The Application Of Geophysical Method In Slope Stability

In recent years,the rapid development of China's economy has led to the increasing of basic engineering construction,and the geological environment of site engineering has become increasingly complex.Slope is one of the most common forms of engineering in engineering construction.Various geological disasters caused by artificial excavation,heavy rainfall,etc.are increasingly attracting the attention of scholars and staff from all walks of life.To minimize various losses caused by the failure of the slope,it is necessary to accurately judge and evaluate the stability of the slope.Slope stability evaluation is to analyze the nature and characteristics of the rock slope by using the basic principles and methods of engineering geology,geotechnical mechanics and other disciplines,then studing the interrelationships between various features,in order to judge the stability of the slope.Due to the complexity of engineering geological conditions,no universal method has been found so far to evaluate the engineering geology of all slopes.In this paper,the author through to the engineering geophysical exploration and geotechnical professional theory knowledge,the application of similar survey of geophysical prospecting in the high density resistivity method and numerical simulation method to do the system analysis,to study the limitations and applicability of the high density resistivity method of each unit and simulation calculation methods.The high density electrical method has the characteristics of large sampling density and rich information,which can conduct fine survey on the surface layer and make reasonable stratification of rock and soil.Geological simulation can be used to study geological archetypes according to actual geological conditions,establish simplified engineering geological model,and use numerical calculation to predict the gestation development process of undesirable geological phenomena.In this paper,the high density electrical method combined with geological model simulation,give full play to the electrical prospecting precision detection and simulated the advantages of accurate predictions,formed a set of geophysical prospecting,geological route of slope stability analysis,and applied in practical engineering,to verify the accuracy and practicability of this route.The main content of this article is as follows:Firstly,the high density electrical method and engineering geological numerical simulation in geophysical exploration of slope engineering are discussed in detail.After studying the working principle of high density resistivity method,the sensitivity of device types,parameter selection,etc,on the basis of combining work area geological conditions and engineering purposes,and through many experiments,determined the exploration device types for alpha device and minimum exploration polar distance is 6 m.On the basis of finite element method,Lagrange finite difference method principle and ANSYS software and FLAC3 D software principle,the simulation calculation route is determined as follows: The powerful advantages of the finite element software ANSYS pretreatment module for the establishment of three-dimensional slope engineering geological model,and then in order to adapt to the slope of large deformation problems,decided to adopt a Lagrange finite difference software FLAC3 D numerical calculation to the stability of the slope.Secondly,the results of high-density resistivity exploration were analyzed and summarized.A three-dimensional geological interpretation map was established based on geological data and drilling data.The thickness and distribution of the deposits in the cover layer were preliminarily analyzed,and the distribution of various rock layers in the subsurface.Using the geophysical prospecting map,geophysical and mechanical parameters of rock and soil obtained from multiple indoor and outdoor rock mechanics experiments were used to establish an ANSYS model.The model was then introduced into FLAC3D(Lagrangian finite difference software)using the Mohrcoulleng constitutive model and strength.Calculated by the reduction method,the stress distribution and displacement of the slope are obtained under the two conditions of gravity stress field and rainstorm weather.Finally,the geophysical exploration results and numerical simulation results were organically combined to evaluate the overall stability of the slope in a certain engineering area in western Sichuan.The final result shows that the stability of the slope is poor.In the event of heavy rain,slippage will occur and the most dangerous slip surface will be determined.Fully demonstrates the applicability and effectiveness of geophysical and geological exploration ideas,The uncertainty of the inaccuracy of the slope instability and the empirical uncertainty of the model are avoided.At the same time,it shows that this idea has a good reference value when studying and evaluating slope projects in other regions.