Stability Analysis on Excavated High Slope of Mozong River Power Station in Wulong

The subject matter of this paper is to analyze the stability of excavated high slope. On the base of typical engineering case in Wulong, Chongqing, the geological conditions and potential failure pattern of the high slope are discussed. Then, the limit equilibrium method and the stereographic projection method are used to synthetically analyze the stability of excavated high slope. As a result, it indicates that the stability of the high slope in insufficient and some retaining structures ought to be adopted for the high slope as soon as possible.     

Analysis on the Quasi Monte-Carlo Method and its Application in the Slope Reliability

The critical reliability slip surface with minimum value of reliability index is difficult to be obtained by the Monte-Carlo method. The simplified Bishop method was adopted to calculate the factor of safety for given circular slip surface thereby defining the performance function in reliability analysis. Six variance values of random variables were designed and four sample ranges were assumed. A quasi-Monte Carlo method was defined with fow samples. One hundred and thirty-two potential slip surfaces were randomly generated. The reliability indexes regarding those slip surfaces were calculated by Monte-Carlo method and quasi-Monte Carlo method, respectively. The comparative results show that in the case of one random variable, the reliability index from Monte Carlo method is found to be linear with that from quasi-Monte Carlo method. In the similar conditions, the wider the sample range, the smaller the tangent value of line, and Vice versa. In addition, the bigger the sample number, the bigger the tangent value of line. The Quasi-Monte Carlo method is approved to be practicable for the determination of critical reliability slip surface for homogeneous slope.     

Improved General Limit Equilibrium Method for Slope Stability Analysis

Based on the theory of ultimate equilibrium, an improved General Limit Equilibrium method (IGLE) is studied, and it is implemented in Rslope software. IGLE can simulate various limit equilibrium methods and takes into account external factors(water、tensile crack、external load) and reinforcing measures(anchor、anchor-cable、geotextile、soil nail). Imbalance thrust force method is simulated in this study, and analysis on precisions of safety coefficient and residual pushing force under two conditions of imbalance thrust force which are strength reserve method and overload method respectively by using IGLE is conducted. The study also promotes an effective usage recommendation. Aiming at the problem that engineer is easy to confuse residual pushing force with inter-slice force, comparative analysis on horizontal components of inter-slice force and residual pushing force is conducted. The results show that there is no direct correlation between them. Then the results of calculation examples of Rslope are compared with other commercial soft wares, such as slide, SLOPE/W. Specifically,the comparison includes automatically searched safety factor of circular slip surface, safety factor of sliding surface and safety factor of reinforcement. The results have a good consistency. IGLE is of practical significance for real applications.     

Horizontal Slice Method for the Stability Analysis of Reinforced Slopes

Relevant national codes usually require the transmitting coefficient method to be employed for the stability analysis of slope reinforcement, in which sliding mass is usually divided into a number of vertical slices.For some support technologies, such as rock bolting and anchor cable, the intersections between the slices and the anchor bar, and the forces mobilized in the reinforcements are different from the assumptions in this method.Thus the transmitting coefficient method confronts some difficulties during practical applications, which would influence the project quality of reinforcements.A new Horizontal Slice Method was proposed based on the overseas relevant literatures to overcome these difficulties in the stability analysis of rock bolting and anchor cable slopes.     

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.     

Finite Element Reliability Analysis of the Stability of a Slope

The whole reliability index of a slope is derived through using the strength reduction method in the finite element analysis, which can make use of the former finite element program and can be used to both linear and nonlinear finite element analysis. The affection of the evaluation of derivative and the selection of reliability analysis methods is discussed, which shows that it is very important to select the type of limit state function of the slope stability. A new iterafive formula, which can consider the correlation of fundamental parameters, is proposed for FORM, and the convergence is very well.     

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.     

