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2004, 23 (16): -0 doi:
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FEATURES OF LOAD-UNLOAD RESPONSE RATIO AND ITS SIGNIFICANCE IN PREDICATION OF COLLUVIAL LANDSLIDE INDUCED BY RAINFALL

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2004, 23 (16): -2665 doi:
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A systematic study is carried out on the displacement law，the dynamic process and feature of load and unload for the colluvial landslide induced by rainfall in the Three Gorges by means of load-unload response theory. Through analysis on the displacement response feature，the load-unload parameter and load-unload response parameter are determined and its prediction model is also established for this type of landslide. The calculation of load-unload response ratio of monitoring points A3 and B3 of Xintan landslide in China is completed by using the load-unload response prediction model. The computation results show that an abrupt jump occurs in the curve of load-unload response ratio of monitoring points A3 and B3 just before landslide takes place，and the abrupt jump point agrees with the destabilized time of the landslide. All results above show that the load-unload response ratio theory is a very effective nonlinear dynamic one in the short and middle-term prediction of colluvial landslides.

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MODEL TESTING STUDY ON SLOPE STABILITY UNDER ENVIRONMENT OF SURFACE WATER PERMEATION

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2004, 23 (16): -2671 doi:
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In nature，the instability of slope，which can lead to landslide，is related to the participation of groundwater，which results from water permeation. Through the theoretical and practical study，the influences of groundwater on slope can be generalized into five aspects，(1) softening of rock or soil mass and discontinuities，(2) hydrostatic pressure，(3) hydrodynamic pressure，(4) increasing of moisture content and unit weight of rock or soil mass，and (5) physical and chemical action between rock and groundwater. In order to better understand the above influences，a model test on slope stability was performed. In the test，a homogeneous slope model with soft interlayer was made. Applying similarity factors，the effect of variation of surface water permeation on homogeneous slope stability was drawn through the model test. During the test，the four models were taken into account， (1) water filled in back fissures，(2) front flood fluctuation，(3) rain-fall on slope surface，and (4) combination of above three models. At last，the relationship between water permeation and slope deformation，and the dangerous amount of water permeation in slope are obtained.

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TESTING STUDY ON LANDSLIDE OF LAYERED SLOPE INDUCED BY FLUCTUATION OF WATER LEVEL

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2004, 23 (16): -2676 doi:
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The frequent fluctuation of water level of Yangtse river will greatly influence the stability of the widely existing slopes in the Three Gorges reservoir zone，especially those layered ones. Apart from the fluctuating speed of water level，the behavior variation of geological materials will also play important roles in the failure of slopes. A new experimental setup was designed to study the behavior of a layered slope under the fluctuation of water level. The landslide pattern of a layered slope induced by fluctuation of water level is explored by means of simulating experiments. The influence of fluctuating speed of water level on the stability of layered slope is probed，especially the whole process of deformation and development of the landslide with time. The experimental results show that the slope is stable during the rising of water level，and the sliding body occurs in the upper layer of the slope under certain drawdown speed of water level. In the process of slope failure，some new small sliding body would be developed on the main sliding body，which would speedup the disassembly of the whole slope. A qualitative analysis and explanation about the phenomena occurring in such a kind of landslide are also given. As the permeability of the upper soil is very low，the gradient of out-seepage force of the pore water is very large nearing the crest of the slope. The large gradient of out-seepage force of pore water does cause the tensile cracks on the slope. Of course，the component of weight along the inclination is another unneglectable factor for the occurrence of this landslide. Furthermore，the softening effect of water on soil should be considered for a real landslide，especially for the initially non-saturated slopes. At last，the distribution of stress and displacement of the slope is calculated by using static finite element method，and the computation result is in good agreement with experimental result.

