Study On Stability Judgment Of Surrounding Rock Based On Section Relative Deformation Rate Of Tunnel

With the economic vitality brought by the reform and opening up,China's transportation infrastructure has been constructed on a large scale.Nowadays,in order to improve our infrastructure system,the focus of construction has gradually shifted from the eastern region to the western region with more complicated geological conditions.This puts forward more and higher requirements for our tunnel construction.In recent years,long tunnels and large section tunnels always are constructed in our country.The geological situation of the tunnels is more and more complex.So,how to maintain the stability of the surrounding rock in the construction process is more difficult.And then,it is particularly important to adopt a measurement method that can timely and comprehensively evaluate the stability state of tunnel structure and surrounding rock.So as to guide or adjust the of construction measures.(1)By analyzing the shortcomings of the current method which evaluating the stability of surrounding rock by measuring specific point displacement,we present a new method which evaluating the stability of surrounding rock by measuring area deformation.Through the deduction of elastic-plastic mechanics and Stress-strain law of surrounding rock,establishing the potential function cusp catastrophe model of surrounding rock tunnel system.(2)The relative deformation rate of tunnel section is taken as the state description parameter of the system potential function cusp mutation model.And calculating a large number of models by FLAC3 D on different working conditions to get the relative variations of the tunnel section at the critical instability of the system.And then,summarizing control datum of the monitoring measurement method,which evaluating the stability of surrounding rock by measuring section deformation.(3)Piloting based on the control datum of the monitoring measurement.Collecting data by FARO FOCUS 3D laser scanner,and getting information of the study section by special data processing software.Making a timely evaluation of the stability of surrounding rock by control datum of the monitoring measurement.Verify the effectiveness of the method which evaluating the stability of surrounding rock by measuring section deformation.The new evaluation index of surrounding rock stability provides a new thinking anglefor the evaluation of surrounding rock stability and the new monitoring measurement method provides a new reference tool for ensuring the safety of construction.