农业灌溉作用下黄土边坡失稳引起耕地流失分析

为了明确在大面积农业灌溉作用下,水分入渗土壤进而渗入下部黄土体,改变临空耕地黄土边坡的稳定性状态,造成边坡失稳引起耕地流失的过程。在统计分析甘肃天水耕地流失面积、农田灌溉面积、地质灾害数量和由地质灾害造成耕地流失比例的基础上,在典型地层剖面上采集原状土壤和黄土试样,进行天然状态和灌溉作用下土体的物理力学性质和抗剪强度试验,采用理正岩土边坡稳定性分析系统,利用基于极限平衡条分法的瑞典法进行边坡稳定性定量分析。结果表明：在天然状态下,该边坡稳定性系数为1.074,处于基本稳定状态;而在灌溉作用下,随着水分入渗深度的增加,稳定性系数逐步降低,最后失稳。因农田灌溉仅使土壤层饱和,对该边坡稳定性影响不大;当灌溉水持续入渗使饱和层土体厚度大于2 m时,该边坡稳定性降低一个等级,处欠稳定状态;当饱和层厚度大于10 m时,该边坡失稳,发生滑坡,造成耕地流失。     

Dynamic Influence of Sustained Small Rainfall Infiltration on Stability of Unsaturated Soil Slope

Taking the moisture content as main control parameter of shear strength of the soil, we analyze the variational properties of moisture content and shear strength with the change of rainfall time during the small sustained rainfall infiltration, and establish the relationships between total cohesion as well as effective angle of friction and the time of sustained small rainfall infiltration into an unsaturated slope. With the rainfall infiltration, the influence area of slope expands. Through the strength reduction method based on FLAC3D, the dynamic safety factor of slope in different time and the duration time before the failure of the slope are obtained. The results show that the slope critical sliding surface is yet unsaturated during a sustained small rainfall.     

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.     

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.     

牛病毒性腹泻病毒检测方法的研究进展

为了快速准确地诊断出牛病毒性腹泻病毒,减少养牛业的经济损失。文章综述了近年来检测牛病毒性腹泻病毒的方法,总结出这些方法的优缺点。结果表明：根据养殖户对该病毒快速准确诊断的实际需要,展望了一种新的检测牛病毒性腹泻病毒的方法--免疫胶体金试纸条法。表明免疫胶体金试纸条法完善了牛病毒性腹泻病毒的检测方法,有助于在现场快速诊断该病毒。     

Study on Analysis Methods for Rock Slope FoundationStability of the Highrise Building

Based on the practical project a study on analysis methods for rock slope foundation stability of highrise-building project criterion transfer coefficient method, rotation limit equilibrium method (Sweden slices method) and finite element method was carried out.The authors found that safety factor of criterion transfer coefficient method is larger than that of rotation limit equilibrium method, but is similar to the results of finite element method. So, when rockslope foundation stability of highrise building is to be analysed,the rotation limit equilibrium method is suggested to use.     

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.     

Simulation Analysis on the Tractive Characteristics of Wheels in the Sands

A wheeled vehicle to be fitted with common rubber - tire do not adapt to the desert area because of the wheel slip sinkage. It is important for improving the mobility of vehicle in sand to develop a new running gear of vehicles . Based on the mathematical models and mechanical models for interaction effect between wheel and sand. the influence on the interaction effect between running gear of vehicles and sand on traction performance are analyzed by using the theory of granular limit equilibrium. The results show that the interaction modes between wheel and sand is charged and the mobility of vehicle in sand is improrld.     

食品中丙烯酰胺问题及其分析方法研究进展

自从食品中发现一种潜在的致癌物质——丙烯酰胺后,世界各国的科学家进行了广泛深入的研究,食品中丙烯酰胺的分析方法、形成机理、减少措施、暴露研究及风险评估等方面的科研均有所进展。本文就丙烯酰胺的性质、丙烯酰胺在食品中的分布及其分析方法进行了综述,提出今后丙烯酰胺的深入研究方向。