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RESEARCH ON UNLOADING DEFORMATION AND SUPPORT OF HIGH SLOPE OF THICK SOFT ROCK INTERLACED WITH HARD ROCK

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2004, 23 (16): -2681 doi:
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For the high slope of intake of diversion tunnel of Zipingpu Irrigation Project，the relationships of stress and strain are calculated by traditional mechanical methods of unloading and loading. The results on slope displacement calculated by the two methods of loading and unloading are compared，and the excavation unloading-induced deformation and corresponding support for the slope are shown in this paper.

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PROJECTION PURSUIT CLUSTER MODEL FOR SLOPE STABILITY EVALUATION

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2004, 23 (16): -2687 doi:
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The projection pursuit cluster model (PPC) is applied to study the problem of multi-factor evaluation of slope stability. Projection pursuit can project high dimensional data to low dimensional space.Through studying the main characteristics in 1-D space，the key information in the original data can be obtained，which can be used to classify or evaluate the slope stability. In addition，with application of this method，the subjectivity of safety factors can also be effectively eliminated. The results of case study show that the analysis results are completely consistent with the actual situation，so PPC model is feasible in practice，and at the same time it provides a new approach for slope stability evaluation.

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3D FEM ANALYSIS OF SLOPE STABILITY BASED ON STRENGTH REDUCTION METHOD

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2004, 23 (16): -2690 doi:
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By using the strength reduction method in the analysis on slope stability，the soil strength is reduced，so that the numerical non-convergence occurs，and the safety factor is obtained. The strength reduction method is applied to 3D analysis on slope stability in this paper. At the same time，with a case study，the result analyzed by the traditional method is compared with that by strength reduction FEM，and the results of 2D and 3D analyses are analyzed. It is indicated that strength reduction FEM is appropriate to stability analysis of slope，and 3D analysis should be used in stability analysis of slope if it is possible.

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APPLICATION OF UNIFORM DESIGN TO
GEOTECHNICAL ENGINEERING

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2004, 23 (16): -2694 doi:
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The advantage of uniform design and usage of uniform design table are introduced in this paper. The uniform design seeks experimental points to be uniformly scattered in the experimental domain. The practical success of uniform design is due to its economical and flexible experimental runs to study many factors with high levels simultaneously. Uniform design is widely accepted especially in the situations where little knowledge is known about the function to be modeled，especially for nonlinear model， and also in the field of geotechnical engineering. An example is given about displacement back-analysis problem of rockmass parameter to support the application of uniform design. At last，some suggests are pointed out about uniform designs. It is not good to decrease the number of runs of uniform designs one-sidedly and attention should be paid to the selection of key factor and its range。

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STUDY ON OPTIMUM DESIGN OF LANDSLIDE STABILIZATION BY PARALLEL EVOLUTIONARY NEURAL NETWORK METHOD

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2004, 23 (16): -2698 doi:
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[PDF 188 KB] (988)

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A new method for the optimum design of slope stabilization is presented in this paper. Firstly，the particular treatment method is determined in term of the detailed conditions of the slope. Using finite element method，combined with limit equilibrium method，the slope stability is analysed and the stresses of support structures are calculated. Upon this basis，a group of design parameters are given，and correspondingly the safety factor of the slope after reinforcement and the cost of the treatment engineering are estimated. Secondly，dozens of design parameters，safety factors and costs are given，which can be used as learning samples for neural networks. Then an evolutionary neural network model whose network structure is optimized by genetic algorithm is made to map the complex nonlinear relationship among the design parameters，safety factors and engineering costs. Thirdly，embedding the above evolutionary neural networks model into the genetic algorithm，taking the cost as fitness function and the safety factor as constraint，an optimum model is made. Thus，the design parameters can be optimized in the whole spectrums，and the most economic result is obtained. Lastly，the above process is programmed in parallel environment，and the searching efficiency and accuracy are both improved. This idea was practiced in Shizibao landslide treatment engineering of the Three Gorges Projects，and an excellent economic result was obtained.

