A cusp catastrophe model study of destabilization of soft sandwich rock slope

A slope geomechanical model was proposed based on the destabilization characteristics of soft sandwich rock slopes. Based on an analysis of the effects of internal external factors on slope stability, the cusp catastrophe model of slopes can be employed to analyze and predict the necessary conditions leading to slope catastrophes. During the processing of the mass and energy exchange with the external, this may lead to the change of controlling variables. Slides or quick or slow creeping thus may take place due to environmental complexity. This work helps deepen understanding of the formation of landslides and makes feasible the applcation of the catastrophe model to slope destabilization investigations.     

An Catastrophe Model of the Stock's Inherent Value

An catastrophe model of stock to analysize inherent value of stock is established. Using the model, the investors can easily choose high quality stocks, and reduce risk. In addition, a example is provided.     

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.     

Study on CAD System of Slope Pile-Anchor Retaining Structure

The process of designing the common slope pile-anchor retaining structure in Chongqing is analyzed, the finite element method is applied to calculate the force of the structure and design the anchor bar, pile and holding sheet. The CAD system is developed including fore-process, post-process, calculation of the structure and drawing by computer in order to make the designing of slope pile-anchor retaining structure more quickly, more economical and convenient. It has been applied in practice of the slope engineering with a good result.     

基于突变级数法的长汀水土保持综合效益评价

采用突变级数法,从生态效益、经济效益及社会效益3 个方面构建11 项指标,对长汀县（1999—2011 年）水土保持治理综合效益进行了定量评估和动态趋势分析。研究结果表明：1999 年后长汀县水土保持治理综合效益显著,各项效益值随时间呈上升趋势,单效益突变隶属函数值服从生态效益＞经济效益＞社会效益,效益增幅随时间呈降低趋势,2008 年后发展平稳,生态经济社会效益趋向协调发展态势;研究结果与实际相吻合,说明运用突变级数法评价长汀水土保持综合效益,客观合理、科学可行,该方法可为其他区域的水土保持效益评价提供新思路。     

北京松山自然保护区天然油松林土壤养分与坡位关系的研究

为了阐明坡位对天然油松林地土壤养分状况的影响,并为华北地区天然油松林地的抚育管理提供科学依据,以北京市松山自然保护区内的健康天然油松林地的土壤为研究对象,对样地内上、中、下3个坡位的土壤主要养分含量进行分析测定,探讨林地内土壤主要养分含量与坡位的关系。结果表明：（1）土壤养分主要在下坡位汇集,各坡位油松林土壤全氮含量和速效钾含量：上坡位>中坡位,而有效磷含量为：中坡位>上坡位。（2）各养分元素主要集中于土壤表层,基本随土层深度的加深而降低;土壤全氮和有效磷含量分别在下坡位和中坡位出现了随土层深度加深而先降低后升高的趋势;（3）土壤速效钾含量在0~20 cm土层深度表现为中坡位出现最低值,而在20~60 cm土层深度表现为中坡位出现最高值。     

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.     

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.     

Discussion on Methods for Determining Cracking Angle of Rock Slope

Many mountainous cities are facing slope problems during project construction. At present, there are two methods to determine cracking angle for rock slope, namely, the method from "Technical Specification for Retaining Structure in Excavation" and the method from "Handbook of Engineering Geology". However, there is obvious difference between cracking angles of rock slope by these two methods. In this paper, the theoretical formulas of these two methods are derived and compared. Based on analyzing the results of FLAC numerical simulation for soft rock slope, it is concluded that the cracking angles of rock slope determined by the "Handbook of Engineering Geology" are more reasonable and safe.     

