Numerical Simulation Study On Laminated And Columnar Basalt Jointed Rock Mass

Basalts with layered and columned joints resulted from Quarternary volcanic activities areextensively exposed in Northeast China. At the intermittent periods of voleanic eruption, tuffswith various thickness form in the layers of basalts, which yields Quarternary basalt stratawith layered and columned joints. Recently, with a view to revitalizing the Old Industrial Basesin Northeast China, a significant amount of infrastructure constructions, such as highway andrailway projects, is in process. Inevitably, these projects involve underground excavationspassing through strata with special and complex geological conditions. This brings about theadvent of a new topic in terms of how to avoid the overexcavation and underexcavation, therebyensuring safety and reliability during tunnel constructions.With the rapid development of computer technology and its application of generalized increasein the use of finite element computer software to simulate all kinds of problems in the actualproject has been very common, because of the high cost of theoretical calculations and actualtest simulation study and calculation of demerit notcan be reused, the efficiency is very low,which makes the finite element numerical simulation becomes an important weapon to solvescientific and technical problems. The numerical simulation close to the reality of themathematical parameters and physical model, the material to be simulated in the calculationdesigned into reality completely the same strength and shape, and through the operation to itsdynamic failure process image of the show out and can be repeatedly observed all parameters inthe process simulation and research. Finite element numerical simulation with actual experimentalresults with theoretical calculations mutual authentication, so that we can more effectivelyservice for all kinds of problems in engineering practice.Joined rock masses of research columnar basalt spatial characteristics and physico-mechanicalproperties for the impact of the blasting process, the use of ANSYS12.0/LS-DYNA finite elementsoftware to simulate the dynamic failure process layer of columnar joints in blasting loads.Based on basalt rock explosion characteristics determine the failure criterion and numericalsimulation of rock mass model, as well as used herein, the equation of state of Rock EmulsionExplosive model and its*EOS. On the above analysis results cornerstone for the hole locationand number of different layers of columnar basalt rock blasting dynamic simulation analysis, the basalt rock layer of columnar jointed node in the blasting process stress analysis layeredjointed basalt rock blasting molding effect and the basalt rock mass stress wave propagationand reflection effect.Model used herein ANSYS12.0/LS-DYNA finite element numerical simulation software to establishthe steps described in detail in this paper non-reflective boundary for the boundary design ofthe model to simulate an infinite range of basalt rock, reducedue to the reflection of thecomputational results.3D numerical model based on basalt rock blasting, LS-DYNA3D Lagrangemethod ALE method can be selected. In order to discuss what kind of algorithm is more suitablefor this study were to establish the numerical model of basalt and explosives, through actualblasting analog, to compare. The test model with Euler algorithm model of the Lagrangian methodat the end of the blasting, blasting shape or the shape of destruction are not the same, andthe Lagrangian modeling process more efficient, simple, and so this article research and analysisprocess using Lagrangian.Separate the establishment of emulsion explosives, columnar joints and basalt rockmass numerical model test improve the strength of the columnar joints, select theunit body effect force changes in circumstances, conclusions drawn from the testdescription, the weaker the strength of columnar jointed For Detonation stresswavebarrier capacity of the stronger.Building a columnar joints width of5cm,10cm and15cm basalt rock mass numericalmodel, research and observation during blasting in the width of the joints withinthe basalt rock mass detonation stress wave propagation influential, conclusionsdrawn from the test instructions, With the increase in the width of the columnar jointswithin the basalt rock mass detonation stress wave propagation barrier effect ofsignificantly enhanced.