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SENSIBILITY ANALYSIS OF SLOPE STABILITY BASED ON ARTIFICIAL NEURAL NETWORK

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2004, 23 (16): -2703 doi:
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The traditional sensibility analyses of the affecting factors for slope stability are based on plenty of trial calculation according to the variation of different parameters. These methods need not only plenty of calculation，but also complicated data preparation. A new method of the sensibility analysis of affecting factors for slope stability is proposed，using RBF artificial neural network (ANN) model according to nonlinear mapping function of ANN. Combining the perpendicularity list with theory of utility function and ANN，the assessment model is set up to achieve sensibility analysis. Compared with the results obtained by traditional limit balance analysis，the result by proposed method is of validity and convenience.

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EFFECT OF STRENGTH NONLINEARITY ON SLOPE STABILITY OF HIGH ROCKFILL DAM

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2004, 23 (16): -2708 doi:
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The results of many large scale triaxial tests indicate that the Mohr failure envelopes for rockfill exhibit significant nonlinearity particularly in low and medium stresses，which means that，in low confining pressure，the angle of internal friction is relatively high，but in high confining pressure，it is relatively low. The strength of rockfill exhibits nonlinearity and the curved failure envelope could be described by logarithmic relationship. However，conventional strength is linear with an average friction angle. A computer program is developed for the stability analysis of circular arc slope with strength nonlinearity taken in account. The comparison of safety factors of 7 high rockfill dams with nonlinear strength and linear strength indicates that safety factor of non-linear analysis is bigger than that of linear analysis. The value of nonlinear safety factor is increased with increment of 20%. The slip surface of linear analysis is shallow，but that of nonlinear analysis is deep. The allowable safety factor based on linear rule should be properly increased with increment of 8%，according to the study result of this paper.

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NUMERICAL ANALYSIS ON DEFORMATION AND STRESS OF HIGH SLOPE OF INTAKE AND INTERACTION OF DAM-SLOPE AND TUNNEL AT HUGE HYDROPOWER PROJECT

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2004, 23 (16): -2712 doi:
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[PDF 374 KB] (969)

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3D numerical simulation with nonlinear large-deformation is conducted for a high rock slope engineering with typical antidip laminate structure. A intake dam attached to high slope and four intake tunnels under the dam are simulated simultaneously，and the complicated geological factors，support measures and excavation conditions of the slope are also taken into account. The influence of excavation unloading，dam generating and reservoir filling on the deformation and stress distribution of the slope is studied with numerical model.

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DYNAMICS AND STABILITY CRITERION OF OBLIQUE LAYERED LANDSLIDE WITH PLANE ROTATION UNDER LOCKUP OF CENTRIC SEGMENT

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2004, 23 (16): -2718 doi:
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Landslide with plane rotation under lockup of centric segment is formed in the course of progressive failure of layered rocks on the oblique bank slope. It is characterized that there exists a relative locked segment on bedding plane around the center of a landslide body with bigger shear strength and torsion sliding impeded，whereas the movement of slope increases gradually from the center to the outer segment in which the layered rock mass spins around a hinge located in the center on potential bedding plane. The reason why landslide exhibits plane rotating is that resultant of forces acting on the landslide body does not traverse its center of gravity，which results in a moment of rotation. So the deformation and failure mode of landslide can be described by rotation of a circled rock slab with inner fixed part under combined loading of gravity，friction forces on potential bedding plane，shear strength in centric part，and resistance to rotating on boundary. By means of elasticity theory，the rotation stress field of the circled layered rocks is deduced. Furthermore，the triggering condition of rotating glide is studied and onset mechanism and stability criterion of landslide are established with the approach of limit equilibrium. The study result is proved to be effective in the quantitative evaluation of stability of this kind of landslide.

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ANALYTICAL CALCULATION OF SLOPE STABILITY

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2004, 23 (16): -2726 doi:
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The correct calculation formulas are established on the safety factor of slope by using analytical method. Two kinds of failure surfaces are considered in this study，planar failure surface and circular failure surface. In the case of planar failure surface，the analytical formulas are obtained for the critical slip surface and the minimum safety factor. In the case of circular failure surface，by performing minimization on the function derived，a set of algebraic equations involving two variables are obtained to determine the critical slip surface and the minimum safety factor. As an example，two alternative algebraic equations are given to determine the critical slip surface for the slope involving undrained cohesive soil with friction angle of zero. And the critical slip surfaces and the minimum safety factors are computed for some slopes.

