The Catastrophic Theory Model of Instability of Coal and Rock Mass

In this paper,the stability problems of coal and rock mass exerted by horizontaland vertical forces are studied with the help of the method of catastrophic theory. The expression ofthe total potential energy function for this system is derived. This system can be described by thecusp catastrophe model. The bifurcation set which makes this system to loss its stability in the hori-zontal and vertical force control space is obtained. At the same time ,the process of Sudden statechange of coal and rock due to the changes of horizontal and vertical forces is discussed.     

Nonlinear Creep Damage Model of Water Bearing Carbonaceous Slate and Its Application

Triaxial compression rheological experiments on carbonaceous slate specimens of deep buried tunnel were carried out on the rock rheology testing machine. Along with the increase of loading stress level and the improvement of moisture conditions, the initial attenuation creep phase, the stabilization creep phase, and the speedup creep phase were produced. By connecting Burgers model and the nonlinear viscoplastic body consisted of nonlinear viscous component η(n,t) parallel connected with the plastic component in series, the improved model could describe the speedup creep phase. Using this model to fit and analyze the rheological parameters of different moisture conditions, it is shown that η〖KG0.005mm〗 M、E M、E K and η〖KG0.005mm〗 Kwill decrease with negative exponential trend. Then water damage D(w) was introduced, and through deriving damage evolution equation, the nonlinear viscoelasticplastic model with water damage effect was established. Finally, the time effect deformation of surrounding rock under different times and different moisture conditions was studied by numerical simulation, and the results show that primary support should close in 168 h, and the best construction time for secondary lining is 360 h after the primary support is closed.     

Study on Seepage Model of Rock Mass in Baodingshan Grotto Area of Dazu County

Based on the analysis of hydrogeological condition, and hydraulic characteristics and hydraulic relation in rock mass,the seepage of rock mass in carved stone area has been generalized and its mathematics models established. By numerical simulating,correctness of Seepage models of rock mass have been proved.     

Damage Model of Rock and the Damage Energy Index of Rockburst

Based on research of brittle rock mechanical experiment, damage model was established by damage mechanics theory. Furthermore, interior energy transformation of rock is analyzed from the point of view of damage mechanics. By analyzing the energy transformation of rock burst, the new conception of damage energy index of rock burst is put forward. The condition of rock burst is also established.     

Reflected Wave Isotraveling Time Circle and Its Application in Inverting Jointed Rock Masses

Joints are crucial factors in rock masses engineering,so using stress waves to invert joint attitude is a valuable practice.The stress wave emitted from a vibration source is reflected by joints and returns to the ground.A formula to calculate the reflected wave travel time was deduced using analytic geometry theory.In the formula,a direct relationship was established between a joint's real dip angle,real dip direction and the travel time at test spots on the ground.The reflected wave's isotravel time circle described by the formula has a clear conception and a definite meaning.Using the program on the MATLAB platform,this formula can be applied to invert the joint attitude by searching the center of the circle based on the measured travel time at the testing spots around the wave source.     

An Attribute Mathematical Model and Its Application in Predicting and Classifying Rockbursts

Based on attribute mathematical theory, an attribute recognition model to predict and classify rockbursts was established. Firstly, the main factors of rockburst, such as the maximum tangential stress of cavern walls σθ, uniaxial compressive strength σc, uniaxial tensile strength σt, and the elastic energy index of rockWet, were chosen for the analysis; and three factors, includingσθ/σc,σc/σt andWet, were chosen as the criterion indices for rockburst prediction in the proposed model. Secondly, attribute measurement functions were constructed to compute the attribute measurement of a single index. Thirdly, the index weight was determined by similar weights defined by similar figures. Finally, the possibility and classification of rockburst were recognized by the confidence criterion. A series of underground rock projects were assessed with the proposed model and method to verify the proposed model. The study indicates that the synthetic assessment results agree well with the practical records, and are coherent to those of the fuzzy synthetic evaluation model and the matter-elements model. Moreover, the proposed model was used to predict rockbursts of a hydropower station and Qinling Tunnel. The results are coherent to those of the synthetic evaluation method, such as artificial neural network and distance discriminant analysis method, and others. The research indicates that an attribute recognition model can predict and classify rockbursts in engineering projects deep underground and provides a new method in practice.     

