Study On Deformation Rules Of One Tunnel’s Hipparion Laterite Surrounding Roeks In Lvliang Region

China’s Loess Plateau are widely distributed the Hipparion laterite which Layer thickNess ranging from a few meters to hundreds of meters, and mainly distributed in Gansu, Shaanxi, Shanxi, among is the most typical is Lvliang region of Shanxi. In recent years, a large number of tunnels are built in this region, meanwhile,which encountered a series of engineering geological problem when through the stratum. Recentily, the study on engineering properties of Hipparion laterite is still relatively weak, therefore, the study on deformation rules of Hipparion laterite surrounding roeks is of great important theoretical significance and practical significance.In this paper, relying on a tunnel project in Lvliang region(it does not refer to specific tunnel engineering according the requirements of the ministry of railways), selecting a typical cross-section, combining tunnel monitoring and laboratory tests, as well as qualitative and quantitative analysis, the first to study the deformation rules of surrounding rocks in the Hipparion laterite, the main conclusions are as follows:Firstly, on the basis of research the identified regional environment geological conditions, relying on advanced test means (analysis of grainX-RAY spectroscopy analysis, electric mirror scan, direct shear test, static three axis test, dynamic three axis test, and large direct shear test), from tmaterial components, micro-structure features, static force mechanical nature, a power mechanical nature, to depthly study the engineering geological characteristics of the Hipparion laterite, meanwhile, it provides parameter for the numerical simulation analysis. The results show that high cohesion is the biggest feature of Hipparion laterite strength; the nodules, fissures, water is the main factor affecting the strength of Hipparion laterite.Secondly, selecting the typical cross-section to take tunnel field monitoring, the monitoring content includes vault settlement, around convergence, the stress of surrounding rocks, moisture volume, pore water pressure and stress of steel arch. The result reveals that, when take three steps seven steps excavation method to excavate the deep buried tunnel of Hipparion laterite, the vault settlement is greater than around convergence; the stress of surrounding rocks render a trend of "upper large lower small"; the change law basic consistency of stress of steel arch and the stress of surrounding rocks, measuring point of steel arch mainly appears pressure, individual measuring point appears pull stress in construction process.; the moisture concent and the pore water pressure increases with the construction step, as the water content saturation, pore water pressure gradually stabilized.Further more, using MIDAS/GTS software to built tunneling two-dimensional model, study the change laws of displacement field, stress field, ancher axial force, the axial force and bending moment of initial support during tunnel dynamic construction. By contrast, the results of tunnel numerical simulation in line with the field monitoring results of Hipparion laterite.Finally, taking the grey theory to predict the deformation of surrounding rocks in Hipparion laterite. Based on a part of the monitoring data, using the GM (1,1) model, metabolism GM(1,1) model, Verhulst model of grey theory and a nonlinear regression model to built the prediction model of the Surrounding rocks’ deformation, coMParing with the prediction results and the actual monitoring data. The results show that the metabolism GM (1,1) model is a superior and suitable model to predict the deformation of surrounding rocks in the Hipparion laterite.