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STABILITY ANALYSIS OF SLOPE UNDER EARTHQUAKE WITH FLAC3D

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2004, 23 (16): -2730 doi:
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The stability analysis of slope under earthquake is made with FLAC3D in this paper. The problems about boundary conditions，dynamic time series，and rational damping for geological body are discussed. The study result shows that certain permanent displacement would occur in the potential slide mass of the slope under earthquake，and this must be taken into serious consideration in practical engineering.

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MONITORING AND DESIGN OPTIMIZATION OF SOIL-NAILING SUPPORT FOR HIGH WEAK ROCK SLOPE

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2004, 23 (16): -2734 doi:
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An example of soil-nailing support is introduced for a high weak rock slope and the information from construction monitoring is analyzed based on the principle of soil-nailing support. Based on the construction monitoring，the most dangerous failure surface of high weak rock slope is provided. The slope is designed and analyzed by theory of limit equilibrium. The support parameters are adjusted and the construction period is shorted in time. The sidewall deformation is controlled at every construction stage and the whole slope stability is ensured.

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TESTING STUDY ON EFFECT OF EROSION ON SLOPE OF MUNICIPAL SOLID WASTE

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2004, 23 (16): -2739 doi:
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[PDF 186 KB] (857)

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The artifical rainfall modeling test in lab and stability analysis of slope are made on the effect of erosion on slope of municipal solid waste in the situation with and without vegetation. The law of rainfall erosion to the slope surface of municipal solid waste is studied under three kinds of rain intensity，40，60 and 100 mm/h. The results show that the erosion intensity to slope surface rises along with the rain intensity. But the vegetation decreases the erosion intensity and increases the stability of slope. The erosion module is decreased to zero after two months of vegetation，and the phenomenon of slope surface erosion disappears then.

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TESTING STUDY ON STRENGTH REDUCTION OF GRAVELLY SOIL IN TRIGGERING AREA OF DEBRIS FLOW UNDER EARTHQUAKE

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2004, 23 (16): -2743 doi:
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There is widely distributed gravelly soil in triggering area of debris flow. From the observation，analysis and calculation，it is found that triggering of debris flow results from soil strength reduction. In fact，debris flow areas are often located in earthquake belt. The distribution relation between debris flow and earthquake makes us to suggest that earthquake lead to the strength reduction of gravelly soil and make triggering of debris flow. On the basis of the suggestion，triaxial shear equipment is used to make testing study for the gravelly soil in the triggering area of debris flow. The variables are water content，soil depth or confining pressure，the destroy criterion and earthquake intensity or vibration times. The cohesion and friction are chosen to measure the strength of soil. As a result，it is found that the cohesion increases first and then drops with the increment of water content，and the max value appears when the saturation degree gets up to 84%. With the increment of vibration times the cohesion decreases. For the sample with high water content，the cohesion can drop to zero with enough vibration times. As usual the friction angle decreases with increment of water content and can drop to zero only for the nearly saturated sample. The friction angle always decreases slightly with increment of vibration time. The friction angle changes with vibration times unstably. When the vibration times are lower than 20 and earthquake intensity is under 7.5 grade，the friction angle decreases slightly with the increment of vibration times，but when the vibration times are higher than 20，the friction angle of low saturated sample increases. For the high saturated sample when the vibration times arrive 50 times，the friction angle drops to zero. For the nearly saturated sample with saturated degree of 92%，the friction angle increases or decreases unstably，which is dependent on the other factors. In conclusion，the tests show that earthquake may reduce the soil strength and under some special cases it may leads soil to be liquefied. Therefore earthquake makes an important role in triggering of debris flow.