Research of Failure Model and Life Prediction On Heater Tubes

An experimental research on the Alkylbenzene heater tubes material which has been operated for about 100 thousand hours is carried out. In addition, the corrosion product of heater tube has been examined by using an electronic probe and probe into the corrosion Mechanism of heater tubes. Based on the fault tree analysis on the heater tubes by using the FTA technology, the paper finds the main factors affecting the failure of the heater tubes, discusses the failure model of the heater tubes, put forward the mathematical mode of life prediction and failure model of the heater tubes.     

Factors of Bearing Capacity for Rock Foundation Based on the Nonlinear Failure Criterion

Bearing capacity of foundation is conventionally calculated based on the linear Mohr–Coulomb failure criterion. However, a amount of experimental data shows that the strength envelops of almost all types of rocks are nonlinear over the wide range of normal stresses. The strength envelope of rock masses is considered to follow a modified Hoek Brown nonlinear failure criterion. Therefore, according to the upper bound approach, based on Hoek Brown nonlinear failure criterion and a multi tangential technique method, the relevant programs were developed by means of the software Matlab and the sequential quadratic programming optimization theory. And the calculation and the analysis of affecting factors bearing capacity for rock foundation were employed. It is found that the major factors affecting bearing capacity of rock foundation are GSI and mi, but the weight of foundation ,overload and the disturbance coefficient of excavation D have a considerable influence on bearing capacity of rock foundation when the value of GSI is small . Compared with the generalized tangential and the finite element or finite difference numerical techniques, the single tangential technique method would bring relatively great risk, because the calculation results are larger than those of the actual bearing capacity of foundation.     

Study and Progress of Water Quality Model and Its Application

In the last decade, with the development of environmental science, the studies on water quality models have developed rapidly at home and abroad. The water quality models are mainly used for simulating, assessing and predicting water quality and expounding the transport and transformation of pollutants in aquatic environment, the common models in literature such as fugacity approach, transport model of pollutants in multimedia environment, pollutant exposure model, and water quality management model and so on are discussed. The current situation, history and future trend of the research on aquatic environmental model are summarized. The theories, methodology and application problems which are involved with in this field are analyzed. Several leading objects for study are advanced also in this paper.     

Methods of Rock Crack Density Determination and Their Application

By the methods of micro damage theory, the relations of rock mass parameters and rock parameters in experiments were obtained; it is considered that to make the micro damage theory for determining the rock parameters possible only in condition that the crack density parameters are obtained reasonably. The methods to determine rock mass crack density have been set up through the intactness index of rock mass and elastic wave equation as well as the geological investigating statistical method, The differences of rock crack density given by these three methods were discussed; based on the statistical data, the Taylor method and generalized self consistent method and the Taylor medium method were compared in respect of the influence of crack interaction and the adaptability to the rock parameters . The results show that the reasonable results can be obtained by determining rock crack density from intactness index of rock mass and rock mass parameters by the Taylor medium method.     

Damage Constitutive Equation and Experiment of Layered Rock

The microcosmical study on many speciments of sedimentary rock by SEM and petrography theory show that rock is formed of microcrystalline and micropore with all kinds of forms.Therefrom the microstructure model of rock is established.Further the three dimensional nonlinear damage constitutive equation and damage evolution equation of layered rock including respective process of damage evolution,mechanical parameter,effective stresses,and unequal biaxial stress in different rocks are derived.The results of the experiment indicate that the theoretical curve is fairly close to the experimental curve.     

Analysis of Failure Behaviors in Glass under Shock Loading

The failure wave phenomena in glass media under shock loading are analyzed. The propagating mechanism and dynamic characteristics of failure wave and the property of failure layer are revealed. On the basis of experimental analysis, a damage accumulating model determinated by partial stress impulse is proposed, which describes the phenomenon of failure delay in materials being done with the Heaviside function. The propagating procedure, the evolution characters of transverse stress and longitudinal compression strain in failure layer are simulated. Furthermore a phenomenon is revealed that the failure wave velocity decreases after reflection of rarefaction wave at the boundary of failure layer.     