不同坡位米老排人工林生长量与生物量的研究

为了阐明坡位对米老排人工林生长量及生物量的影响,采用相对生长法分3个坡位对广西大青山28年生米老排人工林生长量及生物量进行研究。结果表明：坡位对米老排人工胸径和树高生长量影响显著,且呈现出下坡位>中坡位>上坡位的规律;人工林群落及各组分生物量和乔木各器官生物量均受坡位的影响,且差异显著,下坡位生物量最高,中坡位居次,上坡位最低。     

Study of Optimization Design of the Excavation and Support of the Zhuziba Material-Yard Slope

Taking Zhuziba material-yard slope as an example,it use FLAC 3D to dynamically simulate the excavation process. Numerical calculation is carried out and strength reduction method is used to identify the plastic zone and the potential sliding surface. Sensitivity analysis is carried out to determine the influence on the the values of c and φ of the monitoring points on displacement. And combined with the measured displacements of the point, back analysis is carried out to determine the mechanical parameter of the potential slip surface. Based on analyzing the effect of anchorage on the anchoring method, 2 excavation - supporting schemes are designed. The results show that it can be accepted to identify the potential sliding surface by using strength reduction method, because the result is similar to what is drawn by using stereographic projection. The displacement of monitor point is linear to φ. The influence of φ(c) is similar on displacement at same c(φ).It also can be accepted to determine the best interval of anchor and length of anchoring section of double anchor by using numerical calculation to make the most considerable use of building materials.     

Influence of Soft Soil Layer on Dynamic Characteristic of the Slope

The dynamic finite element method is used to analyzes the influence on dynamic characteristic of the slope by soft soil layer. The parameters which influencing the earthquake response of the slope, including the depth, the thickness, the obliquity of soft soil layer are analyzed. The influence of soft soil layer is obvious, which must be thought over in the analysis of slope stability. The thicker the soft soil layer is, the more obvious the filter and the amplitude effect is. The deeper the soft soil layer is, the more obvious the filter effect is. The filter effect of the obliquity of the soft soil layer to dynamic time history is not obvious.     

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.     

坡度对云南红壤径流中磷素浓度的影响研究

水体富营养化的发生与农田土壤中磷的淋失有密切的关系。采用模拟降雨试验研究了土壤坡度对地表径流和亚地表径流中磷素浓度的影响。结果表明：在0°—10°范围内,地表径流中总磷、水溶性磷和颗粒态磷浓度和亚地表径流中水溶性磷浓度都随土壤坡度的增加而增加。亚地表径流中总磷和颗粒态磷在坡度为15°时均有一定程度的下降,其下降机理将做下一步分析研究。     

Experimental Study Creep Characteristics on Creep and Cyclic of Saturated Soft Clay

Several long term creep and cyclic creep tests of Shanghai soft clay are performed in the laboratory. Test results have been obtained under various combinations of confining stresses, deviation static stress ratios and deviation cyclic stress ratios. The results reveal that the axial creep strain increases with the increase of deviation static stress ratio under a constant confining stress, while it also increases with the increase of confining stress under a constant deviation stress ratio. Such a phenomenon is similar to that from the cyclic creep tests, but the following creep strain increase will be significantly reduced after a period of cyclic loading. The results will benefit the expressway, railroad and underground constructions.     

Shaking Table Test on Soil Slope Seismic Damage Failure Mechanism

The digital image displacement measurement technology and finite element data smooth were applied in the soil slope shaking table test. The displacement field and strain field were obtained from the whole vibration process. And the seismic failure mode and failure mechanism were discussed as well. The results show the deformation of soil slope increases gradually; there is shear failure from slope middle to toe and tension-shear failure at the top of slope; there forms deep arc-shaped slip surface when the slope model fails. The generalized curvature of displacement time-hisrory curve is used to judge whether the slope seismic failure is feasible.     

Numerical Study on the Thermal-Mechanical Stability ofQinghai-Tibet Railway Embankment in Permafrost Regions

According to some basic theories of physics of frozen soil, heat transfer, frozen soil mechanics and frozen soil rheology, a mathematical model for moisture, heat and stress analysis of frozen embankment is established, in which the moisture and heat field are interacted with each other, the mechanical properties of frozen soil is decided by soil temperature and a in-situ test creep equation of frozen soil is also introduced. Meanwhile, its finite element program is written. Then, an experimental section of Qinghai-Tibet is taken as example, and the thermal-mechanical stability of the embankment is studied in detail. Through comparing with observational data, it is found that, the proposed analytical model is correct and reasonable, and it can well describe and predict the long-term stability of the embankment of Qinghai-Tibet railway.