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TESTING STUDY ON APPLICATIONS OF TIME DOMAIN REFLECTOMETRY TO SLOPE MONITORING

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2004, 23 (16): -2748 doi:
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The principles of time domain reflectometry(TDR) and the properties of electromagnetic wave propagation in coaxial cable are described for the applications of TDR technology to slope monitoring. Based on the shearing tests of three types of coaxial cables，the influences of shear deformation of coaxial cable on TDR signal are studied，and the relationship between reflection coefficient and shear displacement of different types of coaxial cables are summarized. Through experiments on grouted cable assemblies，TDR properties of coaxial cables under different test conditions are investigated and some valuable conclusions are proposed for practical application.

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ANALYSIS ON PRESTRESS STATE OF CABLE APPLIED TO ROCK SLOPE REINFORCEMENT

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2004, 23 (16): -2756 doi:
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Although cable is widely used in slope engineering，the prestress change rules in cable are not studied thoroughly and systematically yet，especial the prestress loss after lock and the lasting prestress of cable in cracked rock slopes. Based on the systematical monitoring and analysis in a slope reinforcement project，the prestress loss after lock，short-term and long-term prestess change rules are studied，and also the influence of rainfall on the cable prestress state is monitored and discussed. It is found that the prestress loss after lock is largely based upon the shrink of the cable after lock，which is affected by friction to some degree. The short-term and long-term prestress loss is nonlinear，and the prestress loss can be divided into three stages. The influence of rain on the prestress loss should be considered. If the slope is not stable，the rain can affect the stabilization of the slope and then affect the prestress state of cable，otherwise，it has no influence on the prestress state.

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REINFORCEMENT OF SURROUNDING ROCKS OF TUNNEL IN LANDSLIDE AREA WITH GROUTING TECHNOLOGY

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2004, 23 (16): -2761 doi:
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The double railway lines are being constructed in centro-west China. Because of the geography condition，many tunnels have to go through landslide areas. If the new tunnel is put in the landslide area，collapse and cave-in will take place during tunneling. More serious outcomes are that the interval between the existing tunnel and new one is very small，so that it is very easy to cause the existing tunnel in soft rocks to deform and fail. This case occurs several times in the centro-west railroad of China. Case study of grouting for the surrounding rocks of tunnel in the landslide area is made，including design，implementation and back-check of grouting effect. The reason of deformation of existing tunnel is analyzed with numerical method，and the grouting method under the special condition is discussed.

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HUMAN-INDUCED LANDSLIDES IN CHINA：MECHANISM STUDY AND ITS IMPLICATIONS ON SLOPE MANAGEMENT*

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2004, 23 (16): -2766 doi:
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Human activity duo to rapid increasing of the economy in China has become so wide and intense since 1980s that it comes to the most active factor affecting the earth¢ surface geomorphology process and provoke the most important impact to environment in recent two decades. Some typical human-induced landslides are introduced. Their general features，including distribution，types，time series of occurrence and mechanism are summarized. A classification system of landslides is suggested based on their geological backgrounds and formation mechanism. Finally，some aspects of slope management and human activity control are discussed to different types of landslides.

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SOME PROBLEMS ON CHEMICAL WATER-ROCK INTERACTION
IN SLOPES

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2004, 23 (16): -2778 doi:
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In humid-tropical and landslide-prone regions，chemical water-rock interaction (CWRI) takes place in various slopes made up of different bedrocks. CWRI can give rise to the progressive aggravation of different initial damages in slopes and the structure，and the mechanical and hydraulic characteristics of mineral，rock and rockmass will all change with CWRI progress. Under many cases，CWRI is the important basis for rainfall or earthquake to trigger landslide events. Despite some attention received and preliminary improvements，the fundamental mechanisms of CWRI have yet to be established. A thorough understanding of CWRI will contribute to landslide mitigation and prediction. The problems necessary to study further include CWRI space，mechanism of water supplying and chemical-mineral relation of CWRI process，the transport theories of water and aqueous matter in low permeable rock，CWRI space spreading，the contribution to landslide preparation process，and so on.