Improved Information Value Model and Its Application in the Spatial Prediction of Landslides

Information Value Model is used frequently in domestic landslide hazard zonation prediction, which plays a very important role for land-use planning especially in mountain area. Through theoretical analysis, the prerequisite of Information Value Model which should be used with influence-factors independent from each other is studied. Factor Analysis is adopted to evaluate and eliminate the influence of correlation between influence-factors in spatial prediction of landslides which are showed through case study. Relationships between landslides and influence-factors are studied based on a certain watershed in which the Information Value Model and Factor Analysis are applied. The probability of landslides changes regularly with the influence-factors, and based on which a method for the discretization of influence-factors is advised. The distribution of landslide susceptibility of above watershed is calculated and validated based on the area-ratio index with landslides occurring in nearly 5 years, which proves the credibility of Information Value Model.     

Effective Expressions for Momenta Normalization and Renormalization to e-(e) Loop propagator

In the electromagnetic minimum coupling model, the authors study the expansion of the finite quantity function in the momenta renormalization e - e loop propagator function, and find that if they use the matrix function expansion they can approach the separation of the finite quantity function, but also can get a strictly analytic solution for one dimension integral calculation method of it. This will give an effective new way to study the question about the exact solving to the renormalization finite quantity function.     

Load Calculation Method of Shallow Tunnel under Unsymmetrical Loadings in Broken Surrounding Rock

Tunnel portal section mostly faces unfavorable geologic and topographical conditions, such as broken surrounding rock, shallow and unsymmetrical loadings. The current Chinese code for design of road tunnel provides the load calculation method of tunnel under unsymmetrical. However, according to the mechanic and deformation characteristics of the tunnel lining on site, the assumption is not suitable for the shallow tunnel under unsymmetrical loadings in broken surrounding rock. Therefore, through engineering case analysis and results of three-dimensional numerical analysis, the failure mechanism of shallow tunnel under unsymmetrical loadings in broken surrounding rock is presented firstly, that is, deep buried side broken surrounding rocks slump down after excavation and squeeze the lining, which makes the lining deform outward and bear passive earth pressure. Through the failure mechanism, the surrounding rock mainly includes slumping area and passive area. Then the corresponding formulas are deduced based on limit equilibrium theory. Finally, a case study is adopted to verify the feasibility of the new method. It is show that the new method is more reasonable than the method of current code.     

水地小麦高产施肥模型及其应用研究

采用三因素二次回归旋转组合设计方法,对影响小麦产量的氮肥、磷肥、有机肥的用量进行了定量研究,建立了中等以上肥力的水地小麦产量形成的施肥函数模型及最佳施肥组合方案,并确定水地小麦施肥模型主因素作用效应顺序:磷肥>氮肥>有机肥.还研究了各项施肥措施间的交互作用效应.     

Rock classification method for tunnel boring machine

In order to study the geological factors which impact penetrating rate of tunnel boring machine (TBM), this paper uses three-dimensional discrete element model 3DEC to build simulated models on rock fragment by TBM cutter. It analyzes the influence of different geological conditions on TBM penetrating rate and classified the surrounding rock in west route of south-to-north transfer project according to the drill ability of TBM in surrounding rock. The results show that the penetrating rate of TBM is closely related to the mechanical properties of rock and joint conditions in rock mass. In certain extent, TBM penetrating rate will be increased with the decrease of rock strength or closely distributed joints. TBM penetrating rate will be decreased with the increase of rock strength or rarely distributed joint. Another result is that the surrounding rock by TBM penetrating can be divided into three classes based on the drill ability of TBM in surrounding rock, which can guide the TBM penetrating.     

Mechanics. Model to Deformation of Covered Rock Strata and Its Application in Deep Mining of Steep or Inclined Seam

Laboratory column leaching tests were conducted with simulated acid rain with pH values of 2.50,3.50,4.50 and 5.60 respectively,to study yellow soil taken from the Three Gorges Reservoir Region.The results showed that the buffer function of yellow soil against acid rain weakened after a long time of leaching,and acid rain of a lower pH exerted stronger impact on the acidification of the soil.The electric conductance (EC) of the leachates through different soil layers first increased,and then decreased.There is an EC peak occurred in the range of simulated acid rain addition,with the shape of the peak obviously different.The Al leaching loss of the soil increased when the acid rain was more acidic.     

The Application of Pre-splitting Blasting to Excavation on High Slope in Soft Rock Section

Based on analyzing about blasting mode of slope in the construction of road, the paper shows that pre splitting blasting is mostly suitable in the section of severely weathering soft rock with developed joints and fractures, introduced the laying out about the hole of pre splitting blasting that can apply in the high slope of the expressway in the section, and designed the parameter. The practice shows that it gained favourable effect by this method.