Algorithm And Implementation Of Slope Stability

Landslide is an important geological disaster, it can make the factories, cities and mines buried, traffic disruption, channel blocked, construction disruption, etc. The landslide not only directly affects the lives of the people, but also has caused tremendous economic losses to the country. As our country is vast, geological disasters occur frequently. In 2008, it had 26580 geological disasters including 13450 times of landslide, 8080 times of collapse, 443 times of debris. There are 1598 human casualties, direct economic losses of 3.27 billion Yuan. In 2009, total of 10840 times from various types of geological disasters, including 6657 times of landslide, 2309 times of collapse, 1426 times of debris. There are 331 human casualties, 155 missing and 315 injured, direct economic losses of 1.765 billion Yuan. It has led to a large number of slope instability In particular the Wenchuan earthquake, it's urgent for us to study slope stability.How to monitor and prevent landslide timely, and avoid landslide disasters positively and effectively, has been the world's great challenge. In recent years, China also attaches great importance to the forecasting of landslide and from different angles, using different methods to do research. Nevertheless, an accurate forecast of landslide is still a world-wide problem.With the development of modern numerical analysis, Landslide Stability Analysis Limiting Equilibrium Algorithm has developed to a very mature level. But then the problem is, this analysis must be adopted by a computer program. The status is: though the computer's hardware has gained rapid development and the theory of mechanics are very advanced, many of the applications of the slope engineering are still in its initial state, and it can not meet the needs of actual engineering. Using the results of modern science and technology to improve the quality and efficiency of slope engineering is not only the desire of engineers, but also a very important means to ensure building safety and reduction of investment.Landslide Stability Monitor system is one of items of Land and Resources Survey by Ministry of Land and Resources P.R.C in "Eleventh Five-Year" period. With the "Eleventh Five-Year" plan implemented, the evaluation of landslide stability has become a general concerned issue of people. As our country is vast, landslide occurs frequently; it may not only impact the lives of people directly, but also cause tremendous economic losses to the country. This paper based on the geologic arithmetic and perambulation criterion and a variety of landslide stability evaluation method, aiming at prevention of the landslide, protection of natural geological landscape and municipal construction, applying engineering geology, rock mechanics, computational mathematics, computer graphics as well as the software frame to develop a set of high practical value of the Landslide Stability Analysis System software.In the system construction, the system uses domain-specific software (DSSA) knowledge which combines geological resources, human resources, analytical methods, management and the calculation technologies to obtain a standard, function and language of program development. The system is based on MapGIS geographic information system platform, using Visual C++ for the development tools, combines with COM component to achieve the entirely system function. The system mainly includes graphic and image module, read module, parameter calculation module, output modules, algorithms COM component and engineering documents six parts. Read module is mainly responsible for the original data of point and line, the project file includes point document, line documents and the outcome document. The line document is used to save the original data file; the point document is used to mark the contents; the outcome document is used to save the relevant calculations. Graphic and image module is mainly responsible for reading the image data, display data and image adjustment data. This system inherited CGISView and CGISEditView in API of MapGIS, realizes image display, cables, strikethrough, rotary line, select lines, mobile lines, highlighting and other functions, meet the parameters calculation demand. Parameter calculation module is mainly to integrate parameters then deliver, and calculate, meanwhile integrate and calculate cohesion; internal friction coefficient, length, angle, the flow of groundwater and other information of slides then passed to the COM, and deliver the results to the output module. Algorithm COM component is to send slope parameters to the stability algorithm, then return to landslide stability coefficient. Output module mainly refers to output and save the results of stability calculation.In the algorithm research, on the basic of a large number of the collection, analysis and processing to study Landslide Stability Theory deeply and choose efficient and feasible limit equilibrium theory to practical application. The paper chose the Swedish slice method, the transfer coefficient method, Sarma method, Janbu method and wedge method to develop the program. The Swedish method is rigid body limit equilibrium method mainly for a single plane or arc-shaped face of the sliding surface, it make the slider to decomposition from the normal. The sliding soil mass is divided into a number of vertical slider, and seek the slider to the center point of the anti-sliding and torque, whichever is the sum of the calculated safety factor. Transfer method applied to the soil cover and folded linear sliding surface slope stability analysis. It makes sliding surface into polyline, and make the slide into the corresponding clods of soil, each clods force has its gravity and thrust of next, normal force and sliding force of the bottom. Sarma method is more complex than other of slope stability method, requiring more of the parameters, and it is not limited slice method. It is not only either vertical slice, but also carry out oblique random points, more suitable for on practical applications and that the calculation is not simply a stability factor, it form a curve from a group of stability factor. Janbu method assuming that between the internal forces of the location (thrust line). Generally need to seek safety factor iteration for arbitrarily shaped slip surface. Wedge method mainly refers to the consideration of three situations: the first it does not consider the pore water pressure, the outside when the load anchorage; the second it consider pulling back edge of the surface crack and two sliding face, the role of pore water pressure; the third, there is anchorage force and building the presence to get slope safety factor. It established physical model and mathematical models of the five methods of slope stability, mathematical models will be converted into program modules, results with the actual data validation, it has completed the initial design requirements of the algorithm.