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SOLUTION OF SLOPE SAFETY FACTOR BY MODIFYING NORMAL STRESSES OVER SLIP SURFACE

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2004, 23 (16): -2788 doi:
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An initial assumption is made on normal stress distribution along the slip surface，which is subsequently modified with a function involving two parameters to be determined to satisfy equilibrium conditions of all the forces and moments for the whole sliding body，and the formula of the slope safety factor is then derived. This method enjoys merits of straightforward computation process, no need of iteration, accommodating arbitrary shape of slip surfaces and the solutions being within the context of rigorous limit equilibrium.

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ENGINEERING GEOLOGY ANALYSIS ON STABILITY OF SLOPE
UNDER EARTHAUAKE

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2004, 23 (16): -2792 doi:
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The factors influencing stability of slope under earthquake are summarized according to characteristics of seismic force. The slopes are classified into two groups and seven subgroups，and their possible failure modes under dynamic force are analyzed. At the same time，the mechanism of earthquake-induced slope instability is discussed. It is concluded that seismic inertia force and building up of excess-static pore pressure are two reasons to induce instability of slope. For different slopes，the predominant factor inducing failure will be different. Plastic flow failure is mainly induced by building up of excess-static pore pressure. Rock fall and toppling failure are mainly caused by seismic inertia force. Slide failure is induced by building up of excess-static pore pressure combined with seismic inertia force in general.

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STUDY ON VERTICAL VIBRATION OF VISCOELASTIC PILE WITH VARIABLE SECTIONS IN LAYERED SOILS

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2004, 23 (16): -2798 doi:
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In order to reasonably interpret pile integrity test，the model of viscoelastic pile with variable sections in layered soils is established. When the pile is subjected to exciting force at its top，the viscoelastic supporting at its tip is taken into account . By means of Laplace transform and matrix theory，the semi-analytical solution of pile-soil systerm is derived. Further，with the help of the convolution theorem and inverse Fourier transform，a semi-analytical solution on the velocity response of pile top to semi-sine impulse exciting is obtained. Later，by numerical methods，the influences of layered soils and pile parameters on velocity response of pile top are simulated，and several significant conclusions for pile integrity test are drawn.

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SLOPE VEGETATION AND ITS APPLICATION IN HONG KONG

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2004, 23 (16): -2804 doi:
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Vegetation on slopes not only serves as landscape function but also aids erosion control and slope stability. Vegetation should be considered as the primary protection method for all man-made slopes of soil and weathered rock. The basic principles and composite effects of vegetation slope are summarized in this paper. All aspects of the slope vegetation technology in Hong Kong，including the principles，design，opportunities，implementation and maintenance of planting，are introduced in detail. According to the experiences in Hong Kong and the situations of the mainland of China，some opinions and suggestions on slope vegetation are proposed.

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STUDY ON REMEDY ENGINEERING OF K28 LANDSLIDE OF
CHENGDU—NANCHONG HIGHWAY

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2004, 23 (16): -2811 doi:
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[PDF 431 KB] (1002)

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K28 area of Chengdu—Nanchong highway is locaded in the landslide section，where the rockmass behaves like fragmentation with low strength and more ground surface water. The construction of the roadbed encountered difficulties resulting from the bad condition. The reason of landslide formation is analyzed，and the comprehensive remedy techniques for landslide control are put forward，which include drainage of surface water，anti-slide piles，anti-slide walls，and bio-engineering for improving the slope stability. The landslide is well controlled after reinforcement with these remedy techniques.

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STUDY ON MECHANISM OF SLOPE REINFORCEMENT

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2004, 23 (16): -2818 doi:
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The stress transfer depth of the prestressed cable，the concept of free section，safety factor of cut slope，the so-called rock crust created by cluster anchoring and supplemental tensioning in slope reinforcement are discussed based on experiences of design，examination and construction of near twenty cases. The slope excavation method with deformation control is introduced，whose main factors include safety monitoring，advance support，cutting in layers and sections，timely slope surface support，intensified slope toe support and management of construction technique. The stress in grout stem in borehole is emphatically analyzed，and this issue is reduced to the problem of stabilization of compressed rod. The new structure of prestressed anchor beam is proposed to increase the bearing capacity of prestressed cable.

