore water pressure increasing further, then impairing the bank slope stability. During DRWWOS project, the river level falling rate control and pore water pressure dissipation must be paid enough attention to. Also, replacing silt lying on the slope toe by good permeable material is a good choice to reinforce the bank slope.     

Experimental study of properties of slope protection through grass jetting on 3D geomat

Based on ecological slope protection models by orthogonal tests, comparative experimental study of properties of slope protection through grass jetting on 3D geomat considered types of 3D geomat, density of grass seeds, types of soil and slope gradient are conducted under different rain intensity. The results show that the sequence of sensibilities for erosion modulus is density of grass seeds, slope gradient, types of soil and 3D geomat under the condition of simulating light rain, geomat can play a remarkable role to erosion modulus under the condition of simulating rainstorm, the erosion modulus for slope protection by grass jetting 3D geomat reduces 5 times than non protection natural slope. Equivalent cohesion of soil grass geomat compound decreases with the increase of depth, and curvilinear regression between equivalent cohesion and depth is cubic polynomial expression. Permeability coefficient of surface soil tends to increase with thicker geomat and bigger density of grassroots.     

Centrifuge Tests on the Instability of Valley-Type Municipal Solid Waste Landfill

The process of valley-type solid waste landfill sliding was simulated in centrifugal model test using container rotated during the centrifuge flight In the test, the displacement of the slope was measured and analyzed. The results showed that large deformation occured in the shoulder of the slope when the front slope angle and the back slope angle reached 40 degree and 45 degree respectively at centrifuge acceleration of 40g. The overall sliding appeared when the front and back slope angels were 51.6 degree, 56.6 degree respectively, and the interface slope angle at the bottom was 11.6 degree. With the increase of rotation angle of the model, the trend of overall sliding was accelerated and there was a large deformation of landfill body as well. The deformation perpendicular to the bottom of the slope was larger than that parallel to the bottom. When the model rotated 26 degree with the front and back slope angel of 66 degree, 71 degree, respectively,the interface slope angle at the bottom was 26 degree, and the failure mode changed from sliding inside the landfill to sliding along the internal interface slopes. The process of waste body sliding along the liner interface was recreated in the test and this process supported the method of choosing liner parameters in stability analyses. Based on measured data, the deformation and destruction characteristic were analyzed, and the main influence factors in selecting the waste shear strength parameter were discussed.     

Reliability Analysis of Wedge Slopes

The material parameters and geometric parameters of wedge slopes have high variability, and there are several failure modes for a wedge slope. It is necessary to carry out system reliability analysis for wedge slopes. We consider a wedge slope as a series system which is composed of four failure modes, and we consider each failure mode as a parallel sub-system with three components. Then, the reliability analysis is carried out by using the product of conditional marginal method and bound method of system reliability analysis. A new method for the linearization of nonlinear performance function is proposed for computing the coefficient of correlation between each failure modes in the parallel sub-system. Through the reliability analysis of a wedge slope, it is illustrated that a wedge slope can be considered as a series-parallel system, and the new linearization method can simulate the failure domain accurately. The failure modes computed from the reliability analysis and the deterministic method is different. Reliability analysis method is suitable for the design and management of wedge slopes.     

Combination of GPS monitoring and ANN prediction for slope deformation

Based on the evolution pattern of slope deformation and failure, stability status of a slope is evaluated through analyzing the data of GPS monitoring. A neural network model of slope displacement time is developed based on the GPS monitoring data. It can be used to forecast slope deformation trends. A neural network displacement prediction model of slope deformation is proposed with Matlab ANN toolbox. Upon a case study, the ANN prediction results based on GPS monitoring data are analyzed.     

Upper bound solution of reliability for slope based on limit analysis method

In order to reduce errors of reliability for slope in function establishment,parameter estimation and algorithm selection,a new reliability model for slope is established based on the upper-bound theory of limit analysis. The statistical characteristics o