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OPTIMAL DESIGN SYSTEM OF SLOPE SUPPORT BASED ON COMPONENT GEOGRAPHIC INFORMATION SYSTEM

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2004, 23 (16): -2824 doi:
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In order to study highway slope stability and support design in mountainous terrain，firstly the general limit equilibrium method(GLE) and stability analysis method for reinforced slope are explained，and a slope support optimal design system (SSODS) based on component geographic information system (ComGIS)is developed. Then，the main features of SSODS are introduced，which are macroscopical appraisal of slope stability，computation of slope stability，design of reinforced slope，map display ，spatial query and analysis capacity，output and print. Finally，several typical examples are put forward for comparing SSODS with commercial software，SLOPE/W(Alberta Canada，GEO-SLOPE International Ltd) and slide(Toronto Canada，Rocscience Inc). The results prove that SSODS is accurate and credible. Besides，SSODS is also successfully used in the real engineering project.

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DEVELOPMENT OF SOFTWARE ZSLOPE FOR SLOPE
STABILITY ANALYSIS

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2004, 23 (16): -2830 doi:
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Simplicity is the important principle for software development. Based on the idea of simplicity and creativity，the software named ZSlope was developed by author for slope stability analysis，which is made up of pre-processor，post-processor，and solver. By the routine stability analysis for slope adopted by ZSlope，some conclusions can be reached. (1) The results of critical slide surface obtained by using golden section methods or conventional optimization methods are often lack of credibility，for they are apt to fall into local limit，while the method of exhaustion can overcome the shortcoming to some degree. (2) There is not a single slide surface corresponding to a certain safe factor，but a cluster of slide surfaces which forms a slide strip with width.

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CLASSIFICATION UNIFICATION OF CALCULATION FORMULATION FOR SAFETY FACTOR OF SLOPE STABILITY

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2004, 23 (16): -2836 doi:
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The currently used 13 limit equilibrium methods of slices are classified into four types based on the equilibrium conditions. These are type M with only considering moment equilibrium condition about specified center，type VM with considering vertical force equilibrium condition and moment equilibrium condition about specified center，type HV with considering both horizontal and vertical force equilibrium condition，and type HVM with considering horizontal and vertical force equilibrium condition as well as moment equilibrium condition about specified center. Type M, Sweden method，has explicit solution. Type VM, simplified Bishop method, has inexplicit expression for the safety factor whose iteration is not difficult. For the first time，the assumptions regarding the inter-slice force associated with the existing limit equilibrium methods of slices are expressed in the unified formulation. The simple and clear recurrent equations of the inter-slice forces and inter-slice moments are derived based on force equilibrium and moment equilibrium. The unified calculation formulation for the safety factor based on force equilibrium (type HV) in the context of conventional methods of slices is developed based on the recurrent equation of the inter-slice forces which keeps the equilibrium conditions and the assumptions regarding the inter-slice force and unknowns. Based on the recurrent equations of the inter-slice forces and inter-slice moments，the unified calculation formulation for the safety factor based on rigorous equilibrium (type HVM) in the context of conventional methods of slices is developed by Newton-Raphson method. Unified calculation formulation facilitates the development of programming and the comparison among the advantages and disadvantages of different methods.

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MATHEMATICAL MODELS OF FLOW-DEFORMATION COUPLING FOR POROUS MEDIA

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2004, 23 (16): -2842 doi:
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NUMERICAL MODEL OF ELASTPLASTIC ANISOTROPIC DAMAGE FOR FAILURE PROCESS OF CONCRETE AND GEO-MATERIALS AND ITS APPLICATIONS

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2004, 23 (16): -2843 doi:
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[PDF 99 KB] (907)

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